import 'package:flutter/material.dart';
import 'backend.dart';

class LoginScreen extends StatelessWidget {
  final Function(String, String) onLogin;
  final bool isSignupMode; // Changed to a boolean

  LoginScreen({required this.onLogin, this.isSignupMode = false}); // Default to false (login mode)

  final TextEditingController usernameController = TextEditingController();
  final TextEditingController passwordController = TextEditingController();
  final TextEditingController emailController = TextEditingController();
  final TextEditingController confirmPasswordController = TextEditingController();

  final FocusNode usernameFocusNode = FocusNode();
  final FocusNode passwordFocusNode = FocusNode();
  final FocusNode emailFocusNode = FocusNode();
  final FocusNode confirmPasswordFocusNode = FocusNode();

  void _handleLogin() {
    onLogin(usernameController.text, passwordController.text);
  }

  void _handleSignup(BuildContext context) async {
    final username = usernameController.text;
    final password = passwordController.text;
    final email = emailController.text;

    if (password != confirmPasswordController.text) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Passwords don't match")),
      );
      return;
    }

    try {
      await Backend.signup(username, email, password);
      _handleLogin();
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Could not signup: $e')),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(isSignupMode ? 'Signup' : 'Login')), // Dynamic title
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              TextField(
                controller: usernameController,
                focusNode: usernameFocusNode,
                decoration: InputDecoration(labelText: 'Username'),
                textInputAction: TextInputAction.next,
                onSubmitted: (_) {
                  if (!isSignupMode) { // If not in signup mode, move to password
                    FocusScope.of(context).requestFocus(passwordFocusNode);
                  } else { // In signup mode, move to email
                    FocusScope.of(context).requestFocus(emailFocusNode);
                  }
                },
              ),
              SizedBox(height: 20),
              if (isSignupMode) ...[ // Conditionally show email field
                TextField(
                  controller: emailController,
                  focusNode: emailFocusNode,
                  decoration: InputDecoration(labelText: 'Email'),
                  keyboardType: TextInputType.emailAddress,
                  textInputAction: TextInputAction.next,
                  onSubmitted: (_) {
                    FocusScope.of(context).requestFocus(passwordFocusNode);
                  },
                ),
                SizedBox(height: 20),
              ],
              TextField(
                controller: passwordController,
                focusNode: passwordFocusNode,
                decoration: InputDecoration(labelText: 'Password'),
                obscureText: true,
                textInputAction: isSignupMode ? TextInputAction.next : TextInputAction.done, // Adjust text action
                onSubmitted: (_) {
                  if (!isSignupMode) { // If not in signup mode, handle login
                    _handleLogin();
                  } else { // In signup mode, move to confirm password
                    FocusScope.of(context).requestFocus(confirmPasswordFocusNode);
                  }
                },
              ),
              SizedBox(height: 20),
              if (isSignupMode) ...[ // Conditionally show confirm password field
                TextField(
                  controller: confirmPasswordController,
                  focusNode: confirmPasswordFocusNode,
                  decoration: InputDecoration(labelText: 'Confirm Password'),
                  obscureText: true,
                  textInputAction: TextInputAction.done,
                  onSubmitted: (_) {
                    _handleSignup(context);
                  },
                ),
                SizedBox(height: 20),
              ],
              ElevatedButton(
                onPressed: () {
                  if (!isSignupMode) { // If not in signup mode, handle login
                    _handleLogin();
                  } else { // In signup mode, handle signup
                    _handleSignup(context);
                  }
                },
                child: Text(isSignupMode ? 'Signup' : 'Login'), // Dynamic button text
              ),
              SizedBox(height: 20),
              TextButton(
                onPressed: () {
                  if (!isSignupMode) { // If in login mode, navigate to signup
                    Navigator.of(context).push(
                      MaterialPageRoute(
                        builder: (context) => LoginScreen(
                          onLogin: onLogin,
                          isSignupMode: true, // Push with signup mode
                        ),
                      ),
                    );
                  } else { // If in signup mode, pop back to login
                    Navigator.of(context).pop();
                  }
                },
                child: Text(
                  isSignupMode
                      ? 'Already have an account? Login' // Text for signup mode
                      : 'Don\'t have an account? Sign Up', // Text for login mode
                  style: TextStyle(color: Colors.blue),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}