[StreamChatPersistence] Add initial implementation

Signed-off-by: Sahil Kumar <[email protected]>

packages/stream_chat_persistence/lib/src/converter/list_converter.dart

@@ -0,0 +1,22 @@
+import 'dart:convert';
+
+import 'package:moor/moor.dart';
+
+///
+class ListConverter<T> extends TypeConverter<List<T>, String> {
+  @override
+  List<T> mapToDart(fromDb) {
+    if (fromDb == null) {
+      return null;
+    }
+    return List<T>.from(jsonDecode(fromDb) ?? []);
+  }
+
+  @override
+  String mapToSql(value) {
+    if (value == null) {
+      return null;
+    }
+    return jsonEncode(value);
+  }
+}

packages/stream_chat_persistence/lib/src/converter/map_converter.dart

@@ -0,0 +1,22 @@
+import 'dart:convert';
+
+import 'package:moor/moor.dart';
+
+///
+class MapConverter<T> extends TypeConverter<Map<String, T>, String> {
+  @override
+  Map<String, T> mapToDart(fromDb) {
+    if (fromDb == null) {
+      return null;
+    }
+    return Map<String, T>.from(jsonDecode(fromDb) ?? {});
+  }
+
+  @override
+  String mapToSql(value) {
+    if (value == null) {
+      return null;
+    }
+    return jsonEncode(value);
+  }
+}

packages/stream_chat_persistence/lib/src/converter/message_sending_status_converter.dart

@@ -0,0 +1,50 @@
+import 'package:moor/moor.dart';
+import 'package:stream_chat/stream_chat.dart';
+
+///
+class MessageSendingStatusConverter
+    extends TypeConverter<MessageSendingStatus, int> {
+  @override
+  MessageSendingStatus mapToDart(int fromDb) {
+    switch (fromDb) {
+      case 0:
+        return MessageSendingStatus.sending;
+      case 1:
+        return MessageSendingStatus.sent;
+      case 2:
+        return MessageSendingStatus.failed;
+      case 3:
+        return MessageSendingStatus.updating;
+      case 4:
+        return MessageSendingStatus.failed_update;
+      case 5:
+        return MessageSendingStatus.deleting;
+      case 6:
+        return MessageSendingStatus.failed_delete;
+      default:
+        return null;
+    }
+  }
+
+  @override
+  int mapToSql(MessageSendingStatus value) {
+    switch (value) {
+      case MessageSendingStatus.sending:
+        return 0;
+      case MessageSendingStatus.sent:
+        return 1;
+      case MessageSendingStatus.failed:
+        return 2;
+      case MessageSendingStatus.updating:
+        return 3;
+      case MessageSendingStatus.failed_update:
+        return 4;
+      case MessageSendingStatus.deleting:
+        return 5;
+      case MessageSendingStatus.failed_delete:
+        return 6;
+      default:
+        return null;
+    }
+  }
+}