feature(mappers): Added data mappers.

solve some TODOs.
Added data_mapper.go. This file implements the functions "GetUserID", "GetDeleteRequest", and "GetEnrolledRequest".

controllers/course/courseController.go

@@ -6,7 +6,7 @@ import (
 	"gorm.io/gorm"
 	"net/http"
 	"rpl-service/constants"
-	"rpl-service/models"
+	"rpl-service/mappers"
 	"rpl-service/services/users"
 )
 
@@ -39,14 +39,23 @@ func Exists(w http.ResponseWriter, r *http.Request, db *gorm.DB) {
 
 func Create(w http.ResponseWriter, r *http.Request, db *gorm.DB) {
 	// Should Create a new course
-	var body models.Course
-	err := json.NewDecoder(r.Body).Decode(&body)
-	if err != nil {
+	body, getCourseRequestErr := mappers.GetCourseRequest(r)
+	if getCourseRequestErr != nil {
 		http.Error(w, "Invalid request body", http.StatusBadRequest)
 		return
 	}
 
-	userID := uuid.New() // TODO: get the actual userID
+	userIDString, getIDError := mappers.GetUserID(r)
+	if getIDError != nil {
+		http.Error(w, "Failed to get user ID", http.StatusInternalServerError)
+		return
+	}
+	userID, parseErr := uuid.Parse(userIDString)
+	if parseErr != nil {
+		http.Error(w, "Invalid user ID", http.StatusBadRequest)
+		return
+	}
+
 	currentCourse, creatingCourseErr := users.CreateCourse(db, userID, body.Name, body.Description)
 	if creatingCourseErr != nil {
 		http.Error(w, "Failed to Create course", http.StatusInternalServerError)
@@ -70,38 +79,30 @@ func Create(w http.ResponseWriter, r *http.Request, db *gorm.DB) {
 
 // EnrollToCourse TODO: Test this function after implementing auth0.
 func EnrollToCourse(w http.ResponseWriter, r *http.Request, db *gorm.DB) {
-	var enrollmentRequest struct {
-		UserID   uuid.UUID `json:"UserID"`
-		CourseID uuid.UUID `json:"CourseID"`
-	}
-
-	if json.NewDecoder(r.Body).Decode(&enrollmentRequest) != nil {
+	enrollmentRequest, enrollmentRequestErr := mappers.GetEnrolledRequest(r)
+	if enrollmentRequestErr != nil {
 		http.Error(w, "Invalid request body", http.StatusBadRequest)
 		return
 	}
 
-	err := users.EnrollToCourse(db, enrollmentRequest.UserID, enrollmentRequest.CourseID)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+	enrollErr := users.EnrollToCourse(db, enrollmentRequest.UserID, enrollmentRequest.CourseID)
+	if enrollErr != nil {
+		http.Error(w, enrollErr.Error(), http.StatusInternalServerError)
 		return
 	}
 
 	w.WriteHeader(http.StatusCreated)
-	_, err = w.Write([]byte("User enrolled in course successfully"))
-	if err != nil {
+	_, writeErr := w.Write([]byte("User enrolled in course successfully"))
+	if writeErr != nil {
 		http.Error(w, "Failed to write response", http.StatusInternalServerError)
 		return
 	}
 }
 
 // StudentExists TODO: Test this function after implementing auth0.
 func StudentExists(w http.ResponseWriter, r *http.Request, db *gorm.DB) {
-	var enrollmentRequest struct {
-		UserID   uuid.UUID `json:"UserID"`
-		CourseID uuid.UUID `json:"CourseID"`
-	}
-
-	if json.NewDecoder(r.Body).Decode(&enrollmentRequest) != nil {
+	enrollmentRequest, enrollmentRequestErr := mappers.GetEnrolledRequest(r)
+	if enrollmentRequestErr != nil {
 		http.Error(w, "Invalid request body", http.StatusBadRequest)
 		return
 	}
@@ -121,13 +122,8 @@ func StudentExists(w http.ResponseWriter, r *http.Request, db *gorm.DB) {
 
 // DeleteStudent TODO: Test this function after implementing auth0.
 func DeleteStudent(w http.ResponseWriter, r *http.Request, db *gorm.DB) {
-	var deleteRequest struct {
-		UserID    uuid.UUID `json:"UserID"`
-		CourseID  uuid.UUID `json:"CourseID"`
-		StudentID uuid.UUID `json:"StudentID"`
-	}
-
-	if json.NewDecoder(r.Body).Decode(&deleteRequest) != nil {
+	deleteRequest, deleteRequestErr := mappers.GetDeleteRequest(r)
+	if deleteRequestErr != nil {
 		http.Error(w, "Invalid request body", http.StatusBadRequest)
 		return
 	}

mappers/data_mapper.go

@@ -0,0 +1,101 @@
+package mappers
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/auth0/go-jwt-middleware/v2/jwks"
+	"github.com/auth0/go-jwt-middleware/v2/validator"
+	"github.com/google/uuid"
+	"net/http"
+	"net/url"
+	"os"
+	"rpl-service/constants"
+	"rpl-service/models"
+	"strings"
+	"time"
+)
+
+func GetCourseRequest(r *http.Request) (models.Course, error) {
+	var body models.Course
+	if decodeErr := json.NewDecoder(r.Body).Decode(&body); decodeErr != nil {
+		return models.Course{}, errors.New("invalid request body")
+	}
+	return body, nil
+}
+
+func GetEnrolledRequest(r *http.Request) (EnrollmentRequest, error) {
+	var result EnrollmentRequest
+	if json.NewDecoder(r.Body).Decode(&result) != nil {
+		return result, errors.New("invalid request body")
+	}
+	return result, nil
+}
+
+func GetDeleteRequest(r *http.Request) (DeleteRequest, error) {
+	var result DeleteRequest
+	if json.NewDecoder(r.Body).Decode(&result) != nil {
+		return result, errors.New("invalid request body")
+	}
+	return result, nil
+}
+
+// GetUserID TODO: Check this when possible.
+func GetUserID(r *http.Request) (string, error) {
+	// Auth0 configuration
+	issuerURL := os.Getenv("AUTH0_DOMAIN")
+	audience := []string{os.Getenv("AUTH0_AUDIENCE")}
+
+	// Parse the issuer URL
+	issuer, err := url.Parse(issuerURL)
+	if err != nil {
+		return constants.EmptyString, fmt.Errorf("failed to parse issuer URL: %w", err)
+	}
+
+	// Set up token validator
+	provider := jwks.NewCachingProvider(issuer, 5*time.Minute)
+	jwtValidator, err := validator.New(
+		provider.KeyFunc,
+		validator.RS256,
+		issuerURL,
+		audience,
+	)
+
+	if err != nil {
+		return constants.EmptyString, fmt.Errorf("failed to setup validator: %w", err)
+	}
+
+	// Validate token
+	token, err := jwtValidator.ValidateToken(r.Context(), r.Header.Get("Authorization"))
+	if err != nil {
+		return constants.EmptyString, fmt.Errorf("invalid token: %w", err)
+	}
+
+	// Extract claims
+	claims, ok := token.(*validator.ValidatedClaims)
+	if !ok {
+		return constants.EmptyString, errors.New("invalid token claims")
+	}
+
+	// Get user ID from subject
+	sub := claims.RegisteredClaims.Subject
+	parts := strings.Split(sub, "|")
+	if len(parts) != 2 {
+		return constants.EmptyString, errors.New("invalid subject format")
+	}
+
+	return parts[1], nil
+}
+
+// AUX
+
+type EnrollmentRequest struct {
+	UserID   uuid.UUID `json:"UserID"`
+	CourseID uuid.UUID `json:"CourseID"`
+}
+
+type DeleteRequest struct {
+	UserID    uuid.UUID `json:"UserID"`
+	CourseID  uuid.UUID `json:"CourseID"`
+	StudentID uuid.UUID `json:"StudentID"`
+}

services/users/userService.go

@@ -8,11 +8,6 @@ import (
 )
 
 func EnrollToCourse(db *gorm.DB, userID, courseID uuid.UUID) error {
-	// TODO: change the following line
-	// if !userExists(db, userID) {
-	//	return errors.New("user does not exist")
-	//}
-
 	if IsUserInCourse(db, userID, courseID) {
 		return errors.New("user is already in course")
 	}
@@ -118,11 +113,6 @@ func CourseExists(db *gorm.DB, courseID uuid.UUID) bool {
 	return db.Model(models.Course{}).Where("ID = ?", courseID).Error == nil
 }
 
-// func userExists(db *gorm.DB, id uint) bool {
-//	// TODO: use Auth0
-//	return true
-//}
-
 func isOwner(db *gorm.DB, userID, courseID uuid.UUID) bool {
 	currentUser := models.IsEnrolled{}
 	db.Model(models.IsEnrolled{}).Where("UserID = ? AND CourseID = ?", userID, courseID).First(&currentUser)