From 7abe36f82007dc0128bc758c3f5a5c401c0e6205 Mon Sep 17 00:00:00 2001
From: Carsten Otto <git@c-otto.de>
Date: Sun, 15 Sep 2024 19:33:55 +0200
Subject: [PATCH] fix(server): prefer explicit timezone over GPS based guess

exiftool-vendored sadly treats the offset +00:00 (used in several countries) as unknown
and may return a timezone which is based on GPS coordinates. Because of this, when
one manually fixes the timezone offset to +00:00, this fix is overwritten. With this fix,
we explicitly prefer +00:00 (if set).
---
 server/src/services/metadata.service.spec.ts | 23 +++++++++++++++++++-
 server/src/services/metadata.service.ts      | 10 ++++-----
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/server/src/services/metadata.service.spec.ts b/server/src/services/metadata.service.spec.ts
index 19aaa2ea1a323..2d1397cebf5dc 100644
--- a/server/src/services/metadata.service.spec.ts
+++ b/server/src/services/metadata.service.spec.ts
@@ -1,4 +1,5 @@
 import { BinaryField, ExifDateTime } from 'exiftool-vendored';
+import { DateTime } from 'luxon';
 import { randomBytes } from 'node:crypto';
 import { Stats } from 'node:fs';
 import { constants } from 'node:fs/promises';
@@ -854,10 +855,30 @@ describe(MetadataService.name, () => {
       metadataMock.readTags.mockResolvedValue(tags);
 
       await sut.handleMetadataExtraction({ id: assetStub.image.id });
-      expect(assetMock.getByIds).toHaveBeenCalledWith([assetStub.image.id]);
       expect(assetMock.upsertExif).toHaveBeenCalledWith(
         expect.objectContaining({
           timeZone: 'UTC+0',
+          dateTimeOriginal: DateTime.fromISO('2024-09-01T00:00:00.000Z').toJSDate(),
+        }),
+      );
+    });
+
+    it('should extract +00:00 timezone from raw value despite conflicting GPS location/timezone', async () => {
+      // exiftool-vendored returns a timezone derived from GPS coordinates even though "+00:00" might be set explicitly
+      // https://github.com/photostructure/exiftool-vendored.js/issues/203
+
+      const tags: ImmichTags = {
+        DateTimeOriginal: ExifDateTime.fromISO('2024-09-15T00:00:00.000+00:00'),
+        tz: 'America/Santiago',
+      };
+      assetMock.getByIds.mockResolvedValue([assetStub.image]);
+      metadataMock.readTags.mockResolvedValue(tags);
+
+      await sut.handleMetadataExtraction({ id: assetStub.image.id });
+      expect(assetMock.upsertExif).toHaveBeenCalledWith(
+        expect.objectContaining({
+          timeZone: 'UTC+0',
+          dateTimeOriginal: DateTime.fromISO('2024-09-15T00:00:00.000Z').toJSDate(),
         }),
       );
     });
diff --git a/server/src/services/metadata.service.ts b/server/src/services/metadata.service.ts
index eaa491c3ee7d8..22f4f9f35eb48 100644
--- a/server/src/services/metadata.service.ts
+++ b/server/src/services/metadata.service.ts
@@ -608,12 +608,10 @@ export class MetadataService {
     }
 
     // timezone
-    let timeZone = exifTags.tz ?? null;
-    if (timeZone == null && dateTime?.rawValue?.endsWith('+00:00')) {
-      // exiftool-vendored returns "no timezone" information even though "+00:00" might be set explicitly
-      // https://github.com/photostructure/exiftool-vendored.js/issues/203
-      timeZone = 'UTC+0';
-    }
+    // exiftool-vendored returns "no timezone" information or one derived from GPS coordinates even though "+00:00"
+    // might be set explicitly
+    // https://github.com/photostructure/exiftool-vendored.js/issues/203
+    const timeZone = dateTime?.rawValue?.endsWith('+00:00') ? 'UTC+0' : (exifTags.tz ?? null);
 
     if (timeZone) {
       this.logger.debug(`Asset ${asset.id} timezone is ${timeZone} (via ${exifTags.tzSource})`);