-- name: EnqueueScrobble :execrows
-- Idempotent: if a row exists for this play_event_id, ON CONFLICT does nothing
-- and the affected-rows count is 0. Caller (MaybeEnqueue) doesn't treat 0 as
-- an error.
INSERT INTO scrobble_queue (user_id, play_event_id, status)
VALUES ($1, $2, 'pending')
ON CONFLICT (play_event_id) DO NOTHING;

-- name: ListPendingScrobbles :many
-- Worker pulls up to N pending rows whose next_attempt_at has passed.
-- Joins play_events + tracks/albums/artists + users so the worker can
-- assemble the LB Listen payload in one round-trip.
SELECT
    sq.id           AS queue_id,
    sq.user_id      AS user_id,
    sq.play_event_id AS play_event_id,
    sq.attempts     AS attempts,
    u.listenbrainz_token AS lb_token,
    u.listenbrainz_enabled AS lb_enabled,
    pe.started_at   AS started_at,
    t.title         AS track_title,
    t.duration_ms   AS track_duration_ms,
    t.mbid          AS track_mbid,
    al.title        AS album_title,
    al.mbid         AS album_mbid,
    ar.name         AS artist_name,
    ar.mbid         AS artist_mbid
FROM scrobble_queue sq
JOIN users u       ON u.id  = sq.user_id
JOIN play_events pe ON pe.id = sq.play_event_id
JOIN tracks t      ON t.id  = pe.track_id
JOIN albums al     ON al.id = t.album_id
JOIN artists ar    ON ar.id = t.artist_id
WHERE sq.status = 'pending'
  AND sq.next_attempt_at <= now()
ORDER BY sq.next_attempt_at
LIMIT $1;

-- name: MarkScrobbleSent :exec
-- Successful submit. Delete the queue row AND stamp play_events.scrobbled_at
-- in one statement via a CTE so partial failure is impossible.
WITH del AS (
    DELETE FROM scrobble_queue
    WHERE scrobble_queue.id = $1
    RETURNING play_event_id
)
UPDATE play_events
SET scrobbled_at = now()
WHERE play_events.id = (SELECT play_event_id FROM del);

-- name: RescheduleScrobble :exec
-- After a transient failure: increment attempts, schedule next attempt,
-- record the error.
UPDATE scrobble_queue
SET attempts        = attempts + 1,
    next_attempt_at = $2,
    last_error      = $3
WHERE id = $1;

-- name: MarkScrobbleRetryAfter :exec
-- After a 429: schedule next attempt per LB's Retry-After header, but do NOT
-- increment attempts (the server told us to wait, not that we failed).
UPDATE scrobble_queue
SET next_attempt_at = $2
WHERE id = $1;

-- name: MarkScrobbleFailed :exec
-- After a permanent failure (4xx, exhausted retries, auth) — mark failed
-- and keep the row for diagnostics.
UPDATE scrobble_queue
SET status     = 'failed',
    last_error = $2
WHERE id = $1;