Update form key to be a final field and add validators for email and password

- Make the form key a final field in the AuthCubit class
- Add validators for email and password fields in the AuthCubit class
- Update the LoginForm widget to use the form key from AuthCubit class
- Add validators for email and password fields in the LoginForm widget

lib/features/auth/bloc/auth_cubit.dart

@@ -20,8 +20,9 @@ class AuthCubit extends Cubit<AuthState> {
 
   static AuthCubit get(context) => BlocProvider.of(context);
 
-  TextEditingController emailController = TextEditingController();
-  TextEditingController passwordController = TextEditingController();
+  final TextEditingController emailController = TextEditingController();
+  final TextEditingController passwordController = TextEditingController();
+  final loginFormKey = GlobalKey<FormState>();
   bool isPasswordVisible = false;
 
   static GlobalKey<FormState> formKey = GlobalKey<FormState>();
@@ -41,6 +42,56 @@ class AuthCubit extends Cubit<AuthState> {
   static UserModel? user;
 
   static Token token = Token.emptyConstructor();
+
+/////////////////////////////////////VALIDATORS/////////////////////////////////////
+  String? passwordValidator(String? value) {
+    if (value != null) {
+      if (value.isNotEmpty) {
+        if (value.length >= 6) {
+          return null;
+          //TODO uncomment this code when the password validation is needed
+          // if (RegExp(
+          //         r'^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$')
+          //     .hasMatch(value)) {
+          //   return null;
+          // } else {
+          //   return 'Password must contain at least one uppercase letter, one lowercase letter, one number and one special character';
+          // }
+        } else {
+          return 'Password must be at least 6 characters';
+        }
+      } else {
+        return 'Please enter your password';
+      }
+    }
+    return null;
+  }
+
+  String? emailAddressValidator(String? value) {
+    if (value != null && value.isNotEmpty && value != "") {
+      if (checkValidityOfEmail(value)) {
+        if (loginFormKey.currentState != null) {
+          loginFormKey.currentState!.save();
+        }
+        return null;
+      } else {
+        return 'Please enter a valid email';
+      }
+    } else {
+      return 'Email address is required';
+    }
+  }
+
+  bool checkValidityOfEmail(String? email) {
+    if (email != null) {
+      return RegExp(
+              r"^[a-zA-Z0-9]+([.!#$%&'*+/=?^_`{|}~-]?[a-zA-Z0-9]+)*@[a-zA-Z0-9]+([.-]?[a-zA-Z0-9]+)*\.[a-zA-Z0-9]{2,}$")
+          .hasMatch(email);
+    } else {
+      return false;
+    }
+  }
+
 /////////////////////////////////////API CALLS/////////////////////////////////////
   login() async {
     emit(AuthLoginLoading());