"""Tests for the music database module (music_db.py)."""

import json
import os
import tempfile

import pytest

# We'll create a fresh MusicDB for each test using a temporary file.


@pytest.fixture
def music_db():
    """Yield a MusicDB backed by a temporary SQLite file."""
    from music_db import MusicDB

    tmp = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
    tmp.close()
    db = MusicDB(tmp.name)
    yield db
    db.close()
    os.unlink(tmp.name)


# ── Helper ────────────────────────────────────────────────────────────────────

_SONG = dict(
    video_id="test_video_001",
    title="Test Song",
    artists=[{"name": "Test Artist", "id": "artist_001"}],
    album={"name": "Test Album", "id": "album_001"},
    duration=240,
    thumbnail="https://example.com/thumb.jpg",
)


def _record_play(db, **overrides):
    kwargs = dict(_SONG)
    kwargs.update(overrides)
    db.record_play(**kwargs)


# ── Tests ─────────────────────────────────────────────────────────────────────


class TestRecordPlay:
    def test_records_play_and_history(self, music_db):
        """record_play creates a song entry and a history row."""
        _record_play(music_db)
        stats = music_db.get_stats()
        assert stats["unique_songs"] == 1
        assert stats["total_plays"] == 1

        history = music_db.get_history(limit=10)
        assert len(history) == 1
        assert history[0]["video_id"] == _SONG["video_id"]

    def test_increments_play_count(self, music_db):
        """Playing the same song multiple times increments play_count."""
        _record_play(music_db)
        _record_play(music_db)
        _record_play(music_db)
        stats = music_db.get_stats()
        assert stats["unique_songs"] == 1
        assert stats["total_plays"] == 3

    def test_updates_last_played(self, music_db):
        """Re-playing a song updates last_played timestamp."""
        _record_play(music_db)
        import time
        time.sleep(0.01)
        _record_play(music_db)
        history = music_db.get_history(limit=10)
        # The latest play should be the one returned
        assert history[0]["video_id"] == _SONG["video_id"]

    def test_without_album(self, music_db):
        """record_play works without album data."""
        _record_play(music_db, album=None)
        stats = music_db.get_stats()
        assert stats["unique_songs"] == 1

    def test_without_thumbnail(self, music_db):
        """record_play works without thumbnail."""
        _record_play(music_db, thumbnail=None)
        stats = music_db.get_stats()
        assert stats["unique_songs"] == 1


class TestFavourites:
    def test_toggle_favourite(self, music_db):
        """toggle_favourite flips the favourite flag."""
        _record_play(music_db)
        # Start unfavoured
        assert music_db.is_favourite(_SONG["video_id"]) is False
        # Toggle on
        assert music_db.toggle_favourite(_SONG["video_id"]) is True
        assert music_db.is_favourite(_SONG["video_id"]) is True
        # Toggle off
        assert music_db.toggle_favourite(_SONG["video_id"]) is False
        assert music_db.is_favourite(_SONG["video_id"]) is False

    def test_toggle_favourite_nonexistent_song(self, music_db):
        """toggle_favourite on a non-existent song returns False."""
        assert music_db.toggle_favourite("nonexistent") is False

    def test_set_favourite(self, music_db):
        """set_favourite explicitly sets the favourite state."""
        _record_play(music_db)
        vid = _SONG["video_id"]
        assert music_db.set_favourite(vid, True) is True
        assert music_db.is_favourite(vid) is True
        assert music_db.set_favourite(vid, False) is True
        assert music_db.is_favourite(vid) is False

    def test_set_favourite_nonexistent(self, music_db):
        """set_favourite on a non-existent song returns False."""
        assert music_db.set_favourite("nonexistent", True) is False

    def test_get_favourites_returns_favourited_songs(self, music_db):
        """get_favourites returns only favourited songs."""
        # Record two songs, favourite one
        _record_play(music_db, video_id="song_a", title="A")
        _record_play(music_db, video_id="song_b", title="B")
        music_db.toggle_favourite("song_a")
        favs = music_db.get_favourites()
        assert len(favs) == 1
        assert favs[0]["video_id"] == "song_a"


class TestHistory:
    def test_history_ordered_by_recent(self, music_db):
        """get_history returns songs ordered by most recent play."""
        _record_play(music_db, video_id="song_a", title="A")
        import time
        time.sleep(0.01)
        _record_play(music_db, video_id="song_b", title="B")
        history = music_db.get_history(limit=10)
        # Most recent (song_b) should be first
        assert history[0]["video_id"] == "song_b"
        assert history[1]["video_id"] == "song_a"

    def test_history_deduplicates_by_video_id(self, music_db):
        """get_history shows each song at most once (most recent play)."""
        _record_play(music_db, video_id="song_a", title="A")
        _record_play(music_db, video_id="song_b", title="B")
        _record_play(music_db, video_id="song_a", title="A")
        history = music_db.get_history(limit=10)
        # song_a appears once, but song_b is in there too
        assert len(history) == 2
        # song_a is most recent since it was played last
        assert history[0]["video_id"] == "song_a"

    def test_history_respects_limit(self, music_db):
        """get_history respects the limit parameter."""
        for i in range(5):
            _record_play(music_db, video_id=f"song_{i}", title=f"S{i}")
        history = music_db.get_history(limit=3)
        assert len(history) == 3

    def test_empty_history(self, music_db):
        """get_history on empty DB returns empty list."""
        assert music_db.get_history() == []


class TestStats:
    def test_get_stats_empty(self, music_db):
        """get_stats on empty DB returns zero counts."""
        stats = music_db.get_stats()
        assert stats["unique_songs"] == 0
        assert stats["total_plays"] is None or stats["total_plays"] == 0
        assert stats["favourites"] == 0
        assert stats["top_played"] == []
        assert stats["recent"] == []
        assert stats["plays_by_day"] == []

    def test_get_stats_with_data(self, music_db):
        """get_stats returns accurate aggregate data."""
        _record_play(music_db, video_id="song_a", title="A", duration=120)
        _record_play(music_db, video_id="song_b", title="B", duration=180)
        _record_play(music_db, video_id="song_a", title="A", duration=120)
        music_db.toggle_favourite("song_b")

        stats = music_db.get_stats()
        assert stats["unique_songs"] == 2
        assert stats["total_plays"] == 3
        assert stats["favourites"] == 1
        assert stats["top_played"][0]["video_id"] == "song_a"
        assert stats["top_played"][0]["play_count"] == 2
        assert len(stats["recent"]) == 3
        assert len(stats["plays_by_day"]) >= 1  # today at least

    def test_top_played_limit_returns_up_to_ten(self, music_db):
        """top_played in stats returns at most 10 entries."""
        for i in range(15):
            _record_play(music_db, video_id=f"song_{i}", title=f"S{i}")
            for _ in range(i + 1):
                _record_play(music_db, video_id=f"song_{i}", title=f"S{i}")
        stats = music_db.get_stats()
        assert len(stats["top_played"]) == 10


class TestEdgeCases:
    def test_unicode_song_title(self, music_db):
        """record_play handles Unicode characters in titles and artists."""
        _record_play(music_db, title="🎵 Джаз", artists=[{"name": "José", "id": "j"}])
        history = music_db.get_history(limit=10)
        assert history[0]["title"] == "🎵 Джаз"

    def test_empty_artists_list(self, music_db):
        """record_play works with empty artists list."""
        _record_play(music_db, artists=[])
        stats = music_db.get_stats()
        assert stats["unique_songs"] == 1

    def test_very_long_title(self, music_db):
        """record_play handles very long titles."""
        long_title = "A" * 1000
        _record_play(music_db, title=long_title)
        history = music_db.get_history(limit=10)
        assert history[0]["title"] == long_title

    def test_concurrent_access(self, music_db):
        """Multiple rapid calls don't cause errors."""
        import threading

        errors = []

        def worker(vid):
            try:
                _record_play(music_db, video_id=vid, title=f"S{vid}")
                music_db.toggle_favourite(vid)
                music_db.is_favourite(vid)
                music_db.get_stats()
            except Exception as e:
                errors.append(e)

        threads = [threading.Thread(target=worker, args=(f"vid_{i}",)) for i in range(20)]
        for t in threads:
            t.start()
        for t in threads:
            t.join(timeout=5)

        assert not errors, f"Concurrent errors: {errors}"
        stats = music_db.get_stats()
        assert stats["unique_songs"] == 20