-- Cheap fingerprint (file names, sizes and modification times) used to skip
-- content hashing of soundtracks that have not changed since the last sync.
ALTER TABLE soundtrack ADD COLUMN fingerprint TEXT NOT NULL DEFAULT '';

-- Play queues. Every client has its own queue, identified by the queue's UUID.
-- Ended queues are kept as history.
CREATE TABLE queue (
    uuid UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    current_song INT4 NOT NULL DEFAULT -1,
    -- The last random song, added to the queue by /music/addQue.
    last_fetched_song_uuid UUID NULL,
    started_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    ended_at TIMESTAMPTZ NULL
);
CREATE INDEX idx_queue_active ON queue(uuid) WHERE ended_at IS NULL;

-- song_uuid has no foreign key: a sync can delete songs. The names are kept for the history.
CREATE TABLE queue_song (
    queue_uuid UUID NOT NULL REFERENCES queue(uuid) ON DELETE CASCADE,
    song_no INT4 NOT NULL,
    song_uuid UUID NOT NULL,
    soundtrack_name VARCHAR NOT NULL,
    song_name VARCHAR NOT NULL,
    added_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    PRIMARY KEY (queue_uuid, song_no)
);