import 'dart:convert';

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../../core/api/api_client.dart';
import '../../../core/api/api_endpoints.dart';
import '../../../core/auth/auth_provider.dart';
import '../../../core/router/app_router.dart';
import '../../../core/theme/app_colors.dart';
import '../../booking/data/booking_repository.dart';
import '../../wallet/data/wallet_repository.dart';
import '../../wash/data/wash_repository.dart';
import 'auth_widgets.dart';

/// Écran de connexion utilisateur.
class LoginScreen extends ConsumerStatefulWidget {
  const LoginScreen({super.key});

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

class _LoginScreenState extends ConsumerState<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _emailController = TextEditingController(text: 'marie.dupont@demo.local');
  final _passwordController = TextEditingController(text: 'password');
  bool _isCheckingHealth = false;
  String? _healthResult;
  bool _healthHasError = false;

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

  Future<void> _checkHealth() async {
    setState(() {
      _isCheckingHealth = true;
      _healthResult = null;
      _healthHasError = false;
    });

    final apiClient = ref.read(apiClientProvider);
    final lines = <String>[
      'URL de base : ${apiClient.baseUrl}',
      '',
    ];
    var hasError = false;

    for (final entry in [
      ('API', ApiEndpoints.health),
      ('Base de données', ApiEndpoints.healthDb),
    ]) {
      final label = entry.$1;
      final path = entry.$2;
      final url = '${apiClient.baseUrl}$path';

      try {
        final response = await apiClient.get(path);
        lines.add('$label : OK (${response.statusCode})');
        lines.add('URL : $url');
        lines.add(_formatResponse(response.data));
      } on DioException catch (error) {
        hasError = true;
        lines.add('$label : Erreur');
        lines.add('URL : $url');
        lines.add(_formatDioError(error));
      }
      lines.add('');
    }

    if (mounted) {
      setState(() {
        _isCheckingHealth = false;
        _healthHasError = hasError;
        _healthResult = lines.join('\n').trim();
      });
    }
  }

  String _formatResponse(dynamic data) {
    if (data is Map || data is List) {
      return const JsonEncoder.withIndent('  ').convert(data);
    }
    return data?.toString() ?? '';
  }

  String _formatDioError(DioException error) {
    final response = error.response;
    if (response != null) {
      final body = response.data;
      if (body is Map || body is List) {
        return 'HTTP ${response.statusCode}\n${_formatResponse(body)}';
      }
      return 'HTTP ${response.statusCode}: $body';
    }

    return switch (error.type) {
      DioExceptionType.connectionTimeout ||
      DioExceptionType.sendTimeout ||
      DioExceptionType.receiveTimeout =>
        'Délai d\'attente dépassé',
      DioExceptionType.connectionError =>
        'Connexion impossible (${error.message ?? 'réseau injoignable'})',
      _ => error.message ?? 'Erreur réseau',
    };
  }

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

    final success = await ref.read(authProvider.notifier).login(
          _emailController.text.trim(),
          _passwordController.text,
        );

    if (success && mounted) {
      ref.invalidate(washesProvider);
      ref.invalidate(bookingsProvider);
      ref.invalidate(walletProvider);
      ref.invalidate(walletTransactionsProvider);
      context.go(AppRoutes.home);
    }
  }

  @override
  Widget build(BuildContext context) {
    final authState = ref.watch(authProvider);

    return AuthScaffold(
      child: AuthFormCard(
        child: Form(
          key: _formKey,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              const AuthHeader(subtitle: 'Connectez-vous pour réserver et laver'),
              TextFormField(
                    controller: _emailController,
                    keyboardType: TextInputType.emailAddress,
                    decoration: const InputDecoration(
                      labelText: 'Email',
                      prefixIcon: Icon(Icons.email_outlined),
                    ),
                    validator: (value) {
                      if (value == null || value.isEmpty) {
                        return 'Email requis';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 16),
                  TextFormField(
                    controller: _passwordController,
                    obscureText: true,
                    decoration: const InputDecoration(
                      labelText: 'Mot de passe',
                      prefixIcon: Icon(Icons.lock_outline),
                    ),
                    validator: (value) {
                      if (value == null || value.isEmpty) {
                        return 'Mot de passe requis';
                      }
                      return null;
                    },
                  ),
                  if (authState.error != null) ...[
                    const SizedBox(height: 12),
                    Container(
                      padding: const EdgeInsets.all(12),
                      decoration: BoxDecoration(
                        color: AppColors.error.withValues(alpha: 0.08),
                        borderRadius: BorderRadius.circular(12),
                        border: Border.all(color: AppColors.error.withValues(alpha: 0.3)),
                      ),
                      child: Row(
                        children: [
                          const Icon(Icons.error_outline_rounded, color: AppColors.error, size: 20),
                          const SizedBox(width: 8),
                          Expanded(
                            child: Text(
                              authState.error!,
                              style: const TextStyle(color: AppColors.error),
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                  const SizedBox(height: 24),
                  ElevatedButton(
                    onPressed: authState.isLoading ? null : _submit,
                    child: authState.isLoading
                        ? const SizedBox(
                            height: 20,
                            width: 20,
                            child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white),
                          )
                        : const Text('Se connecter'),
                  ),
                  const SizedBox(height: 12),
                  TextButton(
                    onPressed: () => context.push(AppRoutes.register),
                    child: const Text('Créer un compte'),
                  ),
                  const SizedBox(height: 8),
                  OutlinedButton.icon(
                    onPressed: _isCheckingHealth ? null : _checkHealth,
                    icon: _isCheckingHealth
                        ? const SizedBox(
                            height: 16,
                            width: 16,
                            child: CircularProgressIndicator(strokeWidth: 2),
                          )
                        : const Icon(Icons.monitor_heart_outlined, size: 18),
                    label: const Text('Vérifier l\'API'),
                  ),
                  if (_healthResult != null) ...[
                    const SizedBox(height: 12),
                    Container(
                      width: double.infinity,
                      padding: const EdgeInsets.all(12),
                      decoration: BoxDecoration(
                        color: (_healthHasError ? AppColors.error : AppColors.primary)
                            .withValues(alpha: 0.08),
                        borderRadius: BorderRadius.circular(8),
                        border: Border.all(
                          color: (_healthHasError ? AppColors.error : AppColors.primary)
                              .withValues(alpha: 0.3),
                        ),
                      ),
                      child: SelectableText(
                        _healthResult!,
                        style: Theme.of(context).textTheme.bodySmall?.copyWith(
                              fontFamily: 'monospace',
                              color: _healthHasError ? AppColors.error : AppColors.primaryDark,
                            ),
                      ),
                    ),
                  ],
                ],
              ),
            ),
          ),
        );
  }
}