added the post /user Endpoint

backend/src/main/java/ovh/herisson/Clyde/Services/UserService.java

@@ -28,6 +28,68 @@ public class UserService {
         }
     }
 
+    /** modify the target data
+     * verify the permission of modifying from the poster
+     *
+     * @param poster the user wanting to modify target's data
+     * @param updates the changes to be made
+     * @param target the user to update
+     * @return if the changes were done or not
+     */
+    public boolean modifyData(User poster, Map<String ,Object> updates, User target){
+
+        System.out.printf("%s and %s",poster.getRegNo(),target.getRegNo());
+        if (poster.getRegNo().equals(target.getRegNo())){
+            for (Map.Entry<String, Object> entry : updates.entrySet()){
+
+                if ( entry.getKey().equals("regNo") || entry.getKey().equals("role")) {return false;}
+
+                switch (entry.getKey()){
+                    case "firstName":
+                        target.setFirstName((String) entry.getValue());
+                        break;
+                    case "lastName":
+                        target.setLastName((String) entry.getValue());
+                        break;
+                    case "email":
+                        target.setEmail((String) entry.getValue());
+                        break;
+                    case "address":
+                        target.setAddress((String) entry.getValue());
+                        break;
+                    case "country":
+                        target.setCountry((String) entry.getValue());
+                        break;
+                    case "birthDate":
+                        target.setBirthDate((Date) entry.getValue());
+                        break;
+                    case "profilePictureUrl":
+                        target.setProfilePictureUrl((String) entry.getValue());
+                        break;
+                    case "password":
+                        target.setPassword(encodePassword((String) entry.getValue()));
+                        break;
+                }
+            }
+            userRepo.save(target);
+            return true;
+        }
+        // the secretary can change roles (for example if a student becomes a teacher)
+        else if (poster.getRole() == Role.Secretary)
+        {
+            for (Map.Entry<String, Object> entry : updates.entrySet()){
+
+                if ( !entry.getKey().equals("role")) {return false;}
+
+                if (entry.getValue() == Role.Admin){return false;}
+
+                target.setRole((Role) entry.getValue());
+                userRepo.save(target);
+                return true;
+            }
+        }
+        return false;
+    }
 
 
     public boolean checkPassword(User user, String tryingPassword){