import 'package:flutter/material.dart';
import 'package:kmobile/api/services/auth_service.dart';
import 'package:kmobile/di/injection.dart';
import 'package:kmobile/features/auth/screens/login_screen.dart';

class SetPasswordScreen extends StatefulWidget {
  final String customerNo;
  const SetPasswordScreen({super.key, required this.customerNo});

  @override
  State<SetPasswordScreen> createState() => _SetPasswordScreenState();
}

enum SetPasswordStep { initial, otp, setPassword, success }

class _SetPasswordScreenState extends State<SetPasswordScreen> {
  final _authService = getIt<AuthService>();
  SetPasswordStep _currentStep = SetPasswordStep.initial;
  bool _isLoading = false;
  String? _error;
  String? _otpToken;

  final _otpController = TextEditingController();
  final _passwordController = TextEditingController();
  final _confirmPasswordController = TextEditingController();

  bool _obscurePassword = true;
  bool _obscureConfirmPassword = true;

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

  Future<void> _sendOtp() async {
    setState(() {
      _isLoading = true;
      _error = null;
    });
    try {
      await _authService.sendOtpForSettingPassword(widget.customerNo);
      setState(() {
        _currentStep = SetPasswordStep.otp;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _error = e.toString();
        _isLoading = false;
      });
    }
  }

  Future<void> _verifyOtp() async {
    if (_otpController.text.isEmpty) {
      setState(() {
        _error = 'Please enter OTP';
      });
      return;
    }
    setState(() {
      _isLoading = true;
      _error = null;
    });
    try {
      final token = await _authService.verifyOtpForSettingPassword(
          widget.customerNo, _otpController.text);
      setState(() {
        _otpToken = token;
        _currentStep = SetPasswordStep.setPassword;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _error = e.toString();
        _isLoading = false;
      });
    }
  }

  Future<void> _setPassword() async {
    if (_passwordController.text.isEmpty ||
        _confirmPasswordController.text.isEmpty) {
      setState(() {
        _error = 'Please fill both password fields';
      });
      return;
    }
    if (_passwordController.text != _confirmPasswordController.text) {
      setState(() {
        _error = 'Passwords do not match';
      });
      return;
    }
    if (_otpToken == null) {
      setState(() {
        _error = 'OTP token is missing. Please restart the process.';
        _currentStep = SetPasswordStep.initial;
      });
      return;
    }

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

    try {
      await _authService.changePassword(_passwordController.text, _otpToken!);
      setState(() {
        _currentStep = SetPasswordStep.success;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _error = e.toString();
        _isLoading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Set New Password'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(24.0),
        child: Center(
          child: SingleChildScrollView(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                if (_error != null) ...[
                  Text(
                    _error!,
                    style: const TextStyle(color: Colors.red),
                    textAlign: TextAlign.center,
                  ),
                  const SizedBox(height: 16),
                ],
                if (_isLoading)
                  const CircularProgressIndicator()
                else
                  _buildStepContent(),
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildStepContent() {
    switch (_currentStep) {
      case SetPasswordStep.initial:
        return _buildInitialStep();
      case SetPasswordStep.otp:
        return _buildOtpStep();
      case SetPasswordStep.setPassword:
        return _buildSetPasswordStep();
      case SetPasswordStep.success:
        return _buildSuccessStep();
    }
  }

  Widget _buildInitialStep() {
    return Column(
      children: [
        const Text(
          'You need to set a new password to continue. We will send an OTP to your registered mobile number.',
          textAlign: TextAlign.center,
          style: TextStyle(fontSize: 16),
        ),
        const SizedBox(height: 24),
        ElevatedButton(
          onPressed: _sendOtp,
          child: const Text('Proceed'),
        ),
      ],
    );
  }

  Widget _buildOtpStep() {
    return Column(
      children: [
        const Text(
          'An OTP has been sent to your registered mobile number. Please enter it below.',
          textAlign: TextAlign.center,
        ),
        const SizedBox(height: 24),
        TextField(
          controller: _otpController,
          decoration: const InputDecoration(
            labelText: 'Enter OTP',
            border: OutlineInputBorder(),
          ),
          keyboardType: TextInputType.number,
        ),
        const SizedBox(height: 24),
        ElevatedButton(
          onPressed: _verifyOtp,
          child: const Text('Verify OTP'),
        ),
      ],
    );
  }

  Widget _buildSetPasswordStep() {
    return Column(
      children: [
        TextFormField(
          controller: _passwordController,
          obscureText: _obscurePassword,
          decoration: InputDecoration(
            labelText: 'New Password',
            border: const OutlineInputBorder(),
            suffixIcon: IconButton(
              icon: Icon(
                _obscurePassword ? Icons.visibility : Icons.visibility_off,
              ),
              onPressed: () {
                setState(() {
                  _obscurePassword = !_obscurePassword;
                });
              },
            ),
          ),
        ),
        const SizedBox(height: 24),
        TextFormField(
          controller: _confirmPasswordController,
          obscureText: _obscureConfirmPassword,
          decoration: InputDecoration(
            labelText: 'Confirm New Password',
            border: const OutlineInputBorder(),
            suffixIcon: IconButton(
              icon: Icon(
                _obscureConfirmPassword
                    ? Icons.visibility
                    : Icons.visibility_off,
              ),
              onPressed: () {
                setState(() {
                  _obscureConfirmPassword = !_obscureConfirmPassword;
                });
              },
            ),
          ),
        ),
        const SizedBox(height: 24),
        ElevatedButton(
          onPressed: _setPassword,
          child: const Text('Set Password'),
        ),
      ],
    );
  }

  Widget _buildSuccessStep() {
    return Column(
      children: [
        const Icon(Icons.check_circle, color: Colors.green, size: 80),
        const SizedBox(height: 24),
        const Text(
          'Password set successfully!',
          style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
        ),
        const SizedBox(height: 8),
        const Text(
          'You can now log in with your new password.',
          textAlign: TextAlign.center,
        ),
        const SizedBox(height: 24),
        ElevatedButton(
          onPressed: () {
            Navigator.of(context).pushAndRemoveUntil(
              MaterialPageRoute(builder: (_) => const LoginScreen()),
              (route) => false,
            );
          },
          child: const Text('Back to Login'),
        ),
      ],
    );
  }
}