增加微信公众号数据统计功能 (#279)

* * fix: 移除代码中的Println

* 增加公众号数据统计

* fix code style

officialaccount/datacube/user.go

@@ -0,0 +1,77 @@
+package datacube
+
+import (
+	"fmt"
+	"github.com/silenceper/wechat/v2/util"
+)
+
+const (
+	getUserSummary    = "https://api.weixin.qq.com/datacube/getusersummary"
+	getUserAccumulate = "https://api.weixin.qq.com/datacube/getusercumulate"
+)
+
+//ResUserSummary 获取用户增减数据响应
+type ResUserSummary struct {
+	util.CommonError
+
+	List []struct {
+		RefDate    string `json:"ref_date"`
+		UserSource int    `json:"user_source"`
+		NewUser    int    `json:"new_user"`
+		CancelUser int    `json:"cancel_user"`
+	} `json:"list"`
+}
+
+//ResUserAccumulate 获取累计用户数据响应
+type ResUserAccumulate struct {
+	util.CommonError
+
+	List []struct {
+		RefDate      string `json:"ref_date"`
+		CumulateUser int    `json:"cumulate_user"`
+	} `json:"list"`
+}
+
+//GetUserSummary 获取用户增减数据
+func (cube *DataCube) GetUserSummary(s string, e string) (resUserSummary ResUserSummary, err error) {
+	accessToken, err := cube.GetAccessToken()
+	if err != nil {
+		return
+	}
+
+	uri := fmt.Sprintf("%s?access_token=%s", getUserSummary, accessToken)
+	reqDate := &reqDate{
+		BeginDate: s,
+		EndDate:   e,
+	}
+
+	response, err := util.PostJSON(uri, reqDate)
+	if err != nil {
+		return
+	}
+
+	err = util.DecodeWithError(response, &resUserSummary, "GetUserSummary")
+	return
+}
+
+//GetUserAccumulate 获取累计用户数据
+func (cube *DataCube) GetUserAccumulate(s string, e string) (resUserAccumulate ResUserAccumulate, err error) {
+	accessToken, err := cube.GetAccessToken()
+	if err != nil {
+		return
+	}
+
+	uri := fmt.Sprintf("%s?access_token=%s", getUserAccumulate, accessToken)
+	reqDate := &reqDate{
+		BeginDate: s,
+		EndDate:   e,
+	}
+
+	response, err := util.PostJSON(uri, reqDate)
+	if err != nil {
+		return
+	}
+
+	err = util.DecodeWithError(response, &resUserAccumulate, "GetUserAccumulate")
+	return
+}