package query

import (
	"errors"
	"fmt"

	"github.com/photoprism/photoprism/internal/entity"
	"github.com/photoprism/photoprism/internal/form"
)

// SelectedPhotos finds photos based on the given selection form, e.g. for adding them to an album.
func SelectedPhotos(f form.Selection) (results entity.Photos, err error) {
	if f.Empty() {
		return results, errors.New("no items selected")
	}

	var concat string

	switch DbDialect() {
	case MySQL:
		concat = "CONCAT(a.path, '/%')"
	case SQLite3:
		concat = "a.path || '/%'"
	default:
		return results, fmt.Errorf("unknown sql dialect: %s", DbDialect())
	}

	where := fmt.Sprintf(`photos.photo_uid IN (?) 
		OR photos.place_id IN (?) 
		OR photos.photo_uid IN (SELECT photo_uid FROM files WHERE file_uid IN (?))
		OR photos.photo_path IN (
			SELECT a.path FROM folders a WHERE a.folder_uid IN (?) UNION
			SELECT b.path FROM folders a JOIN folders b ON b.path LIKE %s WHERE a.folder_uid IN (?))
		OR photos.photo_uid IN (SELECT photo_uid FROM photos_albums WHERE hidden = 0 AND album_uid IN (?))
		OR photos.id IN (SELECT f.photo_id FROM files f JOIN %s m ON f.file_uid = m.file_uid WHERE f.deleted_at IS NULL AND m.subj_uid IN (?))
		OR photos.id IN (SELECT pl.photo_id FROM photos_labels pl JOIN labels l ON pl.label_id = l.id AND l.deleted_at IS NULL WHERE l.label_uid IN (?))
		OR photos.id IN (SELECT pl.photo_id FROM photos_labels pl JOIN categories c ON c.label_id = pl.label_id JOIN labels lc ON lc.id = c.category_id AND lc.deleted_at IS NULL WHERE lc.label_uid IN (?))`,
		concat, entity.Marker{}.TableName())

	s := UnscopedDb().Table("photos").
		Select("photos.*").
		Where(where, f.Photos, f.Places, f.Files, f.Files, f.Files, f.Albums, f.Subjects, f.Labels, f.Labels)

	if result := s.Scan(&results); result.Error != nil {
		return results, result.Error
	}

	return results, nil
}