import 'package:flutter/material.dart';
import '../../widgets/password_reset_form.dart';
import '../../../../core/errors/auth_exceptions.dart';
import '../providers/auth_provider.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

/// Password reset request page where users can initiate password recovery
class ResetPasswordPage extends ConsumerStatefulWidget {
  const ResetPasswordPage({super.key});

  @override
  ConsumerState<ResetPasswordPage> createState() => _ResetPasswordPageState();
}

class _ResetPasswordPageState extends ConsumerState<ResetPasswordPage> {
  final _formKey = GlobalKey<FormState>();
  final _emailController = TextEditingController();
  
  bool _isLoading = false;
  String? _errorMessage;
  String? _successMessage;
  bool _emailSent = false;

  @override
  void dispose() {
    _emailController.dispose();
    super.dispose();
  }

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

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

    try {
      final authProvider = ref.read(authProvider.notifier);
      await authProvider.resetPassword(email.trim());
      
      if (mounted) {
        setState(() {
          _isLoading = false;
          _emailSent = true;
          _successMessage = 'Password reset email sent! Check your inbox for further instructions.';
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _isLoading = false;
          _errorMessage = _mapErrorToMessage(e);
        });
      }
    }
  }

  String _mapErrorToMessage(Object error) {
    if (error is UserNotFoundException) {
      return 'No account found with this email address.';
    } else if (error is TooManyRequestsException) {
      return 'Too many reset attempts. Please try again later.';
    } else if (error is NetworkException) {
      return 'Network error. Please check your connection and try again.';
    } else if (error is AuthException) {
      return error.message;
    } else {
      return 'An unexpected error occurred. Please try again.';
    }
  }

  void _navigateToLogin() {
    Navigator.of(context).pushReplacementNamed('/login');
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Scaffold(
      appBar: AppBar(
        title: const Text('Reset Password'),
        backgroundColor: Colors.transparent,
        elevation: 0,
        leading: IconButton(
          icon: const Icon(Icons.arrow_back),
          onPressed: _navigateToLogin,
          tooltip: 'Back to Login',
        ),
      ),
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              const SizedBox(height: 32),
              _buildHeader(),
              const SizedBox(height: 32),
              if (!_emailSent) ...[
                _buildInstructions(),
                const SizedBox(height: 32),
                PasswordResetForm(
                  formKey: _formKey,
                  emailController: _emailController,
                  isLoading: _isLoading,
                  errorMessage: _errorMessage,
                  onSubmit: _handlePasswordReset,
                ),
              ] else ...[
                _buildSuccessMessage(),
                const SizedBox(height: 32),
                _buildBackToLoginButton(),
              ],
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildHeader() {
    return Column(
      children: [
        Icon(
          Icons.lock_reset_outlined,
          size: 64,
          color: Theme.of(context).colorScheme.primary,
        ),
        const SizedBox(height: 16),
        Text(
          'Forgot Password?',
          style: Theme.of(context).textTheme.headlineMedium?.copyWith(
            fontWeight: FontWeight.bold,
          ),
        ),
      ],
    );
  }

  Widget _buildInstructions() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Theme.of(context).colorScheme.surfaceVariant,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Icon(
                Icons.info_outline,
                size: 20,
                color: Theme.of(context).colorScheme.onSurfaceVariant,
              ),
              const SizedBox(width: 8),
              Expanded(
                child: Text(
                  'Enter your email address below and we\'ll send you a link to reset your password.',
                  style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                    color: Theme.of(context).colorScheme.onSurfaceVariant,
                  ),
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  Widget _buildSuccessMessage() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Theme.of(context).colorScheme.primaryContainer,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Column(
        children: [
          Icon(
            Icons.mark_email_read_outlined,
            size: 48,
            color: Theme.of(context).colorScheme.onPrimaryContainer,
          ),
          const SizedBox(height: 16),
          Text(
            'Check Your Email',
            style: Theme.of(context).textTheme.titleLarge?.copyWith(
              fontWeight: FontWeight.bold,
              color: Theme.of(context).colorScheme.onPrimaryContainer,
            ),
          ),
          const SizedBox(height: 8),
          Text(
            _successMessage ?? 'We\'ve sent password reset instructions to your email address.',
            style: Theme.of(context).textTheme.bodyMedium?.copyWith(
              color: Theme.of(context).colorScheme.onPrimaryContainer,
            ),
            textAlign: TextAlign.center,
          ),
          const SizedBox(height: 16),
          Container(
            padding: const EdgeInsets.all(12),
            decoration: BoxDecoration(
              color: Theme.of(context).colorScheme.surface,
              borderRadius: BorderRadius.circular(8),
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  'Next Steps:',
                  style: Theme.of(context).textTheme.labelMedium?.copyWith(
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const SizedBox(height: 4),
                Text(
                  '1. Open your email inbox\n'
                  '2. Look for the password reset email\n'
                  '3. Click the reset link in the email\n'
                  '4. Create a new password',
                  style: Theme.of(context).textTheme.bodySmall,
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildBackToLoginButton() {
    return OutlinedButton(
      onPressed: _navigateToLogin,
      style: OutlinedButton.styleFrom(
        minimumSize: const Size(double.infinity, 48),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(8),
        ),
      ),
      child: const Text('Back to Login'),
    );
  }
}