-- M7 cover-sources: schema for additional cover-art providers (TheAudioDB
-- as the v1 implementation), artist art (thumb + fanart), and the
-- recheck-on-source-change trigger.

-- (0) Extend the existing albums.cover_art_source CHECK to accept the
-- new 'theaudiodb' value. The constraint was created in migration 0016
-- with the IN list ('embedded','sidecar','mbcaa','none'); without this
-- extension, the enricher's UPDATE setting cover_art_source='theaudiodb'
-- would fail with a CHECK violation.
ALTER TABLE albums DROP CONSTRAINT IF EXISTS albums_cover_art_source_check;
ALTER TABLE albums
    ADD CONSTRAINT albums_cover_art_source_check
    CHECK (cover_art_source IS NULL
           OR cover_art_source IN ('embedded','sidecar','mbcaa','theaudiodb','none'));

-- (1) Artist art columns parallel albums.cover_art_*.
ALTER TABLE artists
    ADD COLUMN artist_thumb_path  text,
    ADD COLUMN artist_fanart_path text,
    ADD COLUMN artist_art_source  text;

ALTER TABLE artists
    ADD CONSTRAINT artists_artist_art_source_check
    CHECK (artist_art_source IS NULL
           OR artist_art_source IN ('theaudiodb','none'));

CREATE INDEX artists_artist_art_source_idx ON artists (artist_art_source);

-- (2) Recheck-trigger version stamps. Default 0; current_version starts
-- at 1, so every existing row is "stale" relative to current — first
-- scan after migrate retries every settled row through the new chain.
ALTER TABLE albums
    ADD COLUMN cover_art_sources_version int NOT NULL DEFAULT 0;
ALTER TABLE artists
    ADD COLUMN artist_art_sources_version int NOT NULL DEFAULT 0;

-- (3) Per-provider settings + singleton meta row.
CREATE TABLE cover_art_provider_settings (
    provider_id   text PRIMARY KEY,
    enabled       boolean NOT NULL DEFAULT true,
    api_key       text,
    display_order int  NOT NULL DEFAULT 0,
    created_at    timestamptz NOT NULL DEFAULT now(),
    updated_at    timestamptz NOT NULL DEFAULT now()
);

CREATE TABLE cover_art_sources_meta (
    id              boolean PRIMARY KEY DEFAULT true,
    current_version int NOT NULL DEFAULT 1,
    CONSTRAINT cover_art_sources_meta_singleton CHECK (id = true)
);
INSERT INTO cover_art_sources_meta (id, current_version) VALUES (true, 1);

-- Seed both v1 providers as enabled. TheAudioDB's api_key stays NULL;
-- the application supplies the test key '2' when the column is NULL,
-- per the no-coercive-settings principle.
INSERT INTO cover_art_provider_settings (provider_id, enabled, display_order) VALUES
    ('mbcaa',      true, 0),
    ('theaudiodb', true, 1);

-- (4) Scan-runs gains a stage tally column for artist art enrichment.
ALTER TABLE scan_runs ADD COLUMN artist_art_enrich jsonb;