main.go

package main

import (
	"log"
	"net/http"
	"strings"
	"time"

	"github.com/dgrijalva/jwt-go"
	"github.com/gin-contrib/cors"
	"github.com/gin-gonic/gin"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

var db *gorm.DB
var jwtKey = []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefgh")

type User struct {
	gorm.Model
	Username string `json:"username"`
	Password string `json:"password"`
}

type Claims struct {
	Username string `json:"username"`
	jwt.StandardClaims
}

type Customer struct {
	gorm.Model
	Name  string `json:"name"`
	Email string `json:"email"`
	Phone string `json:"phone"`
}

func main() {
	// Database connection
	dsn := "root:123@tcp(127.0.0.1:3307)/bontodev_lastproject_test?charset=utf8mb4&parseTime=True&loc=Local"
	var err error
	db, err = gorm.Open(mysql.Open(dsn), &gorm.Config{})
	if err != nil {
		log.Fatal("Failed to connect to database:", err)
	}

	// Auto migrate
	db.AutoMigrate(&User{})
	db.AutoMigrate(&Customer{})
	// Set up Gin
	r := gin.Default()

	// // CORS configuration
	// r.Use(cors.Default())

	// CORS configuration
	config := cors.DefaultConfig()
	config.AllowOrigins = []string{"http://localhost:3000"} // Replace with your desired origin
	config.AllowMethods = []string{"GET", "POST", "PUT", "DELETE"}
	r.Use(cors.New(config))

	// Routes
	r.POST("/login", login)
	r.POST("/signup", signup)

	// Authenticated routes
	auth := r.Group("/auth")
	auth.Use(authMiddleware())
	{
		auth.GET("/profile", profile)
		auth.GET("/customers", getCustomers)
		auth.GET("/customers/:id", getCustomer)
		auth.POST("/customers", createCustomer)
		auth.PUT("/customers/:id", updateCustomer)
		auth.DELETE("/customers/:id", deleteCustomer)
	}

	// Start server
	r.Run(":8080")
}

func signup(c *gin.Context) {
	var user User
	if err := c.ShouldBindJSON(&user); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if err := db.Create(&user).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "User created successfully"})
}

func login(c *gin.Context) {
	var user User
	if err := c.ShouldBindJSON(&user); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var dbUser User
	if err := db.Where("username = ? AND password = ?", user.Username, user.Password).First(&dbUser).Error; err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid credentials"})
		return
	}

	expirationTime := time.Now().Add(5 * time.Minute)
	claims := &Claims{
		Username: user.Username,
		StandardClaims: jwt.StandardClaims{
			ExpiresAt: expirationTime.Unix(),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	tokenString, err := token.SignedString(jwtKey)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Could not generate token"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"token": tokenString})
}

func authMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		tokenString := c.GetHeader("Authorization")
		if tokenString == "" {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "Authorization header required"})
			c.Abort()
			return
		}

		// Remove "Bearer " prefix from the token string
		tokenString = strings.TrimPrefix(tokenString, "Bearer ")

		claims := &Claims{}
		token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
			return jwtKey, nil
		})

		if err != nil || !token.Valid {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token", "msg": err.Error()})
			c.Abort()
			return
		}

		c.Set("username", claims.Username)
		c.Next()
	}
}

func profile(c *gin.Context) {
	username, _ := c.Get("username")
	c.JSON(http.StatusOK, gin.H{"username": username})
}

func getCustomers(c *gin.Context) {
	var customers []Customer
	db.Find(&customers)
	c.JSON(http.StatusOK, customers)
}

func createCustomer(c *gin.Context) {
	var customer Customer
	if err := c.ShouldBindJSON(&customer); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	db.Create(&customer)
	c.JSON(http.StatusCreated, customer)
}

func getCustomer(c *gin.Context) {
	id := c.Param("id")
	var customer Customer
	if err := db.Where("id = ?", id).First(&customer).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Customer not found"})
		return
	}

	c.JSON(http.StatusOK, customer)
}

func updateCustomer(c *gin.Context) {
	id := c.Param("id")
	var customer Customer
	if err := db.Where("id = ?", id).First(&customer).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Customer not found"})
		return
	}

	if err := c.ShouldBindJSON(&customer); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	db.Save(&customer)
	c.JSON(http.StatusOK, customer)
}

func deleteCustomer(c *gin.Context) {
	id := c.Param("id")
	var customer Customer
	if err := db.Where("id = ?", id).Delete(&customer).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Customer not found"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Customer deleted"})
}