from unittest.mock import MagicMock, patch

from lintunes.models import Track
from lintunes.models.library import Library
from lintunes import player as player_module
from lintunes.player import Player


class FakeManager:
    """Minimal stand-in for LibraryManager: the Player reads `library.tracks`,
    calls `record_play` on natural end-of-media, and `set_track_location` when
    the user relocates a moved/renamed file."""

    def __init__(self, library):
        self.library = library
        self.played = []

    def record_play(self, track_id):
        self.played.append(track_id)

    def set_track_location(self, track_id, location):
        self.library.tracks[track_id].location = location


def _make_player(qapp, tracks):
    library = Library()
    for track in tracks:
        library.tracks[track.track_id] = track
    # The Qt multimedia backend (QMediaPlayer/QAudioOutput/QMediaDevices)
    # blocks on init in a headless environment, so stub it out — the
    # missing-file path under test never reaches real playback anyway.
    with patch.multiple(
        player_module,
        QMediaPlayer=MagicMock(),
        QAudioOutput=MagicMock(),
        QAudioBufferOutput=MagicMock(),
        QMediaDevices=MagicMock(),
    ):
        player = Player(FakeManager(library))
    errors, missing = [], []
    player.error_occurred.connect(errors.append)
    player.track_missing.connect(missing.append)
    return player, errors, missing


def test_missing_file_emits_track_missing_and_stops(qapp, tmp_path):
    location = str(tmp_path / "not-mounted" / "song.mp3")
    track = Track(track_id=1, name="Ghost Song", location=location)
    player, errors, missing = _make_player(qapp, [track])

    player.play_queue([1], 0)

    # Routed to track_missing (so the UI can offer "Locate File…"), not the
    # generic error dialog.
    assert errors == []
    assert missing == [track]
    # Stopped, not advanced into a track; setSource was never called.
    assert player.current_track is None
    player._media.setSource.assert_not_called()


def test_all_missing_queue_does_not_recurse(qapp, tmp_path):
    # A whole-library queue with every file gone (drive unmounted) must not
    # cascade through the queue and blow the recursion limit.
    tracks = [
        Track(track_id=i, name=f"T{i}", location=str(tmp_path / f"{i}.mp3"))
        for i in range(5000)
    ]
    player, errors, missing = _make_player(qapp, tracks)

    player.play_queue([t.track_id for t in tracks], 0)

    # One alert for the track we tried to play, then a clean stop.
    assert len(missing) == 1
    assert player.current_track is None


def test_track_not_in_library_emits_error(qapp):
    # Queue references an id that isn't in the library: nothing to locate, so
    # this stays a plain error (not track_missing).
    player, errors, missing = _make_player(qapp, [])

    player.play_queue([99], 0)

    assert missing == []
    assert len(errors) == 1
    assert player.current_track is None


def test_retry_current_plays_after_relocate(qapp, tmp_path):
    real = tmp_path / "real.mp3"
    real.write_bytes(b"audio")
    track = Track(track_id=1, name="Moved Song",
                  location=str(tmp_path / "gone.mp3"))
    player, errors, missing = _make_player(qapp, [track])

    player.play_queue([1], 0)
    assert missing == [track] and player.current_track is None

    # User relocates the file, then the UI retries the same queue position.
    player._manager.set_track_location(1, str(real))
    missing.clear()
    player.retry_current()

    assert errors == [] and missing == []
    assert player.current_track is track
    player._media.setSource.assert_called_once()