fix: un-revert prefectures :BocchiSobSmile: (#173)

Co-authored-by: alexay7 <43906716+alexay7@users.noreply.github.com>

src/main/java/icu/samnyan/aqua/net/UserRegistrar.kt

@@ -161,7 +161,7 @@ class UserRegistrar(
         // Check if user exists, treat as email / username
         val user = async { userRepo.findByEmailIgnoreCase(email) ?: userRepo.findByUsernameIgnoreCase(email) }
             ?: return SUCCESS // obviously dont tell them if the email exists or not
-        
+
         // Check if email is verified
         if (!user.emailConfirmed && emailProps.enable) 400 - "Email not verified"
 
@@ -179,7 +179,7 @@ class UserRegistrar(
 
         // Send a password reset email
         emailService.sendPasswordReset(user)
-    
+
         return SUCCESS
     }
 
@@ -189,7 +189,7 @@ class UserRegistrar(
         @RP token: Str, @RP password: Str,
         request: HttpServletRequest
     ) : Any {
-        
+
         // Find the reset token
         val reset = async { resetPasswordRepo.findByToken(token) }
 
@@ -302,4 +302,17 @@ class UserRegistrar(
 
         SUCCESS
     }
+
+    @API("/change-region")
+    @Doc("Change the region of the user.", "Success message")
+    suspend fun changeRegion(@RP token: Str, @RP regionId: Str) = jwt.auth(token) { u ->
+        // Check if the region is valid (between 1 and 47)
+        val r = regionId.toIntOrNull() ?: (400 - "Invalid region")
+        if (r !in 1..47) 400 - "Invalid region"
+        async {
+	        userRepo.save(u.apply { region = r.toString() })
+        }
+
+        SUCCESS
+        }
 }