Implement password policy for account creation

lib/ui/routes/create_account_route.dart

@@ -1,6 +1,9 @@
 import 'package:comunic/helpers/account_helper.dart';
+import 'package:comunic/helpers/server_config_helper.dart';
 import 'package:comunic/models/config.dart';
 import 'package:comunic/models/new_account.dart';
+import 'package:comunic/ui/widgets/async_screen_widget.dart';
+import 'package:comunic/ui/widgets/new_password_input_widget.dart';
 import 'package:comunic/utils/input_utils.dart';
 import 'package:comunic/utils/intl_utils.dart';
 import 'package:comunic/utils/ui_utils.dart';
@@ -34,7 +37,7 @@ class __CreateAccountRouteBodyState extends State<_CreateAccountRouteBody> {
   final _firstNameController = TextEditingController();
   final _lastNameController = TextEditingController();
   final _emailController = TextEditingController();
-  final _passwordController = TextEditingController();
+  final _passwordInputKey = GlobalKey<NewPasswordInputWidgetState>();
   final _verifyPasswordController = TextEditingController();
   bool _acceptedTOS = false;
 
@@ -49,10 +52,11 @@ class __CreateAccountRouteBodyState extends State<_CreateAccountRouteBody> {
 
   bool get _isEmailValid => validateEmail(_emailController.text);
 
-  bool get _isPasswordValid => _passwordController.text.length > 3;
+  bool get _isPasswordValid => _passwordInputKey.currentState.valid;
 
   bool get _isPasswordConfirmationValid =>
-      _passwordController.text == _verifyPasswordController.text;
+      _passwordInputKey.currentState != null &&
+      _passwordInputKey.currentState.value == _verifyPasswordController.text;
 
   bool get _isFormValid =>
       _isFirstNameValid &&
@@ -69,10 +73,16 @@ class __CreateAccountRouteBodyState extends State<_CreateAccountRouteBody> {
           ? tr(
               "Too many accounts have been created from this IP address for now. Please try again later.")
           : tr(
-              "An error occured while creating your account. Please try again.");
+              "An error occurred while creating your account. Please try again.");
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context) => AsyncScreenWidget(
+        onReload: () => ServerConfigurationHelper.ensureLoaded(),
+        onBuild: () => _buildForm(),
+        errorMessage: tr("Failed to load server configuration !"),
+      );
+
+  Widget _buildForm() {
     if (_isCreating)
       return Center(
         child: CircularProgressIndicator(),
@@ -124,15 +134,14 @@ class __CreateAccountRouteBodyState extends State<_CreateAccountRouteBody> {
               ),
 
               // Password
-              _InputEntry(
-                controller: _passwordController,
+              NewPasswordInputWidget(
+                key: _passwordInputKey,
                 label: tr("Password"),
                 onEdited: _updateUI,
                 icon: Icon(Icons.lock),
-                isPassword: true,
-                error: _showErrors && !_isPasswordValid
-                    ? tr("Invalid password!")
-                    : null,
+                email: _emailController.text,
+                firstName: _firstNameController.text,
+                lastName: _lastNameController.text,
               ),
 
               // Verify password
@@ -206,7 +215,7 @@ class __CreateAccountRouteBodyState extends State<_CreateAccountRouteBody> {
       firstName: _firstNameController.text,
       lastName: _lastNameController.text,
       email: _emailController.text,
-      password: _passwordController.text,
+      password: _passwordInputKey.currentState.value,
     ));
 
     setState(() {

lib/ui/widgets/new_password_input_widget.dart

@@ -0,0 +1,164 @@
+import 'package:comunic/helpers/server_config_helper.dart';
+import 'package:comunic/models/server_config.dart';
+import 'package:comunic/models/user.dart';
+import 'package:comunic/utils/intl_utils.dart';
+import 'package:comunic/utils/ui_utils.dart';
+import 'package:flutter/material.dart';
+
+/// New password input widget
+///
+/// @author Pierre Hubert
+
+class NewPasswordInputWidget extends StatefulWidget {
+  final Widget icon;
+  final VoidCallback onEdited;
+  final String label;
+
+  final User user;
+  final String firstName;
+  final String lastName;
+  final String email;
+
+  const NewPasswordInputWidget({
+    Key key,
+    this.icon,
+    this.onEdited,
+    @required this.label,
+    this.user,
+    this.firstName,
+    this.lastName,
+    this.email,
+  }) : super(key: key);
+
+  @override
+  NewPasswordInputWidgetState createState() => NewPasswordInputWidgetState();
+}
+
+class NewPasswordInputWidgetState extends State<NewPasswordInputWidget> {
+  final TextEditingController _controller = TextEditingController();
+  bool _ready = false;
+
+  String get value => _controller.text;
+
+  bool get valid => _ready && value.isNotEmpty && (_errorMessage ?? "").isEmpty;
+
+  PasswordPolicy get _policy => ServerConfigurationHelper.config.passwordPolicy;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _init();
+  }
+
+  /// Make sure server configuration is loaded
+  void _init() async {
+    try {
+      await ServerConfigurationHelper.ensureLoaded();
+      setState(() => _ready = true);
+    } catch (e, s) {
+      print("Failed to initialize NewPasswordInputWidget! : $e - $s");
+      showSimpleSnack(context, tr("Failed to retrieve server configuration!"));
+    }
+  }
+
+  @override
+  void didUpdateWidget(covariant NewPasswordInputWidget oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    setState(() {});
+  }
+
+  @override
+  Widget build(BuildContext context) => TextField(
+        controller: _controller,
+        obscureText: true,
+        onChanged: (s) => _onChanged(),
+        decoration: InputDecoration(
+          errorText: _errorMessage,
+          errorMaxLines: 3,
+          icon: widget.icon,
+          labelText: widget.label,
+        ),
+      );
+
+  void _onChanged() {
+    setState(() {});
+    if (widget.onEdited != null) widget.onEdited();
+  }
+
+  /// Generate an error message associated with current password
+  String get _errorMessage {
+    if (!_ready || value.isEmpty) return null;
+
+    // Mandatory checks
+    if (!_policy.allowMailInPassword &&
+        (widget.email ?? "").isNotEmpty &&
+        (widget.email.toLowerCase().contains(value.toLowerCase()) ||
+            value.toLowerCase().contains(widget.email.toLowerCase()))) {
+      return tr("Your password must not contains part of your email address!");
+    }
+
+    if (!_policy.allowMailInPassword &&
+        (widget.email ?? "").isNotEmpty &&
+        (widget.email.toLowerCase().contains(value.toLowerCase()) ||
+            value.toLowerCase().contains(widget.email.toLowerCase()))) {
+      return tr("Your password must not contains part of your email address!");
+    }
+
+    if (!_policy.allowNameInPassword &&
+        (widget.firstName ?? "").isNotEmpty &&
+        value.toLowerCase().contains(widget.firstName.toLowerCase())) {
+      return tr("Your password must not contains your first name!");
+    }
+
+    if (!_policy.allowNameInPassword &&
+        (widget.lastName ?? "").isNotEmpty &&
+        value.toLowerCase().contains(widget.lastName.toLowerCase())) {
+      return tr("Your password must not contains your last name!");
+    }
+
+    if (_policy.minPasswordLength > value.length) {
+      return tr(
+        "Your password must be composed of at least %num% characters!",
+        args: {
+          "num": _policy.minPasswordLength.toString(),
+        },
+      );
+    }
+
+    // Characteristics check
+    var count = 0;
+
+    if (_hasCharacteristic(RegExp(r'[A-Z]'), _policy.minNumberUpperCaseLetters))
+      count++;
+
+    if (_hasCharacteristic(RegExp(r'[a-z]'), _policy.minNumberLowerCaseLetters))
+      count++;
+
+    if (_hasCharacteristic(RegExp(r'[0-9]'), _policy.minNumberDigits)) count++;
+
+    if (_hasCharacteristic(
+        RegExp(r'[^A-Za-z0-9]'), _policy.minNumberSpecialCharacters)) count++;
+
+    if (count >= _policy.minCategoriesPresence) return null;
+
+    return tr(
+      "Your password must contains characters of at least %num% of the following categories : %upper% upper case letter, %lower% lowercase letter, %digit% digit, %special% special character.",
+      args: {
+        "num": (_policy.minCategoriesPresence == 4
+            ? tr("ALL")
+            : _policy.minCategoriesPresence.toString()),
+        "upper": _policy.minNumberUpperCaseLetters.toString(),
+        "lower": _policy.minNumberLowerCaseLetters.toString(),
+        "digit": _policy.minNumberDigits.toString(),
+        "special": _policy.minNumberSpecialCharacters.toString(),
+      },
+    );
+  }
+
+  bool _hasCharacteristic(RegExp exp, int requiredCount) {
+    if (requiredCount < 1) return true;
+
+    return exp.allMatches(value).length >= requiredCount;
+  }
+}