feat: 프로필 조회 로직 추가

Author: MEOHIN

src/main/java/com/back/domain/profile/service/ProfileService.java

@@ -0,0 +1,34 @@
+package com.back.domain.profile.service;
+
+import com.back.domain.profile.dto.ProfileResponseDto;
+import com.back.domain.user.entity.User;
+import com.back.domain.user.repository.UserRepository;
+import com.back.domain.user.support.AbvView;
+import com.back.global.exception.ServiceException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class ProfileService {
+
+    private final UserRepository userRepository;
+
+    @Transactional(readOnly = true)
+    public ProfileResponseDto getProfile(Long id) {
+        User user = userRepository.findById(id).orElseThrow(() -> new ServiceException(404, "사용자를 찾을 수 없습니다."));
+
+        Double percent = user.getAbvDegree();
+        int level = AbvView.levelOf(percent);
+        String label = AbvView.percentLabel(percent);
+
+        return ProfileResponseDto.builder()
+                .id(user.getId())
+                .nickname(user.getNickname())
+                .abvDegree(percent)
+                .abvLevel(level)
+                .abvLabel(label)
+                .build();
+    }
+}