Update modified/created as unix timestamp if already in that format

Related to #349

lib/core/note_serializer.dart

@@ -33,6 +33,11 @@ abstract class NoteSerializerInterface {
 
 var emojiParser = EmojiParser();
 
+enum DateFormat {
+  Iso8601,
+  UnixTimeStamp,
+}
+
 class NoteSerializationSettings {
   String modifiedKey = "modified";
   String createdKey = "created";
@@ -45,11 +50,16 @@ class NoteSerializationSettings {
 
   SettingsTitle titleSettings = SettingsTitle.Default;
 
+  var modifiedFormat = DateFormat.Iso8601;
+  var createdFormat = DateFormat.Iso8601;
+
   NoteSerializationSettings.fromConfig(NotesFolderConfig config) {
     modifiedKey = config.yamlModifiedKey;
     createdKey = config.yamlCreatedKey;
     tagsKey = config.yamlTagsKey;
     titleSettings = config.titleSettings;
+
+    // FIXME: modified / created format!
   }
   NoteSerializationSettings();
 }
@@ -65,13 +75,27 @@ class NoteSerializer implements NoteSerializerInterface {
     data.body = emojiParser.unemojify(note.body);
 
     if (note.created != null) {
-      data.props[settings.createdKey] = toIso8601WithTimezone(note.created!);
+      switch (settings.createdFormat) {
+        case DateFormat.Iso8601:
+          data.props[settings.createdKey] =
+              toIso8601WithTimezone(note.created!);
+          break;
+        case DateFormat.UnixTimeStamp:
+          data.props[settings.createdKey] = toUnixTimeStamp(note.created!);
+      }
     } else {
       data.props.remove(settings.createdKey);
     }
 
     if (note.modified != null) {
-      data.props[settings.modifiedKey] = toIso8601WithTimezone(note.modified!);
+      switch (settings.modifiedFormat) {
+        case DateFormat.Iso8601:
+          data.props[settings.modifiedKey] =
+              toIso8601WithTimezone(note.modified!);
+          break;
+        case DateFormat.UnixTimeStamp:
+          data.props[settings.modifiedKey] = toUnixTimeStamp(note.modified!);
+      }
     } else {
       data.props.remove(settings.modifiedKey);
     }
@@ -135,7 +159,13 @@ class NoteSerializer implements NoteSerializerInterface {
     for (var possibleKey in modifiedKeyOptions) {
       var val = data.props[possibleKey];
       if (val != null) {
-        note.modified = parseDateTime(val.toString());
+        if (val is int) {
+          note.modified = parseUnixTimeStamp(val);
+          settings.modifiedFormat = DateFormat.UnixTimeStamp;
+        } else {
+          note.modified = parseDateTime(val.toString());
+          settings.modifiedFormat = DateFormat.Iso8601;
+        }
         settings.modifiedKey = possibleKey;
 
         propsUsed.add(possibleKey);
@@ -152,7 +182,13 @@ class NoteSerializer implements NoteSerializerInterface {
     for (var possibleKey in createdKeyOptions) {
       var val = data.props[possibleKey];
       if (val != null) {
-        note.created = parseDateTime(val.toString());
+        if (val is int) {
+          note.created = parseUnixTimeStamp(val);
+          settings.createdFormat = DateFormat.UnixTimeStamp;
+        } else {
+          note.created = parseDateTime(val.toString());
+          settings.createdFormat = DateFormat.Iso8601;
+        }
         settings.createdKey = possibleKey;
 
         propsUsed.add(possibleKey);

lib/utils/datetime.dart

@@ -80,3 +80,11 @@ DateTime? parseDateTime(String str) {
 
   return dt;
 }
+
+DateTime parseUnixTimeStamp(int val) {
+  return DateTime.fromMillisecondsSinceEpoch(val * 1000, isUtc: true);
+}
+
+int toUnixTimeStamp(DateTime dt) {
+  return dt.toUtc().millisecondsSinceEpoch ~/ 1000;
+}

test/note_test.dart

@@ -253,12 +253,12 @@ Hello
       expect(note.created, DateTime.parse('2021-07-14T10:14:49Z'));
 
       note.modified = DateTime.parse('2020-07-14T10:14:49Z');
-      note.created = DateTime.parse('2020-06-14T10:14:49Z');
+      note.created = DateTime.parse('2020-06-13T10:14:49Z');
 
       var expectedContent = """---
 bar: Foo
-updated: 1626257689
+updated: 1594721689
-created: 1626257689
+created: 1592043289
 ---
 
 Hello
@@ -268,6 +268,6 @@ Hello
 
       var actualContent = File(notePath).readAsStringSync();
       expect(actualContent, equals(expectedContent));
-    }, skip: true);
+    });
   });
 }