tsearch.go

package main

import (
  "encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"os"
	"strings"
)

var consumerKey string
var consumerSecret string

type AccessToken struct {
	Access_Token string
	Token_Type   string
}

func initApp() {
	consumerKey = os.Getenv("TWITTER_CONSUMERKEY")
	consumerSecret = os.Getenv("TWITTER_CONSUMERSECRET")
}

func getSavedAccessToken() string {
	file, err := os.Open(".twitter")

	if err == nil {
		defer file.Close()
		bytes, err := ioutil.ReadAll(file)

		if err == nil {
			line := string(bytes)

			return line
		}
	}

	return ""
}

func authApp() (string, error) {
	const authUrl = "https://api.twitter.com/oauth2/token"
	var accessToken string
	accessToken = ""

	if len(consumerKey) == 0 || len(consumerSecret) == 0 {
		return "", errors.New("You must set the TWITTER_CONSUMERKEY and TWITTER_CONSUMERSECRET.")
	}

	client := &http.Client{}
	values := url.Values{"grant_type": {"client_credentials"}}
	req, err := http.NewRequest("POST", authUrl, strings.NewReader(values.Encode()))

	if err == nil {
		req.SetBasicAuth(consumerKey, consumerSecret)
		resp, err := client.Do(req)

		if err == nil {
			defer resp.Body.Close()
			body, err := ioutil.ReadAll(resp.Body)

			if err == nil {
				token := new(AccessToken)
				decoder := json.NewDecoder(strings.NewReader(string(body)))
				decoder.Decode(token)
				accessToken = token.Access_Token
			}
		}
	}

	return accessToken, err
}

func Get(url string, values url.Values, token string) (string, error) {
	var result string
	client := &http.Client{}

	if values != nil {
		url = url + "?" + values.Encode()
	}

	req, err := http.NewRequest("GET", url, nil)
	req.Header.Set("Authorization", "Bearer "+token)

	resp, err := client.Do(req)
	if err == nil {
		defer resp.Body.Close()
		body, err := ioutil.ReadAll(resp.Body)

		if err == nil {
			result = string(body)
		} 
	}

	return result, err
}

func main() {
	initApp()
	var accessToken string

	accessToken = getSavedAccessToken()

	if accessToken == "" {
		var err error
		accessToken, err = authApp()
		//Save token

		if err == nil {
			file, err := os.Create(".twitter")

			if err == nil {
				defer file.Close()
				file.WriteString(accessToken)
			}
		} else {
			fmt.Println(err)
			os.Exit(0)
		}
	}

	if accessToken != "" {
		result, err := Get("https://api.twitter.com/1.1/search/tweets.json", url.Values{"q": {"http://politicalticker.blogs.cnn.com/2013/03/11/desperate-times-marines-told-to-save-every-round/?on.cnn=1"}}, accessToken)
		
		if err == nil {
			fmt.Println(result)
		}
	}
}