Add handler auth

backend/handlers/auth_handler.go

@@ -0,0 +1,50 @@
+package handlers
+
+import (
+	"net/http"
+	"time"
+	"os"
+
+	"github.com/gin-gonic/gin"
+	"github.com/golang-jwt/jwt/v5"
+	"golang.org/x/crypto/bcrypt"
+
+	"viplight-mrp/database"
+	"viplight-mrp/models"
+)
+
+jwtSecret := os.Getenv("JWT_SECRET")
+jwtKey := []byte(jwtSecret) 
+
+func Login(c *gin.Context) {
+	var input struct {
+		Username string `json:"username"`
+		Password string `json:"password"`
+	}
+
+	if err := c.ShouldBindJSON(&input); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid input"})
+		return
+	}
+
+	var user models.User
+
+	err := database.DB.Where("username = ?", input.Username).First(&user).Error
+
+	passErr := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(input.Password))
+
+	if err != nil || passErr != nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid login or password"})
+		return
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
+		"user_id": user.ID,
+		"role":    user.Role,
+		"exp":     time.Now().Add(time.Hour * 24).Unix(),
+	})
+
+	tokenString, _ := token.SignedString(jwtKey)
+
+	c.JSON(http.StatusOK, gin.H{"token": tokenString})
+}