meifamily/ptt-alertor

package line

import (
    "bytes"
    "encoding/json"
    "errors"
    "fmt"
    "html/template"
    "io/ioutil"
    "net/http"
    "net/url"
    "os"
    "sort"
    "strconv"

    log "github.com/Ptt-Alertor/logrus"
    "github.com/julienschmidt/httprouter"

    "github.com/Ptt-Alertor/ptt-alertor/models"
)

const notifyBotHost string = "https://notify-bot.line.me"
const notifyAPIHost string = "https://notify-api.line.me"

var (
    params       map[string]string
    clientID     = os.Getenv("LINE_CLIENT_ID")
    clientSecret = os.Getenv("LINE_CLIENT_SECRET")
    redirectURI  = os.Getenv("APP_HOST") + "/line/notify/callback"
)

func buildQueryString(params map[string]string) (query string) {
    var keys []string
    for key := range params {
        keys = append(keys, key)
    }
    sort.Strings(keys)
    for _, key := range keys {
        query += fmt.Sprintf("%s=%s&", key, params[key])
    }
    return query
}

func getAuthorizeURL(lineID string) string {
    var uri = "/oauth/authorize"
    params = map[string]string{
        "response_type": "code",
        "client_id":     clientID,
        "redirect_uri":  redirectURI,
        "scope":         "notify",
        "state":         lineID,
        "response_mode": "form_post",
    }
    query := buildQueryString(params)
    return fmt.Sprintf("%s%s?%s", notifyBotHost, uri, query)
}

// CatchCallback accept line notify post request to get user code
func CatchCallback(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
    if r.FormValue("error") != "" {
        log.WithFields(log.Fields{
            "error":       r.FormValue("error"),
            "state":       r.FormValue("state"),
            "description": r.FormValue("error_description"),
        }).Error("Get LINE Notify Callback Failed")
    }

    code, lineID := r.FormValue("code"), r.FormValue("state")
    accessToken, err := fetchAccessToken(code)
    if err != nil {
        log.WithError(err).Error("Fetch Access Token Failed")
    }

    u := models.User().Find(lineID)
    u.Profile.LineAccessToken = accessToken
    if err := u.Update(); err != nil {
        log.WithError(err).Error("User Update Failed")
        Notify(accessToken, "\n連結 LINE Notify 失敗。\n請至 Ptt Alertor LINE 主頁回報區留言。")
    } else {
        Notify(accessToken, "\n請回到 Ptt Alertor 輸入「指令」查看相關功能。\nPtt Alertor: 設定看板、作者、關鍵字\nLINE Notify: 最新文章通知")
    }

    t, err := template.ParseFiles("public/notify.html")
    if err != nil {
        log.WithError(err).Error("Show notify.html Failed")
    }
    t.Execute(w, nil)
}

func checkLineAccessTokenExist(lineID string) bool {
    u := models.User().Find(lineID)
    if u.Profile.LineAccessToken == "" {
        return false
    }
    return true
}

func fetchAccessToken(code string) (string, error) {
    type responseBody struct {
        AccessToken string `json:"access_token"`
    }
    uri := "/oauth/token"
    params = map[string]string{
        "grant_type":    "authorization_code",
        "code":          code,
        "redirect_uri":  redirectURI,
        "client_id":     clientID,
        "client_secret": clientSecret,
    }
    body := buildQueryString(params)
    r, err := http.Post(notifyBotHost+uri, "application/x-www-form-urlencoded", bytes.NewBufferString(body))
    if err != nil {
        log.WithError(err).Error("Post Error")
    }
    if r.StatusCode != http.StatusOK {
        err := errors.New("Get Line Access Token Error, StatusCode:" + strconv.Itoa(r.StatusCode))
        log.WithError(err).Error()
        return "", err
    }
    var rspBody responseBody
    err = json.NewDecoder(r.Body).Decode(&rspBody)
    if err != nil {
        log.WithError(err).Error("Decode Line Access Token Error")
        return "", err
    }
    return rspBody.AccessToken, nil
}

func Notify(accessToken string, message string) {
    uri := "/api/notify"
    queryStr := url.Values{}
    queryStr.Add("message", message)
    encodeQueryStr := queryStr.Encode()
    pr, err := http.NewRequest("POST", notifyAPIHost+uri, bytes.NewBufferString(encodeQueryStr))
    pr.Header.Set("Content-Type", "application/x-www-form-urlencoded")
    pr.Header.Set("Authorization", "Bearer "+accessToken)
    client := &http.Client{}
    r, err := client.Do(pr)
    if err != nil {
        log.WithError(err).Error("Notify Request Failed")
        return
    }
    defer r.Body.Close()
    if r.StatusCode != http.StatusOK {
        data, _ := ioutil.ReadAll(r.Body)
        log.WithFields(log.Fields{
            "status":   r.Status,
            "response": string(data),
        }).Error("LINE Notify Failed")
    }
}