添加微信客服SDK (#436)

* 添加微信客服SDK

* polish:优化签名函数

* polish：优化注释内容

* polish:复用已有的Token以及CommonError,移除无用的输出

* polish:复用已有的消息加解密

* fix:修复错误信息被覆盖的问题

* polish:go fmt 文件

work/kf/syncmsg/syncmsg.go

@@ -0,0 +1,102 @@
+package syncmsg
+
+import "encoding/json"
+
+// Message 同步的消息内容
+type Message struct {
+	MsgID          string `json:"msgid"`           // 消息ID
+	OpenKFID       string `json:"open_kfid"`       // 客服帐号ID
+	ExternalUserID string `json:"external_userid"` // 客户UserID
+	SendTime       uint64 `json:"send_time"`       // 消息发送时间
+	Origin         uint32 `json:"origin"`          // 消息来源。3-客户回复的消息 4-系统推送的消 息
+	MsgType        string `json:"msgtype"`         // 消息类型
+	EventType      string `json:"event_type"`      // 事件类型
+	OriginData     []byte `json:"origin_data"`     // 原始数据内容
+}
+
+// GetOriginMessage 获取原始消息
+func (r Message) GetOriginMessage() (info []byte) {
+	return r.OriginData
+}
+
+// GetTextMessage 获取文本消息
+func (r Message) GetTextMessage() (info Text, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetImageMessage 获取图片消息
+func (r Message) GetImageMessage() (info Image, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetVoiceMessage 获取语音消息
+func (r Message) GetVoiceMessage() (info Voice, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetVideoMessage 获取视频消息
+func (r Message) GetVideoMessage() (info Video, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetFileMessage 获取文件消息
+func (r Message) GetFileMessage() (info File, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetLocationMessage 获取文件消息
+func (r Message) GetLocationMessage() (info Location, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetLinkMessage 获取链接消息
+func (r Message) GetLinkMessage() (info Link, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetBusinessCardMessage 获取名片消息
+func (r Message) GetBusinessCardMessage() (info BusinessCard, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetMiniProgramMessage 获取小程序消息
+func (r Message) GetMiniProgramMessage() (info MiniProgram, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetEnterSessionEvent 用户进入会话事件
+func (r Message) GetEnterSessionEvent() (info EnterSessionEvent, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	info.OpenKFID = info.Event.OpenKFID
+	info.ExternalUserID = info.Event.ExternalUserID
+	return info, err
+}
+
+// GetMsgSendFailEvent 消息发送失败事件
+func (r Message) GetMsgSendFailEvent() (info MsgSendFailEvent, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetReceptionistStatusChangeEvent 客服人员接待状态变更事件
+func (r Message) GetReceptionistStatusChangeEvent() (info ReceptionistStatusChangeEvent, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	return info, err
+}
+
+// GetSessionStatusChangeEvent 会话状态变更事件
+func (r Message) GetSessionStatusChangeEvent() (info SessionStatusChangeEvent, err error) {
+	err = json.Unmarshal(r.OriginData, &info)
+	info.OpenKFID = info.Event.OpenKFID
+	info.ExternalUserID = info.Event.ExternalUserID
+	return info, err
+}