import 'dart:async';
import 'dart:convert';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:go_router/go_router.dart';
import 'package:dio/dio.dart';

import '../core/api_client.dart';
import 'package:hesabix_ui/l10n/app_localizations.dart';
import '../core/locale_controller.dart';
import '../theme/theme_controller.dart';
import '../widgets/auth_footer.dart';
import '../core/auth_store.dart';
import '../widgets/error_notice.dart';

class LoginPage extends StatefulWidget {
  final LocaleController localeController;
  final ThemeController? themeController;
  final AuthStore authStore;
  const LoginPage({super.key, required this.localeController, this.themeController, required this.authStore});

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

class _LoginPageState extends State<LoginPage> with SingleTickerProviderStateMixin {
  // Login
  final _formKey = GlobalKey<FormState>();
  final _identifierCtrl = TextEditingController();
  final _passwordCtrl = TextEditingController();
  final _loginCaptchaCtrl = TextEditingController();
  String? _loginCaptchaId;
  Uint8List? _loginCaptchaImage;
  Timer? _loginCaptchaTimer;
  bool _loadingLogin = false;
  String? _errorText;

  // Register
  final _registerKey = GlobalKey<FormState>();
  final _firstNameCtrl = TextEditingController();
  final _lastNameCtrl = TextEditingController();
  final _emailCtrl = TextEditingController();
  final _mobileCtrl = TextEditingController();
  final _registerPasswordCtrl = TextEditingController();
  final _registerCaptchaCtrl = TextEditingController();
  String? _registerCaptchaId;
  Uint8List? _registerCaptchaImage;
  bool _loadingRegister = false;
  Timer? _registerCaptchaTimer;
  String? _registerErrorText;

  // Forgot password
  final _forgotKey = GlobalKey<FormState>();
  final _forgotIdentifierCtrl = TextEditingController();
  final _forgotCaptchaCtrl = TextEditingController();
  String? _forgotCaptchaId;
  Uint8List? _forgotCaptchaImage;
  bool _loadingForgot = false;
  Timer? _forgotCaptchaTimer;
  String? _forgotErrorText;

  @override
  void dispose() {
    _identifierCtrl.dispose();
    _passwordCtrl.dispose();
    _firstNameCtrl.dispose();
    _lastNameCtrl.dispose();
    _emailCtrl.dispose();
    _mobileCtrl.dispose();
    _registerPasswordCtrl.dispose();
    _registerCaptchaCtrl.dispose();
    _forgotIdentifierCtrl.dispose();
    _loginCaptchaCtrl.dispose();
    _forgotCaptchaCtrl.dispose();
    _loginCaptchaTimer?.cancel();
    _registerCaptchaTimer?.cancel();
    _forgotCaptchaTimer?.cancel();
    super.dispose();
  }

  Future<void> _refreshCaptcha(String scope) async {
    final api = ApiClient();
    final res = await api.post<Map<String, dynamic>>('/api/v1/auth/captcha');
    final data = res.data!['data'] as Map<String, dynamic>;
    final id = data['captcha_id'] as String;
    final imgB64 = data['image_base64'] as String;
    final bytes = base64Decode(imgB64);
    final ttl = (data['ttl_seconds'] as num?)?.toInt();
    setState(() {
      if (scope == 'login') _loginCaptchaId = id;
      if (scope == 'register') _registerCaptchaId = id;
      if (scope == 'forgot') _forgotCaptchaId = id;
      if (scope == 'login') _loginCaptchaImage = bytes;
      if (scope == 'register') _registerCaptchaImage = bytes;
      if (scope == 'forgot') _forgotCaptchaImage = bytes;
    });
    if (ttl != null && ttl > 0) {
      final delay = Duration(seconds: ttl);
      if (scope == 'login') {
        _loginCaptchaTimer?.cancel();
        _loginCaptchaTimer = Timer(delay, () => _refreshCaptcha('login'));
      } else if (scope == 'register') {
        _registerCaptchaTimer?.cancel();
        _registerCaptchaTimer = Timer(delay, () => _refreshCaptcha('register'));
      } else if (scope == 'forgot') {
        _forgotCaptchaTimer?.cancel();
        _forgotCaptchaTimer = Timer(delay, () => _refreshCaptcha('forgot'));
      }
    }
  }

  @override
  void initState() {
    super.initState();
    // پیش‌بارگذاری کپچا برای هر سه تب
    _refreshCaptcha('login');
    _refreshCaptcha('register');
    _refreshCaptcha('forgot');
  }

  String _extractErrorMessage(Object e, AppLocalizations t) {
    try {
      if (e is DioException) {
        final data = e.response?.data;
        if (data is Map && data['error'] is Map && data['error']['message'] is String) {
          return data['error']['message'] as String;
        }
        if (data is Map && data['detail'] is List) {
          final details = data['detail'] as List;
          if (details.isNotEmpty && details.first is Map && (details.first as Map)['msg'] is String) {
            return (details.first as Map)['msg'] as String;
          }
        }
      }
    } catch (_) {}
    return t.loginFailed;
  }

  void _showSnack(String message) {
    if (!mounted) return;
    ScaffoldMessenger.of(context)
      ..hideCurrentSnackBar()
      ..showSnackBar(SnackBar(content: Text(message)));
  }

  Future<void> _onSubmit() async {
    final form = _formKey.currentState;
    final t = AppLocalizations.of(context);
    if (form == null || !form.validate()) return;
    if ((_loginCaptchaCtrl.text.trim().isEmpty) || (_loginCaptchaId == null)) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(t.captchaRequired)));
      return;
    }

    setState(() {
      _loadingLogin = true;
      _errorText = null;
    });

    try {
      final api = ApiClient();
      final res = await api.post<Map<String, dynamic>>(
        '/api/v1/auth/login',
        data: {
          'identifier': _identifierCtrl.text.trim(),
          'password': _passwordCtrl.text,
          'captcha_id': _loginCaptchaId,
          'captcha_code': _loginCaptchaCtrl.text.trim(),
          'device_id': widget.authStore.deviceId,
        },
      );
      final data = res.data?['data'] as Map<String, dynamic>?;
      final apiKey = data?['api_key'] as String?;
      if (apiKey != null && apiKey.isNotEmpty) {
        await widget.authStore.saveApiKey(apiKey);
      }

      if (!mounted) return;
      _showSnack(t.homeWelcome);
      context.go('/');
    } catch (e) {
      final msg = _extractErrorMessage(e, AppLocalizations.of(context));
      _showSnack(msg);
      setState(() {
        _errorText = msg;
      });
    } finally {
      if (mounted) {
        setState(() {
          _loadingLogin = false;
        });
      }
      _refreshCaptcha('login');
    }
  }

  Future<void> _onRegister() async {
    final form = _registerKey.currentState;
    final t = AppLocalizations.of(context);
    if (form == null || !form.validate()) return;

    setState(() => _loadingRegister = true);
    try {
      final api = ApiClient();
      if (_emailCtrl.text.trim().isEmpty && _mobileCtrl.text.trim().isEmpty) {
        final msg = '${t.email} / ${t.mobile} ${t.requiredField}';
        setState(() { _registerErrorText = msg; });
        _showSnack(msg);
        return;
      }
      await api.post<Map<String, dynamic>>(
        '/api/v1/auth/register',
        data: {
          'first_name': _firstNameCtrl.text.trim(),
          'last_name': _lastNameCtrl.text.trim(),
          'email': _emailCtrl.text.trim().isEmpty ? null : _emailCtrl.text.trim(),
          'mobile': _mobileCtrl.text.trim().isEmpty ? null : _mobileCtrl.text.trim(),
          'password': _registerPasswordCtrl.text,
          'captcha_id': _registerCaptchaId,
          'captcha_code': _registerCaptchaCtrl.text.trim(),
        },
      );

      if (!mounted) return;
      setState(() { _registerErrorText = null; });
      _showSnack(t.registerSuccess);
      DefaultTabController.of(context).animateTo(0);
    } catch (e) {
      if (!mounted) return;
      final msg = _extractErrorMessage(e, AppLocalizations.of(context));
      setState(() { _registerErrorText = msg; });
      _showSnack(msg);
    } finally {
      if (mounted) setState(() => _loadingRegister = false);
      _refreshCaptcha('register');
    }
  }

  Future<void> _onForgot() async {
    final form = _forgotKey.currentState;
    final t = AppLocalizations.of(context);
    if (form == null || !form.validate()) return;

    setState(() => _loadingForgot = true);
    try {
      final api = ApiClient();
      await api.post<Map<String, dynamic>>(
        '/api/v1/auth/forgot-password',
        data: {
          'identifier': _forgotIdentifierCtrl.text.trim(),
          'captcha_id': _forgotCaptchaId,
          'captcha_code': _forgotCaptchaCtrl.text.trim(),
        },
      );

      if (!mounted) return;
      _showSnack(t.forgotSent);
    } catch (e) {
      if (!mounted) return;
      final msg = _extractErrorMessage(e, AppLocalizations.of(context));
      setState(() { _forgotErrorText = msg; });
      _showSnack(msg);
    } finally {
      if (mounted) setState(() => _loadingForgot = false);
      _refreshCaptcha('forgot');
    }
  }

  @override
  Widget build(BuildContext context) {
    final t = AppLocalizations.of(context);
    final isDark = Theme.of(context).brightness == Brightness.dark;
    final String logoAsset = isDark
        ? 'assets/images/logo-light.png'
        : 'assets/images/logo-blue.png';
    return DefaultTabController(
      length: 3,
      child: Scaffold(
        body: Center(
          child: ConstrainedBox(
            constraints: const BoxConstraints(maxWidth: 520),
            child: Card(
              elevation: 2,
              margin: const EdgeInsets.all(16),
              child: Padding(
                padding: const EdgeInsets.all(24.0),
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    Row(
                      children: [
                        Image.asset(logoAsset, height: 28),
                        const SizedBox(width: 8),
                        Text(t.welcomeTitle, style: Theme.of(context).textTheme.titleMedium),
                      ],
                    ),
                    const SizedBox(height: 8),
                    Text(t.welcomeSubtitle, style: Theme.of(context).textTheme.bodySmall),
                    const SizedBox(height: 12),
                    TabBar(tabs: [Tab(text: t.login), Tab(text: t.register), Tab(text: t.forgotPassword)]),
                    const SizedBox(height: 16),
                    Builder(builder: (innerContext) {
                      final tabController = DefaultTabController.maybeOf(innerContext);
                      if (tabController == null) {
                        return const SizedBox.shrink();
                      }
                      return AnimatedBuilder(
                        animation: tabController,
                        builder: (context, _) {
                        final idx = tabController.index;
                        Widget body;
                        if (idx == 0) {
                          body = Padding(
                            padding: const EdgeInsets.symmetric(vertical: 16),
                            child: Form(
                              key: _formKey,
                              child: Column(
                                crossAxisAlignment: CrossAxisAlignment.stretch,
                                children: [
                                  TextFormField(
                                    controller: _identifierCtrl,
                                    decoration: InputDecoration(labelText: t.identifier),
                                    validator: (v) => (v == null || v.trim().isEmpty) ? '${t.identifier} ${t.requiredField}' : null,
                                    textInputAction: TextInputAction.next,
                                  ),
                                  const SizedBox(height: 12),
                                  TextFormField(
                                    controller: _passwordCtrl,
                                    decoration: InputDecoration(labelText: t.password),
                                    obscureText: true,
                                    validator: (v) => (v == null || v.isEmpty) ? '${t.password} ${t.requiredField}' : null,
                                    onFieldSubmitted: (_) => _onSubmit(),
                                  ),
                                  const SizedBox(height: 12),
                                  Row(
                                    children: [
                                      Expanded(
                                        child: TextFormField(
                                          controller: _loginCaptchaCtrl,
                                          decoration: InputDecoration(labelText: t.captcha),
                                          validator: (v) => (v == null || v.trim().isEmpty) ? '${t.captcha} ${t.requiredField}' : null,
                                          keyboardType: TextInputType.number,
                                          inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                                        ),
                                      ),
                                      const SizedBox(width: 8),
                                      if (_loginCaptchaImage != null)
                                        ClipRRect(
                                          borderRadius: BorderRadius.circular(4),
                                          child: Image.memory(
                                            _loginCaptchaImage!,
                                            height: 40,
                                            width: 120,
                                            fit: BoxFit.contain,
                                          ),
                                        )
                                      else
                                        const SizedBox(height: 40, width: 120),
                                      const SizedBox(width: 8),
                                      IconButton(
                                        onPressed: () => _refreshCaptcha('login'),
                                        icon: const Icon(Icons.refresh),
                                        tooltip: t.refresh,
                                      ),
                                    ],
                                  ),
                                  const SizedBox(height: 16),
                                  if (_errorText != null)
                                    ErrorNotice(message: _errorText!, onClose: () => setState(() => _errorText = null)),
                                  const SizedBox(height: 12),
                                  FilledButton(
                                    onPressed: _loadingLogin ? null : _onSubmit,
                                    child: _loadingLogin
                                        ? const SizedBox(height: 20, width: 20, child: CircularProgressIndicator(strokeWidth: 2))
                                        : Text(t.submit),
                                  ),
                                ],
                              ),
                            ),
                          );
                        } else if (idx == 1) {
                          body = Padding(
                            padding: const EdgeInsets.symmetric(vertical: 16),
                            child: Form(
                              key: _registerKey,
                              child: Column(
                                crossAxisAlignment: CrossAxisAlignment.stretch,
                                children: [
                                  TextFormField(
                                    controller: _firstNameCtrl,
                                    decoration: InputDecoration(labelText: t.firstName),
                                    validator: (v) => (v == null || v.trim().isEmpty) ? '${t.firstName} ${t.requiredField}' : null,
                                    textInputAction: TextInputAction.next,
                                  ),
                                  const SizedBox(height: 12),
                                  TextFormField(
                                    controller: _lastNameCtrl,
                                    decoration: InputDecoration(labelText: t.lastName),
                                    validator: (v) => (v == null || v.trim().isEmpty) ? '${t.lastName} ${t.requiredField}' : null,
                                    textInputAction: TextInputAction.next,
                                  ),
                                  const SizedBox(height: 12),
                                  TextFormField(
                                    controller: _emailCtrl,
                                    decoration: InputDecoration(labelText: t.email),
                                    keyboardType: TextInputType.emailAddress,
                                    validator: (v) => (v == null || v.trim().isEmpty) ? '${t.email} ${t.requiredField}' : null,
                                    textInputAction: TextInputAction.next,
                                  ),
                                  const SizedBox(height: 12),
                                  TextFormField(
                                    controller: _mobileCtrl,
                                    decoration: InputDecoration(labelText: t.mobile),
                                    keyboardType: TextInputType.phone,
                                    validator: (v) => (v == null || v.trim().isEmpty) ? '${t.mobile} ${t.requiredField}' : null,
                                    textInputAction: TextInputAction.next,
                                  ),
                                  const SizedBox(height: 12),
                                  TextFormField(
                                    controller: _registerPasswordCtrl,
                                    decoration: InputDecoration(labelText: t.password),
                                    obscureText: true,
                                    validator: (v) => (v == null || v.isEmpty) ? '${t.password} ${t.requiredField}' : null,
                                    onFieldSubmitted: (_) => _onRegister(),
                                  ),
                                  const SizedBox(height: 12),
                                  Row(
                                    children: [
                                      Expanded(
                                        child: TextFormField(
                                          controller: _registerCaptchaCtrl,
                                          decoration: InputDecoration(labelText: t.captcha),
                                          validator: (v) => (v == null || v.trim().isEmpty) ? '${t.captcha} ${t.requiredField}' : null,
                                          keyboardType: TextInputType.number,
                                          inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                                        ),
                                      ),
                                      const SizedBox(width: 8),
                                      if (_registerCaptchaImage != null)
                                        ClipRRect(
                                          borderRadius: BorderRadius.circular(4),
                                          child: Image.memory(
                                            _registerCaptchaImage!,
                                            height: 40,
                                            width: 120,
                                            fit: BoxFit.contain,
                                          ),
                                        )
                                      else
                                        const SizedBox(height: 40, width: 120),
                                      const SizedBox(width: 8),
                                      IconButton(
                                        onPressed: () => _refreshCaptcha('register'),
                                        icon: const Icon(Icons.refresh),
                                        tooltip: t.refresh,
                                      ),
                                    ],
                                  ),
                                  const SizedBox(height: 16),
                                  if (_registerErrorText != null)
                                    ErrorNotice(message: _registerErrorText!, onClose: () => setState(() => _registerErrorText = null)),
                                  const SizedBox(height: 12),
                                  FilledButton(
                                    onPressed: _loadingRegister ? null : _onRegister,
                                    child: _loadingRegister
                                        ? const SizedBox(height: 20, width: 20, child: CircularProgressIndicator(strokeWidth: 2))
                                        : Text(t.submit),
                                  ),
                                ],
                              ),
                            ),
                          );
                        } else {
                          body = Padding(
                            padding: const EdgeInsets.symmetric(vertical: 16),
                            child: Form(
                              key: _forgotKey,
                              child: Column(
                                crossAxisAlignment: CrossAxisAlignment.stretch,
                                children: [
                                  TextFormField(
                                    controller: _forgotIdentifierCtrl,
                                    decoration: InputDecoration(labelText: t.identifier),
                                    validator: (v) => (v == null || v.trim().isEmpty) ? '${t.identifier} ${t.requiredField}' : null,
                                    onFieldSubmitted: (_) => _onForgot(),
                                  ),
                                  const SizedBox(height: 12),
                                  Row(
                                    children: [
                                      Expanded(
                                        child: TextFormField(
                                          controller: _forgotCaptchaCtrl,
                                          decoration: InputDecoration(labelText: t.captcha),
                                          validator: (v) => (v == null || v.trim().isEmpty) ? '${t.captcha} ${t.requiredField}' : null,
                                          keyboardType: TextInputType.number,
                                          inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                                        ),
                                      ),
                                      const SizedBox(width: 8),
                                      if (_forgotCaptchaImage != null)
                                        ClipRRect(
                                          borderRadius: BorderRadius.circular(4),
                                          child: Image.memory(
                                            _forgotCaptchaImage!,
                                            height: 40,
                                            width: 120,
                                            fit: BoxFit.contain,
                                          ),
                                        )
                                      else
                                        const SizedBox(height: 40, width: 120),
                                      const SizedBox(width: 8),
                                      IconButton(
                                        onPressed: () => _refreshCaptcha('forgot'),
                                        icon: const Icon(Icons.refresh),
                                        tooltip: t.refresh,
                                      ),
                                    ],
                                  ),
                                  const SizedBox(height: 12),
                                  if (_forgotErrorText != null)
                                    ErrorNotice(message: _forgotErrorText!, onClose: () => setState(() => _forgotErrorText = null)),
                                  const SizedBox(height: 12),
                                  FilledButton(
                                    onPressed: _loadingForgot ? null : _onForgot,
                                    child: _loadingForgot
                                        ? const SizedBox(height: 20, width: 20, child: CircularProgressIndicator(strokeWidth: 2))
                                        : Text(t.submit),
                                  ),
                                ],
                              ),
                            ),
                          );
                        }
                        return AnimatedSize(
                          duration: const Duration(milliseconds: 200),
                          curve: Curves.easeInOut,
                          alignment: Alignment.topCenter,
                          child: body,
                        );
                      });
                    }),
                    const SizedBox(height: 8),
                    Text(t.brandTagline, textAlign: TextAlign.center, style: Theme.of(context).textTheme.bodySmall),
                    const SizedBox(height: 12),
                    AuthFooter(localeController: widget.localeController, themeController: widget.themeController),
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}