facebook messenger platform sample

fbbot.go

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	log "github.com/Sirupsen/logrus"
	"io/ioutil"
	"net/http"
)

const token string = "XXXXXX"

func main() {
	http.HandleFunc("/", handler)
	http.ListenAndServe(":5555", nil)
}

type (
	FBRes struct {
		Object  string    `json:"object"`
		Entries []FBEntry `json:"entry"`
		//Entries []map[string]interface{} `json:"entry"`
	}
	FBEntry struct {
		ID         int           `json:"id"`
		Time       int           `json:"time"`
		Messagings []FBMessaging `json:"messaging"`
	}

	FBMessaging struct {
		Sender    FBSender    `json:"sender"`
		Recipient FBRecipient `json:"recipient"`
		Timestamp int         `json:"timestamp"`
		Message   FBMessage   `json:"message"`
	}
	FBMessage struct {
		Mid  string `json:"mid"`
		Seq  int    `json:"seq"`
		Text string `json:"text"`
	}

	FBSender struct {
		Id int `json:"id"`
	}
	FBRecipient struct {
		Id int `json:"id"`
	}
)

func handler(w http.ResponseWriter, r *http.Request) {
	res := FBRes{}
	json.NewDecoder(r.Body).Decode(&res)
	log.Info(res)

	for _, entry := range res.Entries {
		for _, messaging := range entry.Messagings {
			Send(messaging.Sender.Id, messaging.Message.Text)
		}
	}
}

func Send(id int, message string) {
	url := "https://graph.facebook.com/v2.6/me/messages?access_token=" + token

	data := map[string]interface{}{
		"recipient": map[string]int{"id": id},
		"message":   map[string]string{"text": message},
	}

	b, err := json.Marshal(data)
	log.Info(string(b), err)
	req, err := http.NewRequest("POST", url, bytes.NewBuffer(b))
	req.Header.Set("Content-Type", "application/json")

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()

	r, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Fatal(err)
	}

	log.Info(string(r))

}

func _verify_handler(w http.ResponseWriter, r *http.Request) {
	challenge := r.URL.Query()["hub.challenge"][0]
	fmt.Fprintf(w, challenge)
}