Frontend: Don't change UTC when original time was in UTC #1668

frontend/src/dialog/photo/details.vue

@@ -472,7 +472,13 @@ export default {
         return;
       }
 
-      const utcDate = localDate.toUTC();
+      let utcDate;
+
+      if (this.model.originalTimeZoneUTC()) {
+        utcDate = this.model.utcDate();
+      } else {
+        utcDate = localDate.toUTC();
+      }
 
       this.localTime = localDate.toFormat("HH:mm:ss");
       this.utcTime = utcDate.toFormat("HH:mm:ss");
@@ -494,10 +500,12 @@ export default {
         includeOffset: false,
       }) + "Z";
 
-      this.model.TakenAt = localDate.toUTC().toISO({
-        suppressMilliseconds: true,
-        includeOffset: false,
-      }) + "Z";
+      if (!this.model.originalTimeZoneUTC()) {
+        this.model.TakenAt = localDate.toUTC().toISO({
+          suppressMilliseconds: true,
+          includeOffset: false,
+        }) + "Z";
+      }
     },
     left() {
       this.$emit('next');

frontend/src/model/photo.js

@@ -52,6 +52,7 @@ export const TypeRaw = "raw";
 export const YearUnknown = -1;
 export const MonthUnknown = -1;
 export const DayUnknown = -1;
+export const TimeZoneUTC = "UTC";
 
 const num = "numeric";
 const short = "short";
@@ -231,7 +232,13 @@ export class Photo extends RestModel {
       time = this.TakenAtLocal.substr(11, 8);
     }
 
-    return `${date}T${time}`;
+    let iso = `${date}T${time}`;
+
+    if (this.originalTimeZoneUTC()) {
+      iso += "Z";
+    }
+
+    return iso;
   }
 
   getTimeZone() {
@@ -239,17 +246,30 @@ export class Photo extends RestModel {
       return this.TimeZone;
     }
 
-    return "utc";
+    return "";
+  }
+
+  originalTimeZoneUTC() {
+    const tz = this.originalValue("TimeZone");
+
+    if (tz) {
+      return tz.toLowerCase() === TimeZoneUTC.toLowerCase();
+    }
+
+    return false;
   }
 
   localDate(time) {
-    if (!this.TakenAtLocal) {
+    if (!this.TakenAtLocal || this.getTimeZone().toLowerCase() === TimeZoneUTC.toLowerCase()) {
       return this.utcDate();
+    } else if (this.getTimeZone() === "") {
+      return DateTime.fromISO(this.localDateString(time));
     }
 
     let zone = this.getTimeZone();
+    let iso = this.localDateString(time);
 
-    return DateTime.fromISO(this.localDateString(time), { zone });
+    return DateTime.fromISO(iso, { zone });
   }
 
   utcDate() {

frontend/tests/unit/model/photo_test.js

@@ -213,7 +213,7 @@ describe("model/photo", () => {
     };
     const photo = new Photo(values);
     const result = photo.localDateString();
-    assert.equal(result, "2012-07-08T14:45:39");
+    assert.equal(result, "2012-07-08T14:45:39Z");
   });
 
   it("should get local date", () => {
@@ -228,6 +228,20 @@ describe("model/photo", () => {
     assert.equal(String(result), "2012-07-08T14:45:39.000Z");
   });
 
+  it("UTC", () => {
+    const values = {
+      ID: 9999,
+      Title: "Video",
+      TakenAt: "2012-07-08T14:45:39Z",
+      TakenAtLocal: "2012-07-08T14:45:39Z",
+      TimeZone: "UTC",
+    };
+    const photo = new Photo(values);
+    assert.equal(String(photo.localDateString("10:00:00")), "2012-07-08T10:00:00Z");
+    const result = photo.localDate();
+    assert.equal(String(result), "2012-07-08T14:45:39.000Z");
+  });
+
   it("should get date string", () => {
     const values = {
       ID: 5,