go_winter_work_2025/go/lesson3/controllers/controllers.go

package controllers

import (
	strconv "strconv"
	time "time"

	fiber "github.com/gofiber/fiber/v2"
	jwt "github.com/golang-jwt/jwt"
	bcrypt "golang.org/x/crypto/bcrypt"
	database "lesson3/database"
	models "lesson3/models"
)

func Register(c *fiber.Ctx) error {
	var data map[string]string

	if err := c.BodyParser(&data); err != nil {
		return err
	}

	password, _ := bcrypt.GenerateFromPassword(
		[]byte(data["password"]),
		14,
	) // GenerateFromPassword returns the bcrypt hash of the password at the given cost i.e. (14 in our case).

	user := models.User{
		Name:     data["name"],
		Email:    data["email"],
		Password: password,
	}

	database.DB.Create(&user) // Adds the data to the DB

	return c.JSON(user)
}

const SecretKey = "secret"

func Login(c *fiber.Ctx) error {
	var data map[string]string

	if err := c.BodyParser(&data); err != nil {
		return err
	}

	var user models.User

	database.DB.Where("email = ?", data["email"]).
		First(&user)
		// Check the email is present in the DB

	if user.ID == 0 { // If the ID return is '0' then there is no such email present in the DB
		c.Status(fiber.StatusNotFound)
		return c.JSON(fiber.Map{
			"message": "user not found",
		})
	}

	if err := bcrypt.CompareHashAndPassword(user.Password, []byte(data["password"])); err != nil {
		c.Status(fiber.StatusBadRequest)
		return c.JSON(fiber.Map{
			"message": "incorrect password",
		})
	} // If the email is present in the DB then compare the Passwords and if incorrect password then return error.

	claims := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.StandardClaims{
		Issuer:    strconv.Itoa(int(user.ID)),
		ExpiresAt: time.Now().Add(time.Hour * 24).Unix(), // 1 day
	})

	token, err := claims.SignedString([]byte(SecretKey))
	if err != nil {
		c.Status(fiber.StatusInternalServerError)
		return c.JSON(fiber.Map{
			"message": "could not login",
		})
	}

	cookie := fiber.Cookie{
		Name:     "jwt",
		Value:    token,
		Expires:  time.Now().Add(time.Hour * 24),
		HTTPOnly: true,
	}

	c.Cookie(&cookie)

	return c.JSON(fiber.Map{
		"message": "success",
	})
}

func User(c *fiber.Ctx) error {
	cookie := c.Cookies("jwt")

	token, err := jwt.ParseWithClaims(
		cookie,
		&jwt.StandardClaims{},
		func(token *jwt.Token) (interface{}, error) {
			return []byte(SecretKey), nil
		},
	)
	if err != nil {
		c.Status(fiber.StatusUnauthorized)
		return c.JSON(fiber.Map{
			"message": "unauthenticated",
		})
	}

	claims := token.Claims.(*jwt.StandardClaims)

	var user models.User

	database.DB.Where("id = ?", claims.Issuer).First(&user)

	return c.JSON(user)
}

func Logout(c *fiber.Ctx) error {
	cookie := fiber.Cookie{
		Name:  "jwt",
		Value: "",
		Expires: time.Now().
			Add(-time.Hour),
		// Sets the expiry time an hour ago in the past.
		HTTPOnly: true,
	}

	c.Cookie(&cookie)

	return c.JSON(fiber.Map{
		"message": "success",
	})
}