import 'package:flutter/material.dart';
import '../services/auth_service.dart';
import '../widgets/custom_input_field.dart';

class LoginScreen extends StatefulWidget {
  const LoginScreen({super.key});

  @override
  State<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _userCodeController = TextEditingController();
  final _passwordController = TextEditingController();
  final _authService = AuthService();

  bool _isLoading = false;
  String? _errorMessage;

  @override
  void dispose() {
    _userCodeController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  Future<void> _handleLogin() async {
    if (!_formKey.currentState!.validate()) return;

    setState(() {
      _isLoading = true;
      _errorMessage = null;
    });

    try {
      final input = _userCodeController.text.trim();
      final parsedUserCode = int.tryParse(input);
      if (parsedUserCode == null) {
        throw Exception('User code must be a number');
      }

      final response = await _authService.login(
        userCode: parsedUserCode,
        password: _passwordController.text,
      );

      if (mounted) {
        // Navigate to daily schedule screen
        Navigator.of(context).pushReplacementNamed('/schedule');
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _errorMessage = e.toString().replaceAll('Exception: ', '');
        });
      }
    } finally {
      if (mounted) {
        setState(() => _isLoading = false);
      }
    }
  }

  String? _validateUserCode(String? value) {
    final v = value?.trim();
    if (v?.isEmpty ?? true) {
      return 'User code is required';
    }
    if (int.tryParse(v!) == null) {
      return 'User code must be a number';
    }
    return null;
  }

  String? _validatePassword(String? value) {
    if (value?.isEmpty ?? true) {
      return 'Password is required';
    }
    if ((value?.length ?? 0) < 3) {
      return 'Password must be at least 3 characters';
    }
    return null;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Bus Terminal Login'),
        elevation: 0,
      ),
      body: SingleChildScrollView(
        child: Padding(
          padding: const EdgeInsets.all(24.0),
          child: Form(
            key: _formKey,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                const SizedBox(height: 32),

                // Title
                Text(
                  'Driver Login',
                  style: Theme.of(context).textTheme.headlineMedium?.copyWith(
                        fontWeight: FontWeight.bold,
                      ),
                ),
                const SizedBox(height: 12),
                Text(
                  'Enter your credentials to continue',
                  style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                        color: Colors.grey[600],
                      ),
                ),
                const SizedBox(height: 48),

                // Error message
                if (_errorMessage != null)
                  Container(
                    padding: const EdgeInsets.all(12),
                    decoration: BoxDecoration(
                      color: Colors.red[50],
                      border: Border.all(color: Colors.red[300]!),
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: Text(
                      _errorMessage!,
                      style: TextStyle(
                        color: Colors.red[700],
                        fontSize: 14,
                      ),
                    ),
                  ),
                if (_errorMessage != null) const SizedBox(height: 24),

                // User Code Field
                CustomInputField(
                  label: 'User Code',
                  hint: 'Enter your user code',
                  controller: _userCodeController,
                  validator: _validateUserCode,
                ),
                const SizedBox(height: 24),

                // Password Field
                CustomInputField(
                  label: 'Password',
                  hint: 'Enter your password',
                  controller: _passwordController,
                  obscureText: true,
                  validator: _validatePassword,
                ),
                const SizedBox(height: 40),

                // Login Button - Large for touch accessibility
                FilledButton(
                  onPressed: _isLoading ? null : _handleLogin,
                  style: FilledButton.styleFrom(
                    minimumSize: const Size.fromHeight(56), // Large touch target
                    disabledBackgroundColor: Colors.grey[400],
                  ),
                  child: _isLoading
                      ? const SizedBox(
                          height: 24,
                          width: 24,
                          child: CircularProgressIndicator(
                            strokeWidth: 2,
                            valueColor:
                                AlwaysStoppedAnimation<Color>(Colors.white),
                          ),
                        )
                      : const Text(
                          'Login',
                          style: TextStyle(
                            fontSize: 18,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}