From e89c84f45f79144106e9b7b62c72898b3cbd9c52 Mon Sep 17 00:00:00 2001
From: stz184 <ivanov.bg@gmail.com>
Date: Fri, 24 Jul 2020 20:37:58 +0300
Subject: [PATCH] When a photo is deleted or moved on the file system, the
 coresponding cache folder and database record are deleted. fixes #56

---
 api/scanner/cleanup_media.go | 66 ++++++++++++++++++++++++++++++++++++
 api/scanner/scanner_album.go |  5 +++
 2 files changed, 71 insertions(+)
 create mode 100644 api/scanner/cleanup_media.go

diff --git a/api/scanner/cleanup_media.go b/api/scanner/cleanup_media.go
new file mode 100644
index 00000000..83b8c054
--- /dev/null
+++ b/api/scanner/cleanup_media.go
@@ -0,0 +1,66 @@
+package scanner
+
+import (
+	"database/sql"
+	"github.com/pkg/errors"
+	"github.com/viktorstrate/photoview/api/graphql/models"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+)
+
+func CleanupMedia(db *sql.DB, albumId int, albumPhotos []*models.Media) []error {
+	if len(albumPhotos) == 0 {
+		return nil
+	}
+
+	albumPhotoIds := make([]interface{}, len(albumPhotos))
+	for i, photo := range albumPhotos {
+		albumPhotoIds[i] = photo.MediaID
+	}
+
+	// Delete missing photos
+	media_args := make([]interface{}, 0)
+	media_args = append(media_args, albumId)
+	media_args = append(media_args, albumPhotoIds...)
+
+	media_questions := strings.Repeat("?,", len(albumPhotoIds))[:len(albumPhotoIds)*2-1]
+
+	rows, err := db.Query(
+		"SELECT media_id FROM media WHERE album_id = ? AND media_id NOT IN ("+media_questions+")",
+		media_args...,
+	)
+	if err != nil {
+		return []error{errors.Wrap(err, "get media files to be deleted from database")}
+	}
+	defer rows.Close()
+
+	deleteErrors := make([]error, 0)
+
+	deleted_media_ids := make([]interface{}, 0)
+	for rows.Next() {
+		var media_id int
+		if err := rows.Scan(&media_id); err != nil {
+			deleteErrors = append(deleteErrors, errors.Wrapf(err, "parse media to be removed (media_id %d)", media_id))
+			continue
+		}
+
+		deleted_media_ids = append(deleted_media_ids, media_id)
+		cache_path := path.Join(PhotoCache(), strconv.Itoa(albumId), strconv.Itoa(media_id))
+		err := os.RemoveAll(cache_path)
+		if err != nil {
+			deleteErrors = append(deleteErrors, errors.Wrapf(err, "delete unused cache folder (%s)", cache_path))
+		}
+	}
+
+	if len(deleted_media_ids) > 0 {
+		media_questions = strings.Repeat("?,", len(deleted_media_ids))[:len(deleted_media_ids)*2-1]
+
+		if _, err := db.Exec("DELETE FROM media WHERE media_id IN ("+media_questions+")", deleted_media_ids...); err != nil {
+			deleteErrors = append(deleteErrors, errors.Wrap(err, "delete old media from database"))
+		}
+	}
+
+	return deleteErrors
+}
diff --git a/api/scanner/scanner_album.go b/api/scanner/scanner_album.go
index fcdc44d9..552d36e2 100644
--- a/api/scanner/scanner_album.go
+++ b/api/scanner/scanner_album.go
@@ -67,6 +67,11 @@ func scanAlbum(album *models.Album, cache *AlbumScannerCache, db *sql.DB) {
 		}
 	}
 
+	cleanup_errors := CleanupMedia(db, album.AlbumID, albumPhotos)
+	for _, err := range cleanup_errors {
+		ScannerError("Failed to delete old media: %s", err)
+	}
+
 	if album_has_changes {
 		timeoutDelay := 2000
 		notification.BroadcastNotification(&models.Notification{