CREATE TABLE IF NOT EXISTS playlists (
    id BIGINT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,

    room_id BIGINT NOT NULL REFERENCES rooms(id) ON DELETE RESTRICT,
    creator_id BIGINT REFERENCES users(id) ON DELETE RESTRICT,

    name VARCHAR(255) NOT NULL DEFAULT '',
    description TEXT NOT NULL DEFAULT '',

    cover_file_reference_id BIGINT NULL REFERENCES file_references(id) ON DELETE SET NULL,

    parent_id BIGINT,

    position DOUBLE PRECISION NOT NULL,

    source_provider SMALLINT,
    source_config JSONB,
    provider_instance_name VARCHAR(64),

    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),

    version INTEGER NOT NULL DEFAULT 0,

    CONSTRAINT playlists_parent_not_self
        CHECK (parent_id IS NULL OR parent_id != id),
    CONSTRAINT playlists_source_fields_consistent
        CHECK (
        (source_provider IS NOT NULL AND source_config IS NOT NULL)
        OR (source_provider IS NULL AND source_config IS NULL)
        ),
    CONSTRAINT playlists_source_config_object
        CHECK (source_config IS NULL OR jsonb_typeof(source_config) = 'object'),
    CONSTRAINT playlists_provider_instance_requires_source_provider
        CHECK (
        provider_instance_name IS NULL OR source_provider IS NOT NULL
        ),
    CONSTRAINT playlists_provider_instance_fk
        FOREIGN KEY (provider_instance_name)
        REFERENCES media_provider_instances(name)
        ON DELETE RESTRICT,
    CONSTRAINT playlists_id_room_unique UNIQUE (id, room_id),
    CONSTRAINT playlists_parent_same_room_fk
        FOREIGN KEY (parent_id, room_id)
        REFERENCES playlists(id, room_id)
        ON DELETE RESTRICT
);

CREATE INDEX IF NOT EXISTS idx_playlists_room ON playlists(room_id);
CREATE INDEX IF NOT EXISTS idx_playlists_name_trgm ON playlists USING gin(name gin_trgm_ops);
CREATE INDEX IF NOT EXISTS idx_playlists_description_trgm ON playlists USING gin(description gin_trgm_ops);
CREATE INDEX IF NOT EXISTS idx_playlists_parent ON playlists(parent_id, position, id);
CREATE INDEX IF NOT EXISTS idx_playlists_tree ON playlists(room_id, parent_id, position, id);
CREATE INDEX IF NOT EXISTS idx_playlists_creator ON playlists(creator_id);
CREATE INDEX IF NOT EXISTS idx_playlists_source_provider
    ON playlists(source_provider)
    WHERE source_provider IS NOT NULL;
CREATE INDEX IF NOT EXISTS idx_playlists_provider_name ON playlists(provider_instance_name);
CREATE INDEX IF NOT EXISTS idx_playlists_created_at ON playlists(created_at DESC);

CREATE TRIGGER update_playlists_updated_at
    BEFORE UPDATE ON playlists
    FOR EACH ROW
    EXECUTE FUNCTION update_updated_at_column();