微信文本消息处理

type WeChatVerify struct {
	Signature string `json:"signature" form:"signature"`
	Timestamp string `json:"timestamp" form:"timestamp"`
	Nonce     string `json:"nonce" form:"nonce"`
	Echostr   string `json:"echostr" form:"echostr"`
}

type WeChatMsg struct {
	XMLName      xml.Name `xml:"xml"`
	ToUserName   string
	FromUserName string
	CreateTime   int64
	MsgType      string
	Content      string
}

func wxPost(ctx *gin.Context) {
	log.Info("Get Msg from wechat")
	verify := &WeChatVerify{
		Signature: ctx.Query("signature"),
		Timestamp: ctx.Query("timestamp"),
		Nonce:     ctx.Query("nonce"),
		Echostr:   ctx.Query("echostr"),
	}
	if !verify.Verify() {
		log.Error("WeChat Verify failed")
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "WeChat Verify failed"})
		return
	}
	log.Info("verify pass")

	reqBody := &WeChatMsg{}
	body, err := io.ReadAll(ctx.Request.Body)
	if err != nil {
		log.Errorf("read request body error: %s", err.Error())
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "read request body error"})
		return
	}
	xml.Unmarshal(body, reqBody)
	reqBytes, _ := sonic.Marshal(reqBody)
	log.Infof("Get requset from wechat: %s", string(reqBytes))

	switch reqBody.MsgType {
	case "text":
		resp := &WeChatMsg{}
		resp.FromUserName = reqBody.ToUserName
		resp.ToUserName = reqBody.FromUserName
		resp.CreateTime = time.Now().Unix()
		resp.MsgType = "text"
		resp.Content = reqBody.Content
		respBytes, _ := xml.Marshal(resp)
		log.Infof("return msg to wechat: %s", string(respBytes))
		ctx.Writer.Header().Set("Content-Type", "text/xml")
		ctx.Writer.WriteString(string(respBytes))
	default:
		log.Errorf("unknow MsgType: %s", reqBody.MsgType)
		ctx.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("unknow MsgType: %s", reqBody.MsgType)})
		return
	}
}