import os
import tempfile
import unittest
from pathlib import Path

os.environ['MUSIC_WORKSHOP_DB_PATH'] = str(
  Path(tempfile.gettempdir()) / f'music_workshop_metadata_normalization_{next(tempfile._get_candidate_names())}.db'
)

from backend.app.metadata_normalization import MetadataNormalizationService, can_ingest_metadata, parse_artist_string
from backend.app.task_store import TaskStore


class MetadataNormalizationTests(unittest.TestCase):
  def setUp(self):
    self.db_path = Path(os.environ['MUSIC_WORKSHOP_DB_PATH'])
    if self.db_path.exists():
      self.db_path.unlink()
    self.task_store = TaskStore(self.db_path)
    self.task = self.task_store.create_task_if_idle(
      {
        'input': '/tmp/input',
        'output': '/tmp/output',
        'trash': '/tmp/trash'
      }
    )
    self.service = MetadataNormalizationService(self.task_store)

  def test_parse_artist_string_supports_common_delimiters(self):
    self.assertEqual(parse_artist_string('A / B')['tokens'], ['A', 'B'])
    self.assertEqual(parse_artist_string('A; B')['tokens'], ['A', 'B'])
    self.assertEqual(parse_artist_string('A & B')['tokens'], ['A', 'B'])
    self.assertEqual(parse_artist_string('A feat. B')['tokens'], ['A', 'B'])
    self.assertEqual(parse_artist_string('A、B')['tokens'], ['A', 'B'])

  def test_single_artist_album_derives_album_artist(self):
    item = self._insert_item('track-01.flac', {'title': 'Song 1', 'artist': 'Artist A', 'album': 'Album X'})
    self._insert_item('track-02.flac', {'title': 'Song 2', 'artist': 'Artist A', 'album': 'Album X'})

    normalized = self.service.normalize_item(item)
    self.assertEqual(normalized['album_artist'], 'Artist A')
    self.assertEqual(normalized['normalization_strategy'], 'single_artist')
    self.assertTrue(can_ingest_metadata({**normalized, 'title': 'Song 1'}))

  def test_feat_album_uses_dominant_primary_artist(self):
    item = self._insert_item('track-01.flac', {'title': 'Song 1', 'artist': 'Artist A feat. Guest', 'album': 'Album X'})
    self._insert_item('track-02.flac', {'title': 'Song 2', 'artist': 'Artist A', 'album': 'Album X'})
    self._insert_item('track-03.flac', {'title': 'Song 3', 'artist': 'Artist A & Another', 'album': 'Album X'})

    normalized = self.service.normalize_item(item)
    self.assertEqual(normalized['album_artist'], 'Artist A')
    self.assertEqual(normalized['normalization_strategy'], 'main_artist_feat')

  def test_compilation_album_sets_various_artists(self):
    item = self._insert_item('track-01.flac', {'title': 'Song 1', 'artist': 'Artist A', 'album': 'Top Hits 2025'})
    self._insert_item('track-02.flac', {'title': 'Song 2', 'artist': 'Artist B', 'album': 'Top Hits 2025'})
    self._insert_item('track-03.flac', {'title': 'Song 3', 'artist': 'Artist C', 'album': 'Top Hits 2025'})

    normalized = self.service.normalize_item(item)
    self.assertEqual(normalized['album_artist'], 'Various Artists')
    self.assertEqual(normalized['compilation'], 1)
    self.assertEqual(normalized['normalization_strategy'], 'compilation')

  def test_existing_album_artist_is_preserved(self):
    item = self._insert_item(
      'track-01.flac',
      {'title': 'Song 1', 'artist': '阿信', 'album': 'Solo Album', 'album_artist': '五月天'}
    )

    normalized = self.service.normalize_item(item)
    self.assertEqual(normalized['album_artist'], '五月天')
    self.assertEqual(normalized['normalization_strategy'], 'source_preserved')

  def _insert_item(self, filename: str, matched_metadata_json: dict):
    return self.task_store.insert_task_item(
      self.task['task_id'],
      original_path=f'/tmp/input/{filename}',
      current_file_path=f'/tmp/input/{filename}',
      relative_path=f'Artist/Album/{filename}',
      filename=filename,
      extension='.flac',
      size_bytes=123456,
      modified_at='2024-01-01T00:00:00Z',
      local_cover=None,
      local_lyric=None,
      scan_status='queued',
      scan_reason=None,
      scan_message=None,
      match_status='matched_fallback',
      matched_metadata_json=matched_metadata_json
    )


if __name__ == '__main__':
  unittest.main()