feat: Add authentication DTOs and setup API routes for user and activity management

backend/internal/api/middleware/auth.go

@@ -0,0 +1,198 @@
+package middleware
+
+import (
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/oklog/ulid/v2"
+	"github.com/timetracker/backend/internal/api/utils"
+	"github.com/timetracker/backend/internal/models"
+)
+
+// JWT configuration
+const (
+	// This should be moved to environment variables in production
+	jwtSecret     = "your-secret-key-change-in-production"
+	tokenDuration = 24 * time.Hour
+)
+
+// Claims represents the JWT claims
+type Claims struct {
+	UserID    string `json:"userId"`
+	Email     string `json:"email"`
+	Role      string `json:"role"`
+	CompanyID string `json:"companyId"`
+	jwt.RegisteredClaims
+}
+
+// AuthMiddleware checks if the user is authenticated
+func AuthMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		// Get the Authorization header
+		authHeader := c.GetHeader("Authorization")
+		if authHeader == "" {
+			utils.UnauthorizedResponse(c, "Authorization header is required")
+			c.Abort()
+			return
+		}
+
+		// Check if the header has the Bearer prefix
+		parts := strings.Split(authHeader, " ")
+		if len(parts) != 2 || parts[0] != "Bearer" {
+			utils.UnauthorizedResponse(c, "Invalid authorization format, expected 'Bearer TOKEN'")
+			c.Abort()
+			return
+		}
+
+		tokenString := parts[1]
+		claims, err := validateToken(tokenString)
+		if err != nil {
+			utils.UnauthorizedResponse(c, "Invalid or expired token")
+			c.Abort()
+			return
+		}
+
+		// Store user information in the context
+		c.Set("userID", claims.UserID)
+		c.Set("email", claims.Email)
+		c.Set("role", claims.Role)
+		c.Set("companyID", claims.CompanyID)
+
+		c.Next()
+	}
+}
+
+// RoleMiddleware checks if the user has the required role
+func RoleMiddleware(roles ...string) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		userRole, exists := c.Get("role")
+		if !exists {
+			utils.UnauthorizedResponse(c, "User role not found in context")
+			c.Abort()
+			return
+		}
+
+		// Check if the user's role is in the allowed roles
+		roleStr, ok := userRole.(string)
+		if !ok {
+			utils.InternalErrorResponse(c, "Invalid role type in context")
+			c.Abort()
+			return
+		}
+
+		allowed := false
+		for _, role := range roles {
+			if roleStr == role {
+				allowed = true
+				break
+			}
+		}
+
+		if !allowed {
+			utils.ForbiddenResponse(c, "Insufficient permissions")
+			c.Abort()
+			return
+		}
+
+		c.Next()
+	}
+}
+
+// GenerateToken creates a new JWT token for a user
+func GenerateToken(user *models.User) (string, error) {
+	// Create the claims
+	claims := Claims{
+		UserID:    user.ID.String(),
+		Email:     user.Email,
+		Role:      user.Role,
+		CompanyID: user.CompanyID.String(),
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(tokenDuration)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+			NotBefore: jwt.NewNumericDate(time.Now()),
+		},
+	}
+
+	// Create the token
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+
+	// Sign the token
+	tokenString, err := token.SignedString([]byte(jwtSecret))
+	if err != nil {
+		return "", err
+	}
+
+	return tokenString, nil
+}
+
+// validateToken validates a JWT token and returns the claims
+func validateToken(tokenString string) (*Claims, error) {
+	// Parse the token
+	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
+		// Validate the signing method
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, errors.New("unexpected signing method")
+		}
+		return []byte(jwtSecret), nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the token is valid
+	if !token.Valid {
+		return nil, errors.New("invalid token")
+	}
+
+	// Get the claims
+	claims, ok := token.Claims.(*Claims)
+	if !ok {
+		return nil, errors.New("invalid claims")
+	}
+
+	return claims, nil
+}
+
+// GetUserIDFromContext extracts the user ID from the context
+func GetUserIDFromContext(c *gin.Context) (ulid.ULID, error) {
+	userID, exists := c.Get("userID")
+	if !exists {
+		return ulid.ULID{}, errors.New("user ID not found in context")
+	}
+
+	userIDStr, ok := userID.(string)
+	if !ok {
+		return ulid.ULID{}, errors.New("invalid user ID type in context")
+	}
+
+	id, err := ulid.Parse(userIDStr)
+	if err != nil {
+		return ulid.ULID{}, err
+	}
+
+	return id, nil
+}
+
+// GetCompanyIDFromContext extracts the company ID from the context
+func GetCompanyIDFromContext(c *gin.Context) (ulid.ULID, error) {
+	companyID, exists := c.Get("companyID")
+	if !exists {
+		return ulid.ULID{}, errors.New("company ID not found in context")
+	}
+
+	companyIDStr, ok := companyID.(string)
+	if !ok {
+		return ulid.ULID{}, errors.New("invalid company ID type in context")
+	}
+
+	id, err := ulid.Parse(companyIDStr)
+	if err != nil {
+		return ulid.ULID{}, err
+	}
+
+	return id, nil
+}