import { Inject, Injectable } from '@nestjs/common';
import { loadAppConfig } from '@dukang/shared-types';
import { PrismaService } from '../../common/prisma/prisma.module';
import { WECHAT_PROVIDER } from '../integrations.constants';
import type { IWechatProvider } from '../wechat/wechat.interface';
import type { IPayProvider, PayOrderResult } from './pay.interface';

@Injectable()
export class PayWechatProvider implements IPayProvider {
  private readonly config = loadAppConfig();

  constructor(
    private readonly prisma: PrismaService,
    @Inject(WECHAT_PROVIDER) private readonly wechat: IWechatProvider,
  ) {}

  async payOrder(orderId: bigint, openId?: string): Promise<PayOrderResult> {
    if (this.config.mockPay) {
      return { mode: 'mock', externalNo: `MOCK-${Date.now()}` };
    }
    if (!openId) {
      throw new Error('微信支付需要用户 openId，请先完成微信授权登录');
    }
    if (!this.wechat.isEnabled()) {
      throw new Error('微信能力未启用，请配置 WECHAT_AUTH_ENABLED 与 WX_APP_ID/SECRET');
    }

    const order = await this.prisma.order.findUnique({ where: { id: orderId } });
    if (!order) throw new Error('订单不存在');

    const amountFen = Math.round(Number(order.payAmount) * 100);
    const prepay = await this.wechat.createJsapiPrepay({
      orderNo: order.orderNo,
      description: `杜康好客订单 ${order.orderNo}`,
      amountFen,
      openId,
      notifyUrl: process.env.WX_PAY_NOTIFY_URL ?? '',
    });
    return { mode: 'jsapi', prepay };
  }
}