Created conversation route

lib/helpers/conversations_helper.dart

@@ -1,4 +1,5 @@
 import 'package:comunic/helpers/database/conversations_database_helper.dart';
+import 'package:comunic/helpers/users_helper.dart';
 import 'package:comunic/lists/conversations_list.dart';
 import 'package:comunic/lists/users_list.dart';
 import 'package:comunic/models/api_request.dart';
@@ -22,15 +23,7 @@ class ConversationsHelper {
 
     try {
       ConversationsList list = ConversationsList();
-      response.getArray().forEach((f) => list.add(Conversation(
-            id: f["ID"],
-            ownerID: f["ID_owner"],
-            lastActive: f["last_active"],
-            name: f["name"] == false ? null : f["name"],
-            following: f["following"] == 1,
-            sawLastMessage: f["saw_last_message"] == 1,
-            members: f["members"].map<int>((f) => int.parse(f)).toList(),
-          )));
+      response.getArray().forEach((f) => list.add(_apiToConversation(f)));
 
       // Update the database
       await _conversationsDatabaseHelper.clearTable();
@@ -50,8 +43,38 @@ class ConversationsHelper {
     return list;
   }
 
-  /// Get the name of a [conversation]. This requires information about the
-  /// users of this conversation
+  /// Get information about a single conversation specified by its [id]
+  Future<Conversation> _downloadSingle(int id) async {
+    try {
+      final response = await APIRequest(
+          uri: "conversations/getInfoOne",
+          needLogin: true,
+          args: {"conversationID": id.toString()}).exec();
+
+      if (response.code != 200) return null;
+
+      final conversation = _apiToConversation(response.getObject());
+      _conversationsDatabaseHelper.insertOrUpdate(conversation);
+      return conversation;
+    } on Exception catch (e) {
+      print(e.toString());
+      print("Could not get information about a single conversation !");
+      return null;
+    }
+  }
+
+  /// Get information about a single conversation. If [force] is set to false,
+  /// cached version of the conversation will be used, else it will always get
+  /// the information from the server
+  Future<Conversation> getSingle(int id, {bool force = false}) async {
+    if(force || ! await _conversationsDatabaseHelper.has(id))
+      return await _downloadSingle(id);
+    else
+      return _conversationsDatabaseHelper.get(id);
+  }
+
+  /// Get the name of a [conversation]. This requires information
+  /// about the users of this conversation
   static String getConversationName(
       Conversation conversation, UsersList users) {
     if (conversation.has_name) return conversation.name;
@@ -69,4 +92,35 @@ class ConversationsHelper {
 
     return name;
   }
+
+  /// Asynchronously get the name fo the conversation
+  ///
+  /// Unlike the synchronous method, this method does not need information
+  /// about the members of the conversation
+  ///
+  /// Returns null in case of failure
+  static Future<String> getConversationNameAsync(
+      Conversation conversation) async {
+    if (conversation.has_name) return conversation.name;
+
+    //Get information about the members of the conversation
+    final members = await UsersHelper().getUsersInfo(conversation.members);
+
+    if (members == null) return null;
+
+    return ConversationsHelper.getConversationName(conversation, members);
+  }
+
+  /// Turn an API entry into a [Conversation] object
+  Conversation _apiToConversation(Map<String, dynamic> map){
+    return Conversation(
+      id: map["ID"],
+      ownerID: map["ID_owner"],
+      lastActive: map["last_active"],
+      name: map["name"] == false ? null : map["name"],
+      following: map["following"] == 1,
+      sawLastMessage: map["saw_last_message"] == 1,
+      members: map["members"].map<int>((f) => int.parse(f)).toList(),
+    );
+  }
 }