ADD: added initial page with login

backend/internal/auth/handler.go

@@ -0,0 +1,38 @@
+package auth
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+type LoginRequest struct {
+	Email    string `json:"email"`
+	Password string `json:"password"`
+}
+
+type LoginResponse struct {
+	Token string `json:"token"`
+}
+
+func LoginHandler(c *gin.Context) {
+	var req LoginRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Bad request"})
+		return
+	}
+
+	// Systemnutzer
+	if req.Email == "systemuser@example.com" {
+		token, err := CreateJWT("system-user-id", req.Email, "admin", time.Hour*24*7)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "Token error"})
+			return
+		}
+		c.JSON(http.StatusOK, LoginResponse{Token: token})
+		return
+	}
+
+	c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid credentials"})
+}

backend/internal/auth/jwt.go

@@ -0,0 +1,47 @@
+package auth
+
+import (
+	"errors"
+	"time"
+
+	"github.com/golang-jwt/jwt/v4"
+)
+
+var jwtSecret = []byte("supersecret")
+
+type Claims struct {
+	UserID string
+	Email  string
+	Role   string
+}
+
+func CreateJWT(userID, email, role string, duration time.Duration) (string, error) {
+	claims := jwt.MapClaims{
+		"userId": userID,
+		"email":  email,
+		"role":   role,
+		"exp":    time.Now().Add(duration).Unix(),
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString(jwtSecret)
+}
+
+func ParseJWT(tokenStr string) (*Claims, error) {
+	token, err := jwt.Parse(tokenStr, func(token *jwt.Token) (interface{}, error) {
+		return jwtSecret, nil
+	})
+	if err != nil || !token.Valid {
+		return nil, errors.New("invalid token")
+	}
+	claims, ok := token.Claims.(jwt.MapClaims)
+	if !ok {
+		return nil, errors.New("invalid claims")
+	}
+
+	return &Claims{
+		UserID: claims["userId"].(string),
+		Email:  claims["email"].(string),
+		Role:   claims["role"].(string),
+	}, nil
+}

backend/internal/auth/middleware.go

@@ -0,0 +1,30 @@
+package auth
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+func AuthMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		authHeader := c.GetHeader("Authorization")
+		if !strings.HasPrefix(authHeader, "Bearer ") {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "Missing token"})
+			return
+		}
+		tokenStr := strings.TrimPrefix(authHeader, "Bearer ")
+
+		claims, err := ParseJWT(tokenStr)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "Invalid token"})
+			return
+		}
+
+		c.Set("userId", claims.UserID)
+		c.Set("email", claims.Email)
+		c.Set("role", claims.Role)
+		c.Next()
+	}
+}