import 'package:flutter/material.dart';
import 'package:inou_app/design/inou_theme.dart';
import 'package:inou_app/design/inou_text.dart';
import 'package:inou_app/design/widgets/widgets.dart';

/// Login page with biometric support
class LoginPage extends StatefulWidget {
  const LoginPage({super.key});

  @override
  State<LoginPage> createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  final _formKey = GlobalKey<FormState>();
  final _emailController = TextEditingController();
  final _passwordController = TextEditingController();
  bool _isLoading = false;
  bool _obscurePassword = true;
  bool _rememberMe = false;

  // Biometric state
  bool _biometricAvailable = false;
  bool _biometricEnrolled = false;

  @override
  void initState() {
    super.initState();
    _checkBiometricAvailability();
  }

  Future<void> _checkBiometricAvailability() async {
    // TODO: Check actual biometric availability using local_auth
    // For now, simulate availability on mobile
    setState(() {
      _biometricAvailable = true; // Placeholder
      _biometricEnrolled = false; // Placeholder - check if user has enrolled
    });
  }

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

  @override
  Widget build(BuildContext context) {
    return InouAuthFlowPage(
      child: Form(
        key: _formKey,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text(
              'Welcome back',
              style: InouText.sectionTitle.copyWith(fontWeight: FontWeight.w600),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 8),
            Text(
              'Sign in to access your health dossier',
              style: InouText.body.copyWith(
                color: InouTheme.textMuted,
              ),
              textAlign: TextAlign.center,
            ),
            
            const SizedBox(height: 32),
            
            // Biometric login button (if available and enrolled)
            if (_biometricAvailable && _biometricEnrolled) ...[
              _buildBiometricButton(),
              const SizedBox(height: 24),
              _buildDivider('or sign in with email'),
              const SizedBox(height: 24),
            ],
            
            // Email field
            InouTextField(
              label: 'Email',
              controller: _emailController,
              placeholder: 'you@example.com',
              keyboardType: TextInputType.emailAddress,
              autofillHints: const [AutofillHints.email],
              validator: (value) {
                if (value == null || value.isEmpty) {
                  return 'Please enter your email';
                }
                if (!value.contains('@')) {
                  return 'Please enter a valid email';
                }
                return null;
              },
            ),
            const SizedBox(height: 16),
            
            // Password field
            InouTextField(
              label: 'Password',
              controller: _passwordController,
              placeholder: '••••••••',
              obscureText: _obscurePassword,
              autofillHints: const [AutofillHints.password],
              suffixIcon: IconButton(
                icon: Icon(
                  _obscurePassword ? Icons.visibility_off : Icons.visibility,
                  color: InouTheme.textMuted,
                  size: 20,
                ),
                onPressed: () {
                  setState(() => _obscurePassword = !_obscurePassword);
                },
              ),
              validator: (value) {
                if (value == null || value.isEmpty) {
                  return 'Please enter your password';
                }
                return null;
              },
            ),
            const SizedBox(height: 16),
            
            // Remember me & forgot password row
            Row(
              children: [
                InouCheckbox(
                  value: _rememberMe,
                  label: 'Remember me',
                  onChanged: (value) {
                    setState(() => _rememberMe = value ?? false);
                  },
                ),
                const Spacer(),
                TextButton(
                  onPressed: _handleForgotPassword,
                  child: Text(
                    'Forgot password?',
                    style: InouText.bodySmall.copyWith(
                      color: InouTheme.accent,
                    ),
                  ),
                ),
              ],
            ),
            
            const SizedBox(height: 24),
            
            // Login button
            InouButton(
              text: _isLoading ? 'Signing in...' : 'Sign in',
              onPressed: _isLoading ? null : _handleLogin,
            ),
            
            const SizedBox(height: 24),
            
            // Sign up link
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Text(
                  'Don\'t have an account? ',
                  style: InouText.body.copyWith(
                    color: InouTheme.textMuted,
                  ),
                ),
                TextButton(
                  onPressed: () => Navigator.pushReplacementNamed(context, '/signup'),
                  style: TextButton.styleFrom(
                    padding: EdgeInsets.zero,
                    minimumSize: Size.zero,
                    tapTargetSize: MaterialTapTargetSize.shrinkWrap,
                  ),
                  child: Text(
                    'Sign up',
                    style: InouText.body.copyWith(
                      color: InouTheme.accent,
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildBiometricButton() {
    return OutlinedButton.icon(
      onPressed: _handleBiometricLogin,
      icon: const Icon(Icons.fingerprint, size: 24),
      label: const Text('Sign in with biometrics'),
      style: OutlinedButton.styleFrom(
        foregroundColor: InouTheme.text,
        side: BorderSide(color: InouTheme.border),
        padding: const EdgeInsets.symmetric(vertical: 16),
        shape: RoundedRectangleBorder(
          borderRadius: InouTheme.borderRadiusMd,
        ),
      ),
    );
  }

  Widget _buildDivider(String text) {
    return Row(
      children: [
        Expanded(child: Divider(color: InouTheme.border)),
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 16),
          child: Text(
            text,
            style: InouText.bodySmall.copyWith(
              color: InouTheme.textMuted,
            ),
          ),
        ),
        Expanded(child: Divider(color: InouTheme.border)),
      ],
    );
  }

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

    setState(() => _isLoading = true);

    try {
      // TODO: Implement actual login
      await Future.delayed(const Duration(seconds: 1));

      if (mounted) {
        // After successful login, offer biometric enrollment if available
        if (_biometricAvailable && !_biometricEnrolled) {
          await _offerBiometricEnrollment();
        }

        // Navigate to dashboard
        Navigator.pushNamedAndRemoveUntil(
          context,
          '/dashboard',
          (route) => false,
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Login failed: ${e.toString()}'),
            backgroundColor: InouTheme.danger,
            behavior: SnackBarBehavior.floating,
          ),
        );
      }
    } finally {
      if (mounted) {
        setState(() => _isLoading = false);
      }
    }
  }

  Future<void> _handleBiometricLogin() async {
    // TODO: Implement biometric authentication using local_auth
    // On success, retrieve stored credentials and login
  }

  Future<void> _handleForgotPassword() async {
    // Navigate to forgot password flow
    Navigator.pushNamed(context, '/forgot-password');
  }

  Future<void> _offerBiometricEnrollment() async {
    final shouldEnroll = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        shape: RoundedRectangleBorder(
          borderRadius: InouTheme.borderRadiusLg,
        ),
        title: const Text('Enable biometric login?'),
        content: const Text(
          'Sign in faster next time using your fingerprint or face.',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: Text(
              'Not now',
              style: TextStyle(color: InouTheme.textMuted),
            ),
          ),
          ElevatedButton(
            onPressed: () => Navigator.pop(context, true),
            style: ElevatedButton.styleFrom(
              backgroundColor: InouTheme.accent,
            ),
            child: const Text('Enable'),
          ),
        ],
      ),
    );

    if (shouldEnroll == true) {
      // TODO: Enroll biometric credentials
      // Store encrypted credentials securely
    }
  }
}