Dialogflow webhook sample code

main.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"strconv"

	owm "github.com/briandowns/openweathermap"
	"github.com/julienschmidt/httprouter"
	dfw "github.com/leboncoin/dialogflow-go-webhook"
)

const (
	apiKey = "your_OpenWeatherMap_key"
)

func main() {
	router := httprouter.New()
	router.POST("/webhook", webhook)
	log.Fatal(http.ListenAndServe(":8080", router))
}

func webhook(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
	// 接收 fulfllment request
	dfr := dfw.Request{}

	decoder := json.NewDecoder(r.Body)
	err := decoder.Decode(&dfr)
	if err != nil {
		panic(err)
	}
	// 打印出 fulfillment request 的 body (debug 使用)
	b, err := json.MarshalIndent(dfr, "", "    ")
	if err != nil {
		panic(err)
	}
	log.Println(string(b))

	m, err := jsonStringToMap(string(dfr.QueryResult.Parameters))
	if err != nil {
		log.Fatalln(err)
	}

	// 取出參數
	city := m["geo-city"].(string)
	log.Printf("Action: %s, City: %s", dfr.QueryResult.Action, city)

	// 呼叫 OpenWeatherMap API 查詢氣溫
	temp := getTemperature(city)

	// 構造 fulfillment response 返回
	dff := &dfw.Fulfillment{
		FulfillmentText: fmt.Sprintf(
			"Current temperature of %s is %s", city, temp,
		),
	}
	resp, err := json.Marshal(dff)
	if err != nil {
		log.Fatalln(err)
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	w.Write(resp)
}

func getTemperature(locationName string) string {
	owmCurrent, err := owm.NewCurrent("C", "ZH_TW", apiKey)
	if err != nil {
		log.Fatalln(err)
	}

	owmCurrent.CurrentByName(locationName)
	return strconv.FormatFloat(owmCurrent.Main.Temp, 'f', -1, 64)
}

func jsonStringToMap(jsonString string) (map[string]interface{}, error) {
	var dat map[string]interface{}

	err := json.Unmarshal([]byte(jsonString), &dat)
	if err != nil {
		return nil, err
	}

	return dat, err
}