twitter-application-token.go

package main

import (
	"bytes"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httputil"

	"github.com/davecgh/go-spew/spew"
)

// GetAccessToken is fetch application-only authentication access_token.
func GetAccessToken(consumerKey, consumerSecret string) string {
	bearer := fmt.Sprintf("%s:%s", consumerKey, consumerSecret)
	bearerBase64 := base64.StdEncoding.EncodeToString([]byte(bearer))

	client := &http.Client{}
	r := bytes.NewReader([]byte(`grant_type=client_credentials`))
	req, _ := http.NewRequest("POST", "https://api.twitter.com/oauth2/token", r)
	req.Header.Set("Authorization", fmt.Sprintf("Basic %s", bearerBase64))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8")

	resp, err := client.Do(req)
	if err != nil {
		panic(err)
	}

	var i map[string]string

	dec := json.NewDecoder(resp.Body)
	if err = dec.Decode(&i); err != nil {
		panic(err)
	}
	spew.Dump(i)

	return i["access_token"]
}

func request(req *http.Request) *http.Response {
	client := &http.Client{}

	dump, _ := httputil.DumpRequestOut(req, true)
	fmt.Printf("%s\n", dump)

	resp, err := client.Do(req)
	if err != nil {
		panic(err)
	}

	dumpResp, _ := httputil.DumpResponse(resp, true)
	fmt.Printf("%s\n", dumpResp)

	return resp
}

func GetUserTimeline(token, screenName string) interface{} {

	url := fmt.Sprintf("https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=%s", screenName)
	req, _ := http.NewRequest("GET", url, nil)
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
	req.Header.Set("Content-Type", "application/json")

	resp := request(req)

	var i interface{}

	dec := json.NewDecoder(resp.Body)
	if err := dec.Decode(&i); err != nil {
		panic(err)
	}

	return i
}

func GetRateLimit(token string) interface{} {

	url := "https://api.twitter.com/1.1/application/rate_limit_status.json?resources=statuses"
	req, _ := http.NewRequest("GET", url, nil)
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
	req.Header.Set("Content-Type", "application/json")

	resp := request(req)

	var i interface{}
	dec := json.NewDecoder(resp.Body)
	if err := dec.Decode(&i); err != nil {
		panic(err)
	}

	return i
}

func main() {
	key := "<consumer-key>"
	secret := "<consumer-secret>"

	accessToken := GetAccessToken(key, secret)
	GetUserTimeline(accessToken, "kikoxxx")
	GetRateLimit(accessToken)
}