ds-galo/backend/internal/photos/store.go

package photos

import (
	"context"
	"encoding/json"
	"errors"
	"strings"
	"time"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"
	"github.com/jackc/pgx/v5/pgxpool"

	"galo/internal/auth"
	"galo/internal/models"
)

var ErrNotFound = errors.New("photo not found")

type Store struct {
	pool *pgxpool.Pool
}

func NewStore(pool *pgxpool.Pool) *Store { return &Store{pool: pool} }

// photoColumns selects photo rows together with the keys and physical facts of
// their bound objects (original, thumb, preview) and the original's size,
// dimensions and mime type.
const photoColumns = `p.id, COALESCE(p.album_id, ''), p.uploader_id,
	COALESCE(o_o.storage_key, ''),
	COALESCE(o_t.storage_key, ''),
	COALESCE(o_m.storage_key, ''),
	COALESCE(o_p.storage_key, ''),
	COALESCE(o_pb.storage_key, ''),
	p.original_filename, COALESCE(o_o.size, 0), COALESCE(o_o.width, 0), COALESCE(o_o.height, 0), COALESCE(o_o.mime_type, ''),
	p.kind, COALESCE(p.duration_ms, 0),
	p.taken_at, p.latitude, p.longitude, COALESCE(p.caption, ''), p.created_at,
	u.id, u.name, COALESCE(u.avatar_url, ''),
	(SELECT count(*) FROM likes l WHERE l.photo_id = p.id),
	(SELECT count(*) FROM comments c WHERE c.photo_id = p.id),
	EXISTS(SELECT 1 FROM likes l WHERE l.photo_id = p.id AND l.user_id = $2),
	COALESCE(p.exif, '{}'::jsonb)::text, p.deleted_at,
	COALESCE((SELECT json_agg(json_build_object('id', t.id, 'name', t.name) ORDER BY lower(t.name))
		FROM photo_tags pt JOIN tags t ON t.id = pt.tag_id
		WHERE pt.photo_id = p.id AND t.user_id = $2), '[]')::text`

const photoJoins = `
	LEFT JOIN photo_objects po_o ON po_o.photo_id = p.id AND po_o.role = 'original'
	LEFT JOIN objects o_o ON o_o.id = po_o.object_id
	LEFT JOIN photo_objects po_t ON po_t.photo_id = p.id AND po_t.role = 'thumb'
	LEFT JOIN objects o_t ON o_t.id = po_t.object_id
	LEFT JOIN photo_objects po_m ON po_m.photo_id = p.id AND po_m.role = 'medium'
	LEFT JOIN objects o_m ON o_m.id = po_m.object_id
	LEFT JOIN photo_objects po_p ON po_p.photo_id = p.id AND po_p.role = 'preview'
	LEFT JOIN objects o_p ON o_p.id = po_p.object_id
	LEFT JOIN photo_objects po_pb ON po_pb.photo_id = p.id AND po_pb.role = 'playback'
	LEFT JOIN objects o_pb ON o_pb.id = po_pb.object_id`

func scanPhoto(row pgx.Row) (*models.Photo, error) {
	var p models.Photo
	var exifText, tagsText string
	err := row.Scan(&p.ID, &p.AlbumID, &p.UploaderID, &p.StorageKey,
		&p.ThumbKey, &p.MediumKey, &p.PreviewKey, &p.PlaybackKey,
		&p.OriginalFilename, &p.Size, &p.Width, &p.Height, &p.MimeType,
		&p.Kind, &p.DurationMS,
		&p.TakenAt, &p.Latitude, &p.Longitude, &p.Caption, &p.CreatedAt,
		&p.Uploader.ID, &p.Uploader.Name, &p.Uploader.AvatarURL,
		&p.LikesCount, &p.CommentsCount, &p.LikedByMe, &exifText, &p.DeletedAt, &tagsText)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	setExif(&p, exifText)
	setTags(&p, tagsText)
	return &p, nil
}

func setTags(p *models.Photo, raw string) {
	if raw == "" || raw == "null" || raw == "[]" {
		return
	}
	var tags []models.Tag
	if err := json.Unmarshal([]byte(raw), &tags); err == nil && len(tags) > 0 {
		p.Tags = tags
	}
}

func setExif(p *models.Photo, raw string) {
	if raw == "" || raw == "null" || raw == "{}" {
		return
	}
	var m map[string]any
	if err := json.Unmarshal([]byte(raw), &m); err == nil && len(m) > 0 {
		p.EXIF = m
	}
}

// CreateWithOriginal records a new photo together with its pending original
// object, the original binding and a variant job — all in one transaction. The
// caller stores the bytes and then activates the object. The metadata layer is
// the ledger of record; the storage layer follows.
func (s *Store) CreateWithOriginal(ctx context.Context, p *models.Photo, obj *Object) error {
	exifJSON, err := json.Marshal(p.EXIF)
	if err != nil || len(exifJSON) == 0 {
		exifJSON = []byte("{}")
	}
	tx, err := s.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer func() { _ = tx.Rollback(ctx) }()

	if _, err := tx.Exec(ctx,
		`INSERT INTO objects (id, storage_key, mime_type, size, width, height, checksum, state)
		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8)`,
		obj.ID, obj.StorageKey, obj.MimeType, obj.Size, obj.Width, obj.Height, obj.Checksum, ObjectPending); err != nil {
		return err
	}
	if err := tx.QueryRow(ctx,
		`INSERT INTO photos (id, album_id, uploader_id, original_filename, taken_at, latitude, longitude, caption, exif, kind, duration_ms)
		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9::jsonb, $10, $11)
		 RETURNING created_at`,
		p.ID, p.AlbumID, p.UploaderID, p.OriginalFilename, p.TakenAt, p.Latitude, p.Longitude, p.Caption, string(exifJSON),
		mediaKind(p.Kind), p.DurationMS,
	).Scan(&p.CreatedAt); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx,
		`INSERT INTO photo_objects (photo_id, object_id, role) VALUES ($1, $2, $3)`,
		p.ID, obj.ID, RoleOriginal); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx,
		`INSERT INTO variant_jobs (photo_id, kind) VALUES ($1, $2) ON CONFLICT (photo_id) DO NOTHING`,
		p.ID, mediaKind(p.Kind)); err != nil {
		return err
	}
	return tx.Commit(ctx)
}

// DeleteUpload rolls back a failed upload: the photo (and its bindings and job)
// plus the pending object row are removed.
func (s *Store) DeleteUpload(ctx context.Context, photoID, objectID string) error {
	tx, err := s.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer func() { _ = tx.Rollback(ctx) }()
	if _, err := tx.Exec(ctx, `DELETE FROM photos WHERE id = $1`, photoID); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `DELETE FROM objects WHERE id = $1`, objectID); err != nil {
		return err
	}
	return tx.Commit(ctx)
}

func (s *Store) GetByID(ctx context.Context, id, viewerID string) (*models.Photo, error) {
	return scanPhoto(s.pool.QueryRow(ctx,
		`SELECT `+photoColumns+`
		 FROM photos p JOIN users u ON u.id = p.uploader_id`+photoJoins+`
		 WHERE p.id = $1`, id, viewerID))
}

type ListParams struct {
	AlbumID string
	Viewer  string
	Cursor  string
	Since   *time.Time
	Limit   int
}

func (s *Store) List(ctx context.Context, in ListParams) ([]models.Photo, error) {
	if in.Limit <= 0 || in.Limit > 100 {
		in.Limit = 50
	}
	rows, err := s.pool.Query(ctx,
		`SELECT `+photoColumns+`
		 FROM photos p JOIN users u ON u.id = p.uploader_id`+photoJoins+`
		 WHERE p.album_id = $1
		   AND p.deleted_at IS NULL
		   AND ($3 = '' OR (p.created_at, p.id) < (SELECT created_at, id FROM photos WHERE id = $3))
		   AND ($4::timestamptz IS NULL OR p.created_at > $4)
		 ORDER BY p.created_at DESC, p.id DESC
		 LIMIT $5`,
		in.AlbumID, in.Viewer, in.Cursor, in.Since, in.Limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	out := []models.Photo{}
	for rows.Next() {
		var p models.Photo
		var exifText, tagsText string
		if err := rows.Scan(&p.ID, &p.AlbumID, &p.UploaderID, &p.StorageKey,
			&p.ThumbKey, &p.MediumKey, &p.PreviewKey, &p.PlaybackKey,
			&p.OriginalFilename, &p.Size, &p.Width, &p.Height, &p.MimeType,
			&p.Kind, &p.DurationMS,
			&p.TakenAt, &p.Latitude, &p.Longitude, &p.Caption, &p.CreatedAt,
			&p.Uploader.ID, &p.Uploader.Name, &p.Uploader.AvatarURL,
			&p.LikesCount, &p.CommentsCount, &p.LikedByMe, &exifText, &p.DeletedAt, &tagsText); err != nil {
			return nil, err
		}
		setExif(&p, exifText)
		setTags(&p, tagsText)
		out = append(out, p)
	}
	return out, rows.Err()
}

func (s *Store) SetDeleted(ctx context.Context, id string, deleted bool) error {
	var tag pgconn.CommandTag
	var err error
	if deleted {
		tag, err = s.pool.Exec(ctx,
			`UPDATE photos SET deleted_at = now() WHERE id = $1 AND deleted_at IS NULL`, id)
	} else {
		tag, err = s.pool.Exec(ctx,
			`UPDATE photos SET deleted_at = NULL WHERE id = $1`, id)
	}
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *Store) UpdateAlbum(ctx context.Context, id, albumID string) error {
	tag, err := s.pool.Exec(ctx,
		`UPDATE photos SET album_id = $2 WHERE id = $1 AND deleted_at IS NULL`, id, albumID)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

// Clone creates a new photo row in albumID that references the same objects as
// src. No storage operation is performed: the clone shares the physical files.
func (s *Store) Clone(ctx context.Context, src *models.Photo, albumID, uploaderID, id string) error {
	exifJSON, err := json.Marshal(src.EXIF)
	if err != nil || len(exifJSON) == 0 {
		exifJSON = []byte("{}")
	}
	tx, err := s.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer func() { _ = tx.Rollback(ctx) }()

	if _, err := tx.Exec(ctx,
		`INSERT INTO photos (id, album_id, uploader_id, original_filename, taken_at, latitude, longitude, caption, exif, kind, duration_ms)
		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9::jsonb, $10, $11)`,
		id, albumID, uploaderID, src.OriginalFilename, src.TakenAt, src.Latitude, src.Longitude, src.Caption, string(exifJSON),
		mediaKind(src.Kind), src.DurationMS); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx,
		`INSERT INTO photo_objects (photo_id, object_id, role)
		 SELECT $1, object_id, role FROM photo_objects WHERE photo_id = $2`,
		id, src.ID); err != nil {
		return err
	}
	return tx.Commit(ctx)
}

// HardDelete permanently removes the photo row. Bound objects are not touched
// here; the caller marks orphaned objects for collection.
func (s *Store) HardDelete(ctx context.Context, id string) error {
	tag, err := s.pool.Exec(ctx, `DELETE FROM photos WHERE id = $1`, id)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

// ListTrash returns soft-deleted photos from albums the user belongs to, plus
// their own photos whose album no longer exists.
func (s *Store) ListTrash(ctx context.Context, userID string) ([]models.Photo, error) {
	rows, err := s.pool.Query(ctx,
		`SELECT `+photoColumns+`, COALESCE(a.title, '')
		 FROM photos p
		 JOIN users u ON u.id = p.uploader_id
		 LEFT JOIN albums a ON a.id = p.album_id`+photoJoins+`
		 WHERE p.deleted_at IS NOT NULL
		   AND (
		   	(a.id IS NOT NULL AND (a.owner_id = $1 OR EXISTS(
		   		SELECT 1 FROM album_members m WHERE m.album_id = a.id AND m.user_id = $1)))
		   	OR (p.album_id IS NULL AND p.uploader_id = $1)
		   )
		 ORDER BY p.deleted_at DESC
		 LIMIT 200`,
		userID, userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	out := []models.Photo{}
	for rows.Next() {
		var p models.Photo
		var exifText, tagsText string
		if err := rows.Scan(&p.ID, &p.AlbumID, &p.UploaderID, &p.StorageKey,
			&p.ThumbKey, &p.MediumKey, &p.PreviewKey, &p.PlaybackKey,
			&p.OriginalFilename, &p.Size, &p.Width, &p.Height, &p.MimeType,
			&p.Kind, &p.DurationMS,
			&p.TakenAt, &p.Latitude, &p.Longitude, &p.Caption, &p.CreatedAt,
			&p.Uploader.ID, &p.Uploader.Name, &p.Uploader.AvatarURL,
			&p.LikesCount, &p.CommentsCount, &p.LikedByMe, &exifText, &p.DeletedAt, &p.AlbumTitle, &tagsText); err != nil {
			return nil, err
		}
		setExif(&p, exifText)
		setTags(&p, tagsText)
		out = append(out, p)
	}
	return out, rows.Err()
}

// TrashCount counts soft-deleted photos accessible to the user.
func (s *Store) TrashCount(ctx context.Context, userID string) (int, error) {
	var n int
	err := s.pool.QueryRow(ctx,
		`SELECT count(*) FROM photos p
		 LEFT JOIN albums a ON a.id = p.album_id
		 WHERE p.deleted_at IS NOT NULL
		   AND (
		   	(a.id IS NOT NULL AND (a.owner_id = $1 OR EXISTS(
		   		SELECT 1 FROM album_members m WHERE m.album_id = a.id AND m.user_id = $1)))
		   	OR (p.album_id IS NULL AND p.uploader_id = $1)
		   )`, userID).Scan(&n)
	return n, err
}

// ListTrashIdentities returns every trashed photo accessible to the user
// (no display cap) so a bulk purge can authorize and remove each one.
func (s *Store) ListTrashIdentities(ctx context.Context, userID string) ([]TrashIdentity, error) {
	rows, err := s.pool.Query(ctx,
		`SELECT p.id, COALESCE(p.album_id, ''), p.uploader_id
		 FROM photos p
		 LEFT JOIN albums a ON a.id = p.album_id
		 WHERE p.deleted_at IS NOT NULL
		   AND (
		   	(a.id IS NOT NULL AND (a.owner_id = $1 OR EXISTS(
		   		SELECT 1 FROM album_members m WHERE m.album_id = a.id AND m.user_id = $1)))
		   	OR (p.album_id IS NULL AND p.uploader_id = $1)
		   )
		 ORDER BY p.deleted_at DESC`,
		userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []TrashIdentity{}
	for rows.Next() {
		var it TrashIdentity
		if err := rows.Scan(&it.ID, &it.AlbumID, &it.UploaderID); err != nil {
			return nil, err
		}
		out = append(out, it)
	}
	return out, rows.Err()
}

// RestoreToAlbum reassigns a soft-deleted photo to an album and clears the trash flag.
func (s *Store) RestoreToAlbum(ctx context.Context, id, albumID string) error {
	tag, err := s.pool.Exec(ctx,
		`UPDATE photos SET album_id = $2, deleted_at = NULL WHERE id = $1`, id, albumID)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

// AlbumExists reports whether an album row exists.
func (s *Store) AlbumExists(ctx context.Context, albumID string) (bool, error) {
	var ok bool
	err := s.pool.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM albums WHERE id = $1)`, albumID).Scan(&ok)
	return ok, err
}

func (s *Store) ListTags(ctx context.Context, userID, q string) ([]models.Tag, error) {
	rows, err := s.pool.Query(ctx,
		`SELECT id, name FROM tags
		 WHERE user_id = $1 AND ($2 = '' OR name ILIKE '%' || $2 || '%')
		 ORDER BY lower(name) LIMIT 50`, userID, q)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []models.Tag{}
	for rows.Next() {
		var t models.Tag
		if err := rows.Scan(&t.ID, &t.Name); err != nil {
			return nil, err
		}
		out = append(out, t)
	}
	return out, rows.Err()
}

// EnsureTag returns the user's tag with the given name, creating it if needed.
func (s *Store) EnsureTag(ctx context.Context, userID, name string) (*models.Tag, error) {
	name = strings.TrimSpace(name)
	if name == "" || len(name) > 64 {
		return nil, ErrNotFound
	}
	var t models.Tag
	err := s.pool.QueryRow(ctx,
		`SELECT id, name FROM tags WHERE user_id = $1 AND lower(name) = lower($2)`, userID, name).
		Scan(&t.ID, &t.Name)
	if err == nil {
		return &t, nil
	}
	if !errors.Is(err, pgx.ErrNoRows) {
		return nil, err
	}
	id := auth.NewID()
	err = s.pool.QueryRow(ctx,
		`INSERT INTO tags (id, user_id, name) VALUES ($1,$2,$3) RETURNING id, name`, id, userID, name).
		Scan(&t.ID, &t.Name)
	if err != nil {
		if e2 := s.pool.QueryRow(ctx,
			`SELECT id, name FROM tags WHERE user_id = $1 AND lower(name) = lower($2)`, userID, name).
			Scan(&t.ID, &t.Name); e2 == nil {
			return &t, nil
		}
		return nil, err
	}
	return &t, nil
}

func (s *Store) AttachTag(ctx context.Context, photoID, tagID string) error {
	_, err := s.pool.Exec(ctx,
		`INSERT INTO photo_tags (photo_id, tag_id) VALUES ($1,$2) ON CONFLICT DO NOTHING`, photoID, tagID)
	return err
}

func (s *Store) DetachTag(ctx context.Context, photoID, tagID string) error {
	_, err := s.pool.Exec(ctx,
		`DELETE FROM photo_tags WHERE photo_id = $1 AND tag_id = $2`, photoID, tagID)
	return err
}

func (s *Store) TagOwnedBy(ctx context.Context, tagID, userID string) (bool, error) {
	var ok bool
	err := s.pool.QueryRow(ctx,
		`SELECT EXISTS(SELECT 1 FROM tags WHERE id = $1 AND user_id = $2)`, tagID, userID).Scan(&ok)
	return ok, err
}

func (s *Store) SetCoverIfEmpty(ctx context.Context, albumID, photoID string) {
	_, _ = s.pool.Exec(ctx,
		`UPDATE albums SET cover_photo_id = $2 WHERE id = $1 AND cover_photo_id IS NULL`,
		albumID, photoID)
}

// ClearCoverIfMatches removes the album cover only when it currently points at
// photoID, so a concurrent cover change is not clobbered.
func (s *Store) ClearCoverIfMatches(ctx context.Context, albumID, photoID string) {
	_, _ = s.pool.Exec(ctx,
		`UPDATE albums SET cover_photo_id = NULL WHERE id = $1 AND cover_photo_id = $2`,
		albumID, photoID)
}

func (s *Store) UpdateFilename(ctx context.Context, id, filename string) error {
	tag, err := s.pool.Exec(ctx, `UPDATE photos SET original_filename = $2 WHERE id = $1`, id, filename)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

// SetMediaMeta records probed video facts: duration on the photo and frame
// dimensions on the original object.
func (s *Store) SetMediaMeta(ctx context.Context, photoID, objectID string, durationMS int64, width, height int) error {
	tx, err := s.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer func() { _ = tx.Rollback(ctx) }()
	if _, err := tx.Exec(ctx, `UPDATE photos SET duration_ms = $2 WHERE id = $1`, photoID, durationMS); err != nil {
		return err
	}
	if _, err := tx.Exec(ctx, `UPDATE objects SET width = $2, height = $3 WHERE id = $1`, objectID, width, height); err != nil {
		return err
	}
	return tx.Commit(ctx)
}

type backfillRow struct {
	ID         string
	StorageKey string
}

// BackfillEXIF re-reads the original object of every photo with empty exif and
// fills the exif/geo fields on the photo.
func (s *Store) BackfillEXIF(ctx context.Context, fetch func(context.Context, string) ([]byte, error)) (int, error) {
	rows, err := s.pool.Query(ctx,
		`SELECT p.id, o.storage_key
		 FROM photos p
		 JOIN photo_objects po ON po.photo_id = p.id AND po.role = 'original'
		 JOIN objects o ON o.id = po.object_id
		 WHERE p.exif IS NULL OR p.exif = '{}'::jsonb
		 ORDER BY p.created_at`)
	if err != nil {
		return 0, err
	}
	var pending []backfillRow
	for rows.Next() {
		var r backfillRow
		if err := rows.Scan(&r.ID, &r.StorageKey); err != nil {
			rows.Close()
			return 0, err
		}
		pending = append(pending, r)
	}
	rows.Close()
	if err := rows.Err(); err != nil {
		return 0, err
	}

	updated := 0
	for _, r := range pending {
		data, err := fetch(ctx, r.StorageKey)
		if err != nil {
			continue
		}
		meta := extractEXIF(data)
		if len(meta.Attributes) == 0 && meta.TakenAt == nil && meta.Latitude == nil && meta.Longitude == nil {
			continue
		}
		attrs, err := json.Marshal(meta.Attributes)
		if err != nil || len(attrs) == 0 {
			attrs = []byte("{}")
		}
		_, err = s.pool.Exec(ctx,
			`UPDATE photos SET exif = $2::jsonb,
				taken_at = COALESCE(taken_at, $3),
				latitude = COALESCE(latitude, $4),
				longitude = COALESCE(longitude, $5)
			 WHERE id = $1`,
			r.ID, string(attrs), meta.TakenAt, meta.Latitude, meta.Longitude)
		if err != nil {
			continue
		}
		updated++
	}
	return updated, nil
}