Automatically get current user ID

lib/helpers/account_credentials_helper.dart

@@ -10,10 +10,6 @@ import 'package:shared_preferences/shared_preferences.dart';
 /// @author Pierre HUBERT
 
 class AccountCredentialsHelper {
-  /// Checkout whether current user is signed in or not
-  Future<bool> signedIn() async {
-    return await get() != null;
-  }
 
   /// Set new login tokens
   Future<void> set(LoginTokens tokens) async {

lib/helpers/account_helper.dart

@@ -3,6 +3,7 @@ import 'package:comunic/helpers/api_helper.dart';
 import 'package:comunic/models/api_request.dart';
 import 'package:comunic/models/authentication_details.dart';
 import 'package:comunic/models/login_tokens.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 /// Account helper
 ///
@@ -16,6 +17,23 @@ enum AuthResult {
 }
 
 class AccountHelper {
+  static const _USER_ID_PREFERENCE_NAME = "user_id";
+
+  // Current user ID
+  static int _currentUserID = -1;
+
+  /// Checkout whether current user is signed in or not
+  ///
+  /// Warning : This method MUST BE CALLED AT LEAST ONCE AFTER APP START !!!
+  Future<bool> signedIn() async {
+    bool signedIn = await AccountCredentialsHelper().get() != null;
+
+    // Load current user ID for later use
+    if (signedIn && _currentUserID == -1) await _loadCurrentUserID();
+
+    return signedIn;
+  }
+
   /// Sign in user
   Future<AuthResult> signIn(AuthenticationDetails auth) async {
     final request = APIRequest(uri: "account/login");
@@ -31,17 +49,53 @@ class AccountHelper {
       return AuthResult.TOO_MANY_ATTEMPTS;
     else if (response.code != 200) return AuthResult.NETWORK_ERROR;
 
-    //Save login tokens
+    // Save login tokens
     final tokensObj = response.getObject()["tokens"];
     await AccountCredentialsHelper()
         .set(LoginTokens(tokensObj["token1"], tokensObj["token2"]));
 
+    // Get current user ID
+    final userID = await _downloadCurrentUserID();
+    if (userID == null) {
+      await signOut(); // We can not stay signed in without current user ID
+      return AuthResult.NETWORK_ERROR;
+    }
+
+    // Save current user ID
+    final preferences = await SharedPreferences.getInstance();
+    await preferences.setInt(_USER_ID_PREFERENCE_NAME, userID);
+    _currentUserID = userID;
+
     return AuthResult.SUCCESS;
   }
 
   /// Sign out user
   Future<void> signOut() async {
     await AccountCredentialsHelper().set(null);
+    _currentUserID = 0;
   }
 
+  /// Get current user ID from the server
+  Future<int> _downloadCurrentUserID() async {
+    final response = await APIRequest(
+      uri: "user/getCurrentUserID",
+      needLogin: true,
+    ).exec();
+
+    if (response.code != 200) return null;
+
+    return response.getObject()["userID"];
+  }
+
+  /// Get the ID of the currently signed in user
+  Future<void> _loadCurrentUserID() async {
+    final preferences = await SharedPreferences.getInstance();
+    _currentUserID = preferences.getInt(_USER_ID_PREFERENCE_NAME);
+  }
+
+  /// Get the ID of the currently signed in user
+  static int getCurrentUserID() {
+    if (_currentUserID == -1) throw "Current user ID has not been loaded yet!";
+    return _currentUserID;
+  }
 }