import 'dart:async';

import 'package:fluwx/fluwx.dart' as fluwx;
import 'package:tobias/tobias.dart' as tobias;

import '../config/app_config.dart';
import 'models.dart';
import 'order_api.dart';

/// 支付服务抽象：创建订单 + 拉起渠道支付 + 返回支付结果
abstract class PaymentService {
  /// 支付完成后会通知服务端落授权；成功与否以 [PayResult.success] 为准
  Future<PayResult> pay(Plan plan, PayChannel channel);
}

/// 微信支付（fluwx 实现）
class WechatPayService implements PaymentService {
  WechatPayService({required this.orderApi});

  final OrderApi orderApi;

  @override
  Future<PayResult> pay(Plan plan, PayChannel channel) async {
    assert(channel == PayChannel.wechat);
    final order =
        await orderApi.createOrder(planId: plan.id, channel: channel);
    final p = order.wechatParams;

    final launched = await fluwx.Fluwx().pay(
      which: fluwx.Payment(
        appId: AppConfig.wechatAppId,
        partnerId: p['partnerId'] as String? ?? '',
        prepayId: p['prepayId'] as String? ?? '',
        packageValue: p['packageValue'] as String? ?? 'Sign=WXPay',
        nonceStr: p['nonceStr'] as String? ?? '',
        timestamp: int.tryParse('${p['timeStamp'] ?? p['timestamp']}') ?? 0,
        sign: p['sign'] as String? ?? '',
      ),
    );
    if (!launched) {
      return const PayResult(
          success: false, message: '未安装微信或拉起支付失败，请稍后再试');
    }

    // 等待微信回调（errCode == 0 为成功），10s 超时
    final completer = Completer<PayResult>();
    final cancel = fluwx.Fluwx().addSubscriber((response) {
      if (response is! fluwx.WeChatPaymentResponse) return;
      completer.complete(PayResult(
        success: response.isSuccessful,
        message: response.isSuccessful ? null : (response.errStr ?? '微信支付未完成'),
        orderId: order.orderId,
      ));
    });
    try {
      final result =
          await completer.future.timeout(const Duration(seconds: 10));
      if (result.success) await orderApi.confirmOrder(order.orderId);
      return result;
    } on TimeoutException {
      return PayResult(
          success: false,
          message: '等待微信支付结果超时，请确认支付状态',
          orderId: order.orderId);
    } finally {
      cancel.cancel();
    }
  }
}

/// 支付宝支付（tobias 实现，resultStatus 9000 为成功）
class AlipayService implements PaymentService {
  AlipayService({required this.orderApi});

  final OrderApi orderApi;

  @override
  Future<PayResult> pay(Plan plan, PayChannel channel) async {
    assert(channel == PayChannel.alipay);
    final order =
        await orderApi.createOrder(planId: plan.id, channel: channel);
    final orderStr = order.alipayOrderStr;
    if (orderStr == null) {
      return const PayResult(success: false, message: '订单缺少支付参数');
    }

    final map = await tobias.Tobias().pay(
      orderStr,
      universalLink: AppConfig.alipayUniversalLink,
    );
    final status = map['resultStatus']?.toString() ?? '';
    final ok = status == '9000';
    if (ok) await orderApi.confirmOrder(order.orderId);
    return PayResult(
      success: ok,
      message: ok ? null : _alipayMessage(status),
      orderId: order.orderId,
    );
  }

  static String _alipayMessage(String status) => switch (status) {
        '8000' => '支付结果确认中，请稍后查看',
        '6001' => '用户取消支付',
        '6002' => '网络异常，支付未完成',
        '6004' => '支付结果未知，请查询订单状态',
        _ => '支付宝支付未完成',
      };
}