music-assistant-server

1"""
2Protocol Linking Mixin for the Player Controller.
3
4Handles all logic for linking protocol players (AirPlay, Chromecast, DLNA) to
5native players or wrapping them in Universal Players.
6
7This module provides the ProtocolLinkingMixin class which is inherited by
8PlayerController to add protocol linking capabilities.
9"""
10
11from __future__ import annotations
12
13import asyncio
14import logging
15from contextlib import suppress
16from copy import deepcopy
17from typing import TYPE_CHECKING, cast
18
19from music_assistant_models.enums import (
20    EventType,
21    IdentifierType,
22    PlaybackState,
23    PlayerFeature,
24    PlayerType,
25    ProviderType,
26)
27from music_assistant_models.errors import PlayerCommandFailed, PlayerUnavailableError
28
29from music_assistant.constants import (
30    CONF_CACHED_ARP_MAC,
31    CONF_GROUP_MEMBERS,
32    CONF_LINKED_PROTOCOL_IDS,
33    CONF_PLAYER_DSP,
34    CONF_PLAYER_QUEUES,
35    CONF_PLAYERS,
36    CONF_PREFERRED_OUTPUT_PROTOCOL,
37    CONF_PROTOCOL_KEY_SPLITTER,
38    CONF_PROTOCOL_PARENT_ID,
39    CONF_REPORTED_MAC,
40    CONF_UNDERLYING_PLAYER_ID,
41    PROTOCOL_PRIORITY,
42    VERBOSE_LOG_LEVEL,
43)
44from music_assistant.helpers.util import (
45    is_locally_administered_mac,
46    is_valid_mac_address,
47    normalize_mac_for_matching,
48)
49from music_assistant.models.player import LinkedOutputProtocol, Player
50from music_assistant.providers.sync_group.constants import CONF_ALLOWED_MEMBERS
51from music_assistant.providers.universal_player import UniversalPlayer, UniversalPlayerProvider
52from music_assistant.providers.universal_player.constants import (
53    CONF_CREATED_AT,
54    CONF_DEVICE_IDENTIFIERS,
55    CONF_DEVICE_INFO,
56)
57
58if TYPE_CHECKING:
59    from collections.abc import Coroutine
60    from typing import Any
61
62    from music_assistant_models.player import OutputProtocol
63
64    from music_assistant import MusicAssistant
65
66# Config value keys that are bookkeeping of the universal player wrapper itself
67# (protocol links, device-identity caches and its creation moment) and must never
68# be carried over when a native player replaces a universal player, or when one
69# universal player absorbs another.
70UNIVERSAL_PLAYER_INTERNAL_CONF_KEYS = (
71    CONF_LINKED_PROTOCOL_IDS,
72    CONF_PROTOCOL_PARENT_ID,
73    CONF_UNDERLYING_PLAYER_ID,
74    CONF_DEVICE_IDENTIFIERS,
75    CONF_DEVICE_INFO,
76    CONF_CACHED_ARP_MAC,
77    CONF_REPORTED_MAC,
78    CONF_CREATED_AT,
79)
80
81
82class ProtocolLinkingMixin:
83    """
84    Mixin class providing protocol linking functionality for PlayerController.
85
86    Handles the complex logic of:
87    - Matching protocol players to native players via device identifiers
88    - Creating Universal Players for devices without native support
89    - Managing protocol links and their lifecycle
90    - Selecting the best output protocol for playback
91
92    This mixin expects to be mixed with a class that provides:
93    - mass: MusicAssistant instance
94    - _players: dict of registered players
95    - _pending_protocol_evaluations: dict of pending protocol evaluations
96    - logger: logging.Logger instance
97    - all(): method to get all players
98    - get(): method to get a player by ID
99    - unregister(): method to unregister a player
100    """
101
102    # Type hints for attributes provided by the class this mixin is used with
103    if TYPE_CHECKING:
104        mass: MusicAssistant
105        _players: dict[str, Player]
106        _pending_protocol_evaluations: dict[str, asyncio.TimerHandle]
107        _delayed_evaluation_lock: asyncio.Lock
108        logger: logging.Logger
109
110        def all_players(  # noqa: D102
111            self,
112            return_unavailable: bool = True,
113            return_disabled: bool = False,
114            provider_filter: str | None = None,
115            return_protocol_players: bool = False,
116        ) -> list[Player]: ...
117
118        def get_player(self, player_id: str) -> Player | None: ...  # noqa: D102
119
120        def unregister(  # noqa: D102
121            self,
122            player_id: str,
123            permanent: bool = False,
124            replacement_player_id: str | None = None,
125        ) -> Coroutine[Any, Any, None]: ...
126
127    def _is_protocol_player(self, player: Player) -> bool:
128        """
129        Check if a player is a generic protocol player without native support.
130
131        Protocol players have PlayerType.PROTOCOL set by their provider, indicating
132        they are generic streaming endpoints (e.g., AirPlay receiver, Chromecast device)
133        without vendor-specific native support in Music Assistant.
134        """
135        return player.state.type == PlayerType.PROTOCOL
136
137    def _evaluate_protocol_links(self, player: Player) -> None:
138        """
139        Evaluate and establish protocol links for a player.
140
141        Called when a player is registered to:
142        1. If it's from a protocol provider - try to link to a native player.
143        2. If it's a native player - try to link any existing protocol players.
144        """
145        if player.state.type == PlayerType.PROTOCOL:
146            # Protocol player: try to find a native parent
147            self._try_link_protocol_to_native(player)
148        elif player.state.type == PlayerType.GROUP:
149            return
150        else:
151            # A player that registers with a non-protocol type can no longer be a
152            # protocol child: drop a leftover persisted parent link (e.g. from a
153            # bridge client that turned web player) so the startup repair pass
154            # doesn't heal its player type back to protocol.
155            if self._get_cached_protocol_parent_id(player.player_id):
156                self._clear_protocol_parent_id(player.player_id)
157            # Native player (including STEREO_PAIR): try to find protocol players to link
158            self._try_link_protocols_to_native(player)
159
160    def _try_link_protocol_to_native(self, protocol_player: Player) -> None:
161        """Try to link a protocol player to a native player."""
162        protocol_domain = protocol_player.provider.domain
163
164        # Derived protocol players (e.g. Sendspin bridges riding on another
165        # protocol) resolve strictly via their underlying player - no identifier
166        # matching or delayed evaluation. If the underlying player has no parent
167        # yet, the link is established by _link_derived_protocols_of as soon as
168        # the underlying player gets linked.
169        if protocol_player.underlying_player_id:
170            self._try_link_derived_protocol(protocol_player)
171            return
172
173        # Check for cached parent_id from previous session and restore link immediately
174        cached_parent_id = self._get_cached_protocol_parent_id(protocol_player.player_id)
175        if cached_parent_id:
176            result = self._try_restore_cached_parent(
177                protocol_player, cached_parent_id, protocol_domain
178            )
179            if result:
180                return
181            if not self.get_player(cached_parent_id):
182                # The persisted owner has not registered yet: wait for it instead of
183                # letting another parent's cached ids or identifiers claim this
184                # protocol. Delayed evaluation links it elsewhere if the owner
185                # never shows up.
186                self._schedule_protocol_evaluation(protocol_player)
187                return
188            # The parent is registered but did not take the link (it is a group, the
189            # cached id points at the protocol player itself, or the parent already
190            # has an active link from this domain) - fall through to generic matching.
191
192        # Look for a matching native player
193        if self._try_link_to_existing_player(protocol_player, protocol_domain):
194            return
195
196        # No native player found - schedule delayed evaluation to allow other protocols to register
197        if not protocol_player.protocol_parent_id:
198            self._schedule_protocol_evaluation(protocol_player)
199
200    def _try_restore_cached_parent(
201        self, protocol_player: Player, cached_parent_id: str, protocol_domain: str
202    ) -> bool:
203        """
204        Try to restore a cached parent link from a previous session.
205
206        :param protocol_player: The protocol player to link.
207        :param cached_parent_id: The cached parent player ID.
208        :param protocol_domain: The protocol domain (e.g., "airplay").
209        :return: True if the link was restored, False if the caller must resolve the parent.
210        """
211        if parent_player := self.get_player(cached_parent_id):
212            if parent_player.state.type == PlayerType.GROUP:
213                self._clear_protocol_parent_id(protocol_player.player_id)
214                return False
215            already_linked = any(
216                link.output_protocol_id == protocol_player.player_id
217                for link in parent_player.linked_output_protocols
218            )
219            if already_linked:
220                # Already linked from a previous call - just restore parent and identifiers
221                protocol_player.set_protocol_parent_id(cached_parent_id)
222            else:
223                # Try to add the link (may be refused if domain already has active link)
224                self._add_protocol_link(parent_player, protocol_player, protocol_domain)
225            if protocol_player.protocol_parent_id:
226                protocol_player.refresh_state()
227                parent_player.refresh_state()
228                # Merge the protocol player's identifiers into the universal player
229                # so identifiers discovered since the last persist (e.g. an
230                # ARP-resolved MAC) are included and new protocol players
231                # (like Sendspin bridges) can match via identifiers.
232                if parent_player.provider.domain == "universal_player" and isinstance(
233                    parent_player, UniversalPlayer
234                ):
235                    for conn_type, value in protocol_player.device_info.identifiers.items():
236                        parent_player.device_info.add_identifier(conn_type, value)
237                    self._update_universal_device_info(parent_player, protocol_player)
238                    # Check if this universal player should now be merged with another
239                    # (e.g., DLNA brought a MAC via ARP that matches an AirPlay universal)
240                    self._check_merge_universal_players(parent_player)
241                return True
242            # Link was refused (domain already active on parent) - fall through
243            return False
244
245        # Parent is not registered yet. Leave the protocol player unparented
246        # so the caller schedules delayed evaluation, which can wait for the
247        # cached parent without stranding the protocol player on a dangling id.
248        return False
249
250    def _try_link_to_existing_player(self, protocol_player: Player, protocol_domain: str) -> bool:
251        """
252        Try to link a protocol player to an existing native or universal player.
253
254        :param protocol_player: The protocol player to link.
255        :param protocol_domain: The protocol domain (e.g., "airplay").
256        :return: True if linked successfully, False if no match found.
257        """
258        # Protocol players should only link to:
259        # 1. True native players (Sonos, etc.)
260        # 2. Universal players
261        # NOT to other protocol players (they get merged via universal_player)
262        for native_player in self.all_players(return_protocol_players=False):
263            if native_player.player_id == protocol_player.player_id:
264                continue
265            if native_player.state.type in (PlayerType.PROTOCOL, PlayerType.GROUP):
266                continue
267
268            # For universal players, check if this protocol player is in its stored list
269            # or if identifiers match (for new protocol players like Sendspin bridges
270            # that weren't previously known to the Universal Player)
271            if native_player.provider.domain == "universal_player":
272                if isinstance(native_player, UniversalPlayer):
273                    is_known = protocol_player.player_id in native_player._protocol_player_ids
274                    is_match = not is_known and self._identifiers_match(
275                        native_player, protocol_player, protocol_domain
276                    )
277                    if is_known or is_match:
278                        self._add_protocol_link(native_player, protocol_player, protocol_domain)
279                        # Check if linking actually succeeded (may be refused for
280                        # duplicate domain)
281                        if not protocol_player.protocol_parent_id:
282                            continue
283                        # Merge the protocol player's identifiers into the universal
284                        # player so newly discovered identifiers are included as well
285                        for conn_type, value in protocol_player.device_info.identifiers.items():
286                            native_player.device_info.add_identifier(conn_type, value)
287                        # Update model/manufacturer if universal player has generic values
288                        self._update_universal_device_info(native_player, protocol_player)
289                        # Register newly matched protocol player with the universal player
290                        if is_match:
291                            native_player.add_protocol_player(protocol_player.player_id)
292                        # Persist updated data to config (async via task)
293                        self._save_universal_player_data(native_player)
294                        # Check if this universal player should now be merged with another
295                        self._check_merge_universal_players(native_player)
296                        protocol_player.refresh_state()
297                        native_player.refresh_state()
298                        return True
299                continue
300
301            # Check cached protocol IDs first for fast matching on restart
302            cached_ids = self._get_cached_protocol_ids(native_player.player_id)
303            if protocol_player.player_id in cached_ids:
304                self._add_protocol_link(native_player, protocol_player, protocol_domain)
305                if protocol_player.protocol_parent_id:
306                    protocol_player.refresh_state()
307                    native_player.refresh_state()
308                    return True
309                # Link refused (domain duplicate) - try next native player
310                continue
311
312            # Fallback to identifier matching
313            if self._identifiers_match(native_player, protocol_player, protocol_domain):
314                self._add_protocol_link(native_player, protocol_player, protocol_domain)
315                if protocol_player.protocol_parent_id:
316                    protocol_player.refresh_state()
317                    native_player.refresh_state()
318                    return True
319                # Link refused (domain duplicate) - try next native player
320                continue
321
322            # Final fallback: check if any already-linked protocol player on this native
323            # player shares identifiers with the new protocol player ("sibling matching").
324            # This handles native players (e.g., HEOS) that don't have their own MAC/serial
325            # identifiers but have protocol players (e.g., AirPlay) from the same device
326            # that do share identifiers with the new protocol player (e.g., Sendspin bridge).
327            if self._match_via_linked_protocols(native_player, protocol_player, protocol_domain):
328                return True
329
330        return False
331
332    def _match_via_linked_protocols(
333        self,
334        native_player: Player,
335        protocol_player: Player,
336        protocol_domain: str,
337    ) -> bool:
338        """
339        Try to match a protocol player to a native player via sibling protocol identifiers.
340
341        Check if any of the native player's already-linked protocol players share
342        identifiers with the new protocol player. This handles native players that lack
343        their own device identifiers but have sibling protocols from the same physical device.
344
345        :param native_player: The native player to potentially link to.
346        :param protocol_player: The new protocol player to link.
347        :param protocol_domain: The protocol domain of the new player.
348        :return: True if linked successfully, False if no match found.
349        """
350        for linked in native_player.linked_output_protocols:
351            linked_player = self.get_player(linked.output_protocol_id)
352            if not linked_player:
353                continue
354            if self._identifiers_match(linked_player, protocol_player, protocol_domain):
355                self._add_protocol_link(native_player, protocol_player, protocol_domain)
356                if protocol_player.protocol_parent_id:
357                    protocol_player.refresh_state()
358                    native_player.refresh_state()
359                    return True
360                # Link refused (domain duplicate) - stop checking siblings
361                break
362        return False
363
364    def _try_link_derived_protocol(self, protocol_player: Player) -> bool:
365        """
366        Link a derived protocol player to the parent of its underlying player.
367
368        Derived protocol players carry an underlying_player_id declared by their
369        bridge, which makes the parent resolution deterministic: they always join
370        the parent of the player they ride on (or that player itself when it is
371        not a protocol player). Callers must ensure the player is not linked yet.
372
373        :param protocol_player: The derived protocol player to link.
374        :return: True if the player got linked, False if the underlying player
375            (or its parent) is not available yet or the link was refused.
376        """
377        underlying = self.get_player(protocol_player.underlying_player_id or "")
378        if underlying is None:
379            return False
380        if underlying.state.type == PlayerType.PROTOCOL:
381            parent = (
382                self.get_player(underlying.protocol_parent_id)
383                if underlying.protocol_parent_id
384                else None
385            )
386        else:
387            parent = underlying
388        if parent is None or parent.state.type == PlayerType.GROUP:
389            return False
390
391        self._add_protocol_link(parent, protocol_player, protocol_player.provider.domain)
392        if not protocol_player.protocol_parent_id:
393            # Link refused (e.g. parent already has an active link from this domain)
394            return False
395
396        if parent.provider.domain == "universal_player" and isinstance(parent, UniversalPlayer):
397            # Track membership and identifiers on the universal player so the
398            # derived protocol restores quickly on the next start.
399            parent.add_protocol_player(protocol_player.player_id)
400            for conn_type, value in protocol_player.device_info.identifiers.items():
401                parent.device_info.add_identifier(conn_type, value)
402            self._save_universal_player_data(parent)
403
404        protocol_player.refresh_state()
405        parent.refresh_state()
406        self.logger.debug(
407            "Linked derived protocol %s to %s (via underlying %s)",
408            protocol_player.player_id,
409            parent.player_id,
410            underlying.player_id,
411        )
412        return True
413
414    def _link_derived_protocols_of(self, underlying_player: Player) -> None:
415        """
416        Link any waiting derived protocol players that ride on the given player.
417
418        Called after a player is linked to a parent (or registered as a native
419        player), so derived protocol players that registered earlier can join
420        the same parent.
421        """
422        for candidate in self.all_players(return_protocol_players=True):
423            if candidate.underlying_player_id != underlying_player.player_id:
424                continue
425            if candidate.protocol_parent_id:
426                continue
427            self._try_link_derived_protocol(candidate)
428
429    def _schedule_protocol_evaluation(self, protocol_player: Player) -> None:
430        """
431        Schedule a delayed protocol evaluation.
432
433        Delays evaluation to allow other protocol players and native players to register.
434        Uses a longer delay (30s) if this protocol player was previously linked to a native
435        player that hasn't registered yet, giving native providers time to start up.
436        """
437        player_id = protocol_player.player_id
438
439        # Cancel any existing pending evaluation for this player
440        if player_id in self._pending_protocol_evaluations:
441            self._pending_protocol_evaluations[player_id].cancel()
442
443        # Check if this protocol player has a cached parent (was previously linked)
444        cached_parent_id = self._get_cached_protocol_parent_id(player_id)
445        if cached_parent_id and not self.get_player(cached_parent_id):
446            # Previously linked to a native player that hasn't registered yet
447            # Use longer delay to give native providers time to start up
448            delay = 45.0
449            self.logger.debug(
450                "Protocol player %s waiting for cached parent %s (45s delay)",
451                player_id,
452                cached_parent_id,
453            )
454        else:
455            # Standard delay for protocol player discovery
456            # Allows time for other protocols and native players to register
457            delay = 15.0
458
459        # Schedule evaluation after the delay
460        handle = self.mass.loop.call_later(
461            delay,
462            lambda: self.mass.create_task(self._delayed_protocol_evaluation(player_id)),
463        )
464        self._pending_protocol_evaluations[player_id] = handle
465
466    async def _delayed_protocol_evaluation(self, player_id: str) -> None:
467        """
468        Perform delayed protocol evaluation.
469
470        Called after a delay to allow all protocol players for a device to register.
471        Decides whether to create a universal player, join an existing one, or
472        promote a single protocol player directly.
473
474        Uses a shared lock to serialize evaluations - multiple protocol players from the
475        same device may trigger concurrent evaluations that would otherwise race each other.
476        """
477        self._pending_protocol_evaluations.pop(player_id, None)
478
479        async with self._delayed_evaluation_lock:
480            protocol_player = self.get_player(player_id)
481            if not protocol_player or protocol_player.protocol_parent_id:
482                return
483            if protocol_player.state.type != PlayerType.PROTOCOL:
484                # The player changed type while the evaluation was pending
485                # (e.g. re-registered as a regular player); it must never be
486                # linked as a protocol or wrapped in a universal player.
487                return
488
489            # Derived protocol players resolve strictly via their underlying
490            # player and never match by identifiers or wrap into universal
491            # players; they wait for _link_derived_protocols_of otherwise.
492            if protocol_player.underlying_player_id:
493                self._try_link_derived_protocol(protocol_player)
494                return
495
496            protocol_domain = protocol_player.provider.domain
497
498            # Re-try linking to an existing native/universal player
499            if self._try_link_to_existing_player(protocol_player, protocol_domain):
500                return
501
502            # Check if there's an existing universal player we should join
503            if existing_universal := self._find_matching_universal_player(protocol_player):
504                await self._add_protocol_to_existing_universal(
505                    existing_universal, protocol_player, protocol_domain
506                )
507                if protocol_player.protocol_parent_id is not None:
508                    return
509                # Link refused (domain duplicate) - fall through to create separate UP
510
511            # Refuse to create a universal player wrapper when the cached parent
512            # config exists but is disabled. The user explicitly turned the
513            # parent device off; surfacing its protocols as a separate player
514            # would defeat that intent.
515            cached_parent_id = self._get_cached_protocol_parent_id(player_id)
516            if cached_parent_id:
517                parent_raw = self.mass.config.get(f"{CONF_PLAYERS}/{cached_parent_id}")
518                if parent_raw and not parent_raw.get("enabled", True):
519                    self.logger.debug(
520                        "Skipping universal player creation for %s: cached parent %s is disabled",
521                        player_id,
522                        cached_parent_id,
523                    )
524                    return
525
526            # Find all protocol players that match this device's identifiers
527            matching_protocols = self._find_matching_protocol_players(protocol_player)
528
529            # Create or update UniversalPlayer for all protocol players
530            await self._create_or_update_universal_player(matching_protocols)
531
532    def _find_matching_protocol_players(self, protocol_player: Player) -> list[Player]:
533        """
534        Find all protocol players that match the same device as the given player.
535
536        Searches through all registered protocol players to find ones that share
537        identifiers (MAC, IP, UUID) with the given player, indicating they represent
538        the same physical device.
539        """
540        matching = [protocol_player]
541        protocol_domain = protocol_player.provider.domain
542
543        for other_player in self.all_players(return_protocol_players=True):
544            if other_player.player_id == protocol_player.player_id:
545                continue
546            if other_player.state.type != PlayerType.PROTOCOL:
547                continue
548            if other_player.protocol_parent_id:
549                continue
550            if other_player.underlying_player_id:
551                # Derived protocol players follow their underlying player
552                # once it is linked; they never seed a universal player.
553                continue
554            # Skip players from the same protocol domain
555            # Multiple instances of the same protocol on one host are separate players
556            if other_player.provider.domain == protocol_domain:
557                continue
558            if self._identifiers_match(protocol_player, other_player):
559                matching.append(other_player)
560
561        return matching
562
563    def _find_matching_universal_player(self, protocol_player: Player) -> Player | None:
564        """Find an existing universal player that matches this protocol player."""
565        for player in self._players.values():
566            if not isinstance(player, UniversalPlayer):
567                continue
568            if self._identifiers_match(protocol_player, player, ""):
569                return player
570        return None
571
572    async def _add_protocol_to_existing_universal(
573        self, universal_player: Player, protocol_player: Player, protocol_domain: str
574    ) -> None:
575        """Add a protocol player to an existing universal player."""
576        # Refuse if the universal player already has a registered player from this domain.
577        # This prevents a second instance (e.g., two snapcast players on the same host)
578        # from replacing the first. The caller falls through to create a separate UP.
579        for link in universal_player.linked_output_protocols:
580            if link.protocol_domain == protocol_domain and self.get_player(link.output_protocol_id):
581                return
582
583        self._add_protocol_link(universal_player, protocol_player, protocol_domain)
584
585        # Check if linking actually succeeded (may be refused for duplicate domain)
586        if not protocol_player.protocol_parent_id:
587            return
588
589        if isinstance(universal_player, UniversalPlayer):
590            universal_player.add_protocol_player(protocol_player.player_id)
591            for conn_type, value in protocol_player.device_info.identifiers.items():
592                universal_player.device_info.add_identifier(conn_type, value)
593            # Update model/manufacturer if universal player has generic values
594            self._update_universal_device_info(universal_player, protocol_player)
595
596            # Persist all player data (protocol IDs, identifiers, device info) to config
597            for provider in self.mass.get_providers(ProviderType.PLAYER):
598                if provider.domain == "universal_player":
599                    await cast("UniversalPlayerProvider", provider)._save_player_data(
600                        universal_player.player_id, universal_player
601                    )
602                    break
603
604            # Check if this universal player should now be merged with another
605            self._check_merge_universal_players(universal_player)
606
607        protocol_player.refresh_state()
608        universal_player.refresh_state()
609
610    def _update_universal_device_info(
611        self, universal_player: UniversalPlayer, protocol_player: Player
612    ) -> None:
613        """
614        Update universal player's device info from protocol player if needed.
615
616        A universal player carries generic placeholder device info
617        (model="Universal Player", manufacturer="Music Assistant") when no real
618        values are known for it (yet). This method updates those values from a
619        protocol player that has real device info.
620        """
621        # Check if universal player has generic placeholder device info
622        device_info = universal_player.device_info
623        protocol_info = protocol_player.device_info
624
625        # Update model if universal player has generic value
626        if device_info.model in (None, "Universal Player") and protocol_info.model:
627            device_info.model = protocol_info.model
628
629        # Update manufacturer if universal player has generic value
630        if device_info.manufacturer in (None, "Music Assistant") and protocol_info.manufacturer:
631            device_info.manufacturer = protocol_info.manufacturer
632
633    def _save_universal_player_data(self, universal_player: UniversalPlayer) -> None:
634        """
635        Save universal player data to config via background task.
636
637        This is a helper to persist player data from synchronous code.
638        """
639
640        async def _do_save() -> None:
641            for provider in self.mass.get_providers(ProviderType.PLAYER):
642                if provider.domain == "universal_player":
643                    await cast("UniversalPlayerProvider", provider)._save_player_data(
644                        universal_player.player_id, universal_player
645                    )
646                    break
647
648        self.mass.create_task(_do_save())
649
650    def _get_known_protocol_ids(self, parent: Player) -> list[str]:
651        """
652        Get all protocol IDs tracked for a parent player.
653
654        Includes both active links and cached/inactive protocol IDs so callers can
655        safely migrate or clean up the full parent/protocol relationship.
656        """
657        result: list[str] = []
658        seen: set[str] = set()
659
660        for linked in parent.linked_output_protocols:
661            if linked.output_protocol_id not in seen:
662                result.append(linked.output_protocol_id)
663                seen.add(linked.output_protocol_id)
664
665        if parent.provider.domain == "universal_player" and isinstance(parent, UniversalPlayer):
666            cached_ids = parent._protocol_player_ids
667        else:
668            cached_ids = self._get_cached_protocol_ids(parent.player_id)
669
670        for protocol_id in cached_ids:
671            if protocol_id not in seen:
672                result.append(protocol_id)
673                seen.add(protocol_id)
674
675        return result
676
677    def _migrate_protocol_ids_to_parent(self, parent: Player, protocol_ids: set[str]) -> None:
678        """
679        Persist protocol ownership on a new parent without requiring active links.
680
681        This is used when protocol ownership moves from one parent to another during
682        promotion/merge flows. Active protocols are already linked in memory, but
683        disabled or temporarily unavailable protocols still need their cached parent
684        relationship moved as well.
685        """
686        if not protocol_ids:
687            return
688
689        if parent.provider.domain == "universal_player" and isinstance(parent, UniversalPlayer):
690            for protocol_id in protocol_ids:
691                parent.add_protocol_player(protocol_id)
692            self._save_universal_player_data(parent)
693        else:
694            conf_key = f"{CONF_PLAYERS}/{parent.player_id}/values/{CONF_LINKED_PROTOCOL_IDS}"
695            cached_ids = self._get_cached_protocol_ids(parent.player_id)
696            changed = False
697            for protocol_id in protocol_ids:
698                if protocol_id not in cached_ids:
699                    cached_ids.append(protocol_id)
700                    changed = True
701            if changed:
702                self.mass.config.set(conf_key, cached_ids)
703
704        for protocol_id in protocol_ids:
705            if self.mass.config.get(f"{CONF_PLAYERS}/{protocol_id}"):
706                self._save_protocol_parent_id(protocol_id, parent.player_id)
707
708    def _remove_protocol_ids_from_parent(self, parent: Player, protocol_ids: set[str]) -> None:
709        """
710        Remove protocol ownership from a parent before it is permanently cleaned up.
711
712        This prevents `_cleanup_protocol_links` from treating already-migrated
713        protocols as orphaned when the obsolete parent is unregistered.
714        """
715        if not protocol_ids:
716            return
717
718        remaining_links = [
719            link
720            for link in parent.linked_output_protocols
721            if link.output_protocol_id not in protocol_ids
722        ]
723        if len(remaining_links) != len(parent.linked_output_protocols):
724            parent.set_linked_output_protocols(remaining_links)
725
726        if parent.provider.domain == "universal_player" and isinstance(parent, UniversalPlayer):
727            for protocol_id in protocol_ids:
728                parent.remove_protocol_player(protocol_id)
729            if self.mass.config.get(f"{CONF_PLAYERS}/{parent.player_id}"):
730                self.mass.config.set(
731                    f"{CONF_PLAYERS}/{parent.player_id}/values/{CONF_LINKED_PROTOCOL_IDS}",
732                    parent._protocol_player_ids,
733                )
734        else:
735            for protocol_id in protocol_ids:
736                self._remove_protocol_id_from_cache(parent.player_id, protocol_id)
737
738    def _check_merge_universal_players(self, universal_player: UniversalPlayer) -> None:
739        """
740        Check if another universal player should be merged into this one.
741
742        Called after identifiers are copied from a protocol player to a universal player.
743        When a protocol player brings new identifiers (e.g., MAC from ARP enrichment),
744        the universal player may now match another universal player that was created
745        from a different protocol (e.g., DLNA-based universal player now matches
746        AirPlay-based universal player because they share the same MAC address).
747
748        The oldest universal player absorbs the other one. Only one merge is performed
749        per call; re-evaluation will catch cascading merges.
750        """
751        if not (match := self._find_mergeable_universal_player(universal_player)):
752            return
753        keep, remove = self._select_merge_winner(universal_player, match)
754        self.logger.info(
755            "Merging universal player %s into %s (shared identifiers)",
756            remove.player_id,
757            keep.player_id,
758        )
759        self._merge_universal_players(keep, remove)
760
761    def _find_mergeable_universal_player(
762        self, universal_player: UniversalPlayer
763    ) -> UniversalPlayer | None:
764        """
765        Return the first other universal player that represents the same device, if any.
766
767        Players that share a protocol domain are not returned: they are separate devices
768        that merely share an identifier, so merging them would orphan a protocol.
769
770        :param universal_player: The universal player to find a merge candidate for.
771        """
772        for player in list(self._players.values()):
773            if player.provider.domain != "universal_player":
774                continue
775            if player.player_id == universal_player.player_id:
776                continue
777            if not isinstance(player, UniversalPlayer):
778                continue
779
780            if not self._identifiers_match(universal_player, player, ""):
781                continue
782
783            # Do not merge if both UPs have protocols from the same domain.
784            # Multiple instances of the same protocol on one host (e.g., several
785            # squeezelite players on the same VM) are separate devices that happen
786            # to share an IP. Merging them would orphan one instance's protocol.
787            domains_a = {
788                link.protocol_domain
789                for link in universal_player.linked_output_protocols
790                if link.protocol_domain
791            }
792            domains_b = {
793                link.protocol_domain
794                for link in player.linked_output_protocols
795                if link.protocol_domain
796            }
797            if domains_a & domains_b:
798                self.logger.debug(
799                    "Skipping merge of %s and %s: shared protocol domain(s) %s",
800                    universal_player.player_id,
801                    player.player_id,
802                    domains_a & domains_b,
803                )
804                continue
805
806            return player
807
808        return None
809
810    def _select_merge_winner(
811        self, universal_player: UniversalPlayer, other_player: UniversalPlayer
812    ) -> tuple[UniversalPlayer, UniversalPlayer]:
813        """
814        Return which of the two universal players absorbs the other, as (keeper, absorbed).
815
816        The oldest player wins, on a tie the one with the most protocol links.
817
818        :param universal_player: The universal player the merge was triggered for.
819        :param other_player: The universal player it matched with.
820        """
821        # The outcome must be stable across server restarts. Without that, which
822        # UniversalPlayer "wins" depends on iteration order of self._players.values(),
823        # which can shift between runs and causes downstream player_id reshuffling
824        # (and broken entity bindings in consumers like the Home Assistant MA integration).
825        if self._merge_rank(universal_player) <= self._merge_rank(other_player):
826            return universal_player, other_player
827        return other_player, universal_player
828
829    def _merge_rank(self, universal_player: Player) -> tuple[int, int, str]:
830        """
831        Return the sort key of a universal player in a merge, lowest wins.
832
833        Age comes first because the keeper's player id is the one that survives, and the
834        oldest player is the one API consumers have been bound to the longest. The links
835        of the absorbed player move over either way, so nothing is lost by keeping the
836        smaller one. A player from before player ids were minted has no stored moment and
837        counts as the oldest, which is exactly what it is.
838        """
839        created_at = self.mass.config.get(
840            f"{CONF_PLAYERS}/{universal_player.player_id}/values/{CONF_CREATED_AT}", 0
841        )
842        return (
843            created_at if isinstance(created_at, int) else 0,
844            -len(universal_player.linked_output_protocols),
845            universal_player.player_id,
846        )
847
848    def _merge_universal_players(self, keep: UniversalPlayer, remove: UniversalPlayer) -> None:
849        """
850        Absorb one universal player into another and schedule the absorbed one's removal.
851
852        :param keep: The universal player that stays.
853        :param remove: The universal player that is absorbed.
854        """
855        known_protocol_ids = set(self._get_known_protocol_ids(remove))
856        active_protocol_ids = {link.output_protocol_id for link in remove.linked_output_protocols}
857        moved_protocol_ids: set[str] = set()
858
859        # Transfer protocol links from the removed player to the keeper
860        for linked in list(remove.linked_output_protocols):
861            if protocol_player := self.get_player(linked.output_protocol_id):
862                protocol_player.set_protocol_parent_id(None)
863                domain = linked.protocol_domain or protocol_player.provider.domain
864
865                # Check if keeper already has an active link from this domain
866                if self._parent_has_active_protocol_from_domain(keep, domain):
867                    self.logger.debug(
868                        "Skipping duplicate %s link during merge: %s",
869                        domain,
870                        linked.output_protocol_id,
871                    )
872                    continue
873
874                self._add_protocol_link(keep, protocol_player, domain)
875                if protocol_player.protocol_parent_id == keep.player_id:
876                    moved_protocol_ids.add(protocol_player.player_id)
877                    protocol_player.refresh_state()
878
879        # Move cached-only protocol ownership as well so old-parent cleanup
880        # does not wipe protocols that were intentionally preserved.
881        cached_only_ids = known_protocol_ids - active_protocol_ids
882        preserved_protocol_ids = moved_protocol_ids | cached_only_ids
883        self._migrate_protocol_ids_to_parent(keep, preserved_protocol_ids)
884        self._remove_protocol_ids_from_parent(remove, preserved_protocol_ids)
885
886        # Merge identifiers
887        for conn_type, value in remove.device_info.identifiers.items():
888            keep.device_info.add_identifier(conn_type, value)
889        keep.refresh_state()
890
891        # Persist updated data before the obsolete player is removed
892        self._save_universal_player_data(keep)
893
894        # Carry over the user's configuration and re-point group memberships
895        # before the permanent removal below deletes the losing wrapper's config
896        self._migrate_universal_player_config(remove.player_id, keep.player_id)
897        self._update_group_memberships(remove.player_id, keep.player_id)
898
899        # Stop playback and remove the obsolete player
900        self.mass.create_task(self._stop_and_unregister(remove, keep.player_id))
901
902    def _link_protocols_to_universal(
903        self, universal_player: Player, protocol_players: list[Player]
904    ) -> None:
905        """Link protocol players to a universal player, cleaning up existing links."""
906        for player in protocol_players:
907            # Clean up if linked to another player
908            if player.protocol_parent_id:
909                if parent := self.get_player(player.protocol_parent_id):
910                    self._remove_protocol_link(parent, player.player_id)
911                player.set_protocol_parent_id(None)
912            # Link to universal player
913            self._add_protocol_link(universal_player, player, player.provider.domain)
914            player.refresh_state()
915
916        # Update availability from protocol players
917        universal_player.refresh_state()
918
919    async def _create_or_update_universal_player(self, protocol_players: list[Player]) -> None:
920        """
921        Create or update a UniversalPlayer for a set of protocol players.
922
923        Delegates to the universal player provider which handles orchestration,
924        locking, and player creation. The controller then links the protocols
925        to the universal player.
926        """
927        # Filter out players that got linked during the async delay
928        protocol_players = [p for p in protocol_players if not p.protocol_parent_id]
929        if not protocol_players:
930            return
931
932        # Get the universal_player provider
933        universal_provider: UniversalPlayerProvider | None = None
934        for provider in self.mass.get_providers(ProviderType.PLAYER):
935            if provider.domain == "universal_player":
936                universal_provider = cast("UniversalPlayerProvider", provider)
937                break
938
939        if not universal_provider:
940            return
941
942        # Delegate to provider - it handles locking, create/update decision, etc.
943        # It reports which universal player each protocol player belongs to, as a
944        # device with several instances of one protocol domain gets more than one.
945        assignments = await universal_provider.ensure_universal_players_for_protocols(
946            protocol_players
947        )
948
949        # Link the protocols to their universal player (the controller manages
950        # cross-provider state), skipping players that were linked in the meantime.
951        by_universal_player: dict[str, list[Player]] = {}
952        for player in protocol_players:
953            if player.protocol_parent_id:
954                continue
955            if universal_player := assignments.get(player.player_id):
956                by_universal_player.setdefault(universal_player.player_id, []).append(player)
957
958        for universal_player_id, players in by_universal_player.items():
959            if universal_player := self.get_player(universal_player_id):
960                self._link_protocols_to_universal(universal_player, players)
961
962    def _try_link_protocols_to_native(self, native_player: Player) -> None:
963        """Try to link protocol players to a native player."""
964        # First, check if there's a universal player for this device that should be replaced
965        self._check_replace_universal_player(native_player)
966
967        # Look for protocol players that should be linked
968        for protocol_player in self.all_players(return_protocol_players=True):
969            if protocol_player.state.type != PlayerType.PROTOCOL:
970                continue
971            if protocol_player.protocol_parent_id:
972                # Already linked to a parent (could be this native player after replacement)
973                continue
974            if protocol_player.underlying_player_id:
975                # Derived protocol players link via their underlying player instead
976                continue
977            if self._awaits_unregistered_owner(protocol_player, native_player.player_id):
978                continue
979
980            protocol_domain = protocol_player.provider.domain
981
982            # Skip if this native player already has an active link from this domain
983            # (prevents a second instance of the same protocol from trying to link)
984            if self._parent_has_active_protocol_from_domain(native_player, protocol_domain):
985                continue
986
987            if self._identifiers_match(native_player, protocol_player, protocol_domain):
988                self._add_protocol_link(native_player, protocol_player, protocol_domain)
989                # Check if linking succeeded (may be refused for duplicate domain)
990                if protocol_player.protocol_parent_id is not None:
991                    protocol_player.refresh_state()
992                    native_player.refresh_state()
993
994        # Proactively recover disabled/missing protocols from config
995        # This ensures disabled protocols show up in the UI so they can be re-enabled
996        self._recover_cached_protocol_links(native_player)
997
998        # Second pass: match remaining unlinked protocol players via sibling identifiers.
999        # After cache recovery, the native player has linked protocols (e.g., AirPlay)
1000        # whose identifiers can be used to match new protocol players (e.g., Sendspin bridge)
1001        # that share the same device identifiers but couldn't match the native player directly.
1002        for protocol_player in self.all_players(return_protocol_players=True):
1003            if protocol_player.state.type != PlayerType.PROTOCOL:
1004                continue
1005            if protocol_player.protocol_parent_id:
1006                continue
1007            if protocol_player.underlying_player_id:
1008                continue
1009            if self._awaits_unregistered_owner(protocol_player, native_player.player_id):
1010                continue
1011            protocol_domain = protocol_player.provider.domain
1012            if self._parent_has_active_protocol_from_domain(native_player, protocol_domain):
1013                continue
1014            if self._match_via_linked_protocols(native_player, protocol_player, protocol_domain):
1015                self.logger.debug(
1016                    "Linked %s to %s via sibling protocol identifiers",
1017                    protocol_player.player_id,
1018                    native_player.player_id,
1019                )
1020
1021        # Finally, link derived protocol players that ride directly on this
1022        # native player (derived players riding on the protocol players linked
1023        # above are handled by _add_protocol_link itself).
1024        self._link_derived_protocols_of(native_player)
1025
1026    def _awaits_unregistered_owner(self, protocol_player: Player, candidate_parent_id: str) -> bool:
1027        """
1028        Check if a protocol player is reserved for a persisted owner that is still starting up.
1029
1030        :param protocol_player: The unlinked protocol player.
1031        :param candidate_parent_id: The player that wants to claim it.
1032        """
1033        owner_id = self._get_cached_protocol_parent_id(protocol_player.player_id)
1034        if owner_id is None or owner_id == candidate_parent_id:
1035            return False
1036        return self.get_player(owner_id) is None
1037
1038    def _check_replace_universal_player(self, native_player: Player) -> None:
1039        """Check if a universal player should be replaced by this native player."""
1040        # Skip if native_player is itself a universal player (prevent self-replacement)
1041        if native_player.provider.domain == "universal_player":
1042            return
1043
1044        # Look for universal players that match this native player
1045        for player in list(self._players.values()):
1046            if player.provider.domain != "universal_player":
1047                continue
1048
1049            # Check by identifiers first
1050            identifiers_match = self._identifiers_match(native_player, player, "")
1051
1052            # Also check if native player's ID is in the universal player's stored protocol list
1053            # This handles players that changed type (e.g., sendspin web players changed from
1054            # PROTOCOL to PLAYER type) and have no identifiers to match against
1055            player_id_in_protocols = (
1056                isinstance(player, UniversalPlayer)
1057                and native_player.player_id in player._protocol_player_ids
1058            )
1059
1060            if not identifiers_match and not player_id_in_protocols:
1061                continue
1062
1063            known_protocol_ids = set(self._get_known_protocol_ids(player))
1064            refused_protocol_ids: set[str] = set()
1065            moved_protocol_ids: set[str] = set()
1066
1067            # Transfer the protocol links from the universal player to the native player.
1068            # A derived protocol rides on another output, so a base and everything riding
1069            # on it can only move together: refusing one of them holds back the group.
1070            for group in self._group_protocol_links(player):
1071                domains = {
1072                    protocol_player.player_id: linked.protocol_domain
1073                    or protocol_player.provider.domain
1074                    for linked, protocol_player in group
1075                }
1076                if any(
1077                    self._parent_has_active_protocol_from_domain(
1078                        native_player, domain, exclude_player_id=protocol_id
1079                    )
1080                    for protocol_id, domain in domains.items()
1081                ):
1082                    refused_protocol_ids.update(domains.keys())
1083                    continue
1084                for _, protocol_player in group:
1085                    protocol_player.set_protocol_parent_id(None)
1086                    self._add_protocol_link(
1087                        native_player, protocol_player, domains[protocol_player.player_id]
1088                    )
1089                    if protocol_player.protocol_parent_id != native_player.player_id:
1090                        # Link refused, keep the protocol owned by the universal player.
1091                        protocol_player.set_protocol_parent_id(player.player_id)
1092                        refused_protocol_ids.add(protocol_player.player_id)
1093                        continue
1094                    protocol_player.refresh_state()
1095                    moved_protocol_ids.add(protocol_player.player_id)
1096
1097            # A refused link leaves the universal player in charge, so only hand over what
1098            # actually moved: ownership that exists in config alone stays with it, which
1099            # keeps a protocol derived from a refused one with the parent it will link to.
1100            migrated_protocol_ids = (
1101                moved_protocol_ids if refused_protocol_ids else known_protocol_ids
1102            )
1103            # A device that kept its id across a type change lists itself here.
1104            # It must never become its own protocol, and it must also be dropped
1105            # from the obsolete universal player so the permanent cleanup below
1106            # doesn't treat it as an orphaned protocol (which would re-wrap the
1107            # native player in a fresh universal player).
1108            migrated_protocol_ids.discard(native_player.player_id)
1109            self._migrate_protocol_ids_to_parent(native_player, migrated_protocol_ids)
1110            self._remove_protocol_ids_from_parent(
1111                player, migrated_protocol_ids | {native_player.player_id}
1112            )
1113            native_player.refresh_state()
1114
1115            if refused_protocol_ids:
1116                # Registered protocols that the native player refused remain on the wrapper.
1117                continue
1118
1119            # Carry over the user's configuration and re-point group memberships
1120            # before the permanent removal below deletes the universal player's config
1121            self._migrate_universal_player_config(player.player_id, native_player.player_id)
1122            self._update_group_memberships(player.player_id, native_player.player_id)
1123
1124            # Stop playback and remove the now-obsolete universal player
1125            self.mass.create_task(self._stop_and_unregister(player, native_player.player_id))
1126
1127    def _group_protocol_links(
1128        self, parent: Player
1129    ) -> list[list[tuple[LinkedOutputProtocol, Player]]]:
1130        """
1131        Group a parent's registered protocol links with the protocols riding on them.
1132
1133        Each group holds one base protocol followed by the derived protocols that ride
1134        on it. A protocol whose underlying player is not one of the parent's own links
1135        forms a group of its own.
1136
1137        :param parent: The parent player whose protocol links should be grouped.
1138        """
1139        registered = [
1140            (linked, protocol_player)
1141            for linked in parent.linked_output_protocols
1142            if (protocol_player := self.get_player(linked.output_protocol_id))
1143        ]
1144        link_ids = {protocol_player.player_id for _, protocol_player in registered}
1145        riders: dict[str, list[tuple[LinkedOutputProtocol, Player]]] = {}
1146        bases: list[tuple[LinkedOutputProtocol, Player]] = []
1147        for linked, protocol_player in registered:
1148            underlying_id = protocol_player.underlying_player_id
1149            if underlying_id and underlying_id in link_ids:
1150                riders.setdefault(underlying_id, []).append((linked, protocol_player))
1151            else:
1152                bases.append((linked, protocol_player))
1153
1154        groups = [
1155            [(linked, protocol_player), *riders.get(protocol_player.player_id, [])]
1156            for linked, protocol_player in bases
1157        ]
1158        # A derived protocol riding on another derived protocol has no base group here,
1159        # so it moves on its own rather than being dropped from the transfer.
1160        grouped_ids = {
1161            protocol_player.player_id for group in groups for _, protocol_player in group
1162        }
1163        groups.extend([entry] for entry in registered if entry[1].player_id not in grouped_ids)
1164        return groups
1165
1166    def _migrate_universal_player_config(self, universal_id: str, native_id: str) -> None:
1167        """
1168        Carry over user-set configuration from a replaced universal player.
1169
1170        Copies the custom display name, player config values, DSP settings and
1171        per-queue settings of the (obsolete) universal player onto the native
1172        player that replaces it, without overwriting values explicitly set on
1173        the native player itself. Must be called while the universal player's
1174        config still exists, as the permanent removal deletes it.
1175
1176        :param universal_id: Player id of the obsolete universal player being replaced.
1177        :param native_id: Player id of the native player that replaces it.
1178        """
1179        source_raw = self.mass.config.get(f"{CONF_PLAYERS}/{universal_id}")
1180        source_raw = source_raw if isinstance(source_raw, dict) else {}
1181        target_key = f"{CONF_PLAYERS}/{native_id}"
1182        target_raw = self.mass.config.get(target_key)
1183        target_raw = target_raw if isinstance(target_raw, dict) else {}
1184        player_config_changed = False
1185
1186        # only carry an actual user rename, not the auto-generated default name;
1187        # likewise a name on the native player only counts as a user override when
1188        # it differs from the default name
1189        custom_name = source_raw.get("name")
1190        target_name = target_raw.get("name")
1191        target_has_custom_name = bool(target_name) and target_name != target_raw.get("default_name")
1192        if (
1193            custom_name
1194            and custom_name != source_raw.get("default_name")
1195            and not target_has_custom_name
1196        ):
1197            self.mass.config.set(f"{target_key}/name", custom_name)
1198            player_config_changed = True
1199
1200        source_values = source_raw.get("values")
1201        source_values = source_values if isinstance(source_values, dict) else {}
1202        target_values = target_raw.get("values")
1203        target_values = target_values if isinstance(target_values, dict) else {}
1204        for key, value in source_values.items():
1205            if key in UNIVERSAL_PLAYER_INTERNAL_CONF_KEYS:
1206                continue
1207            if CONF_PROTOCOL_KEY_SPLITTER in key:
1208                # stale virtual mirror of a protocol player's own config
1209                continue
1210            if key in target_values:
1211                continue
1212            self.mass.config.set(f"{target_key}/values/{key}", deepcopy(value))
1213            player_config_changed = True
1214
1215        # DSP settings follow wholesale, unless the native player has its own
1216        dsp_changed = False
1217        source_dsp = self.mass.config.get(f"{CONF_PLAYER_DSP}/{universal_id}")
1218        if source_dsp and not self.mass.config.get(f"{CONF_PLAYER_DSP}/{native_id}"):
1219            self.mass.config.set(f"{CONF_PLAYER_DSP}/{native_id}", deepcopy(source_dsp))
1220            dsp_changed = True
1221
1222        queue_changed = self._migrate_universal_queue_config(universal_id, native_id)
1223
1224        if not (player_config_changed or dsp_changed or queue_changed):
1225            return
1226        self.logger.info(
1227            "Carried over configuration of universal player %s to %s", universal_id, native_id
1228        )
1229        if player_config_changed:
1230            # the native player's in-place config was loaded before the carry-over,
1231            # so reload it to make the migrated values (e.g. custom name) effective
1232            self.mass.create_task(self._reapply_player_config(native_id))
1233
1234    def _migrate_universal_queue_config(self, universal_id: str, native_id: str) -> bool:
1235        """
1236        Move the per-queue settings of a replaced universal player to its replacement.
1237
1238        Queue ids equal player ids, so the source entry is removed once it is carried over.
1239
1240        :param universal_id: Player id of the obsolete universal player.
1241        :param native_id: Player id of the native player that replaces it.
1242        :return: True if any queue setting was carried over.
1243        """
1244        queue_changed = False
1245        source_queue_raw = self.mass.config.get(f"{CONF_PLAYER_QUEUES}/{universal_id}")
1246        source_queue_raw = source_queue_raw if isinstance(source_queue_raw, dict) else None
1247        if source_queue_values := (source_queue_raw or {}).get("values"):
1248            target_queue_key = f"{CONF_PLAYER_QUEUES}/{native_id}"
1249            target_queue_raw = self.mass.config.get(target_queue_key)
1250            target_queue_raw = (
1251                deepcopy(target_queue_raw) if isinstance(target_queue_raw, dict) else {}
1252            )
1253            target_queue_values = target_queue_raw.setdefault("values", {})
1254            for key, value in source_queue_values.items():
1255                if key in target_queue_values:
1256                    continue
1257                target_queue_values[key] = deepcopy(value)
1258                queue_changed = True
1259            if queue_changed:
1260                target_queue_raw["queue_id"] = native_id
1261                self.mass.config.set(target_queue_key, target_queue_raw)
1262        if source_queue_raw is not None:
1263            self.mass.config.remove(f"{CONF_PLAYER_QUEUES}/{universal_id}")
1264        return queue_changed
1265
1266    async def _reapply_player_config(self, player_id: str) -> None:
1267        """Reload the stored config onto a registered player and refresh its state."""
1268        if not (player := self.get_player(player_id)):
1269            return
1270        config = await self.mass.config.get_player_config(player_id)
1271        player.set_config(config)
1272        player.update_state()
1273        self.mass.signal_event(EventType.PLAYER_CONFIG_UPDATED, object_id=player_id, data=config)
1274
1275    def _update_group_memberships(self, old_player_id: str, new_player_id: str | None) -> None:
1276        """
1277        Hand a removed player's group memberships over to its successor, or drop them.
1278
1279        Other players that list the removed player as a group member (or allowed
1280        member) must follow its successor so those memberships are not silently
1281        lost. Without a successor the player is gone for good and its id is dropped
1282        from the group members instead, so it can not linger in a group and pull a
1283        device that returns under the same id back in. Its allow-list entry is left
1284        alone there, since an allow-list that runs empty stops restricting at all.
1285        Updates the persisted config and keeps any registered player whose
1286        membership changed in sync.
1287
1288        :param old_player_id: Player id that is being removed.
1289        :param new_player_id: Player id that replaces it, or None if there is none.
1290        """
1291        all_player_configs = self.mass.config.get(CONF_PLAYERS, {})
1292        if not isinstance(all_player_configs, dict):
1293            return
1294        for other_id, other_cfg in all_player_configs.items():
1295            if not isinstance(other_cfg, dict):
1296                continue
1297            other_values = other_cfg.get("values")
1298            if not isinstance(other_values, dict):
1299                continue
1300            other_player = self.get_player(other_id)
1301            changed = False
1302            for key in (CONF_GROUP_MEMBERS, CONF_ALLOWED_MEMBERS):
1303                members = other_values.get(key)
1304                if not isinstance(members, list) or old_player_id not in members:
1305                    continue
1306                if new_player_id is None and key == CONF_ALLOWED_MEMBERS:
1307                    # an allow-list that runs empty reads as "everyone may join", so the
1308                    # entry of a removed player stays: it can never join again anyway
1309                    continue
1310                new_members: list[str] = []
1311                for member_id in members:
1312                    resolved = new_player_id if member_id == old_player_id else member_id
1313                    if resolved is not None and resolved not in new_members:
1314                        new_members.append(resolved)
1315                self.mass.config.set(f"{CONF_PLAYERS}/{other_id}/values/{key}", new_members)
1316                changed = True
1317                # keep a registered player's in-place config copy in sync
1318                if other_player and (entry := other_player.config.values.get(key)):
1319                    entry.value = new_members
1320            if changed and other_player:
1321                self.mass.create_task(self._reload_group_members(other_player))
1322
1323    async def _reload_group_members(self, player: Player) -> None:
1324        """
1325        Let a group re-read its member config so its live member list follows along.
1326
1327        :param player: The group player whose stored member list changed.
1328        """
1329        await player.on_config_updated()
1330        player.refresh_state()
1331
1332    async def _stop_and_unregister(self, player: Player, replacement_player_id: str) -> None:
1333        """
1334        Stop active playback on a player and then permanently unregister it.
1335
1336        Used when an obsolete universal player is replaced or merged away: while
1337        it is not idle its protocol child keeps playing the dead queue's stream
1338        until the buffer drains, so playback is stopped first. Queue ownership is
1339        intentionally not transferred.
1340
1341        :param player: The obsolete player to stop and permanently remove.
1342        :param replacement_player_id: Player ID that takes the obsolete player's place.
1343        """
1344        if player.playback_state != PlaybackState.IDLE:
1345            with suppress(PlayerCommandFailed, PlayerUnavailableError):
1346                await self.mass.player_queues.stop(player.player_id)
1347        await self.unregister(
1348            player.player_id, permanent=True, replacement_player_id=replacement_player_id
1349        )
1350
1351    def _parent_has_active_protocol_from_domain(
1352        self, parent: Player, domain: str, exclude_player_id: str | None = None
1353    ) -> bool:
1354        """
1355        Check if a parent already has an active (registered) protocol player from a given domain.
1356
1357        This prevents a second protocol player of the same domain (e.g., a second AirPlay
1358        instance on the same host) from replacing the first one's link on the same parent.
1359
1360        :param parent: The parent player to check.
1361        :param domain: The protocol domain to check for (e.g., "airplay", "dlna").
1362        :param exclude_player_id: Optional player ID to exclude from the check
1363            (used when checking if a player's own domain is already linked).
1364        """
1365        for link in parent.linked_output_protocols:
1366            if link.protocol_domain != domain:
1367                continue
1368            if exclude_player_id and link.output_protocol_id == exclude_player_id:
1369                continue
1370            # A registered player from this domain blocks the link, even if unavailable.
1371            # Being offline doesn't make it a different device — it's still occupying
1372            # this domain slot. The provider should remove stale players explicitly.
1373            if self.get_player(link.output_protocol_id):
1374                return True
1375        return False
1376
1377    def _add_protocol_link(
1378        self, native_player: Player, protocol_player: Player, protocol_domain: str
1379    ) -> None:
1380        """Add a protocol link from native player to protocol player."""
1381        # Never link a player to itself (hides it as its own protocol child).
1382        if native_player.player_id == protocol_player.player_id:
1383            return
1384        # Guard: refuse to replace an existing active link from the same domain.
1385        # This prevents a second instance of the same protocol (e.g., two AirPlay
1386        # instances on the same host) from silently replacing the first one.
1387        if self._parent_has_active_protocol_from_domain(
1388            native_player, protocol_domain, exclude_player_id=protocol_player.player_id
1389        ):
1390            self.logger.debug(
1391                "Refusing to link %s to %s: parent already has an active %s link",
1392                protocol_player.player_id,
1393                native_player.player_id,
1394                protocol_domain,
1395            )
1396            return
1397
1398        # Remove any existing link for the same protocol domain
1399        updated_protocols = [
1400            link
1401            for link in native_player.linked_output_protocols
1402            if link.protocol_domain != protocol_domain
1403        ]
1404
1405        # Get priority for this protocol
1406        priority = PROTOCOL_PRIORITY.get(protocol_domain, 100)
1407
1408        # Derived transports (e.g. a Sendspin bridge riding on an AirPlay player)
1409        # reference the base output they run on top of; "native" when they ride
1410        # on the parent player itself
1411        derived_from = protocol_player.underlying_player_id
1412        if derived_from == native_player.player_id:
1413            derived_from = "native"
1414
1415        # Add the new link
1416        updated_protocols.append(
1417            LinkedOutputProtocol(
1418                output_protocol_id=protocol_player.player_id,
1419                protocol_domain=protocol_domain,
1420                priority=priority,
1421                derived_from=derived_from,
1422            )
1423        )
1424        native_player.set_linked_output_protocols(updated_protocols)
1425
1426        # Set protocol player's parent
1427        protocol_player.set_protocol_parent_id(native_player.player_id)
1428        # Ownership is exclusive: a parent that still lists this protocol would show it
1429        # twice and hold its domain slot against a genuine protocol of that domain.
1430        self._evict_protocol_from_other_parents(protocol_player.player_id, native_player.player_id)
1431
1432        # Persist linked protocol IDs to config for fast restart
1433        # (only for non-universal players, as universal players handle this themselves)
1434        if native_player.provider.domain != "universal_player":
1435            self._save_linked_protocol_ids(native_player)
1436        # Always save the parent ID on the protocol player for reverse lookup on restart
1437        # (needed for both native and universal parents to enable fast restore)
1438        self._save_protocol_parent_id(protocol_player.player_id, native_player.player_id)
1439
1440        # The freshly linked player may have derived protocol players (e.g. a
1441        # Sendspin bridge riding on it) waiting to join the same parent.
1442        self._link_derived_protocols_of(protocol_player)
1443
1444    def _remove_protocol_link(
1445        self, native_player: Player, protocol_player_id: str, permanent: bool = False
1446    ) -> None:
1447        """
1448        Remove a protocol link.
1449
1450        :param native_player: The parent player to remove the link from.
1451        :param protocol_player_id: The protocol player ID to unlink.
1452        :param permanent: If True, also removes the protocol ID from the cached list.
1453            Use this when the protocol player config is being deleted. If False,
1454            the protocol ID remains in the cache so it can be shown as disabled
1455            and re-enabled later.
1456        """
1457        updated_protocols = [
1458            link
1459            for link in native_player.linked_output_protocols
1460            if link.output_protocol_id != protocol_player_id
1461        ]
1462        native_player.set_linked_output_protocols(updated_protocols)
1463
1464        # Clear parent reference on protocol player if it still exists
1465        if protocol_player := self.get_player(protocol_player_id):
1466            if protocol_player.protocol_parent_id == native_player.player_id:
1467                protocol_player.set_protocol_parent_id(None)
1468
1469        # Update persisted linked protocol IDs
1470        if native_player.provider.domain != "universal_player":
1471            if permanent:
1472                # Permanently remove from cache (player config is being deleted)
1473                self._remove_protocol_id_from_cache(native_player.player_id, protocol_player_id)
1474            # Note: we don't call _save_linked_protocol_ids here anymore for non-permanent
1475            # removals because the merge approach will preserve the ID in the cache
1476        # Always clear the cached parent ID (for both native and universal parents)
1477        self._clear_protocol_parent_id(protocol_player_id)
1478
1479    def _evict_protocol_from_other_parents(self, protocol_player_id: str, parent_id: str) -> None:
1480        """
1481        Drop a protocol's output entry from every parent except the one that owns it.
1482
1483        A parent that still holds an active entry while another parent takes the protocol
1484        is out of date, so its stored ownership is dropped as well. Parents that already gave
1485        up the active entry keep theirs and can still offer the protocol for re-enabling.
1486
1487        :param protocol_player_id: Player id of the protocol player that got a new parent.
1488        :param parent_id: Player id of the parent that now owns it.
1489        """
1490        for player in list(self._players.values()):
1491            if player.player_id == parent_id:
1492                continue
1493            if not any(
1494                link.output_protocol_id == protocol_player_id
1495                for link in player.linked_output_protocols
1496            ):
1497                continue
1498            self._remove_protocol_ids_from_parent(player, {protocol_player_id})
1499            self.logger.debug(
1500                "Removed stale output %s from %s: it is owned by %s",
1501                protocol_player_id,
1502                player.player_id,
1503                parent_id,
1504            )
1505
1506    def _save_linked_protocol_ids(self, native_player: Player) -> None:
1507        """
1508        Save linked protocol IDs to config for persistence across restarts.
1509
1510        This method merges active protocol IDs with existing cached IDs to preserve
1511        disabled protocol players in the cache. This allows disabled protocols to be
1512        shown in the UI so they can be re-enabled.
1513        """
1514        conf_key = f"{CONF_PLAYERS}/{native_player.player_id}/values/{CONF_LINKED_PROTOCOL_IDS}"
1515        # Get existing cached IDs to preserve disabled protocols
1516        existing_ids: list[str] = self.mass.config.get(conf_key, [])
1517        # Get currently active protocol IDs
1518        active_ids = {link.output_protocol_id for link in native_player.linked_output_protocols}
1519        # Merge: keep existing IDs and add any new active ones
1520        merged_ids = list(existing_ids)
1521        for protocol_id in active_ids:
1522            if protocol_id not in merged_ids:
1523                merged_ids.append(protocol_id)
1524        self.mass.config.set(conf_key, merged_ids)
1525
1526    def _get_cached_protocol_ids(self, player_id: str) -> list[str]:
1527        """Get cached linked protocol IDs from config."""
1528        conf_key = f"{CONF_PLAYERS}/{player_id}/values/{CONF_LINKED_PROTOCOL_IDS}"
1529        result = self.mass.config.get(conf_key, [])
1530        return list(result) if result else []
1531
1532    def _remove_protocol_id_from_cache(
1533        self, parent_player_id: str, protocol_player_id: str
1534    ) -> None:
1535        """
1536        Permanently remove a protocol player ID from the cached linked protocol IDs.
1537
1538        Use this when a protocol player config is being deleted, not just disabled.
1539        """
1540        conf_key = f"{CONF_PLAYERS}/{parent_player_id}/values/{CONF_LINKED_PROTOCOL_IDS}"
1541        cached_ids: list[str] = self.mass.config.get(conf_key, [])
1542        if protocol_player_id in cached_ids:
1543            cached_ids.remove(protocol_player_id)
1544            self.mass.config.set(conf_key, cached_ids)
1545
1546    def _save_protocol_parent_id(self, protocol_player_id: str, parent_id: str) -> None:
1547        """Save the parent ID for a protocol player for persistence across restarts."""
1548        # Only save if the player config still exists to avoid creating partial entries
1549        if not self.mass.config.get(f"{CONF_PLAYERS}/{protocol_player_id}"):
1550            return
1551        conf_key = f"{CONF_PLAYERS}/{protocol_player_id}/values/{CONF_PROTOCOL_PARENT_ID}"
1552        self.mass.config.set(conf_key, parent_id)
1553
1554    def _save_underlying_player_id(self, player: Player) -> None:
1555        """
1556        Persist the derived-transport edge of a player to config.
1557
1558        Allows the edge to be resolved (e.g. by the config UI) even while the
1559        player is not registered. Clears a previously persisted edge when the
1560        player is no longer derived (e.g. a bridge client turned web player).
1561        """
1562        # Only save if the player config still exists to avoid creating partial entries
1563        if not self.mass.config.get(f"{CONF_PLAYERS}/{player.player_id}"):
1564            return
1565        conf_key = f"{CONF_PLAYERS}/{player.player_id}/values/{CONF_UNDERLYING_PLAYER_ID}"
1566        if player.underlying_player_id:
1567            self.mass.config.set(conf_key, player.underlying_player_id)
1568        elif self.mass.config.get(conf_key) is not None:
1569            self.mass.config.set(conf_key, None)
1570
1571    def _get_cached_protocol_parent_id(self, protocol_player_id: str) -> str | None:
1572        """Get cached parent ID for a protocol player from config."""
1573        conf_key = f"{CONF_PLAYERS}/{protocol_player_id}/values/{CONF_PROTOCOL_PARENT_ID}"
1574        result = self.mass.config.get(conf_key, None)
1575        return str(result) if result else None
1576
1577    def _clear_protocol_parent_id(self, protocol_player_id: str) -> None:
1578        """Clear the cached parent ID for a protocol player."""
1579        # Only clear if the player config still exists to avoid creating partial entries
1580        if not self.mass.config.get(f"{CONF_PLAYERS}/{protocol_player_id}"):
1581            return
1582        conf_key = f"{CONF_PLAYERS}/{protocol_player_id}/values/{CONF_PROTOCOL_PARENT_ID}"
1583        self.mass.config.set(conf_key, None)
1584
1585    def _recover_cached_protocol_links(self, native_player: Player) -> None:
1586        """
1587        Recover protocol links from config for disabled/missing protocols.
1588
1589        This ensures that disabled protocols show up in the output_protocols list
1590        so they can be re-enabled by the user. It also handles the case where
1591        protocol players haven't registered yet during startup.
1592        """
1593        # Get currently linked protocol IDs
1594        linked_protocol_ids = {
1595            link.output_protocol_id for link in native_player.linked_output_protocols
1596        }
1597
1598        # Get cached protocol IDs from config (includes protocols that were explicitly linked)
1599        cached_protocol_ids = self._get_cached_protocol_ids(native_player.player_id)
1600
1601        # Also check all protocol players that have protocol_parent_id pointing to this player
1602        # (this handles disabled protocols that may not be in linked_protocol_ids)
1603        all_player_configs = self.mass.config.get(CONF_PLAYERS, {})
1604        for protocol_id, protocol_config in all_player_configs.items():
1605            # Skip if not a protocol player
1606            if protocol_config.get("player_type") != "protocol":
1607                continue
1608            # Check if this protocol has a parent_id pointing to this native player
1609            protocol_values = protocol_config.get("values", {})
1610            protocol_parent_id = protocol_values.get(CONF_PROTOCOL_PARENT_ID)
1611            if protocol_parent_id == native_player.player_id:
1612                if protocol_id not in cached_protocol_ids:
1613                    cached_protocol_ids.append(protocol_id)
1614
1615        if not cached_protocol_ids:
1616            return
1617
1618        # Add link entries for any cached protocols that aren't currently linked
1619        updated_protocols = list(native_player.linked_output_protocols)
1620        for protocol_id in cached_protocol_ids:
1621            if protocol_id in linked_protocol_ids:
1622                continue  # Already linked
1623
1624            protocol_player = self.get_player(protocol_id)
1625            # A protocol that another parent owns is not ours to claim: it would show up
1626            # on both parents and occupy this parent's domain slot, keeping a genuine
1627            # protocol of that domain out. The live owner leads; a protocol that is still
1628            # waiting for its owner to register only has the persisted one. The cached id
1629            # is kept, so the protocol is recovered once its owner releases it.
1630            owner_id = protocol_player.protocol_parent_id if protocol_player else None
1631            if owner_id is None:
1632                owner_id = self._get_cached_protocol_parent_id(protocol_id)
1633            if owner_id is not None and owner_id != native_player.player_id:
1634                continue
1635
1636            # Get protocol player config to determine the protocol domain
1637            protocol_config = self.mass.config.get(f"{CONF_PLAYERS}/{protocol_id}")
1638            if not protocol_config:
1639                continue
1640
1641            # Determine protocol domain from provider
1642            protocol_provider: str = protocol_config.get("provider")
1643            if not protocol_provider:
1644                continue
1645
1646            # Extract domain from provider instance_id (e.g., "airplay--uuid" -> "airplay")
1647            protocol_domain = protocol_provider.split("--", maxsplit=1)[0]
1648
1649            # Skip if parent already has a link from this domain
1650            existing_domains = {link.protocol_domain for link in updated_protocols}
1651            if protocol_domain in existing_domains:
1652                continue
1653
1654            # Get priority for this protocol
1655            priority = PROTOCOL_PRIORITY.get(protocol_domain, 100)
1656
1657            # Resolve the derived-transport edge from the live player when
1658            # registered, else from the persisted edge in config
1659            derived_from = (
1660                protocol_player.underlying_player_id
1661                if protocol_player
1662                else protocol_config.get("values", {}).get(CONF_UNDERLYING_PLAYER_ID)
1663            )
1664            if derived_from == native_player.player_id:
1665                derived_from = "native"
1666
1667            updated_protocols.append(
1668                LinkedOutputProtocol(
1669                    output_protocol_id=protocol_id,
1670                    protocol_domain=protocol_domain,
1671                    priority=priority,
1672                    derived_from=derived_from,
1673                )
1674            )
1675            self.logger.debug(
1676                "Recovered cached protocol link %s -> %s",
1677                native_player.player_id,
1678                protocol_id,
1679            )
1680
1681        if len(updated_protocols) != len(native_player.linked_output_protocols):
1682            native_player.set_linked_output_protocols(updated_protocols)
1683
1684    def _cleanup_protocol_links(self, player: Player) -> None:
1685        """Clean up protocol links when a player is permanently removed."""
1686        if player.state.type == PlayerType.PROTOCOL:
1687            self._unlink_from_protocol_parent(player)
1688            return
1689        self._detach_owned_protocols(player)
1690
1691    def _unlink_from_protocol_parent(self, player: Player) -> None:
1692        """Release a protocol player from the parent it is attached to."""
1693        if parent_id := player.protocol_parent_id:
1694            if parent_player := self.get_player(parent_id):
1695                # Use permanent=True to also remove from cached protocol IDs
1696                self._remove_protocol_link(parent_player, player.player_id, permanent=True)
1697                if (
1698                    parent_player.provider.domain == "universal_player"
1699                    and len(parent_player.linked_output_protocols) == 0
1700                ):
1701                    # No protocols left - the universal player has nothing to play
1702                    # on. Its config is deliberately kept: the player id is opaque
1703                    # and cannot be recreated, so deleting it here would orphan the
1704                    # entities API consumers bound to it. Only an explicit removal
1705                    # by the user deletes a universal player for good.
1706                    self.logger.info(
1707                        "Universal player %s has no protocols left",
1708                        parent_id,
1709                    )
1710                    self.mass.create_task(self.mass.players.unregister(parent_id, permanent=False))
1711                else:
1712                    parent_player.refresh_state()
1713            else:
1714                # Parent not registered yet — still purge the cached id
1715                self._remove_protocol_id_from_cache(parent_id, player.player_id)
1716
1717    def _detach_owned_protocols(self, player: Player) -> None:
1718        """Detach the protocol players a parent owns so they can find a new parent."""
1719        # collect the ids from both the active links and the cached state, since
1720        # disabled/inactive protocols may only exist in the cached parent data
1721        all_protocol_ids = set(self._get_known_protocol_ids(player))
1722        for protocol_id in all_protocol_ids:
1723            if protocol_player := self.get_player(protocol_id):
1724                # Protocol player is available: clear parent and schedule re-evaluation
1725                # so it can be matched to a new parent or a new universal player
1726                self.logger.debug(
1727                    "Player %s no longer owns protocol %s - scheduling evaluation",
1728                    player.player_id,
1729                    protocol_id,
1730                )
1731                self._detach_protocol_child(protocol_player)
1732            else:
1733                # Clear cached parent ID in config so protocol won't try to
1734                # restore a link to its former parent on next restart
1735                self._clear_protocol_parent_id(protocol_id)
1736                # Protocol player is not registered yet — it may still be
1737                # mid-discovery (e.g., DLNA connecting via SSDP). Don't delete
1738                # its config as that would cause a KeyError when it finishes
1739                # registering. Stale configs are harmless and get cleaned up
1740                # naturally on subsequent restarts.
1741                self.logger.debug(
1742                    "Player %s no longer owns protocol %s - not registered, skipping cleanup",
1743                    player.player_id,
1744                    protocol_id,
1745                )
1746
1747    def _cleanup_player_type_transition(self, existing: Player, *, becomes_protocol: bool) -> None:
1748        """
1749        Release the protocol topology a player owned before its type changed.
1750
1751        :param existing: The registered player instance for the changed player.
1752        :param becomes_protocol: True if the player moves into the protocol role,
1753            False if it leaves it.
1754        """
1755        if not becomes_protocol:
1756            # a provider may announce the new type with the live parent link already
1757            # dropped, so fall back to the persisted one to still reach the parent
1758            parent_id = existing.protocol_parent_id or self._get_cached_protocol_parent_id(
1759                existing.player_id
1760            )
1761            if not parent_id:
1762                return
1763            parent = self.get_player(parent_id)
1764            if parent is not None and parent.provider.domain == "universal_player":
1765                # drop only the active edge and leave the rest to the link evaluation,
1766                # which replaces the wrapper with this player: a leftover edge makes it
1767                # hand the player over to itself, which it refuses, abandoning the swap
1768                self._remove_protocol_link(parent, existing.player_id)
1769                return
1770            existing.set_protocol_parent_id(parent_id)
1771            # unlink at the parent and drop the persisted parent id, which would
1772            # otherwise heal the player's type back to protocol
1773            self._unlink_from_protocol_parent(existing)
1774            # a player leaving the protocol role has no parent, also when that parent
1775            # is not registered (anymore) and only the cached link could be cleaned up
1776            existing.set_protocol_parent_id(None)
1777            return
1778        # the player becomes a child itself: detach the protocol players it owned so they
1779        # can find a new parent, then give up their ownership in its (kept) config - the
1780        # reverse of the removal path, which drops the ownership before the detach
1781        protocol_ids = set(self._get_known_protocol_ids(existing))
1782        self._detach_owned_protocols(existing)
1783        self._remove_protocol_ids_from_parent(existing, protocol_ids)
1784
1785    def _detach_protocol_children(self, parent_id: str) -> None:
1786        """
1787        Detach the registered protocol players of a parent player that is going away.
1788
1789        Covers the removal paths that don't unregister the parent first (e.g. its
1790        provider is unloaded), where the parent is not around anymore to enumerate
1791        its protocol players.
1792
1793        :param parent_id: Player id of the parent that is being removed.
1794        """
1795        for protocol_player in list(self._players.values()):
1796            if protocol_player.state.type != PlayerType.PROTOCOL:
1797                continue
1798            # a protocol player waiting for a parent that never registered only has
1799            # the link in its config, so fall back to the cached parent
1800            linked_parent_id = protocol_player.protocol_parent_id or (
1801                self._get_cached_protocol_parent_id(protocol_player.player_id)
1802            )
1803            if linked_parent_id != parent_id:
1804                continue
1805            self.logger.debug(
1806                "Player %s removed - scheduling evaluation for protocol %s",
1807                parent_id,
1808                protocol_player.player_id,
1809            )
1810            self._detach_protocol_child(protocol_player)
1811
1812    def _detach_protocol_child(self, protocol_player: Player) -> None:
1813        """Clear a protocol player's parent link and schedule a fresh evaluation."""
1814        self._clear_protocol_parent_id(protocol_player.player_id)
1815        protocol_player.set_protocol_parent_id(None)
1816        protocol_player.refresh_state()
1817        self._schedule_protocol_evaluation(protocol_player)
1818
1819    def _identifiers_match(
1820        self, player_a: Player, player_b: Player, protocol_domain: str = ""
1821    ) -> bool:
1822        """
1823        Check if identifiers match between two players.
1824
1825        Matching is done by comparing connection identifiers (MAC, serial, UUID).
1826        As a last resort, IP address is used when at least one player has a
1827        locally-administered MAC, indicating the device uses MAC randomization
1828        and ARP could not resolve the real hardware address.
1829
1830        Invalid identifiers (e.g., 00:00:00:00:00:00 MAC addresses) are filtered out
1831        to prevent false matches between unrelated devices.
1832        """
1833        identifiers_a = player_a.device_info.identifiers
1834        identifiers_b = player_b.device_info.identifiers
1835
1836        # Check identifiers in order of reliability
1837        # MAC_ADDRESS > SERIAL_NUMBER > UUID > CAST_UUID > AIRPLAY_ID
1838        for conn_type in (
1839            IdentifierType.MAC_ADDRESS,
1840            IdentifierType.SERIAL_NUMBER,
1841            IdentifierType.UUID,
1842            IdentifierType.CAST_UUID,
1843            IdentifierType.AIRPLAY_ID,
1844        ):
1845            val_a = identifiers_a.get(conn_type)
1846            val_b = identifiers_b.get(conn_type)
1847
1848            if not val_a or not val_b:
1849                continue
1850
1851            # Filter out invalid MAC addresses (00:00:00:00:00:00, ff:ff:ff:ff:ff:ff)
1852            if conn_type == IdentifierType.MAC_ADDRESS:
1853                if not is_valid_mac_address(val_a) or not is_valid_mac_address(val_b):
1854                    self.logger.log(
1855                        VERBOSE_LOG_LEVEL,
1856                        "Skipping invalid MAC address for matching: %s=%s, %s=%s",
1857                        player_a.display_name,
1858                        val_a,
1859                        player_b.display_name,
1860                        val_b,
1861                    )
1862                    continue
1863
1864            # Normalize values for comparison
1865            if conn_type == IdentifierType.MAC_ADDRESS:
1866                # Use MAC normalization that handles locally-administered bit differences
1867                # Some protocols (like AirPlay) report a locally-administered MAC variant
1868                # where bit 1 of the first octet is set (e.g., 54:78:... vs 56:78:...)
1869                val_a_norm = normalize_mac_for_matching(val_a)
1870                val_b_norm = normalize_mac_for_matching(val_b)
1871
1872                # Direct match on current MAC
1873                if val_a_norm == val_b_norm:
1874                    return True
1875
1876                # Multi-MAC matching: also check original reported MACs.
1877                # Devices with multiple interfaces (WiFi + Ethernet) may have ARP
1878                # resolve one MAC while the protocol reports a different one.
1879                macs_a = {val_a_norm}
1880                macs_b = {val_b_norm}
1881                reported_a = player_a.extra_data.get("reported_mac")
1882                reported_b = player_b.extra_data.get("reported_mac")
1883                if reported_a and is_valid_mac_address(reported_a):
1884                    macs_a.add(normalize_mac_for_matching(reported_a))
1885                if reported_b and is_valid_mac_address(reported_b):
1886                    macs_b.add(normalize_mac_for_matching(reported_b))
1887                if macs_a & macs_b:
1888                    return True
1889
1890                # No MAC match - continue to next identifier type
1891                continue
1892
1893            val_a_norm = val_a.lower().replace(":", "").replace("-", "")
1894            val_b_norm = val_b.lower().replace(":", "").replace("-", "")
1895
1896            # Direct match
1897            if val_a_norm == val_b_norm:
1898                return True
1899
1900            # Special case: Sonos UUID matching with DLNA _MR suffix
1901            # Sonos uses RINCON_xxx, DLNA uses RINCON_xxx_MR for Media Renderer
1902            if conn_type == IdentifierType.UUID:
1903                if val_b_norm.endswith("_mr") and val_b_norm[:-3] == val_a_norm:
1904                    return True
1905                if val_a_norm.endswith("_mr") and val_a_norm[:-3] == val_b_norm:
1906                    return True
1907
1908        # Last resort: IP-based matching.
1909        # Two players on the same IP are very likely the same physical device.
1910        # This handles two cases:
1911        # 1. MAC randomization: at least one player has no real MAC (LA or missing),
1912        #    so ARP couldn't resolve a usable address.
1913        # 2. Different MACs per protocol: some devices (e.g., Yamaha MusicCast) report
1914        #    different valid globally-unique MACs per protocol (DLNA vs AirPlay differ
1915        #    by 1 in the last octet). IP matching is safe here because two different
1916        #    devices on a LAN cannot share the same IP simultaneously.
1917        #    To avoid false positives between unrelated native players, this path
1918        #    requires at least one player to be a protocol or universal player.
1919        ip_a = identifiers_a.get(IdentifierType.IP_ADDRESS)
1920        ip_b = identifiers_b.get(IdentifierType.IP_ADDRESS)
1921        if ip_a and ip_b and ip_a == ip_b:
1922            mac_a = identifiers_a.get(IdentifierType.MAC_ADDRESS)
1923            mac_b = identifiers_b.get(IdentifierType.MAC_ADDRESS)
1924            a_is_real = (
1925                mac_a is not None
1926                and is_valid_mac_address(mac_a)
1927                and not is_locally_administered_mac(mac_a)
1928            )
1929            b_is_real = (
1930                mac_b is not None
1931                and is_valid_mac_address(mac_b)
1932                and not is_locally_administered_mac(mac_b)
1933            )
1934            # Case 1: at least one player has no real hardware MAC
1935            if not (a_is_real and b_is_real):
1936                return True
1937            # Case 2: both have real MACs but at least one is a protocol/universal player
1938            a_is_protocol = (
1939                player_a.type == PlayerType.PROTOCOL
1940                or player_a.provider.domain == "universal_player"
1941            )
1942            b_is_protocol = (
1943                player_b.type == PlayerType.PROTOCOL
1944                or player_b.provider.domain == "universal_player"
1945            )
1946            if a_is_protocol or b_is_protocol:
1947                return True
1948
1949        return False
1950
1951    def _select_best_output_protocol(self, player: Player) -> tuple[Player, OutputProtocol | None]:
1952        """
1953        Select the best available output protocol for a player.
1954
1955        Selection priority:
1956        1. Output protocol that is currently grouped/synced with other players.
1957        2. User's preferred output protocol (from player settings).
1958        3. Native playback (if player supports PLAY_MEDIA).
1959        4. The player's declared default output protocol domain, if available.
1960        5. Best available protocol by priority.
1961
1962        Returns tuple of (target_player, output_protocol).
1963        output_protocol is None when using native playback.
1964        """
1965        self.logger.log(
1966            VERBOSE_LOG_LEVEL,
1967            "Selecting output protocol for %s",
1968            player.state.name,
1969        )
1970
1971        # 1. Check if any output protocol is currently grouped
1972        for linked in player.linked_output_protocols:
1973            if protocol_player := self.get_player(linked.output_protocol_id):
1974                if protocol_player.available_for_playback and self._is_protocol_grouped(
1975                    protocol_player
1976                ):
1977                    self.logger.log(
1978                        VERBOSE_LOG_LEVEL,
1979                        "Selected protocol for %s: %s (grouped)",
1980                        player.state.name,
1981                        protocol_player.state.name,
1982                    )
1983                    return protocol_player, player.get_linked_protocol(linked.output_protocol_id)
1984
1985        # 2. Check for user's preferred output protocol.
1986        # The value is only stored while it differs from the entry's default: "native" when a
1987        # native output is available, otherwise "auto". A player without a native output (e.g. a
1988        # LinkPlay shell) therefore has no stored preference by default and gets its default
1989        # output domain applied in step 4.
1990        preferred = self.mass.config.get_raw_player_config_value(
1991            player.player_id, CONF_PREFERRED_OUTPUT_PROTOCOL
1992        )
1993        if preferred and preferred != "auto":
1994            if preferred == "native":
1995                if PlayerFeature.PLAY_MEDIA in player.supported_features:
1996                    self.logger.log(
1997                        VERBOSE_LOG_LEVEL,
1998                        "Selected protocol for %s: native (user preference)",
1999                        player.state.name,
2000                    )
2001                    return player, None
2002            else:
2003                for linked in player.linked_output_protocols:
2004                    if linked.output_protocol_id == preferred:
2005                        if protocol_player := self.get_player(linked.output_protocol_id):
2006                            if protocol_player.available_for_playback:
2007                                self.logger.log(
2008                                    VERBOSE_LOG_LEVEL,
2009                                    "Selected protocol for %s: %s (user preference)",
2010                                    player.state.name,
2011                                    protocol_player.state.name,
2012                                )
2013                                return protocol_player, player.get_linked_protocol(
2014                                    linked.output_protocol_id
2015                                )
2016                        break
2017
2018        # 3. Use native playback if available
2019        if PlayerFeature.PLAY_MEDIA in player.supported_features:
2020            self.logger.log(
2021                VERBOSE_LOG_LEVEL, "Selected protocol for %s: native", player.state.name
2022            )
2023            return player, None
2024
2025        # 4. Use the player's preferred default protocol domain, if it declares one and a
2026        # matching linked protocol is available (e.g. a LinkPlay shell prefers DLNA). This
2027        # never influences grouping; it only steers the default output for playback. "Auto"
2028        # is the entry default here, so it consistently resolves to this domain default.
2029        if default_domain := player.default_output_protocol_domain:
2030            for linked in sorted(player.linked_output_protocols, key=lambda x: x.priority):
2031                if linked.protocol_domain != default_domain:
2032                    continue
2033                if (protocol_player := self.get_player(linked.output_protocol_id)) and (
2034                    protocol_player.available_for_playback
2035                ):
2036                    self.logger.log(
2037                        VERBOSE_LOG_LEVEL,
2038                        "Selected protocol for %s: %s (default domain %s)",
2039                        player.state.name,
2040                        protocol_player.state.name,
2041                        default_domain,
2042                    )
2043                    return protocol_player, player.get_linked_protocol(linked.output_protocol_id)
2044
2045        # 5. Fall back to best protocol by priority
2046        for linked in sorted(player.linked_output_protocols, key=lambda x: x.priority):
2047            if protocol_player := self.get_player(linked.output_protocol_id):
2048                if protocol_player.available_for_playback:
2049                    self.logger.log(
2050                        VERBOSE_LOG_LEVEL,
2051                        "Selected protocol for %s: %s (priority-based)",
2052                        player.state.name,
2053                        protocol_player.state.name,
2054                    )
2055                    return protocol_player, player.get_linked_protocol(linked.output_protocol_id)
2056
2057        raise PlayerCommandFailed(f"Player {player.state.name} has no available output protocols")
2058
2059    def _get_control_target(
2060        self,
2061        player: Player,
2062        required_feature: PlayerFeature,
2063        require_active: bool = False,
2064    ) -> Player | None:
2065        """
2066        Get the best player(protocol) to send audio-path commands to.
2067
2068        Resolves commands that travel with the audio (enqueue, pause, announcements),
2069        so the output that renders the audio outranks the native player. Volume and
2070        mute are control-plane instead and resolve through
2071        :meth:`Player._get_protocol_player_for_feature`, which orders differently.
2072
2073        :param player: The player the command was issued on.
2074        :param required_feature: The feature the resolved target has to support.
2075        :param require_active: Only accept the output that is already rendering,
2076            instead of falling back to an idle one.
2077        """
2078        # If we have an active protocol, use that
2079        if (
2080            player.active_output_protocol
2081            and player.active_output_protocol != "native"
2082            and (protocol_player := self.mass.players.get_player(player.active_output_protocol))
2083            and required_feature in protocol_player.supported_features
2084        ):
2085            return protocol_player
2086
2087        # if the player natively supports the required feature, use that
2088        if (
2089            player.active_output_protocol == "native"
2090            and required_feature in player.supported_features
2091        ):
2092            return player
2093
2094        # If require_active is set, and no active protocol found, return None
2095        if require_active:
2096            return None
2097
2098        # if the player natively supports the required feature, use that
2099        if required_feature in player.supported_features:
2100            return player
2101
2102        # An output the user explicitly picked owns the audio, so a command that has to
2103        # start playback on an idle player follows it rather than the priority below.
2104        # The stored value survives a relink, so it only counts while it still names one
2105        # of this player's own outputs.
2106        preferred = self.mass.config.get_raw_player_config_value(
2107            player.player_id, CONF_PREFERRED_OUTPUT_PROTOCOL
2108        )
2109        if preferred and preferred not in ("auto", "native"):
2110            for linked in player.linked_output_protocols:
2111                if linked.output_protocol_id != preferred:
2112                    continue
2113                if (
2114                    (preferred_player := self.mass.players.get_player(str(preferred)))
2115                    and preferred_player.available_for_playback
2116                    and required_feature in preferred_player.supported_features
2117                ):
2118                    return preferred_player
2119                break
2120
2121        # Otherwise, use the best available linked protocol, ordered by the same
2122        # priority that regular playback selection applies.
2123        for linked in sorted(player.linked_output_protocols, key=lambda x: x.priority):
2124            if (
2125                (protocol_player := self.mass.players.get_player(linked.output_protocol_id))
2126                and protocol_player.available_for_playback
2127                and required_feature in protocol_player.supported_features
2128            ):
2129                return protocol_player
2130
2131        return None
2132
2133    def _is_protocol_grouped(self, protocol_player: Player) -> bool:
2134        """
2135        Check if a protocol player is currently grouped/synced with other players.
2136
2137        Used to prefer protocols that are actively participating in a group,
2138        ensuring consistent playback across grouped players.
2139        """
2140        is_grouped = bool(
2141            protocol_player.state.synced_to
2142            or (
2143                protocol_player.state.group_members and len(protocol_player.state.group_members) > 1
2144            )
2145            or protocol_player.state.active_group
2146        )
2147        if is_grouped:
2148            self.logger.log(
2149                VERBOSE_LOG_LEVEL,
2150                "Protocol player %s is grouped",
2151                protocol_player.state.name,
2152            )
2153        return is_grouped
2154
2155    def _translate_members_to_remove_for_protocols(
2156        self,
2157        parent_player: Player,
2158        player_ids: list[str],
2159        parent_protocol_player: Player | None,
2160        parent_protocol_domain: str | None,
2161    ) -> tuple[list[str], list[str]]:
2162        """
2163        Translate member IDs to remove into protocol and native lists.
2164
2165        :param parent_player: The parent player to remove members from.
2166        :param player_ids: List of visible player IDs to remove.
2167        :param parent_protocol_player: The parent's protocol player if available.
2168        :param parent_protocol_domain: The parent's protocol domain if available.
2169        """
2170        self.logger.debug(
2171            "Translating members to remove for %s: player_ids=%s, parent_protocol_domain=%s",
2172            parent_player.state.name,
2173            player_ids,
2174            parent_protocol_domain,
2175        )
2176        protocol_members: list[str] = []
2177        native_members: list[str] = []
2178
2179        for child_player_id in player_ids:
2180            child_player = self.get_player(child_player_id)
2181            if not child_player:
2182                continue
2183
2184            # Check if this member is in the parent's group via protocol
2185            if parent_protocol_domain and parent_protocol_player:
2186                child_protocol = child_player.get_output_protocol_by_domain(parent_protocol_domain)
2187                if child_protocol and child_protocol.available:
2188                    # For native protocol players, use the child's player_id directly
2189                    child_protocol_id = (
2190                        child_player.player_id
2191                        if child_protocol.is_native
2192                        else child_protocol.output_protocol_id
2193                    )
2194                    if child_protocol_id in parent_protocol_player.group_members:
2195                        self.logger.debug(
2196                            "Translating removal: %s -> protocol %s",
2197                            child_player_id,
2198                            child_protocol_id,
2199                        )
2200                        protocol_members.append(child_protocol_id)
2201                        continue
2202
2203            # Check if child's protocol player is in parent's native group_members
2204            # This handles native protocol players (e.g., native AirPlay player like Apple TV)
2205            # where the parent itself contains protocol player IDs in its group_members
2206            translated = False
2207            for linked in child_player.linked_output_protocols:
2208                if linked.output_protocol_id in parent_player.group_members:
2209                    self.logger.debug(
2210                        "Translating removal (native parent): %s -> protocol %s",
2211                        child_player_id,
2212                        linked.output_protocol_id,
2213                    )
2214                    native_members.append(linked.output_protocol_id)
2215                    translated = True
2216                    break
2217
2218            if not translated:
2219                native_members.append(child_player_id)
2220
2221        return protocol_members, native_members
2222
2223    def _filter_protocol_members(self, member_ids: list[str], protocol_player: Player) -> list[str]:
2224        """Filter member IDs to only include players from the same protocol domain."""
2225        return [
2226            pid
2227            for pid in member_ids
2228            if (p := self.get_player(pid)) and p.provider.domain == protocol_player.provider.domain
2229        ]
2230
2231    def _filter_native_members(self, member_ids: list[str], parent_player: Player) -> list[str]:
2232        """Filter member IDs to only include players compatible with the parent."""
2233        return [
2234            pid
2235            for pid in member_ids
2236            if (p := self.get_player(pid))
2237            and (
2238                p.provider.instance_id == parent_player.provider.instance_id
2239                or pid in parent_player._attr_can_group_with
2240                or p.provider.instance_id in parent_player._attr_can_group_with
2241            )
2242        ]
2243
2244    def _try_child_preferred_protocol(
2245        self,
2246        child_player: Player,
2247        parent_player: Player,
2248    ) -> tuple[str | None, str | None]:
2249        """
2250        Try to use child's preferred output protocol for grouping.
2251
2252        Returns tuple of (child_protocol_id, protocol_domain) or (None, None).
2253        """
2254        child_preferred = self.mass.config.get_raw_player_config_value(
2255            child_player.player_id, CONF_PREFERRED_OUTPUT_PROTOCOL
2256        )
2257        if not child_preferred or child_preferred in {"auto", "native"}:
2258            return None, None
2259
2260        # Find child's preferred protocol, with its current availability
2261        child_protocol = None
2262        for output_protocol in child_player.output_protocols:
2263            if output_protocol.output_protocol_id == child_preferred:
2264                child_protocol = output_protocol
2265                break
2266
2267        if not child_protocol or not child_protocol.available:
2268            return None, None
2269
2270        # Check if parent supports this protocol (including native protocol)
2271        parent_protocol = parent_player.get_output_protocol_by_domain(
2272            child_protocol.protocol_domain
2273        )
2274        if not parent_protocol or not parent_protocol.available:
2275            return None, None
2276
2277        # Check if this protocol supports set_members
2278        protocol_player = parent_player.get_protocol_player(parent_protocol.output_protocol_id)
2279        if (
2280            not protocol_player
2281            or PlayerFeature.SET_MEMBERS not in protocol_player.state.supported_features
2282        ):
2283            return None, None
2284
2285        return child_protocol.output_protocol_id, child_protocol.protocol_domain
2286
2287    def _can_use_native_grouping(
2288        self,
2289        child_player: Player,
2290        parent_player: Player,
2291        parent_supports_native: bool,
2292    ) -> bool:
2293        """Check if child can be grouped with parent using native grouping."""
2294        if not parent_supports_native:
2295            return False
2296        return (
2297            parent_player.is_native_group_compatible(child_player)
2298            or child_player.player_id in parent_player._attr_can_group_with
2299            or child_player.provider.instance_id in parent_player._attr_can_group_with
2300        )
2301
2302    def _try_find_common_protocol(
2303        self, child_player: Player, parent_player: Player
2304    ) -> tuple[OutputProtocol | None, OutputProtocol | None]:
2305        """
2306        Find common protocol that supports set_members.
2307
2308        Returns tuple of (parent_protocol, child_protocol) or (None, None).
2309        """
2310        for parent_output_protocol in parent_player.output_protocols:
2311            if not parent_output_protocol.available:
2312                continue
2313            child_protocol = child_player.get_output_protocol_by_domain(
2314                parent_output_protocol.protocol_domain
2315            )
2316            if not child_protocol or not child_protocol.available:
2317                continue
2318            protocol_player = parent_player.get_protocol_player(
2319                parent_output_protocol.output_protocol_id
2320            )
2321            if protocol_player and PlayerFeature.SET_MEMBERS in protocol_player.supported_features:
2322                return parent_output_protocol, child_protocol
2323        return None, None
2324
2325    def _parent_has_live_native_session(self, parent_player: Player) -> bool:
2326        """
2327        Return True when the parent currently holds a live native playback session.
2328
2329        The active output protocol lingers for a few seconds after stop, so a non-idle
2330        playback state is required to distinguish a real session from a just-stopped one.
2331        """
2332        return parent_player.active_output_protocol == "native" and (
2333            parent_player.state.playback_state in (PlaybackState.PLAYING, PlaybackState.PAUSED)
2334        )
2335
2336    def _order_members_for_native_join(
2337        self,
2338        player_ids: list[str],
2339        parent_player: Player,
2340        parent_supports_native_grouping: bool,
2341    ) -> list[str]:
2342        """
2343        Order members so a live native session can be joined without splitting the group.
2344
2345        When the parent already holds a live native session, children that cannot group
2346        natively are evaluated first: they may force a shared protocol for the whole group,
2347        and processing them before the native-capable children lets those join that same
2348        protocol instead of being stranded in a separate native sub-group. The order is left
2349        untouched when the parent is not playing natively, so fresh-group selection is unchanged.
2350
2351        :param player_ids: The member IDs to be added, in their original order.
2352        :param parent_player: The parent player being joined.
2353        :param parent_supports_native_grouping: Whether the parent can group natively.
2354        """
2355        if not self._parent_has_live_native_session(parent_player):
2356            return player_ids
2357        return sorted(
2358            player_ids,
2359            key=lambda pid: bool(
2360                (child := self.get_player(pid))
2361                and self._can_use_native_grouping(
2362                    child, parent_player, parent_supports_native_grouping
2363                )
2364            ),
2365        )
2366
2367    def _try_join_active_native_session(
2368        self,
2369        child_player: Player,
2370        parent_player: Player,
2371        parent_protocol_domain: str | None,
2372        parent_supports_native_grouping: bool,
2373        native_members: list[str],
2374    ) -> bool:
2375        """
2376        Add the child to native_members if it can join the parent's active native session.
2377
2378        A child's preferred output protocol must only steer protocol selection when the child
2379        initiates its own playback; when it joins a parent that is already playing natively it
2380        should adopt native grouping if compatible, rather than forcing the whole group onto
2381        the child's preferred protocol. Skipped once a protocol has been selected for the group,
2382        so mixed batches stay cohesive on a single protocol.
2383
2384        :param child_player: The player being added to the group.
2385        :param parent_player: The parent player being joined.
2386        :param parent_protocol_domain: The protocol domain already selected for the group, if any.
2387        :param parent_supports_native_grouping: Whether the parent can group natively.
2388        :param native_members: The native members list to append to when the child joins.
2389        """
2390        if not (
2391            self._parent_has_live_native_session(parent_player)
2392            and not parent_protocol_domain
2393            and self._can_use_native_grouping(
2394                child_player, parent_player, parent_supports_native_grouping
2395            )
2396        ):
2397            return False
2398        native_members.append(child_player.player_id)
2399        self.logger.log(
2400            VERBOSE_LOG_LEVEL,
2401            "Joining parent's active native session for %s",
2402            child_player.state.name,
2403        )
2404        return True
2405
2406    def _translate_native_members_to_protocol(
2407        self, parent_player: Player, protocol_domain: str, member_ids: list[str]
2408    ) -> list[str]:
2409        """
2410        Translate natively grouped members onto the protocol domain the parent plays through.
2411
2412        Members that do not have that protocol cannot follow the parent at all and are
2413        dropped with a warning instead.
2414
2415        :param parent_player: The parent player the members are grouped with.
2416        :param protocol_domain: The protocol domain selected for the group.
2417        :param member_ids: The member IDs that were selected for native grouping.
2418        """
2419        translated: list[str] = []
2420        for member_id in member_ids:
2421            member_player = self.get_player(member_id)
2422            if not member_player:
2423                continue
2424            # a native group's members may be listed by their protocol player id
2425            if member_player.protocol_parent_id:
2426                member_player = self.get_player(member_player.protocol_parent_id) or member_player
2427            member_protocol = member_player.get_output_protocol_by_domain(protocol_domain)
2428            if not member_protocol or not member_protocol.available:
2429                self.logger.warning(
2430                    "Cannot group %s with %s: the group plays through the %s protocol, "
2431                    "which %s does not support",
2432                    member_player.state.name,
2433                    parent_player.state.name,
2434                    protocol_domain,
2435                    member_player.state.name,
2436                )
2437                continue
2438            # For native protocol players, use the member's player_id directly
2439            translated.append(
2440                member_player.player_id
2441                if member_protocol.is_native
2442                else member_protocol.output_protocol_id
2443            )
2444            self.logger.log(
2445                VERBOSE_LOG_LEVEL,
2446                "Moving %s from native grouping to the %s protocol",
2447                member_player.state.name,
2448                protocol_domain,
2449            )
2450        return translated
2451
2452    def _move_native_members_to_group_protocol(
2453        self,
2454        parent_player: Player,
2455        parent_protocol_player: Player | None,
2456        parent_protocol_domain: str | None,
2457        protocol_members: list[str],
2458        native_members: list[str],
2459    ) -> None:
2460        """
2461        Move the members selected for native grouping onto the protocol the group ended up on.
2462
2463        Does nothing unless the group ends up on one of the parent's protocols while the
2464        parent's native grouping needs the parent's own stream: only then do those members
2465        have no session left to attach to.
2466
2467        :param parent_player: The parent player being joined.
2468        :param parent_protocol_player: The protocol player selected for the group, if any.
2469        :param parent_protocol_domain: The protocol domain selected for the group, if any.
2470        :param protocol_members: The protocol member list the translated IDs are added to.
2471        :param native_members: The native member IDs, emptied when they are moved over.
2472        """
2473        if not (
2474            native_members
2475            and parent_protocol_domain
2476            and parent_protocol_player
2477            and parent_protocol_player.player_id != parent_player.player_id
2478            and parent_player.native_grouping_requires_own_stream
2479        ):
2480            return
2481        protocol_members.extend(
2482            self._translate_native_members_to_protocol(
2483                parent_player, parent_protocol_domain, native_members
2484            )
2485        )
2486        native_members.clear()
2487
2488    def _migrate_stranded_native_members(
2489        self,
2490        parent_player: Player,
2491        parent_protocol_player: Player,
2492        protocol_members: list[str],
2493    ) -> list[str]:
2494        """
2495        Move the native members that a switch to the given protocol strands onto that protocol.
2496
2497        Returns the member IDs that are still attached to the parent's own stream, so the
2498        caller can release them from it. Empty unless the parent renders that stream itself
2499        while its native grouping attaches the members to exactly that stream: only then are
2500        they left without anything to play.
2501
2502        :param parent_player: The parent player that is about to switch protocol.
2503        :param parent_protocol_player: The protocol player the parent will render through.
2504        :param protocol_members: The protocol member list the translated IDs are added to.
2505        """
2506        if parent_protocol_player.player_id == parent_player.player_id:
2507            return []
2508        if not parent_player.native_grouping_requires_own_stream:
2509            return []
2510        if parent_player.active_output_protocol not in (None, "native"):
2511            return []
2512        if parent_player.state.playback_state not in (PlaybackState.PLAYING, PlaybackState.PAUSED):
2513            return []
2514        stranded = [
2515            member_id
2516            for member_id in parent_player.group_members
2517            if member_id != parent_player.player_id
2518        ]
2519        for protocol_id in self._translate_native_members_to_protocol(
2520            parent_player, parent_protocol_player.provider.domain, stranded
2521        ):
2522            if protocol_id not in protocol_members:
2523                protocol_members.append(protocol_id)
2524        return stranded
2525
2526    async def _stop_native_session(
2527        self,
2528        parent_player: Player,
2529        parent_protocol_player: Player,
2530        stranded_native_members: list[str],
2531    ) -> None:
2532        """
2533        Release the given members from the parent's own stream and stop it.
2534
2535        :param parent_player: The parent player whose native session is handed over.
2536        :param parent_protocol_player: The protocol player taking the output over.
2537        :param stranded_native_members: The members to release, already migrated.
2538        """
2539        self.logger.debug(
2540            "Stopping the native session of %s before switching to %s, migrated members: %s",
2541            parent_player.state.name,
2542            parent_protocol_player.state.name,
2543            stranded_native_members,
2544        )
2545        # The members already joined the protocol group, so the native session only has to
2546        # release them and stop. Releasing them first also clears the native group, which
2547        # keeps a later native playback command from resurrecting it. Both calls take the
2548        # provider's own lock, so they must run one after the other.
2549        await parent_player.set_members(player_ids_to_remove=stranded_native_members)
2550        await parent_player.stop()
2551
2552    def _translate_members_for_protocols(
2553        self,
2554        parent_player: Player,
2555        player_ids: list[str],
2556        parent_protocol_player: Player | None,
2557        parent_protocol_domain: str | None,
2558    ) -> tuple[list[str], list[str], Player | None, str | None]:
2559        """
2560        Translate member IDs to protocol or native IDs.
2561
2562        The grouping method is picked per member, see _select_grouping_for_member.
2563
2564        Returns tuple of (protocol_members, native_members, protocol_player, protocol_domain).
2565        """
2566        protocol_members: list[str] = []
2567        native_members: list[str] = []
2568        parent_supports_native_grouping = (
2569            PlayerFeature.SET_MEMBERS in parent_player.supported_features
2570        )
2571        player_ids = self._order_members_for_native_join(
2572            player_ids, parent_player, parent_supports_native_grouping
2573        )
2574
2575        self.logger.log(
2576            VERBOSE_LOG_LEVEL,
2577            "Translating members for %s: parent_supports_native=%s, parent_protocol=%s (%s)",
2578            parent_player.state.name,
2579            parent_supports_native_grouping,
2580            parent_protocol_player.state.name if parent_protocol_player else "none",
2581            parent_protocol_domain or "none",
2582        )
2583
2584        for child_player_id in player_ids:
2585            child_player = self.get_player(child_player_id)
2586            if not child_player:
2587                continue
2588
2589            self.logger.log(
2590                VERBOSE_LOG_LEVEL,
2591                "Processing child %s (type=%s, protocols=%s)",
2592                child_player.state.name,
2593                child_player.state.type,
2594                [p.protocol_domain for p in child_player.output_protocols],
2595            )
2596
2597            parent_protocol_player, parent_protocol_domain = self._select_grouping_for_member(
2598                child_player,
2599                parent_player,
2600                parent_protocol_player,
2601                parent_protocol_domain,
2602                parent_supports_native_grouping,
2603                protocol_members,
2604                native_members,
2605            )
2606
2607        # Post-pass: the protocol selected for the group is only known once every child has
2608        # been processed, so the members picked for native grouping are corrected here.
2609        self._move_native_members_to_group_protocol(
2610            parent_player,
2611            parent_protocol_player,
2612            parent_protocol_domain,
2613            protocol_members,
2614            native_members,
2615        )
2616
2617        return protocol_members, native_members, parent_protocol_player, parent_protocol_domain
2618
2619    def _select_grouping_for_member(
2620        self,
2621        child_player: Player,
2622        parent_player: Player,
2623        parent_protocol_player: Player | None,
2624        parent_protocol_domain: str | None,
2625        parent_supports_native_grouping: bool,
2626        protocol_members: list[str],
2627        native_members: list[str],
2628    ) -> tuple[Player | None, str | None]:
2629        """
2630        Pick the grouping method for a single member and add it to the matching member list.
2631
2632        Selection priority when grouping:
2633        0. If the parent is already playing natively and the child can be grouped
2634           natively, join that native session (a child joining an existing group must
2635           not force the whole group onto its own preferred output protocol)
2636        1. Try child's preferred output protocol (from player settings)
2637        2. Try parent's active output protocol (if any and child supports it)
2638        3. Try native grouping (if parent and child are compatible)
2639        4. Search for common protocol that supports set_members
2640        5. Log warning if no option works
2641
2642        Returns the protocol player/domain the group is on, which the picked method may have
2643        changed.
2644
2645        :param child_player: The player being added to the group.
2646        :param parent_player: The parent player being joined.
2647        :param parent_protocol_player: The protocol player selected for the group so far, if any.
2648        :param parent_protocol_domain: The protocol domain selected for the group so far, if any.
2649        :param parent_supports_native_grouping: Whether the parent can group natively.
2650        :param protocol_members: The protocol member list to append to.
2651        :param native_members: The native member list to append to.
2652        """
2653        # Priority 0: The parent is already playing natively and the child can join
2654        # that native session directly - adopt it before considering the child's own
2655        # preferred output protocol.
2656        if self._try_join_active_native_session(
2657            child_player,
2658            parent_player,
2659            parent_protocol_domain,
2660            parent_supports_native_grouping,
2661            native_members,
2662        ):
2663            return parent_protocol_player, parent_protocol_domain
2664
2665        # Priority 0.5: a player that runs its own multiroom (e.g. a LinkPlay control shell)
2666        # keeps grouping on its native path rather than routing it through a linked protocol
2667        # that is merely its preferred playback output. Native compatibility still decides
2668        # whether this is possible, so an incompatible/cross-backend pair falls through.
2669        if child_player.prefer_native_grouping and self._can_use_native_grouping(
2670            child_player, parent_player, parent_supports_native_grouping
2671        ):
2672            native_members.append(child_player.player_id)
2673            self.logger.log(
2674                VERBOSE_LOG_LEVEL,
2675                "Using native grouping (preferred) for %s",
2676                child_player.state.name,
2677            )
2678            return parent_protocol_player, parent_protocol_domain
2679
2680        # Priority 1: the child's preferred output protocol
2681        grouped, parent_protocol_player, parent_protocol_domain = (
2682            self._try_group_via_preferred_protocol(
2683                child_player,
2684                parent_player,
2685                parent_protocol_player,
2686                parent_protocol_domain,
2687                protocol_members,
2688            )
2689        )
2690        if grouped:
2691            return parent_protocol_player, parent_protocol_domain
2692
2693        # Priority 2: the protocol the group is already on
2694        grouped, parent_protocol_player, parent_protocol_domain = (
2695            self._try_group_via_active_protocol(
2696                child_player,
2697                parent_protocol_player,
2698                parent_protocol_domain,
2699                protocol_members,
2700            )
2701        )
2702        if grouped:
2703            return parent_protocol_player, parent_protocol_domain
2704
2705        # Priority 3: native grouping
2706        if self._can_use_native_grouping(
2707            child_player, parent_player, parent_supports_native_grouping
2708        ):
2709            native_members.append(child_player.player_id)
2710            self.logger.log(
2711                VERBOSE_LOG_LEVEL,
2712                "Using native grouping for %s",
2713                child_player.state.name,
2714            )
2715            return parent_protocol_player, parent_protocol_domain
2716
2717        # Priority 4: a protocol both players share that supports set_members
2718        grouped, parent_protocol_player, parent_protocol_domain = (
2719            self._try_group_via_common_protocol(
2720                child_player,
2721                parent_player,
2722                parent_protocol_player,
2723                parent_protocol_domain,
2724                protocol_members,
2725            )
2726        )
2727        if grouped:
2728            return parent_protocol_player, parent_protocol_domain
2729
2730        # Priority 5: no option worked
2731        self.logger.warning(
2732            "Cannot group %s with %s: no compatible grouping method found "
2733            "(tried: child preferred protocol, parent active protocol, "
2734            "native grouping, common protocols)",
2735            child_player.state.name,
2736            parent_player.state.name,
2737        )
2738        return parent_protocol_player, parent_protocol_domain
2739
2740    def _try_group_via_preferred_protocol(
2741        self,
2742        child_player: Player,
2743        parent_player: Player,
2744        parent_protocol_player: Player | None,
2745        parent_protocol_domain: str | None,
2746        protocol_members: list[str],
2747    ) -> tuple[bool, Player | None, str | None]:
2748        """
2749        Try to group the child through the output protocol it prefers in its player settings.
2750
2751        Only used when the group is not on a protocol yet or is already on that same protocol.
2752        Returns whether the child was grouped, together with the protocol player/domain the
2753        group is on: the child's preferred protocol may become the group's protocol.
2754
2755        :param child_player: The player being added to the group.
2756        :param parent_player: The parent player being joined.
2757        :param parent_protocol_player: The protocol player selected for the group so far, if any.
2758        :param parent_protocol_domain: The protocol domain selected for the group so far, if any.
2759        :param protocol_members: The protocol member list to append to.
2760        """
2761        child_protocol_id, protocol_domain = self._try_child_preferred_protocol(
2762            child_player, parent_player
2763        )
2764        if not (
2765            child_protocol_id
2766            and protocol_domain
2767            and (not parent_protocol_domain or protocol_domain == parent_protocol_domain)
2768        ):
2769            return False, parent_protocol_player, parent_protocol_domain
2770
2771        if not parent_protocol_player or parent_protocol_domain != protocol_domain:
2772            parent_protocol = parent_player.get_output_protocol_by_domain(protocol_domain)
2773            if parent_protocol:
2774                parent_protocol_player = parent_player.get_protocol_player(
2775                    parent_protocol.output_protocol_id
2776                )
2777                parent_protocol_domain = protocol_domain
2778        protocol_members.append(child_protocol_id)
2779        self.logger.log(
2780            VERBOSE_LOG_LEVEL,
2781            "Using child's preferred protocol %s for %s",
2782            protocol_domain,
2783            child_player.state.name,
2784        )
2785        return True, parent_protocol_player, parent_protocol_domain
2786
2787    def _try_group_via_active_protocol(
2788        self,
2789        child_player: Player,
2790        parent_protocol_player: Player | None,
2791        parent_protocol_domain: str | None,
2792        protocol_members: list[str],
2793    ) -> tuple[bool, Player | None, str | None]:
2794        """
2795        Try to group the child through the protocol the group is already on.
2796
2797        Returns whether the child was grouped, together with the protocol player/domain the
2798        group is on: the selection is dropped when that protocol cannot group members itself,
2799        so a later grouping method can select another one.
2800
2801        :param child_player: The player being added to the group.
2802        :param parent_protocol_player: The protocol player selected for the group so far, if any.
2803        :param parent_protocol_domain: The protocol domain selected for the group so far, if any.
2804        :param protocol_members: The protocol member list to append to.
2805        """
2806        if not parent_protocol_domain or not parent_protocol_player:
2807            return False, parent_protocol_player, parent_protocol_domain
2808
2809        if PlayerFeature.SET_MEMBERS not in parent_protocol_player.state.supported_features:
2810            self.logger.log(
2811                VERBOSE_LOG_LEVEL,
2812                "Parent's active protocol %s does not support SET_MEMBERS, "
2813                "will search for alternative",
2814                parent_protocol_domain,
2815            )
2816            # Drop the selection so a later grouping method can select a new protocol
2817            return False, None, None
2818
2819        child_protocol = child_player.get_output_protocol_by_domain(parent_protocol_domain)
2820        if not child_protocol or not child_protocol.available:
2821            return False, parent_protocol_player, parent_protocol_domain
2822
2823        # For native protocol players, use the child's player_id directly
2824        # (e.g., a native sendspin web player IS the protocol player)
2825        child_protocol_id = (
2826            child_player.player_id
2827            if child_protocol.is_native
2828            else child_protocol.output_protocol_id
2829        )
2830        protocol_members.append(child_protocol_id)
2831        self.logger.log(
2832            VERBOSE_LOG_LEVEL,
2833            "Using parent's active protocol %s for %s",
2834            parent_protocol_domain,
2835            child_player.state.name,
2836        )
2837        return True, parent_protocol_player, parent_protocol_domain
2838
2839    def _try_group_via_common_protocol(
2840        self,
2841        child_player: Player,
2842        parent_player: Player,
2843        parent_protocol_player: Player | None,
2844        parent_protocol_domain: str | None,
2845        protocol_members: list[str],
2846    ) -> tuple[bool, Player | None, str | None]:
2847        """
2848        Try to group the child through a protocol both players share.
2849
2850        Returns whether the child was grouped, together with the protocol player/domain the
2851        group is on: the shared protocol may become the group's protocol.
2852
2853        :param child_player: The player being added to the group.
2854        :param parent_player: The parent player being joined.
2855        :param parent_protocol_player: The protocol player selected for the group so far, if any.
2856        :param parent_protocol_domain: The protocol domain selected for the group so far, if any.
2857        :param protocol_members: The protocol member list to append to.
2858        """
2859        parent_protocol, child_protocol = self._try_find_common_protocol(
2860            child_player, parent_player
2861        )
2862        if not parent_protocol or not child_protocol:
2863            return False, parent_protocol_player, parent_protocol_domain
2864
2865        if not parent_protocol_player or parent_protocol_domain != parent_protocol.protocol_domain:
2866            parent_protocol_player = parent_player.get_protocol_player(
2867                parent_protocol.output_protocol_id
2868            )
2869            if parent_protocol_player:
2870                parent_protocol_domain = parent_protocol_player.provider.domain
2871        # For native protocol players, use the child's player_id directly
2872        child_protocol_id = (
2873            child_player.player_id
2874            if child_protocol.is_native
2875            else child_protocol.output_protocol_id
2876        )
2877        protocol_members.append(child_protocol_id)
2878        self.logger.log(
2879            VERBOSE_LOG_LEVEL,
2880            "Selected common protocol %s for grouping %s with %s",
2881            parent_protocol.protocol_domain,
2882            child_player.state.name,
2883            parent_player.state.name,
2884        )
2885        return True, parent_protocol_player, parent_protocol_domain
2886
2887    async def _forward_protocol_set_members(
2888        self,
2889        parent_player: Player,
2890        parent_protocol_player: Player,
2891        protocol_members_to_add: list[str],
2892        protocol_members_to_remove: list[str],
2893    ) -> None:
2894        """
2895        Forward protocol members to protocol player's set_members and manage active output protocol.
2896
2897        :param parent_player: The parent player (native/universal).
2898        :param parent_protocol_player: The protocol player to forward commands to.
2899        :param protocol_members_to_add: Protocol player IDs to add.
2900        :param protocol_members_to_remove: Protocol player IDs to remove.
2901        """
2902        filtered_protocol_add = self._filter_protocol_members(
2903            protocol_members_to_add, parent_protocol_player
2904        )
2905        filtered_protocol_remove = self._filter_protocol_members(
2906            protocol_members_to_remove, parent_protocol_player
2907        )
2908        self.logger.debug(
2909            "Protocol grouping on %s: filtered_add=%s, filtered_remove=%s",
2910            parent_protocol_player.state.name,
2911            filtered_protocol_add,
2912            filtered_protocol_remove,
2913        )
2914
2915        if not filtered_protocol_add and not filtered_protocol_remove:
2916            return
2917
2918        # Safety check: verify protocol player supports SET_MEMBERS
2919        if PlayerFeature.SET_MEMBERS not in parent_protocol_player.state.supported_features:
2920            self.logger.error(
2921                "Protocol player %s does not support SET_MEMBERS, cannot perform grouping. "
2922                "This should have been caught earlier in the flow.",
2923                parent_protocol_player.state.name,
2924            )
2925            return
2926
2927        # Members that ride the parent's own stream are stranded by the protocol switch below,
2928        # so they join the protocol group in this very same call and their native session is
2929        # torn down afterwards.
2930        stranded_native_members = (
2931            self._migrate_stranded_native_members(
2932                parent_player, parent_protocol_player, filtered_protocol_add
2933            )
2934            if filtered_protocol_add
2935            else []
2936        )
2937
2938        # This runs before set_members because a member's own stream starts inside that call
2939        # and the provider resolves the member's volume control as it starts: unless its parent
2940        # already points at this protocol, that resolution picks a sibling interface of the same
2941        # device (e.g. its cast side) over the one carrying the audio.
2942        self._activate_protocol_on_added_children(filtered_protocol_add)
2943
2944        self.logger.debug(
2945            "Calling set_members on protocol player %s with add=%s, remove=%s",
2946            parent_protocol_player.state.name,
2947            filtered_protocol_add,
2948            filtered_protocol_remove,
2949        )
2950        await parent_protocol_player.set_members(
2951            player_ids_to_add=filtered_protocol_add or None,
2952            player_ids_to_remove=filtered_protocol_remove or None,
2953        )
2954
2955        if filtered_protocol_add:
2956            await self._activate_group_output_protocol(
2957                parent_player, parent_protocol_player, stranded_native_members
2958            )
2959
2960        self.logger.debug(
2961            "After set_members, protocol player %s state: group_members=%s, synced_to=%s",
2962            parent_protocol_player.state.name,
2963            parent_protocol_player.group_members,
2964            parent_protocol_player.synced_to,
2965        )
2966
2967    def _activate_protocol_on_added_children(self, protocol_member_ids: list[str]) -> None:
2968        """
2969        Point the parent of each given protocol member at the protocol carrying the group audio.
2970
2971        :param protocol_member_ids: The protocol player IDs joining the group.
2972        """
2973        for child_protocol_id in protocol_member_ids:
2974            if not (child_protocol := self.get_player(child_protocol_id)):
2975                continue
2976            if not child_protocol.protocol_parent_id:
2977                continue
2978            if not (child_player := self.get_player(child_protocol.protocol_parent_id)):
2979                continue
2980            if child_player.active_output_protocol == child_protocol_id:
2981                continue
2982            self.logger.debug(
2983                "Setting active output protocol on child %s to %s",
2984                child_player.state.name,
2985                child_protocol_id,
2986            )
2987            child_player.set_active_output_protocol(child_protocol_id)
2988
2989    async def _activate_group_output_protocol(
2990        self,
2991        parent_player: Player,
2992        parent_protocol_player: Player,
2993        stranded_native_members: list[str],
2994    ) -> None:
2995        """
2996        Mark the given protocol as the parent's output and hand the playback over to it.
2997
2998        The handover only runs when the parent is actually switching protocol while it is
2999        rendering; playback is resumed only for a parent that was playing, so adding a member
3000        never starts playback on its own.
3001
3002        :param parent_player: The parent player that just gained protocol members.
3003        :param parent_protocol_player: The protocol player the members joined.
3004        :param stranded_native_members: The members left without a stream by the switch.
3005        """
3006        previous_protocol = parent_player.active_output_protocol
3007        was_playing = parent_player.state.playback_state == PlaybackState.PLAYING
3008        # A paused player still holds its output, so the handover has to run for it too.
3009        was_rendering = was_playing or parent_player.state.playback_state == PlaybackState.PAUSED
3010
3011        # Native protocol: parent_protocol_player is the same as parent_player
3012        is_native_protocol = parent_protocol_player.player_id == parent_player.player_id
3013        already_using_native = previous_protocol in (None, "native")
3014        already_using_this_protocol = previous_protocol == parent_protocol_player.player_id
3015        switching_protocols = not (
3016            (is_native_protocol and already_using_native) or already_using_this_protocol
3017        )
3018
3019        self.logger.debug(
3020            "Protocol grouping: is_native=%s, already_native=%s, already_this=%s, "
3021            "switching=%s, was_rendering=%s",
3022            is_native_protocol,
3023            already_using_native,
3024            already_using_this_protocol,
3025            switching_protocols,
3026            was_rendering,
3027        )
3028
3029        if not (is_native_protocol and already_using_native):
3030            parent_player.set_active_output_protocol(parent_protocol_player.player_id)
3031
3032        if not (was_rendering and switching_protocols):
3033            return
3034
3035        self.logger.info(
3036            "Handing the output of %s over to the %s protocol%s",
3037            parent_player.state.name,
3038            parent_protocol_player.provider.domain,
3039            " and resuming playback" if was_playing else "",
3040        )
3041        if stranded_native_members:
3042            await self._stop_native_session(
3043                parent_player, parent_protocol_player, stranded_native_members
3044            )
3045        old_parent_members = await self._stop_previous_protocol(
3046            parent_player, parent_protocol_player, previous_protocol
3047        )
3048        if was_playing:
3049            await self.mass.players.cmd_resume(parent_player.player_id)
3050        if old_parent_members:
3051            self.logger.debug(
3052                "Re-adding migrated members %s to %s on new protocol",
3053                old_parent_members,
3054                parent_player.state.name,
3055            )
3056            # Use internal handler because we are already inside a
3057            # _handle_set_members call chain that holds the play lock.
3058            await self.mass.players._handle_set_members(
3059                parent_player,
3060                player_ids_to_add=old_parent_members,
3061            )
3062
3063    async def _stop_previous_protocol(
3064        self,
3065        parent_player: Player,
3066        parent_protocol_player: Player,
3067        previous_protocol: str | None,
3068    ) -> list[str]:
3069        """
3070        Stop the protocol player the parent was rendering through and return its members.
3071
3072        The returned IDs are parent player IDs, so the caller can re-add them to the group
3073        once the new protocol carries the audio. Empty if there is nothing to hand over.
3074
3075        :param parent_player: The parent player that is switching protocol.
3076        :param parent_protocol_player: The protocol player taking the output over.
3077        :param previous_protocol: The parent's previous active output protocol, if any.
3078        """
3079        if previous_protocol in (None, "native"):
3080            return []
3081        if not (old_protocol_player := self.get_player(previous_protocol)):
3082            return []
3083        if old_protocol_player.player_id == parent_protocol_player.player_id:
3084            return []
3085        # Translate the old protocol's child members back to parent player IDs
3086        old_parent_members: list[str] = []
3087        for member_id in old_protocol_player.group_members:
3088            if member_id == old_protocol_player.player_id:
3089                continue
3090            if not (member_player := self.get_player(member_id)):
3091                continue
3092            parent_id = member_player.protocol_parent_id or member_id
3093            if parent_id != parent_player.player_id:
3094                old_parent_members.append(parent_id)
3095        self.logger.debug(
3096            "Stopping old protocol player %s before switching to %s, migrating members: %s",
3097            old_protocol_player.state.name,
3098            parent_protocol_player.state.name,
3099            old_parent_members,
3100        )
3101        # Use internal handler to stop the specific protocol player,
3102        # bypassing group/sync redirect and queue redirect logic.
3103        await self.mass.players._handle_cmd_stop(old_protocol_player.player_id)
3104        return old_parent_members
3105