import {
  Controller,
  Get,
  HttpStatus,
  Logger,
  Post,
  Query,
  Req,
  Res,
} from '@nestjs/common';
import type { Request, Response } from 'express';
import {
  decryptWechatEncrypt,
  normalizeTradeManageEvent,
  parseWechatPushBody,
  verifyWechatMsgSignature,
  verifyWechatUrlSignature,
} from '../integrations/wechat/wechat-msg-crypto.util';
import { WechatTradeManageService } from '../integrations/wechat/wechat-trade-manage.service';

/**
 * 小程序消息推送（发货信息管理事件）。
 * 后台配置 URL：https://{host}/api/v1/callbacks/wechat/message
 * 需配置 WX_MINI_MSG_TOKEN；安全模式另需 WX_MINI_MSG_AES_KEY。
 */
@Controller('callbacks/wechat')
export class WechatMessageCallbackController {
  private readonly logger = new Logger(WechatMessageCallbackController.name);

  constructor(private readonly tradeManage: WechatTradeManageService) {}

  @Get('message')
  verify(
    @Query('signature') signature: string,
    @Query('timestamp') timestamp: string,
    @Query('nonce') nonce: string,
    @Query('echostr') echostr: string,
    @Res() res: Response,
  ) {
    const token = (process.env.WX_MINI_MSG_TOKEN || '').trim();
    if (!token) {
      this.logger.error('WX_MINI_MSG_TOKEN 未配置，无法完成消息推送 URL 验证');
      return res.status(HttpStatus.SERVICE_UNAVAILABLE).send('msg token not configured');
    }
    if (!verifyWechatUrlSignature(token, timestamp, nonce, signature)) {
      this.logger.warn('wechat message URL verify failed');
      return res.status(HttpStatus.FORBIDDEN).send('invalid signature');
    }
    return res.status(HttpStatus.OK).send(echostr ?? '');
  }

  @Post('message')
  async receive(
    @Req() req: Request & { rawBody?: Buffer },
    @Query('signature') signature: string,
    @Query('timestamp') timestamp: string,
    @Query('nonce') nonce: string,
    @Query('msg_signature') msgSignature: string,
    @Query('encrypt_type') encryptType: string,
    @Res() res: Response,
  ) {
    const token = (process.env.WX_MINI_MSG_TOKEN || '').trim();
    if (!token) {
      return res.status(HttpStatus.SERVICE_UNAVAILABLE).send('msg token not configured');
    }

    try {
      const raw =
        req.rawBody?.toString('utf8') ??
        (typeof req.body === 'string'
          ? req.body
          : Buffer.isBuffer(req.body)
            ? req.body.toString('utf8')
            : JSON.stringify(req.body ?? {}));

      let body = parseWechatPushBody(raw);
      const encrypt = typeof body.Encrypt === 'string' ? body.Encrypt : undefined;
      const secure = encryptType === 'aes' || !!encrypt;

      if (secure) {
        if (!encrypt) {
          return res.status(HttpStatus.BAD_REQUEST).send('missing Encrypt');
        }
        const aesKey = (process.env.WX_MINI_MSG_AES_KEY || '').trim();
        if (!aesKey) {
          this.logger.error('安全模式推送但未配置 WX_MINI_MSG_AES_KEY');
          return res.status(HttpStatus.SERVICE_UNAVAILABLE).send('aes key not configured');
        }
        if (
          !verifyWechatMsgSignature(token, timestamp, nonce, encrypt, msgSignature || String(body.MsgSignature || ''))
        ) {
          return res.status(HttpStatus.FORBIDDEN).send('invalid msg_signature');
        }
        const appId = (process.env.WX_MINI_APP_ID || process.env.WX_APP_ID || '').trim();
        const plain = decryptWechatEncrypt(encrypt, aesKey, appId || undefined);
        body = parseWechatPushBody(plain);
      } else if (!verifyWechatUrlSignature(token, timestamp, nonce, signature)) {
        return res.status(HttpStatus.FORBIDDEN).send('invalid signature');
      }

      // 云托管探活
      if (String(body.action || '') === 'CheckContainerPath') {
        return res.status(HttpStatus.OK).send('success');
      }

      const evt = normalizeTradeManageEvent(body);
      if (evt.event) {
        await this.tradeManage.handleEvent(evt);
      }
      return res.status(HttpStatus.OK).send('success');
    } catch (err) {
      const message = err instanceof Error ? err.message : String(err);
      this.logger.error(`wechat message push failed: ${message}`);
      // 仍回 success，避免微信疯狂重试；错误已记日志
      return res.status(HttpStatus.OK).send('success');
    }
  }
}