wechat_hitxy/outMsg.go

package main

import (
	"crypto/sha1"
	"errors"
	"fmt"
	"log"
	"math/rand"
	"sort"
	"strings"
	"time"
)

//Article is one item in News Message
// one such message can contains upto 10 Articles
type Article struct {
	title, description, picURL, url string
}

//BuildTextMsg Given a text message send it to wechat client
func BuildTextMsg(txt string, ToUserName string) (xml string, err error) {
	if txt == "" || ToUserName == "" {
		err = errors.New("Empty text body or Empty destination")
		xml = ""
		return
	}

	msg := fmt.Sprintf(txtMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), txt)
	e := Encode(msg)
	xml, _, _, _ = signMsg(e)
	return
}

func signMsg(content string) (xml string, timestamp int32, nonce int32, signature string) {
	timestamp = int32(time.Now().Unix())
	nonce = rand.Int31()

	strTimestamp := fmt.Sprintf("%d", timestamp)
	strNonce := fmt.Sprintf("%d", nonce)
	signature = getSignature(APIConfig.Token, strTimestamp, strNonce, content)
	xml = "<xml>" +
		"<Encrypt>" + content + "</Encrypt>" +
		"<MsgSignature>" + signature + "</MsgSignature>" +
		"<TimeStamp>" + strTimestamp + "</TimeStamp>" +
		"<Nonce>" + strNonce + "</Nonce>" +
		"</xml>"
	return
}

func getSignature(token string, timestamp string, nonce string, content string) (signature string) {
	strs := []string{token, timestamp, nonce, content}
	sort.Strings(strs)
	s := strings.Join(strs, "")
	h := sha1.New()
	h.Write([]byte(s))
	signature = fmt.Sprintf("%x", h.Sum(nil))
	return
}

func buildTxtMsg(ToUserName, content string) (msg string) {
	msg = fmt.Sprintf(txtMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), content)
	return
}
func txtMsgTemplate() string {
	return `<xml>
 <ToUserName><![CDATA[%s]]></ToUserName>
 <FromUserName><![CDATA[%s]]></FromUserName>
 <CreateTime>%d</CreateTime>
 <MsgType><![CDATA[text]]></MsgType>
 <Content><![CDATA[%s]]></Content>
 </xml>`
}

func buildPicMsg(ToUserName, mediaID string) (msg string) {
	msg = fmt.Sprintf(picMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), mediaID)
	return
}
func picMsgTemplate() string {
	return `<xml>
<ToUserName><![CDATA[%s]]></ToUserName>
<FromUserName><![CDATA[%s]]></FromUserName>
<CreateTime>%d</CreateTime>
<MsgType><![CDATA[image]]></MsgType>
<Image>
<MediaId><![CDATA[%s]]></MediaId>
</Image>
</xml>`
}

func buildVoiceMsg(ToUserName, mediaID string) (msg string) {
	msg = fmt.Sprintf(voiceMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), mediaID)
	return
}
func voiceMsgTemplate() string {
	return `<xml>
<ToUserName><![CDATA[%s]]></ToUserName>
<FromUserName><![CDATA[%s]]></FromUserName>
<CreateTime>%d</CreateTime>
<MsgType><![CDATA[voice]]></MsgType>
<Voice>
<MediaId><![CDATA[%s]]></MediaId>
</Voice>
</xml>`
}

func buildVideoMsg(ToUserName, mediaID, title, description string) (msg string) {
	msg = fmt.Sprintf(videoMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), mediaID, title, description)
	return
}
func videoMsgTemplate() string {
	return `<xml>
<ToUserName><![CDATA[%s]]></ToUserName>
<FromUserName><![CDATA[%s]]></FromUserName>
<CreateTime>%d</CreateTime>
<MsgType><![CDATA[video]]></MsgType>
<Video>
<MediaId><![CDATA[%s]]></MediaId>
<Title><![CDATA[%s]]></Title>
<Description><![CDATA[%s]]></Description>
</Video> 
</xml>`
}

func bulidMusicMsg(ToUserName, mediaID, title, description, url, hqURL string) (msg string) {
	msg = fmt.Sprintf(musicMsgTemplate(),
		ToUserName,
		APIConfig.PublicAccountID,
		int32(time.Now().Unix()),
		title,
		description,
		url,
		hqURL,
		mediaID)
	return
}
func musicMsgTemplate() string {
	return `<xml>
<ToUserName><![CDATA[toUser]]></ToUserName>
<FromUserName><![CDATA[fromUser]]></FromUserName>
<CreateTime>12345678</CreateTime>
<MsgType><![CDATA[music]]></MsgType>
<Music>
<Title><![CDATA[TITLE]]></Title>
<Description><![CDATA[DESCRIPTION]]></Description>
<MusicUrl><![CDATA[MUSIC_Url]]></MusicUrl>
<HQMusicUrl><![CDATA[HQ_MUSIC_Url]]></HQMusicUrl>
<ThumbMediaId><![CDATA[media_id]]></ThumbMediaId>
</Music>
</xml>`
}

func buildNewsMsg(ToUserName, title, description string, articles []Article) (msg string) {
	count := 0
	items := []string{}
	for _, a := range articles {
		if count >= 8 {
			err := errors.New("too many articles, only take first 8")
			log.Fatal(err)
			break
		}
		s := buildArticleItem(a)
		items = append(items, s)
		count++
	}
	strItems := strings.Join(items, "")

	msg = fmt.Sprintf(newsMsgTemplate(),
		ToUserName,
		APIConfig.PublicAccountID,
		int32(time.Now().Unix()),
		count,
		strItems)
	return
}

func buildArticleItem(item Article) (article string) {
	template := `<item>
<Title><![CDATA[%s]]></Title> 
<Description><![CDATA[%s]]></Description>
<PicUrl><![CDATA[%s]]></PicUrl>
<Url><![CDATA[%s]]></Url>
</item>
`
	article = fmt.Sprintf(template,
		item.title, item.description, item.picURL, item.url)
	return article
}

func newsMsgTemplate() string {
	return `<xml>
<ToUserName><![CDATA[%s]]></ToUserName>
<FromUserName><![CDATA[%s]]></FromUserName>
<CreateTime>%d</CreateTime>
<MsgType><![CDATA[news]]></MsgType>
<ArticleCount>%d</ArticleCount>
<Articles>
%s
</Articles>
</xml>`
}