feat(miniapp): 小程序订阅消息 (#429)

1. 用户订阅消息服务端回调处理
2. 用户订阅消息订阅通知事件推送

Co-authored-by: houseme <qzg40737@163.com>

miniprogram/server/server.go

@@ -0,0 +1,199 @@
+package server
+
+import (
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"github.com/silenceper/wechat/v2/miniprogram/context"
+	"github.com/silenceper/wechat/v2/miniprogram/message"
+	"github.com/silenceper/wechat/v2/util"
+	"io/ioutil"
+	"net/http"
+	"reflect"
+	"runtime/debug"
+	"strconv"
+)
+
+// Server struct
+type Server struct {
+	*context.Context
+	Write        http.ResponseWriter
+	Request      *http.Request
+	skipValidate bool
+	openID       string
+
+	messageHandler func(mixMessage *message.MiniProgramMixMessage) *message.Reply
+
+	RequestRawXMLMsg []byte
+	RequestMsg       *message.MiniProgramMixMessage
+
+	ResponseRawXMLMsg []byte
+	ResponseMsg       interface{}
+
+	isSafeMode bool
+	random     []byte
+	nonce      string
+	timestamp  int64
+}
+
+func NewServer(context *context.Context) *Server {
+	srv := new(Server)
+	srv.Context = context
+	return srv
+}
+
+func (srv *Server) Server() error {
+	if !srv.Validate() {
+		return fmt.Errorf("请求签名校验失败")
+	}
+	echoStr := srv.Query("echostr")
+	if echoStr != "" {
+		srv.SetResponseWrite(echoStr)
+		return nil
+	}
+
+	response, err := srv.handleRequest()
+	if err != nil {
+		return err
+	}
+
+	return srv.buildResponse(response)
+
+}
+
+// SkipValidate 设置跳过签名校验
+func (srv *Server) SkipValidate(skip bool) {
+	srv.skipValidate = skip
+}
+
+// Validate 校验请求是否合法
+func (srv *Server) Validate() bool {
+	if srv.skipValidate {
+		return true
+	}
+	timestamp := srv.Query("timestamp")
+	nonce := srv.Query("nonce")
+	signature := srv.Query("signature")
+	return signature == util.Signature(srv.Token, timestamp, nonce)
+}
+
+func (srv *Server) handleRequest() (reply *message.Reply, err error) {
+	//set isSafeMode
+	srv.isSafeMode = false
+	encryptType := srv.Query("encrypt_type")
+	if encryptType == "aes" {
+		srv.isSafeMode = true
+	}
+	//set openID
+	srv.openID = srv.Query("openid")
+
+	var msg interface{}
+	msg, err = srv.getMessage()
+	if err != nil {
+		return
+	}
+	mixMessage, success := msg.(*message.MiniProgramMixMessage)
+	if !success {
+		err = errors.New("消息类型转换失败")
+	}
+	srv.RequestMsg = mixMessage
+	reply = srv.messageHandler(mixMessage)
+	return
+}
+
+//GetOpenID return openID
+func (srv *Server) GetOpenID() string {
+	return srv.openID
+}
+
+func (srv *Server) getMessage() (interface{}, error) {
+	var rawXMLMsgBytes []byte
+	var err error
+	if srv.isSafeMode {
+		var encryptedXMLMsg message.EncryptedXMLMsg
+		if err := xml.NewDecoder(srv.Request.Body).Decode(&encryptedXMLMsg); err != nil {
+			return nil, fmt.Errorf("从body中解析xml失败，err=%v", err)
+		}
+		//验证消息签名
+		timestamp := srv.Query("timestamp")
+		srv.timestamp, err = strconv.ParseInt(timestamp, 10, 32)
+		if err != nil {
+			return nil, err
+		}
+		nonce := srv.Query("nonce")
+		srv.nonce = nonce
+		msgSignature := srv.Query("msg_signature")
+		msgSignatureGen := util.Signature(srv.Token, timestamp, nonce, encryptedXMLMsg.EncryptedMsg)
+		if msgSignature != msgSignatureGen {
+			return nil, fmt.Errorf("消息不合法，验证签名失败")
+		}
+
+		// 解密
+		srv.random, rawXMLMsgBytes, err = util.DecryptMsg(srv.AppID, encryptedXMLMsg.EncryptedMsg, srv.EncodingAESKey)
+		if err != nil {
+			return nil, fmt.Errorf("消息解密失败, err=%v", err)
+		}
+	} else {
+		rawXMLMsgBytes, err = ioutil.ReadAll(srv.Request.Body)
+		if err != nil {
+			return nil, fmt.Errorf("从body中解析xml失败, err=%v", err)
+		}
+	}
+	srv.RequestRawXMLMsg = rawXMLMsgBytes
+	return srv.parseRequestMessage(rawXMLMsgBytes)
+}
+
+func (srv *Server) parseRequestMessage(rawXMLMsgBytes []byte) (msg *message.MiniProgramMixMessage, err error) {
+	msg = &message.MiniProgramMixMessage{}
+	err = xml.Unmarshal(rawXMLMsgBytes, msg)
+	return
+}
+
+func (srv *Server) SetMessageHandler(handler func(*message.MiniProgramMixMessage) *message.Reply) {
+	srv.messageHandler = handler
+}
+
+func (srv *Server) buildResponse(reply *message.Reply) (err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			err = fmt.Errorf("panic error: %v\n%s", e, debug.Stack())
+		}
+	}()
+	if reply == nil {
+		return nil
+	}
+	msgType := reply.MsgType
+	switch msgType {
+	case message.MsgTypeEvent:
+	case message.MsgTypeImage:
+	case message.MsgTypeLink:
+	case message.MsgTypeText:
+	case message.MsgTypeMiniProgramPage:
+	default:
+		err = message.ErrUnsupportedReply
+		return
+	}
+	msgData := reply.MsgData
+	value := reflect.ValueOf(msgData)
+	//msgData must be a ptr
+	kind := value.Kind().String()
+	if kind != "ptr" {
+		return message.ErrUnsupportedReply
+	}
+	params := make([]reflect.Value, 1)
+	params[0] = reflect.ValueOf(srv.RequestMsg.FromUserName)
+	value.MethodByName("SetToUserName").Call(params)
+
+	params[0] = reflect.ValueOf(srv.RequestMsg.ToUserName)
+	value.MethodByName("SetFromUserName").Call(params)
+
+	params[0] = reflect.ValueOf(srv.RequestMsg.MsgType)
+	value.MethodByName("SetMsgType").Call(params)
+
+	params[0] = reflect.ValueOf(util.GetCurrTS())
+	value.MethodByName("SetCreateTime").Call(params)
+
+	srv.ResponseMsg = msgData
+	srv.ResponseRawXMLMsg, err = xml.Marshal(msgData)
+	return
+}

miniprogram/server/util.go

@@ -0,0 +1,29 @@
+package server
+
+import "net/http"
+
+var textContentType = []string{"text/plain; charset=utf-8"}
+
+//Set http response Content-Type
+func setContentType(w http.ResponseWriter, value []string) {
+	header := w.Header()
+	if val := header["Content-Type"]; len(val) == 0 {
+		header["Content-Type"] = value
+	}
+}
+
+// Query 查询 URL query string
+func (srv *Server) Query(key string) string {
+	req := srv.Request
+	return req.URL.Query().Get(key)
+}
+
+// SetResponseWrite 设置回调返回值
+func (srv *Server) SetResponseWrite(str string) {
+	setContentType(srv.Write, textContentType)
+	srv.Write.WriteHeader(http.StatusOK)
+	_, err := srv.Write.Write([]byte(str))
+	if err != nil {
+		panic(err)
+	}
+}