-- Artist photos (auto-fetched or manually overridden) reuse the
-- existing cover_art table rather than a parallel one, so photo
-- resizing/caching/serving (internal/coverart, /cover-art/{id}) works
-- unchanged for artists. That requires adding an artist_id column and
-- widening the "must belong to something" CHECK, which SQLite can only
-- do by rebuilding the table.
--
-- albums.cover_art_id and podcast_channels.cover_art_id are declared
-- "ON DELETE SET NULL" against cover_art(id), and SQLite's DROP TABLE
-- performs an implicit DELETE FROM first when foreign_keys=ON — which
-- would fire that SET NULL and silently wipe every album's/channel's
-- chosen cover on upgrade. Back those columns up and restore them
-- after the rebuild.
CREATE TEMP TABLE _cover_art_migration_backup_albums AS
    SELECT id, cover_art_id FROM albums WHERE cover_art_id IS NOT NULL;
CREATE TEMP TABLE _cover_art_migration_backup_podcasts AS
    SELECT id, cover_art_id FROM podcast_channels WHERE cover_art_id IS NOT NULL;

CREATE TABLE cover_art_new (
    id              TEXT PRIMARY KEY,
    album_id        TEXT REFERENCES albums(id) ON DELETE CASCADE,
    media_file_id   TEXT REFERENCES media_files(id) ON DELETE CASCADE,
    artist_id       TEXT REFERENCES artists(id) ON DELETE CASCADE,
    source          TEXT NOT NULL CHECK (source IN ('embedded','folder','external')),
    source_path     TEXT NOT NULL DEFAULT '',
    mime_type       TEXT NOT NULL DEFAULT '',
    content_hash    TEXT NOT NULL DEFAULT '',
    width            INTEGER NOT NULL DEFAULT 0,
    height           INTEGER NOT NULL DEFAULT 0,
    updated_at      TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now')),
    CHECK ((album_id IS NOT NULL) OR (media_file_id IS NOT NULL) OR (artist_id IS NOT NULL))
);

INSERT INTO cover_art_new (id, album_id, media_file_id, artist_id, source, source_path, mime_type, content_hash, width, height, updated_at)
SELECT id, album_id, media_file_id, NULL, source, source_path, mime_type, content_hash, width, height, updated_at FROM cover_art;

DROP TABLE cover_art;
ALTER TABLE cover_art_new RENAME TO cover_art;

CREATE INDEX idx_cover_art_album ON cover_art(album_id);
CREATE INDEX idx_cover_art_media_file ON cover_art(media_file_id);
CREATE INDEX idx_cover_art_artist ON cover_art(artist_id);

UPDATE albums SET cover_art_id = (
    SELECT cover_art_id FROM _cover_art_migration_backup_albums WHERE _cover_art_migration_backup_albums.id = albums.id
) WHERE id IN (SELECT id FROM _cover_art_migration_backup_albums);
UPDATE podcast_channels SET cover_art_id = (
    SELECT cover_art_id FROM _cover_art_migration_backup_podcasts WHERE _cover_art_migration_backup_podcasts.id = podcast_channels.id
) WHERE id IN (SELECT id FROM _cover_art_migration_backup_podcasts);

DROP TABLE _cover_art_migration_backup_albums;
DROP TABLE _cover_art_migration_backup_podcasts;

-- Artist bio + photo (auto-fetched or admin-overridden).
ALTER TABLE artists ADD COLUMN bio TEXT NOT NULL DEFAULT '';
ALTER TABLE artists ADD COLUMN cover_art_id TEXT REFERENCES cover_art(id);
ALTER TABLE artists ADD COLUMN photo_manual INTEGER NOT NULL DEFAULT 0;

-- Lets an admin edit a song's title/track/disc/composer/conductor
-- without a later library rescan silently overwriting the edit.
ALTER TABLE songs ADD COLUMN metadata_locked INTEGER NOT NULL DEFAULT 0;