import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:go_router/go_router.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:shadcn_ui/shadcn_ui.dart';

import '../../data/providers.dart';
import '../../data/state/app_interaction_state.dart';
import '../../routing/app_routes.dart';
import '../../theme/app_icons.dart';
import '../../theme/yanting_text.dart';
import '../../theme/yanting_tokens.dart';
import '../../widgets/app_buttons.dart';
import '../../widgets/app_card.dart';
import '../../widgets/page_header.dart';
import '../../widgets/states.dart';

class LoginPage extends HookConsumerWidget {
  const LoginPage({super.key, this.next});

  final String? next;

  String _backTargetFromNext() {
    final rawNext = next;
    if (rawNext == null || rawNext.isEmpty) return AppRoutes.profile;
    final decoded = Uri.decodeComponent(rawNext);
    final uri = Uri.tryParse(decoded);
    if (uri == null) return AppRoutes.profile;
    if (!uri.path.startsWith('/')) return AppRoutes.profile;
    return decoded;
  }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final phoneController = useTextEditingController();
    final codeController = useTextEditingController();
    final codeFocusNode = useFocusNode();
    final codeSent = useState(false);
    final sendingCode = useState(false);
    final verifying = useState(false);
    final countdown = useState(0);
    final error = useState<String?>(null);
    final agreed = useState(false);
    final timerRef = useRef<Timer?>(null);
    final auth = ref.watch(authControllerProvider);
    final theme = ShadTheme.of(context);

    useEffect(() {
      return () {
        timerRef.value?.cancel();
      };
    }, const []);

    Future<void> sendCode() async {
      final phone = phoneController.text.trim();
      if (phone.length != 11) {
        error.value = '请输入正确的手机号';
        return;
      }
      sendingCode.value = true;
      error.value = null;
      try {
        codeSent.value = true;
        countdown.value = 60;
        timerRef.value?.cancel();
        timerRef.value = Timer.periodic(const Duration(seconds: 1), (timer) {
          if (countdown.value <= 1) {
            timer.cancel();
            countdown.value = 0;
          } else {
            countdown.value = countdown.value - 1;
          }
        });
        codeFocusNode.requestFocus();
      } finally {
        sendingCode.value = false;
      }
    }

    Future<void> verify() async {
      final phone = phoneController.text.trim();
      final code = codeController.text.trim();
      if (phone.length != 11) {
        error.value = '请输入正确的手机号';
        return;
      }
      if (code.length != 6) {
        error.value = '请输入 6 位验证码';
        return;
      }
      if (!agreed.value) {
        error.value = '请先同意用户协议和隐私政策';
        return;
      }

      verifying.value = true;
      error.value = null;
      try {
        await ref
            .read(authControllerProvider.notifier)
            .login(LoginMethod.phone, phone: phone);
        await ref.read(profileControllerProvider.notifier).refresh();
        if (!context.mounted) return;
        showAppToast(context, '已登录 ${maskPhone(phone)}');
        final nextPath = next?.trim();
        if (nextPath != null && nextPath.isNotEmpty) {
          context.go(Uri.decodeComponent(nextPath));
        } else if (context.canPop()) {
          context.pop();
        } else {
          context.go(AppRoutes.profile);
        }
      } finally {
        verifying.value = false;
      }
    }

    Future<void> submitLogin() async {
      final phone = phoneController.text.trim();
      final code = codeController.text.trim();
      if (phone.length != 11) {
        error.value = '请输入正确的手机号';
        return;
      }
      if (code.length != 6) {
        error.value = '请输入 6 位验证码';
        return;
      }
      await verify();
    }

    void showPrivacyCheckDialog(VoidCallback onAgreed) {
      showModalBottomSheet<void>(
        context: context,
        enableDrag: false,
        barrierColor: Colors.black.withValues(alpha: 0.75),
        builder: (innerContext) => SafeArea(
          child: SingleChildScrollView(
            child: Padding(
              padding: const EdgeInsets.fromLTRB(22, 28, 22, 24),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Center(
                    child: Text(
                      '请阅读并同意以下条款',
                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
                        fontWeight: FontWeight.w500,
                      ),
                    ),
                  ),
                  const SizedBox(height: 14),
                  Center(
                    child: Text.rich(
                      textAlign: TextAlign.center,
                      TextSpan(
                        style: Theme.of(context).textTheme.bodySmall?.copyWith(
                          color: theme.colorScheme.mutedForeground,
                          height: 1.7,
                          fontSize: 12,
                        ),
                        children: [
                          const TextSpan(text: '登录前需要先阅读并同意 '),
                          TextSpan(
                            text: '《用户协议》',
                            style: Theme.of(context).textTheme.bodySmall
                                ?.copyWith(
                                  color: theme.colorScheme.primary,
                                  fontSize: 12,
                                  decoration: TextDecoration.underline,
                                  decorationColor: theme.colorScheme.primary,
                                ),
                          ),
                          const TextSpan(text: ' 和 '),
                          TextSpan(
                            text: '《隐私政策》',
                            style: Theme.of(context).textTheme.bodySmall
                                ?.copyWith(
                                  color: theme.colorScheme.primary,
                                  fontSize: 12,
                                  decoration: TextDecoration.underline,
                                  decorationColor: theme.colorScheme.primary,
                                ),
                          ),
                        ],
                      ),
                    ),
                  ),
                  const SizedBox(height: 24),
                  SizedBox(
                    width: double.infinity,
                    child: AppButton(
                      label: '同意并发送验证码',
                      expand: true,
                      onPressed: () {
                        Navigator.of(innerContext).pop();
                        agreed.value = true;
                        onAgreed();
                      },
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
      );
    }

    Future<void> onSendCodeTap() async {
      if (sendingCode.value || countdown.value > 0) return;
      if (!agreed.value) {
        showPrivacyCheckDialog(() {
          unawaited(sendCode());
        });
        return;
      }
      unawaited(sendCode());
    }

    final clickable = !sendingCode.value && !verifying.value;

    return PopScope(
      canPop: (next ?? '').isEmpty,
      onPopInvokedWithResult: (didPop, _) {
        if (didPop) return;
        if (!context.mounted) return;
        final nextPath = next;
        if (nextPath != null && nextPath.isNotEmpty) {
          context.go(_backTargetFromNext());
          return;
        }
        if (context.canPop()) {
          context.pop();
          return;
        }
        context.go(AppRoutes.profile);
      },
      child: Scaffold(
        backgroundColor: theme.colorScheme.background,
        appBar: AppBar(
          leading: IconButton(
            icon: const Icon(AppIcons.arrowLeft),
            onPressed: () {
              final nextPath = next;
              if (nextPath != null && nextPath.isNotEmpty) {
                context.go(_backTargetFromNext());
                return;
              }
              if (context.canPop()) {
                context.pop();
              } else {
                context.go(AppRoutes.profile);
              }
            },
          ),
          title: const Text('登录 · Login'),
        ),
        body: ListView(
          padding: const EdgeInsets.fromLTRB(
            YantingSpacing.screenX,
            4,
            YantingSpacing.screenX,
            20,
          ),
          children: [
            const PageHeader(title: '登录研听', subtitle: '先把登录逻辑接通，弹窗入口保持不变'),
            if (auth.loggedIn) ...[
              AppCard(
                color: theme.colorScheme.secondary,
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text('当前已登录', style: YantingText.cardTitle),
                    const SizedBox(height: 6),
                    Text(
                      auth.phone == null
                          ? '本地登录态已生效'
                          : '手机号 ${maskPhone(auth.phone!)}',
                      style: YantingText.body.copyWith(
                        color: theme.colorScheme.mutedForeground,
                      ),
                    ),
                  ],
                ),
              ),
              const SizedBox(height: YantingSpacing.x3),
            ],
            AppCard(
              padding: const EdgeInsets.all(18),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text('手机号登录', style: YantingText.sectionTitle),
                  const SizedBox(height: 12),
                  ShadInput(
                    controller: phoneController,
                    placeholder: const Text('请输入手机号'),
                    keyboardType: TextInputType.phone,
                    inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                  ),
                  const SizedBox(height: 12),
                  ShadInput(
                    controller: codeController,
                    focusNode: codeFocusNode,
                    placeholder: const Text('验证码'),
                    keyboardType: TextInputType.number,
                    inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                    trailing: Padding(
                      padding: const EdgeInsets.only(right: 4),
                      child: AppButton(
                        label: countdown.value > 0
                            ? '${countdown.value}s'
                            : '发送验证码',
                        kind: AppButtonKind.ghost,
                        compact: true,
                        onPressed: onSendCodeTap,
                      ),
                    ),
                  ),
                  const SizedBox(height: 14),
                  Row(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Padding(
                        padding: const EdgeInsets.only(top: 2),
                        child: ShadCheckbox(
                          value: agreed.value,
                          onChanged: (value) => agreed.value = value,
                        ),
                      ),
                      const SizedBox(width: 10),
                      Expanded(
                        child: Text.rich(
                          TextSpan(
                            style: YantingText.meta.copyWith(
                              color: theme.colorScheme.mutedForeground,
                              height: 1.7,
                            ),
                            children: [
                              const TextSpan(text: '已阅读并同意 '),
                              TextSpan(
                                text: '《用户协议》',
                                style: YantingText.meta.copyWith(
                                  color: theme.colorScheme.primary,
                                ),
                              ),
                              const TextSpan(text: ' 和 '),
                              TextSpan(
                                text: '《隐私政策》',
                                style: YantingText.meta.copyWith(
                                  color: theme.colorScheme.primary,
                                ),
                              ),
                            ],
                          ),
                        ),
                      ),
                    ],
                  ),
                  if (error.value != null) ...[
                    const SizedBox(height: 10),
                    Text(
                      error.value!,
                      style: YantingText.meta.copyWith(
                        color: theme.colorScheme.destructive,
                      ),
                    ),
                  ],
                  const SizedBox(height: 18),
                  AppButton(
                    label: verifying.value ? '登录中...' : '登录',
                    expand: true,
                    onPressed: clickable
                        ? () {
                            if (!agreed.value) {
                              showPrivacyCheckDialog(() {
                                unawaited(submitLogin());
                              });
                              return;
                            }
                            unawaited(submitLogin());
                          }
                        : null,
                    kind: AppButtonKind.primary,
                  ),
                ],
              ),
            ),
            const SizedBox(height: YantingSpacing.x3),
            AppCard(
              color: theme.colorScheme.secondary,
              child: Text(
                codeSent.value
                    ? '验证码逻辑已接通，当前先用本地登录态串起页面流转。'
                    : '当前版本先做本地登录态和页面流转，后端接口接入后再替换为真实校验。',
                style: YantingText.meta.copyWith(
                  color: theme.colorScheme.mutedForeground,
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

String maskPhone(String phone) {
  if (phone.length < 7) return phone;
  return '${phone.substring(0, 3)}****${phone.substring(phone.length - 4)}';
}