feat(server): use the earliest date between file creation and modification timestamps when missing exif tags (#14874)

* feat(server): Use the earliest date between file creation and modification timestamps when missing exif tags

* PR fixes

* PR fixes

* Switch log to debug

* fix linter for min date

* apply prettier

server/src/services/metadata.service.ts

@@ -450,14 +450,14 @@ export class MetadataService extends BaseService {
         }
       } else {
         const motionAssetId = this.cryptoRepository.randomUUID();
-        const createdAt = asset.fileCreatedAt ?? asset.createdAt;
+        const dates = this.getDates(asset, tags);
         motionAsset = await this.assetRepository.create({
           id: motionAssetId,
           libraryId: asset.libraryId,
           type: AssetType.VIDEO,
-          fileCreatedAt: createdAt,
-          fileModifiedAt: asset.fileModifiedAt,
-          localDateTime: createdAt,
+          fileCreatedAt: dates.dateTimeOriginal,
+          fileModifiedAt: dates.modifyDate,
+          localDateTime: dates.localDateTime,
           checksum,
           ownerId: asset.ownerId,
           originalPath: StorageCore.getAndroidMotionPath(asset, motionAssetId),
@@ -589,9 +589,12 @@ export class MetadataService extends BaseService {
     let dateTimeOriginal = dateTime?.toDate();
     let localDateTime = dateTime?.toDateTime().setZone('UTC', { keepLocalTime: true }).toJSDate();
     if (!localDateTime || !dateTimeOriginal) {
-      this.logger.warn(`Asset ${asset.id} has no valid date, falling back to asset.fileCreatedAt`);
-      dateTimeOriginal = asset.fileCreatedAt;
-      localDateTime = asset.fileCreatedAt;
+      this.logger.debug(
+        `No valid date found in exif tags from asset ${asset.id}, falling back to earliest timestamp between file creation and file modification`,
+      );
+      const earliestDate = this.earliestDate(asset.fileModifiedAt, asset.fileCreatedAt);
+      dateTimeOriginal = earliestDate;
+      localDateTime = earliestDate;
     }
 
     this.logger.verbose(`Asset ${asset.id} has a local time of ${localDateTime.toISOString()}`);
@@ -609,6 +612,10 @@ export class MetadataService extends BaseService {
     };
   }
 
+  private earliestDate(a: Date, b: Date) {
+    return new Date(Math.min(a.valueOf(), b.valueOf()));
+  }
+
   private async getGeo(tags: ImmichTags, reverseGeocoding: SystemConfig['reverseGeocoding']) {
     let latitude = validate(tags.GPSLatitude);
     let longitude = validate(tags.GPSLongitude);