-- name: UpsertAlbum :one
INSERT INTO albums (title, sort_title, artist_id, release_date, mbid, cover_art_path)
VALUES ($1, $2, $3, $4, $5, $6)
ON CONFLICT (mbid) WHERE mbid IS NOT NULL
DO UPDATE SET
    title = EXCLUDED.title,
    sort_title = EXCLUDED.sort_title,
    artist_id = EXCLUDED.artist_id,
    release_date = EXCLUDED.release_date,
    cover_art_path = EXCLUDED.cover_art_path,
    updated_at = now()
RETURNING *;

-- name: GetAlbumByID :one
SELECT * FROM albums WHERE id = $1;

-- name: GetAlbumWithArtist :one
-- Combined fetch for /api/albums/{id}: returns the album row + the
-- joined artist name in a single round trip. Replaces a sequential
-- GetAlbumByID + GetArtistByID pair on the hot detail-page path.
SELECT sqlc.embed(albums), artists.name AS artist_name
FROM albums
JOIN artists ON artists.id = albums.artist_id
WHERE albums.id = $1;

-- name: ListAlbumsByArtistWithTrackCount :many
-- Replaces the N+1 pattern in handleGetArtist (1 + N CountTracksByAlbum
-- per album). Returns each album joined with its track count via a
-- correlated subquery — single round trip regardless of album count.
SELECT sqlc.embed(albums),
       (SELECT count(*) FROM tracks t WHERE t.album_id = albums.id)::bigint
           AS track_count
FROM albums
WHERE albums.artist_id = $1
ORDER BY release_date NULLS LAST, sort_title;

-- name: GetAlbumByArtistAndTitle :one
-- Scanner uses this for the no-mbid dedupe path: resolve-or-create.
SELECT * FROM albums WHERE artist_id = $1 AND title = $2 LIMIT 1;

-- name: ListAlbumsByArtist :many
SELECT * FROM albums WHERE artist_id = $1 ORDER BY release_date NULLS LAST, sort_title;

-- name: ListAlbumsAlphaByName :many
SELECT * FROM albums ORDER BY sort_title LIMIT $1 OFFSET $2;

-- name: ListAlbumsAlphaByArtist :many
-- Sorted by the owning artist's sort_name. Needed by Subsonic's
-- alphabeticalByArtist album list type.
SELECT sqlc.embed(albums), artists.sort_name AS artist_sort_name
FROM albums
JOIN artists ON artists.id = albums.artist_id
ORDER BY artists.sort_name, albums.sort_title
LIMIT $1 OFFSET $2;

-- name: ListAlbumsNewest :many
SELECT * FROM albums ORDER BY created_at DESC LIMIT $1 OFFSET $2;

-- name: ListAlbumsRandom :many
SELECT * FROM albums ORDER BY random() LIMIT $1;

-- name: ListAlbumsByGenre :many
-- Album "belongs to" a genre if any of its tracks carry that genre.
-- Serves Subsonic getAlbumList?type=byGenre.
--
-- Splits tracks.genre on [;,] as of #367. It previously compared the whole
-- column verbatim, so a track tagged "Rock;Pop" was unreachable from EITHER
-- "Rock" or "Pop" — a Subsonic client asking for a genre silently missed
-- every multi-genre track. This also aligns the endpoint with
-- recommendation.sql / discover.sql, which have always split, and with the
-- genre browse index that #367 adds.
--
-- EXISTS rather than JOIN + DISTINCT ON: the lateral split emits one row per
-- (track, genre-fragment), so a join would multiply rows per album and lean
-- on DISTINCT to undo it. EXISTS asks the question directly.
SELECT albums.*
FROM albums
WHERE EXISTS (
    SELECT 1
    FROM tracks
    JOIN LATERAL regexp_split_to_table(coalesce(tracks.genre, ''), '[;,]') AS g(genre) ON true
    WHERE tracks.album_id = albums.id
      AND trim(g.genre) = trim(sqlc.arg(genre)::text)
)
ORDER BY albums.sort_title, albums.id
LIMIT sqlc.arg(lim) OFFSET sqlc.arg(off);

-- name: SearchAlbums :many
SELECT * FROM albums
WHERE title ILIKE '%' || $1 || '%'
ORDER BY sort_title
LIMIT $2 OFFSET $3;

-- name: CountAlbumsMatching :one
SELECT COUNT(*) FROM albums WHERE title ILIKE '%' || $1::text || '%';

-- name: ListRecentlyAddedAlbumsWithArtist :many
-- M6a: recently-added albums joined with artist_name + artist_id for the
-- home-page section. created_at is the row-insert timestamp from the
-- scanner — the closest proxy to "added to library". Stable secondary
-- ordering by id keeps pagination tie-break deterministic.
SELECT sqlc.embed(albums), artists.name AS artist_name
FROM albums
JOIN artists ON artists.id = albums.artist_id
ORDER BY albums.created_at DESC, albums.id
LIMIT $1;

-- name: ListAlbumsAlphaWithArtist :many
-- M6a: alpha-sorted album list joined with artist_name. Used by
-- /api/library/albums for the wrapping-grid page. Stable id-tiebreak.
SELECT sqlc.embed(albums), artists.name AS artist_name
FROM albums
JOIN artists ON artists.id = albums.artist_id
ORDER BY albums.sort_title, albums.id
LIMIT $1 OFFSET $2;

-- name: CountAlbums :one
-- M6a: total album count for the /api/library/albums envelope.
SELECT COUNT(*) FROM albums;

-- name: CountAlbumsByArtist :one
-- Used by request-progress reporting to count how many albums have been
-- ingested for a matched artist while a request is still in flight.
SELECT COUNT(*) FROM albums WHERE artist_id = $1;

-- name: DeleteAlbumIfEmpty :one
-- M7 #372: deletes the album row only when it has no remaining tracks.
-- Used after a track delete to tidy up orphaned albums. RETURNING gives
-- us the artist_id so the service can chain into the artist-empty check.
-- Returns no rows when the album still has tracks; the service treats
-- pgx.ErrNoRows as "album not orphaned, skip cascade".
DELETE FROM albums a
WHERE a.id = $1
  AND NOT EXISTS (SELECT 1 FROM tracks t WHERE t.album_id = a.id)
RETURNING a.id, a.artist_id;

-- name: SetAlbumMbidIfNull :exec
-- M7 #379: heal MBID on existing album rows during rescan. Idempotent —
-- only updates when the existing mbid is NULL.
UPDATE albums
   SET mbid = $2,
       updated_at = now()
 WHERE id = $1 AND mbid IS NULL;

-- name: ListAlbumsMissingMbidWithTrack :many
-- One-shot MBID backfill: returns each album where mbid IS NULL alongside
-- one of its tracks' file_path so the worker can re-read tags. LIMIT
-- supplied by caller for batching/progress purposes.
SELECT a.id          AS album_id,
       a.artist_id   AS artist_id,
       a.title       AS title,
       t.file_path   AS track_file_path
  FROM albums a
  JOIN LATERAL (
    SELECT file_path
      FROM tracks
     WHERE album_id = a.id
     ORDER BY disc_number NULLS LAST, track_number NULLS LAST, id
     LIMIT 1
  ) t ON true
 WHERE a.mbid IS NULL
 ORDER BY a.created_at ASC
 LIMIT $1;

-- name: GetAlbumCoverageRollup :one
-- M7 coverage-gauge: library-wide cover-art coverage rollup for the
-- admin gauge. Single sequential scan with FILTER aggregates —
-- sub-millisecond on realistic libraries. pending_no_mbid is a SUBSET
-- of pending; the UI surfaces it separately so operators can see how
-- many "pending" albums are blocked on missing MBID and won't be
-- helped by another scan.
--
-- Invariant: with_art + pending + settled = total. (pending_no_mbid is
-- not part of the sum — it's a subset of pending, surfaced separately.)
--
-- The IN list below must stay in sync with the cover_art_source CHECK
-- constraint — currently relaxed by migration 0020 to include 'deezer'
-- and 'lastfm', and migration 0030 further relaxed it to any non-empty
-- string. If a new source value is added without updating this query,
-- with_art will silently undercount. Drift #556 caught the deezer +
-- lastfm omission introduced by migration 0020.
SELECT
  COUNT(*)                                                                   AS total,
  COUNT(*) FILTER (WHERE cover_art_source IN
      ('sidecar','embedded','mbcaa','theaudiodb','deezer','lastfm'))         AS with_art,
  COUNT(*) FILTER (WHERE cover_art_source IS NULL)                           AS pending,
  COUNT(*) FILTER (WHERE cover_art_source = 'none')                          AS settled,
  COUNT(*) FILTER (WHERE cover_art_source IS NULL AND mbid IS NULL)          AS pending_no_mbid
FROM albums;

-- name: SetAlbumCoverWithVersion :exec
-- M7 cover-sources: records a successful or settled enrichment with the
-- current sources_version stamp. cover_art_path is NULL when source is
-- 'none' (no file written). Atomic; called per album per pass.
UPDATE albums
   SET cover_art_path            = $2,
       cover_art_source          = $3,
       cover_art_sources_version = $4,
       updated_at                = now()
 WHERE id = $1;


-- name: GetAlbumsByIDs :many
-- Batched lookup used by /api/library/sync to hydrate upsert payloads
-- (#357). Mirror of GetArtistsByIDs.
SELECT * FROM albums WHERE id = ANY($1::uuid[]);
