feat: add user medal selection and display

backend/src/main/java/com/openisle/controller/MedalController.java

@@ -1,12 +1,12 @@
 package com.openisle.controller;
 
 import com.openisle.dto.MedalDto;
+import com.openisle.dto.MedalSelectRequest;
 import com.openisle.service.MedalService;
 import lombok.RequiredArgsConstructor;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestParam;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.*;
 
 import java.util.List;
 
@@ -20,4 +20,14 @@ public class MedalController {
     public List<MedalDto> getMedals(@RequestParam(value = "userId", required = false) Long userId) {
         return medalService.getMedals(userId);
     }
+
+    @PostMapping("/select")
+    public ResponseEntity<Void> selectMedal(@RequestBody MedalSelectRequest req, Authentication auth) {
+        try {
+            medalService.selectMedal(auth.getName(), req.getType());
+            return ResponseEntity.ok().build();
+        } catch (IllegalArgumentException e) {
+            return ResponseEntity.badRequest().build();
+        }
+    }
 }