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

import '../../core/network/api_exception.dart';
import '../../core/theme/app_theme.dart';
import '../../providers/auth_provider.dart';
import '../../providers/payment_provider.dart';
import '../../services/pay_launcher.dart';
import '../../services/payment_service.dart';
import '../../services/user_service.dart';
import '../feed/widgets/feed_overlays.dart';

/// 充值页：余额展示 / 套餐网格 / 自定义金额 / 支付方式 / 立即支付
class RechargeScreen extends ConsumerWidget {
  const RechargeScreen({super.key});

  static const Map<int, IconData> _methodIcons = {
    1: Icons.account_balance,
    2: Icons.chat_bubble,
    3: Icons.paid,
  };

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final state = ref.watch(paymentProvider);
    final user = ref.watch(authProvider).user;

    return Scaffold(
      appBar: AppBar(title: const Text('充值')),
      body: state.isLoading && state.result == null
          ? const Center(child: CircularProgressIndicator())
          : state.loadFailed && state.result == null
              ? _LoadFailed(
                  onRetry: () => ref.read(paymentProvider.notifier).load(),
                )
              : RefreshIndicator(
                  onRefresh: () => ref.read(paymentProvider.notifier).load(),
                  child: ListView(
                    padding: const EdgeInsets.all(16),
                    children: [
                      // 当前积分
                      _PointsHeader(points: user?.points ?? 0),
                      const SizedBox(height: 20),

                      // 套餐网格
                      if (state.result?.packages.isNotEmpty == true)
                        _PackageGrid(
                          packages: state.result!.packages,
                          selectedId: state.selectedPackageId,
                          onSelect: (id) =>
                              ref.read(paymentProvider.notifier).selectPackage(id),
                        ),

                      // 自定义金额
                      if (state.result?.custom.enabled == true) ...[
                        const SizedBox(height: 12),
                        _CustomAmountInput(
                          custom: state.result!.custom,
                          value: state.customYuan,
                          onChanged: (v) => ref
                              .read(paymentProvider.notifier)
                              .setCustomYuan(v),
                        ),
                      ],

                      const SizedBox(height: 20),
                      // 支付方式
                      if (state.result?.payMethods.isNotEmpty == true)
                        _PayMethodSelector(
                          methods: state.result!.payMethods,
                          selected: state.selectedMethod,
                          onSelect: (m) =>
                              ref.read(paymentProvider.notifier).selectMethod(m),
                        ),

                      const SizedBox(height: 24),
                      // 立即支付
                      ElevatedButton(
                        onPressed: state.creating ? null : () => _pay(context, ref),
                        child: state.creating
                            ? const SizedBox(
                                width: 20,
                                height: 20,
                                child: CircularProgressIndicator(
                                  strokeWidth: 2,
                                  color: Colors.white,
                                ),
                              )
                            : Text(
                                '立即支付${state.amountYuan != null ? ' ¥${state.amountYuan}' : ''}',
                                style: const TextStyle(fontSize: 16),
                              ),
                      ),
                      const SizedBox(height: 12),
                      const Center(
                        child: Text(
                          '1 元 = 10 积分，充值后积分实时到账',
                          style: TextStyle(
                              color: AppColors.textWeak, fontSize: 12),
                        ),
                      ),
                    ],
                  ),
                ),
    );
  }

  Future<void> _pay(BuildContext context, WidgetRef ref) async {
    final notifier = ref.read(paymentProvider.notifier);
    final current = ref.read(paymentProvider);
    if (current.amountYuan == null || current.selectedMethod == null) {
      showTopToast(context, '请选择充值金额与支付方式');
      return;
    }
    try {
      final order = await notifier.createOrder();
      if (!context.mounted) return;
      if (order.isUsdt) {
        context.push('/recharge/usdt', extra: order);
        return;
      }
      await _launchAndPoll(context, order);
    } on ApiException catch (e) {
      if (!context.mounted) return;
      if (e.code == 1001) {
        showTopToast(context, '充值金额不在可选档位，请重新选择');
      } else {
        showTopToast(context, e.message);
      }
    } catch (_) {
      if (context.mounted) showTopToast(context, '下单失败，请稍后重试');
    }
  }

  /// 调起原生 SDK；无有效调起参数时降级为「外部完成支付」轮询弹窗
  Future<void> _launchAndPoll(
      BuildContext context, RechargeOrderInfo order) async {
    // 服务端未配置商户密钥（dev）：返回 dev_mock，直接走轮询兜底
    if (order.payParams['dev_mock'] == true) {
      _showAliWechatSheet(context, order);
      return;
    }

    final result = await PayLauncher.launch(order);
    if (!context.mounted) return;
    switch (result) {
      case PayLaunchResult.success:
      case PayLaunchResult.unsupported:
        // 成功仍需服务端查单确认；参数不可用时降级到手动轮询
        _showAliWechatSheet(context, order);
      case PayLaunchResult.canceled:
        showTopToast(context, '已取消支付');
      case PayLaunchResult.failed:
        showTopToast(context, '调起支付失败，请确认已安装对应 App');
    }
  }

  /// 支付宝/微信：底部轮询弹窗（无 SDK 集成期以「我已完成支付」兜底）
  void _showAliWechatSheet(BuildContext context, RechargeOrderInfo order) {
    showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      backgroundColor: AppColors.surface,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
      ),
      builder: (ctx) => _AliWechatPollSheet(order: order),
    );
  }
}

/// 顶部积分余额
class _PointsHeader extends StatelessWidget {
  const _PointsHeader({required this.points});

  final int points;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: AppColors.surface,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        children: [
          const Icon(Icons.account_balance_wallet_outlined,
              color: AppColors.gold),
          const SizedBox(width: 8),
          Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              const Text('当前积分',
                  style: TextStyle(
                      color: AppColors.textSecondary, fontSize: 12)),
              Text('$points',
                  style: const TextStyle(
                      fontSize: 28,
                      fontWeight: FontWeight.w800,
                      color: AppColors.gold)),
            ],
          ),
        ],
      ),
    );
  }
}

/// 套餐网格
class _PackageGrid extends StatelessWidget {
  const _PackageGrid({
    required this.packages,
    required this.selectedId,
    required this.onSelect,
  });

  final List<RechargePackage> packages;
  final int? selectedId;
  final ValueChanged<int> onSelect;

  @override
  Widget build(BuildContext context) {
    return Wrap(
      spacing: 10,
      runSpacing: 10,
      children: packages.map((pkg) {
        final selected = selectedId == pkg.id;
        return GestureDetector(
          onTap: () => onSelect(pkg.id),
          child: Container(
            width: (MediaQuery.of(context).size.width - 42) / 2,
            padding: const EdgeInsets.all(12),
            decoration: BoxDecoration(
              color: AppColors.surface,
              borderRadius: BorderRadius.circular(10),
              border: selected
                  ? Border.all(color: AppColors.primary, width: 1.5)
                  : null,
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Text('¥${pkg.amountYuan}',
                        style: const TextStyle(
                            fontSize: 18, fontWeight: FontWeight.w700)),
                    if (pkg.bonus > 0)
                      Container(
                        padding:
                            const EdgeInsets.symmetric(horizontal: 5, vertical: 1),
                        decoration: BoxDecoration(
                          gradient: AppColors.goldGradient,
                          borderRadius: BorderRadius.circular(4),
                        ),
                        child: Text('赠 ${pkg.bonus}',
                            style: const TextStyle(
                                color: Colors.black,
                                fontSize: 10,
                                fontWeight: FontWeight.w700)),
                      ),
                  ],
                ),
                const SizedBox(height: 4),
                Text('到账 ${pkg.totalPoints} 积分',
                    style: const TextStyle(
                        color: AppColors.textSecondary, fontSize: 12)),
              ],
            ),
          ),
        );
      }).toList(),
    );
  }
}

/// 自定义金额输入
class _CustomAmountInput extends StatefulWidget {
  const _CustomAmountInput({
    required this.custom,
    required this.value,
    required this.onChanged,
  });

  final CustomRechargeConfig custom;
  final int? value;
  final ValueChanged<int?> onChanged;

  @override
  State<_CustomAmountInput> createState() => _CustomAmountInputState();
}

class _CustomAmountInputState extends State<_CustomAmountInput> {
  late final TextEditingController _ctrl;

  @override
  void initState() {
    super.initState();
    _ctrl = TextEditingController(
        text: widget.value == null ? '' : widget.value.toString());
  }

  @override
  void didUpdateWidget(covariant _CustomAmountInput oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (widget.value != oldWidget.value) {
      final newText = widget.value == null ? '' : widget.value.toString();
      if (_ctrl.text != newText) {
        _ctrl.text = newText;
      }
    }
  }

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

  @override
  Widget build(BuildContext context) {
    return TextField(
      controller: _ctrl,
      keyboardType: TextInputType.number,
      inputFormatters: [FilteringTextInputFormatter.digitsOnly],
      decoration: InputDecoration(
        hintText: '自定义金额（${widget.custom.minYuan}-${widget.custom.maxYuan} 元）',
        prefixIcon: const Icon(Icons.edit_outlined),
        suffixText: '元',
      ),
      onChanged: (v) {
        final n = int.tryParse(v);
        widget.onChanged(n);
      },
    );
  }
}

/// 支付方式单选
class _PayMethodSelector extends StatelessWidget {
  const _PayMethodSelector({
    required this.methods,
    required this.selected,
    required this.onSelect,
  });

  final List<PayMethod> methods;
  final int? selected;
  final ValueChanged<int> onSelect;

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const Text('支付方式',
            style: TextStyle(fontSize: 15, fontWeight: FontWeight.w700)),
        const SizedBox(height: 10),
        ...methods.map((m) {
          final active = selected == m.method;
          final icon = RechargeScreen._methodIcons[m.method] ?? Icons.payment;
          return ListTile(
            contentPadding: EdgeInsets.zero,
            dense: true,
            leading: Icon(icon, color: AppColors.gold),
            title: Text(m.name),
            trailing: active
                ? const Icon(Icons.check_circle, color: AppColors.primary)
                : const Icon(Icons.radio_button_off,
                    color: AppColors.textWeak),
            onTap: () => onSelect(m.method),
          );
        }),
      ],
    );
  }
}

/// 支付宝/微信轮询弹窗（底部 Sheet）
class _AliWechatPollSheet extends ConsumerStatefulWidget {
  const _AliWechatPollSheet({required this.order});

  final RechargeOrderInfo order;

  @override
  ConsumerState<_AliWechatPollSheet> createState() =>
      _AliWechatPollSheetState();
}

class _AliWechatPollSheetState
    extends ConsumerState<_AliWechatPollSheet> {
  @override
  Widget build(BuildContext context) {
    final poll = ref.watch(orderPollProvider(widget.order));

    // 状态变化时自动关闭（成功/超时/关闭）
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (poll.status == OrderPollStatus.paid) {
        _refreshUser();
        _showResult('支付成功', '已到账 ${widget.order.points} 积分');
      } else if (poll.status == OrderPollStatus.closed) {
        _showResult('订单已关闭', '该订单已被取消或超时');
      } else if (poll.status == OrderPollStatus.timeout) {
        _showResult('查询超时', '请前往「钱包-充值记录」稍后查看结果');
      }
    });

    return SafeArea(
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Container(
              width: 40,
              height: 4,
              decoration: BoxDecoration(
                color: AppColors.textWeak,
                borderRadius: BorderRadius.circular(2),
              ),
            ),
            const SizedBox(height: 16),
            Text(
              '支付中…',
              style:
                  const TextStyle(fontSize: 18, fontWeight: FontWeight.w700),
            ),
            const SizedBox(height: 8),
            Text(
              '订单号：${widget.order.orderNo}',
              style: const TextStyle(
                  color: AppColors.textSecondary, fontSize: 12),
            ),
            const SizedBox(height: 16),
            const SizedBox(
              width: 36,
              height: 36,
              child: CircularProgressIndicator(strokeWidth: 3),
            ),
            const SizedBox(height: 16),
            Text(
              widget.order.isUsdt
                  ? '请完成 USDT 转账'
                  : '请在外部完成支付，完成后返回本页',
              textAlign: TextAlign.center,
              style: const TextStyle(color: AppColors.textSecondary),
            ),
            const SizedBox(height: 20),
            TextButton(
              onPressed: () => _cancel(context),
              child: const Text('取消订单',
                  style: TextStyle(color: AppColors.textSecondary)),
            ),
          ],
        ),
      ),
    );
  }

  void _cancel(BuildContext context) async {
    final ok = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppColors.surface,
        title: const Text('取消订单', style: TextStyle(fontSize: 16)),
        content: const Text('取消后该笔订单将关闭，是否继续？'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx, false),
            child: const Text('继续支付'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(ctx, true),
            child:
                const Text('取消订单', style: TextStyle(color: AppColors.primary)),
          ),
        ],
      ),
    );
    if (ok == true) {
      await ref.read(orderPollProvider(widget.order).notifier).cancel();
    }
  }

  void _refreshUser() async {
    // 支付成功后刷新全局用户信息（积分余额）
    try {
      final user = await UserService.fetchMe();
      await ref.read(authProvider.notifier).onLoginSuccess(user);
    } catch (_) {}
  }

  void _showResult(String title, String body) {
    if (!context.mounted) return;
    Navigator.of(context).pop();
    showDialog<void>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppColors.surface,
        title: Text(title, style: const TextStyle(fontSize: 16)),
        content: Text(body),
        actions: [
          TextButton(
            onPressed: () {
              Navigator.pop(ctx);
              context.pop();
            },
            child: const Text('确定'),
          ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    // 停止轮询避免后台泄漏
    ref.read(orderPollProvider(widget.order).notifier).stop();
    super.dispose();
  }
}

class _LoadFailed extends StatelessWidget {
  const _LoadFailed({required this.onRetry});

  final VoidCallback onRetry;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Text('加载失败', style: TextStyle(color: AppColors.textSecondary)),
          const SizedBox(height: 12),
          TextButton(onPressed: onRetry, child: const Text('点击重试')),
        ],
      ),
    );
  }
}