-- Re-acquisition of missing files (milestone #290, reworked for M502 #5520).
-- The unit is the album: an album whose files went missing becomes a want for
-- its release group, and the search schedule (#5521) looks for it.

-- name: GetReacquisitionSettings :one
SELECT * FROM reacquisition_settings WHERE id = true;

-- name: UpdateReacquisitionSettings :one
-- Whole-row write from the admin card; the CHECKs in migration 0056 are the
-- validation, so a bad value fails loudly rather than being clamped silently.
UPDATE reacquisition_settings
   SET enabled      = sqlc.arg(enabled),
       grace_hours  = sqlc.arg(grace_hours),
       max_per_pass = sqlc.arg(max_per_pass)
 WHERE id = true
RETURNING *;

-- name: ListAlbumsDueReacquisition :many
-- The sweeper's selection. An album qualifies when:
--
--   * it still has at least one track whose file has been missing longer than
--     the grace window. Measured on missing_since, which reconcile never
--     re-stamps (#2523), so it is a genuine "gone since" clock;
--   * MusicBrainz can name it: the artist has an MBID, and the album a
--     release MBID or a release group. The release MBID is only ever used to
--     find the group, and 238 albums matched to a group carried no release
--     id, so their losses were never wanted back (#6167). Albums failing this
--     are counted separately (CountAlbumsMissingWithoutMbid);
--   * it is on the wanted list (#5567): an album taken off the list, or
--     dropped into the library by hand, is not fetched back;
--   * no want already covers it: none open, and none held since its files
--     went missing. A want held after the loss means the library has a full
--     copy despite the missing rows (#5245), so asking again would loop.
SELECT albums.id                 AS album_id,
       albums.title              AS album_title,
       albums.mbid               AS album_mbid,
       albums.release_group_mbid AS album_release_group_mbid,
       artists.name              AS artist_name,
       artists.mbid              AS artist_mbid,
       COUNT(tracks.id)::bigint  AS missing_track_count,
       MAX(tracks.missing_since)::timestamptz AS last_missing_since
  FROM albums
  JOIN artists ON artists.id = albums.artist_id
  JOIN tracks  ON tracks.album_id = albums.id
 WHERE tracks.missing_since IS NOT NULL
   AND tracks.missing_since <= now() - make_interval(hours => sqlc.arg(grace_hours)::int)
   AND (albums.mbid IS NOT NULL OR albums.release_group_mbid IS NOT NULL)
   AND artists.mbid IS NOT NULL
 GROUP BY albums.id, albums.title, albums.mbid, albums.release_group_mbid,
          artists.name, artists.mbid
HAVING EXISTS (
       SELECT 1 FROM wants w
        WHERE w.album_id = albums.id OR w.release_group_mbid = albums.release_group_mbid)
   AND NOT EXISTS (
       SELECT 1 FROM wants w
        WHERE (w.album_id = albums.id OR w.release_group_mbid = albums.release_group_mbid)
          AND (w.fulfilled_at IS NULL OR w.fulfilled_at > MAX(tracks.missing_since)))
 ORDER BY MIN(tracks.missing_since), albums.sort_title
 LIMIT sqlc.arg(page_limit);

-- name: CountAlbumsMissingWithoutMbid :one
-- Albums with missing files that can never be wanted automatically because
-- nothing identifies them to MusicBrainz. Surfaced on the admin card so the
-- gap is visible: silently doing nothing for these would read as broken.
SELECT COUNT(DISTINCT albums.id)::bigint
  FROM albums
  JOIN artists ON artists.id = albums.artist_id
  JOIN tracks  ON tracks.album_id = albums.id
 WHERE tracks.missing_since IS NOT NULL
   AND ((albums.mbid IS NULL AND albums.release_group_mbid IS NULL) OR artists.mbid IS NULL);

-- name: WantMissingAlbum :one
-- Records an album with missing files as wanted. A held want for the same
-- group is reopened; an open one is left as it is, and no row comes back.
INSERT INTO wants (release_group_mbid, artist_mbid, artist_name, title, reason, album_id)
VALUES (sqlc.arg(release_group_mbid), sqlc.arg(artist_mbid), sqlc.arg(artist_name),
        sqlc.arg(title), 'missing', sqlc.arg(album_id))
ON CONFLICT (release_group_mbid) DO UPDATE
   SET reason       = 'missing',
       album_id     = EXCLUDED.album_id,
       wanted_at    = now(),
       fulfilled_at = NULL,
       updated_at   = now()
 WHERE wants.fulfilled_at IS NOT NULL
RETURNING *;

-- name: GetWantsForAlbums :many
-- What the wanted list says about each album on the missing-files page.
SELECT a.id AS album_id, w.id AS want_id, w.wanted_at, w.fulfilled_at
  FROM albums a
  JOIN wants w ON w.album_id = a.id OR w.release_group_mbid = a.release_group_mbid
 WHERE a.id = ANY(sqlc.arg(album_ids)::uuid[])
 ORDER BY w.wanted_at DESC;