Greatly improve database update

app/model.py

@@ -14,6 +14,7 @@ from sqlalchemy import (
     String,
     func
 )
+from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm.exc import MultipleResultsFound, NoResultFound
 from sqlalchemy.orm import relationship, sessionmaker
 
@@ -106,6 +107,14 @@ class Playdates(Base):
         track.update_lastplayed()
         session.commit()
 
+    @staticmethod
+    def last_played(session, track):
+        "Return datetime track last played or None"
+
+        return session.query(Playdates).filter(
+            (Playdates.track_id == track.id)
+            ).order_by(Playdates.lastplayed.desc()).first()
+
 
 class Playlists(Base):
     """
@@ -279,6 +288,20 @@ class PlaylistTracks(Base):
         session.add(plt)
         session.commit()
 
+    @staticmethod
+    def get_playlists_containing_track_id(session, track_id):
+
+        playlists = []
+        playlist_ids = session.query(PlaylistTracks.playlist_id).filter(
+            PlaylistTracks.track_id == track_id).all()
+        for p in playlist_ids:
+            playlist = session.query(Playlists).filter(
+                Playlists.id == p[0]).first()
+            if playlist:
+                playlists.append(playlist)
+
+        return playlists
+
     @staticmethod
     def move_track(session, from_playlist_id, row, to_playlist_id):
         DEBUG(
@@ -458,6 +481,44 @@ class Tracks(Base):
             ERROR(f"get_track({id}): not found")
             return None
 
+    @staticmethod
+    def get_track_from_filename(session, filename):
+        """
+        Return track if one and only one track in database has passed
+        filename (ie, basename of path). Return None if zero or more
+        than one track matches.
+        """
+
+        DEBUG(f"Tracks.get_track_from_filename({filename=})")
+        try:
+            track = session.query(Tracks).filter(Tracks.path.ilike(
+                # TODO: filename separator is hardcoded here
+                f'%/{filename}')).one()
+            return track
+        except (NoResultFound, MultipleResultsFound):
+            return None
+
+    @staticmethod
+    def get_track_from_path(session, path):
+        """
+        Return track with passee path, or None.
+        """
+
+        DEBUG(f"Tracks.get_track_from_path({path=})")
+
+        return session.query(Tracks).filter(Tracks.path == path).first()
+
+    @staticmethod
+    def remove_path(session, path):
+        "Remove track with passed path from database"
+
+        DEBUG(f"Tracks.remove_path({path=})")
+
+        try:
+            session.query(Tracks).filter(Tracks.path == path).delete()
+        except IntegrityError as exception:
+            ERROR(f"Can't remove track with {path=} ({exception=})")
+
     @staticmethod
     def search_titles(session, text):
         return (
@@ -473,3 +534,6 @@ class Tracks(Base):
 
     def update_lastplayed(self):
         self.lastplayed = datetime.now()
+
+    def update_path(self, newpath):
+        self.path = newpath

app/songdb.py

@@ -7,7 +7,7 @@ import tempfile
 
 from config import Config
 from log import DEBUG, INFO
-from model import Tracks, Session
+from model import Tracks, Playdates, PlaylistTracks, Session
 from mutagen.flac import FLAC
 from pydub import AudioSegment, effects
 from tinytag import TinyTag
@@ -22,7 +22,10 @@ def main():
     p = argparse.ArgumentParser()
     p.add_argument('-u', '--update',
                    action="store_true", dest="update",
-                   default=True, help="Update database")
+                   default=False, help="Update database")
+    p.add_argument('-f', '--full-update',
+                   action="store_true", dest="full_update",
+                   default=False, help="Update database")
     args = p.parse_args()
 
     # Run as required
@@ -30,25 +33,32 @@ def main():
         INFO("Updating database")
         with Session() as session:
             update_db(session)
+    elif args.full_update:
+        INFO("Full update of database")
+        with Session() as session:
+            full_update_db(session)
+    else:
+        INFO("No action specified")
 
     INFO("Finished")
 
 
 def create_track_from_file(session, path):
     """
-    Create track in database from passed path.
+    Create track in database from passed path, or update database entry
+    if path already in database.
 
     Return track.
     """
 
     track = Tracks.get_or_create(session, path)
-    tag = TinyTag.get(path)
-    audio = get_audio_segment(path)
+    t = get_music_info(path)
+    track.title = t['title']
+    track.artist = t['artist']
+    track.duration = int(round(
+        t['duration'], Config.MILLISECOND_SIGFIGS) * 1000)
 
-    track.title = tag.title
-    track.artist = tag.artist
-    track.duration = int(round(tag.duration,
-                               Config.MILLISECOND_SIGFIGS) * 1000)
+    audio = get_audio_segment(path)
     track.start_gap = leading_silence(audio)
     track.fade_at = round(fade_point(audio) / 1000,
                           Config.MILLISECOND_SIGFIGS) * 1000
@@ -92,6 +102,12 @@ def create_track_from_file(session, path):
     return track
 
 
+def full_update_db():
+    "Rescan all entries in database"
+
+    pass
+
+
 def get_audio_segment(path):
     try:
         if path.endswith('.mp3'):
@@ -102,6 +118,21 @@ def get_audio_segment(path):
         return None
 
 
+def get_music_info(path):
+    """
+    Return a dictionary of title, artist, duration-in-milliseconds and path.
+    """
+
+    tag = TinyTag.get(path)
+
+    return dict(
+        title=tag.title,
+        artist=tag.artist,
+        duration=tag.duration,
+        path=path
+    )
+
+
 def leading_silence(audio_segment, silence_threshold=Config.DBFS_SILENCE,
                     chunk_size=Config.AUDIO_SEGMENT_CHUNK_SIZE):
     """
@@ -187,14 +218,47 @@ def update_db(session):
                 os_paths_list.append(path)
     os_paths = set(os_paths_list)
 
-    for path in list(db_paths - os_paths):
-        # TODO
-        INFO(f"To remove from database: {path}")
+    # If a track is moved, only the path will have changed.
+    # For any files we have found whose paths are not in the database,
+    # check to see whether the filename (basename) is present in the
+    # database:
 
     for path in list(os_paths - db_paths):
-        # TODO
-        INFO(f"Adding to dataabase: {path}")
-        create_track_from_file(session, path)
+        DEBUG(f"songdb.update_db: {path=} not in database")
+        # is filename in database?
+        track = Tracks.get_track_from_filename(session, os.path.basename(path))
+        if not track:
+            DEBUG(f"songdb.update_db: Adding to database: {path}")
+            create_track_from_file(session, path)
+        else:
+            # Check track info matches found track
+            t = get_music_info(path)
+            if t['artist'] == track.artist and t['title'] == track.title:
+                track.update_path(path)
+            else:
+                create_track_from_file(session, path)
+
+    # Refresh database paths
+    db_paths = set(Tracks.get_all_paths(session))
+    # Remote any tracks from database whose paths don't exist
+    for path in list(db_paths - os_paths):
+        track = Tracks.get_track_from_path(session, path)
+        DEBUG(f"songdb.update_db(): remove from database: {path=} {track=}")
+        played = Playdates.last_played(session, track)
+        playlists = PlaylistTracks.get_playlists_containing_track_id(
+            session, track.id)
+        if played:
+            INFO(
+                f"songdb.update_db: Can't remove {track.id=} ({track.path=}) "
+                f"as it's in playdates.id={played.id}"
+            )
+        elif playlists:
+            INFO(
+                f"songdb.update_db: Can't remove {track.id=} ({track.path=} "
+                f"as it's in playlists {[p.name for p in playlists]}"
+            )
+        else:
+            Tracks.remove_path(session, path)
 
 
 if __name__ == '__main__' and '__file__' in globals():