Converting time zone settings if a non supported one was picked #139

TrackMyIndoorWorkout · Mar 4, 2023 · 21e8843 · 21e8843
1 parent 60f2eb3
commit 21e8843
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Showing 3 changed files with 48 additions and 2 deletions.
diff --git a/lib/preferences/generic.dart b/lib/preferences/generic.dart
@@ -11,7 +11,8 @@ const preferencesVersionExclusiveSportOrDeviceLeaderboard = 7;
 const preferencesVersionTimeDisplayMode = 8;
 const preferencesVersionNoWhitespaceInNetworkAddresses = 9;
 const preferencesVersionPerMetricColoringByZone = 10;
-const preferencesVersionDefault = preferencesVersionPerMetricColoringByZone;
+const preferencesVersionDefaultingOldTimeZone = 11;
+const preferencesVersionDefault = preferencesVersionDefaultingOldTimeZone;
 const preferencesVersionNext = preferencesVersionDefault + 1;
 
 const intTagPostfix = "_int";
diff --git a/lib/utils/init_preferences.dart b/lib/utils/init_preferences.dart
@@ -64,6 +64,7 @@ import '../preferences/workout_mode.dart';
 import '../preferences/zone_index_display_coloring.dart';
 import '../utils/logging.dart';
 import '../utils/preferences.dart';
+import '../utils/time_zone.dart';
 import 'constants.dart';
 
 Future<void> migrateStringIntegerPreference(
@@ -375,6 +376,21 @@ Future<BasePrefService> initPreferences() async {
     }
   }
 
+  if (prefVersion <= preferencesVersionDefaultingOldTimeZone) {
+    final enforcedTimeZone =
+        prefService.get<String>(enforcedTimeZoneTag) ?? enforcedTimeZoneDefault;
+
+    if (enforcedTimeZone != enforcedTimeZoneDefault) {
+      final closestTimeZone = getClosestTimeZone(enforcedTimeZone);
+      if (closestTimeZone != enforcedTimeZone) {
+        prefService.set<String>(enforcedTimeZoneTag, closestTimeZone);
+      }
+    }
+
+    // Activities have stored timeZone, but we would need to convert those
+    // only if TrackManager.getTrack would get the timeZone besides the sport
+  }
+
   await prefService.set<int>(preferencesVersionTag, preferencesVersionNext);
 
   for (var sport in SportSpec.sportPrefixes) {

diff --git a/lib/utils/time_zone.dart b/lib/utils/time_zone.dart
@@ -1,7 +1,9 @@
+import 'package:collection/collection.dart';
 import 'package:flutter_timezone/flutter_timezone.dart';
 import 'package:get/get.dart';
 import 'package:pref/pref.dart';
 import 'package:timezone/timezone.dart' as tz;
+import 'package:tuple/tuple.dart';
 import '../preferences/enforced_time_zone.dart';
 
 Future<String> getTimeZone() async {
@@ -12,7 +14,34 @@ Future<String> getTimeZone() async {
     return timeZone;
   }
 
-  return await FlutterTimezone.getLocalTimezone();
+  return getClosestTimeZone(await FlutterTimezone.getLocalTimezone());
+}
+
+int timeZoneOffset(String timeZoneName) {
+  DateTime? now;
+  if (timeZoneName == enforcedTimeZoneDefault ||
+      !tz.timeZoneDatabase.locations.containsKey(timeZoneName)) {
+    now = DateTime.now();
+  } else {
+    final location = tz.getLocation(getClosestTimeZone(timeZoneName));
+    now = tz.TZDateTime.now(location);
+  }
+
+  return now.timeZoneOffset.inMinutes;
+}
+
+String getClosestTimeZone(String timeZoneName) {
+  if (tz.timeZoneDatabase.locations.containsKey(timeZoneName)) {
+    return timeZoneName;
+  }
+
+  final timeOffset = timeZoneOffset(timeZoneName);
+  return tz.timeZoneDatabase.locations.entries
+      .map((loc) => Tuple2<String, int>(
+          loc.key, (loc.value.currentTimeZone.offset ~/ 60000 - timeOffset).abs()))
+      .sortedByCompare((loc) => loc.item2, (int o1, int o2) => o1.compareTo(o2))
+      .first
+      .item1;
 }
 
 Future<List<String>> getSortedTimezones() async {