main.go

package main

import (
	"crypto/rand"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"log"
	"net/http"

	"golang.org/x/crypto/bcrypt"
)

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

type SigninResponse struct {
	Success bool   `json:"success"`
	Message string `json:"message"`
	Token   string `json:"token"`
}

type User struct {
	Email    string
	Password string
}

func main() {
	user := User{
		Email:    "[email protected]",
		Password: "$2y$10$Q4W1ewsTLmvX20lLwKn/..jBIqsxiVrkt5wi/vnE3hjA4R/Uz6SKW",
	}

	http.HandleFunc("POST /signin", func(response http.ResponseWriter, request *http.Request) {
		signinRequest := SigninRequest{}

		decodeError := json.NewDecoder(request.Body).Decode(&signinRequest)

		if decodeError != nil {
			fmt.Fprintln(response, "Decoding request has failed because", decodeError)

			return
		}

		response.WriteHeader(http.StatusOK)

		response.Header().Add("Content-Type", "application/json")

		compareError := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(signinRequest.Password))

		bytes := make([]byte, 32)

		_, readError := rand.Read(bytes)

		if readError != nil {
			response.WriteHeader(http.StatusInternalServerError)
			response.Header().Set("Content-Type", "text/plain")
			fmt.Fprintln(response, "Unable to generate enough entropy")
			return
		}

		token := base64.RawURLEncoding.EncodeToString(bytes)

		signinResponse := SigninResponse{
			Success: true,
			Message: "All checked",
			Token:   token,
		}

		if compareError != nil {
			signinResponse.Success = false
			signinResponse.Message = "Bad credentials"
		}

		encodeError := json.NewEncoder(response).Encode(signinResponse)

		if encodeError != nil {
			response.WriteHeader(http.StatusInternalServerError)
			response.Header().Set("Content-Type", "text/plain")

			fmt.Fprintln(response, "Cannot encode response because", encodeError)
		}
	})

	fmt.Println("Démarrage du serveur...")

	address := ":8080"
	listenError := http.ListenAndServe(address, nil)

	if listenError != nil {
		log.Fatal("Erreur, le serveur n'a pas démarré : ", listenError)
	}

	fmt.Println("Hello, ESGI!")
}