udemy-go-microservices/broker-service/cmd/api/handlers.go

package main

import (
	"bytes"
	"encoding/json"
	"errors"
	"log"
	"net/http"
)

type RequestPayload struct {
	Action string      `string:"action"`
	Auth   AuthPayload `                json:"auth,omitempty"`
}

type AuthPayload struct {
	Email    string `json:"email"`
	Password string `json:"password"`
}

func (app *Config) Broker(w http.ResponseWriter, r *http.Request) {
	payload := jsonResponse{
		Error:   false,
		Message: "Hit the broker",
	}

	app.writeJSON(w, http.StatusOK, payload)
}

func (app *Config) HandleSubmission(w http.ResponseWriter, r *http.Request) {
	var requestPayload RequestPayload

	err := app.readJSON(w, r, &requestPayload)
	if err != nil {
		app.errorJSON(w, err, http.StatusBadRequest)
		return
	}

	switch requestPayload.Action {
	case "auth":
		app.authenticate(w, requestPayload.Auth)
	default:
		app.errorJSON(w, errors.New("unknown action"))
	}
}

func (app *Config) authenticate(w http.ResponseWriter, a AuthPayload) {
	// create some json we'll send to the auth microservice
	authPayload, err := json.MarshalIndent(a, "", "\t")
	if err != nil {
		app.errorJSON(w, err, http.StatusBadRequest)
		return
	}

	// call the service
	req, err := http.NewRequest(
		"POST",
		"http://authentication-service:4000/authenticate",
		bytes.NewBuffer(authPayload),
	)
	if err != nil {
		app.errorJSON(w, err, http.StatusBadRequest)
		return
	}
	req.Header.Add("Content-Type", "application/json")
	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		app.errorJSON(w, err, http.StatusInternalServerError)
		return
	}
	defer resp.Body.Close()

	log.Println(resp.Body)

	// make sure we get back the correct status code
	if resp.StatusCode != http.StatusAccepted {
		app.errorJSON(w, errors.New("invalid credentials"))
		return
	}

	// create a variable we'll read resp.Body into
	var respPayload jsonResponse

	err = json.NewDecoder(resp.Body).Decode(&respPayload)
	if err != nil {
		app.errorJSON(w, err, http.StatusBadRequest)
		return
	}

	if respPayload.Error {
		app.errorJSON(w, errors.New(respPayload.Message), http.StatusUnauthorized)
		return
	}

	var payload jsonResponse
	payload.Error = false
	payload.Message = "Authenticated!"
	payload.Data = respPayload.Data

	app.writeJSON(w, http.StatusOK, payload)
}