-- 0047_taste_profile_moods.up.sql — mood taste facet (#1534, milestone #160
-- Opt 2b). A fourth taste facet alongside artists + tags + eras: signed weights
-- over canonical mood buckets (melancholic / energetic / chill / …) derived
-- from a track's enriched folksonomy tags (#1490) via the internal/mood
-- vocabulary, rebuilt daily. Weight is a signed float — positive = drawn to
-- that mood, negative = passively avoided. Coverage is partial (grows with tag
-- enrichment), so it's a supplement, not a foundation. Mirrors
-- taste_profile_tags: CASCADE on user delete, indexed by (user_id, weight DESC).
CREATE TABLE taste_profile_moods (
    user_id    uuid             NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    mood       text             NOT NULL,
    weight     double precision NOT NULL,
    updated_at timestamptz      NOT NULL DEFAULT now(),
    PRIMARY KEY (user_id, mood)
);

CREATE INDEX taste_profile_moods_user_weight_idx
    ON taste_profile_moods (user_id, weight DESC);

-- Mood-facet build knob, tunable in the lab (mirrors era_scale / enriched_tag_
-- scale): scales how strongly a mood-tagged play imprints on the profile.
-- DEFAULT 0.5 backfills the existing singleton and matches
-- taste.DefaultConfig().MoodScale; 0 disables the mood facet entirely.
ALTER TABLE taste_tuning
    ADD COLUMN mood_scale double precision NOT NULL DEFAULT 0.5;