refactor: Post 프로덕션 코드 리팩토링 (#252)

* refactor: infrastructure 유닛테스트, comment 유닛테스트 리팩토링

* test: Post 관련 유닛테스트 리팩토링

* test: Post application 레이어 관련 테스트 리팩토링

* test: Post 인수 테스트 리팩토링

* test: PostControllerTest 리팩토링 추가

* test: post builder를 사용하도록 변경

* refactor: 리베이스 후 깨지는 테스트 수정 및 누락된 테스트 추가

refactor: Post의 Tag관련 비즈니스 로직 PostTags로 이동 (#259)

이동과 함께 Post의 Build 패턴 적용과 리팩토링.

refactor: PostService와 PostController의 책임 분리. 및 s3Storage 파일 저장 방식 추가 (#259)

feed관련과, 게시물 관련으로 분리하여 관심사를 맞춤.

refactor: 전체적인 import 정리 (#259)

refactor: 패키지 정리 (#259)

refactor: Post의 getImageUrl 중복 메서드 제거 (#259)

refactor: CommentResponse의 도메인 참조 제거 및 DtoAssembler 리팩토링 (#259)

refactor: Feed관련 컨트롤러, 서비스, PostDto어셈블러  리팩토링, 레이어에 맞지 않는 DTO 이동 (#259)

refactor: CommentRequestDto 패키지 변경 및 PostController 리팩토링 (#259)

refactor: PostResponseDto가 presentation~presentation까지 사용되던것을 분리 (#259)

refactor: showRepositories -> userRepositories 메서드명 변경 (#259)

refactor: RepositoryResponse, domain -> controller까지 사용 되던것을 분리 (#259)

style: domain을 제외한 레이어의 구글 컨벤션 체크 (#259)

refactor: PostImageUrlResponseDto Builder 사용하도록 변경

refactor: Post 컨벤션 및 메서드 순서 정리 (#259)

refactor: Post user 관련 메서드명 author로 변경 및 필드, 메서드 정리 (#249)

refactor: PostTag equals getId()로 변경 및 필드 순서 정리 (#249)

refactor: Like를 VO로 취급, Likes를 컨테이너로 취급하도록 변경 (#249)

refactor: Image VO로 취급 및 도움 메서드 네이밍 변경, PostContent validation로직 변경 (#249)

refactor: CommentContent VO 취급, comment 도움메서드 이름 변경 및 책임 변경 (#249)

refactor: Post equals getter를 사용하도록 변경 (#249)

refactor: 연관관계 도움 메서드 반환깂 없도록 변경 (#249)

style: 구글 컨벤션 적용 (#249)

refactor: 추상화 수준 평탄화 작업 (#249)

backend/pick-git/src/main/java/com/woowacourse/pickgit/authentication/application/JwtTokenProvider.java

@@ -1,7 +1,5 @@
 package com.woowacourse.pickgit.authentication.application;
 
-import com.woowacourse.pickgit.user.domain.User;
-
 public interface JwtTokenProvider {
 
     String createToken(String payload);

backend/pick-git/src/main/java/com/woowacourse/pickgit/authentication/infrastructure/GithubOAuthClient.java

@@ -4,7 +4,6 @@
 import com.woowacourse.pickgit.authentication.domain.OAuthClient;
 import com.woowacourse.pickgit.authentication.infrastructure.dto.OAuthAccessTokenRequest;
 import com.woowacourse.pickgit.authentication.infrastructure.dto.OAuthAccessTokenResponse;
-import com.woowacourse.pickgit.exception.platform.PlatformException;
 import com.woowacourse.pickgit.exception.platform.PlatformHttpErrorException;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.HttpEntity;

backend/pick-git/src/main/java/com/woowacourse/pickgit/authentication/presentation/AuthenticationPrincipalArgumentResolver.java

@@ -5,7 +5,6 @@
 import com.woowacourse.pickgit.authentication.presentation.interceptor.AuthHeader;
 import javax.servlet.http.HttpServletRequest;
 import org.springframework.core.MethodParameter;
-import org.springframework.http.HttpHeaders;
 import org.springframework.web.bind.support.WebDataBinderFactory;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.method.support.HandlerMethodArgumentResolver;

backend/pick-git/src/main/java/com/woowacourse/pickgit/common/network/RestTemplateClient.java

@@ -1,6 +1,6 @@
 package com.woowacourse.pickgit.common.network;
 
-import com.woowacourse.pickgit.post.infrastructure.RestClient;
+import com.woowacourse.pickgit.post.domain.util.RestClient;
 import java.net.URI;
 import java.util.Map;
 import java.util.Set;

backend/pick-git/src/main/java/com/woowacourse/pickgit/exception/post/PostNotFoundException.java

@@ -4,11 +4,16 @@
 
 public class PostNotFoundException extends PostException {
 
-    public PostNotFoundException(
-        String errorCode,
-        HttpStatus httpStatus,
-        String message)
-    {
+    private static final String ERROR_CODE = "P0002";
+    private static final HttpStatus HTTP_STATUS = HttpStatus.INTERNAL_SERVER_ERROR;
+    private static final String MESSAGE = "해당하는 게시물을 찾을 수 없습니다.";
+
+    public PostNotFoundException() {
+        this(ERROR_CODE, HTTP_STATUS, MESSAGE);
+    }
+
+    public PostNotFoundException(String errorCode, HttpStatus httpStatus,
+        String message) {
         super(errorCode, httpStatus, message);
     }
 }

backend/pick-git/src/main/java/com/woowacourse/pickgit/exception/post/RepositoryParseException.java

@@ -3,6 +3,13 @@
 import org.springframework.http.HttpStatus;
 
 public class RepositoryParseException extends PostException {
+    private static final String ERROR_CODE = "V0001";
+    private static final HttpStatus HTTP_STATUS = HttpStatus.BAD_REQUEST;
+    private static final String MESSAGE = "레포지토리 목록을 불러올 수 없습니다.";
+
+    public RepositoryParseException() {
+        this(ERROR_CODE, HTTP_STATUS, MESSAGE);
+    }
 
     public RepositoryParseException(
         String errorCode, HttpStatus httpStatus, String message

backend/pick-git/src/main/java/com/woowacourse/pickgit/exception/user/UserNotFoundException.java

@@ -4,8 +4,15 @@
 
 public class UserNotFoundException extends UserException {
 
-    public UserNotFoundException(String errorCode, HttpStatus httpStatus,
-        String message) {
+    private static final String ERROR_CODE = "U0001";
+    private static final HttpStatus HTTP_STATUS = HttpStatus.INTERNAL_SERVER_ERROR;
+    private static final String MESSAGE = "해당하는 사용자를 찾을 수 없습니다.";
+
+    public UserNotFoundException() {
+        this(ERROR_CODE, HTTP_STATUS, MESSAGE);
+    }
+
+    public UserNotFoundException(String errorCode, HttpStatus httpStatus, String message) {
         super(errorCode, httpStatus, message);
     }
 }

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/application/PostDtoAssembler.java

@@ -1,46 +1,80 @@
 package com.woowacourse.pickgit.post.application;
 
-import com.woowacourse.pickgit.authentication.domain.user.AppUser;
-import com.woowacourse.pickgit.post.application.dto.CommentResponse;
+import static java.util.stream.Collectors.toList;
+
+import com.woowacourse.pickgit.post.application.dto.response.CommentResponseDto;
 import com.woowacourse.pickgit.post.application.dto.response.PostResponseDto;
 import com.woowacourse.pickgit.post.domain.Post;
+import com.woowacourse.pickgit.post.domain.comment.Comment;
 import com.woowacourse.pickgit.tag.domain.Tag;
 import com.woowacourse.pickgit.user.domain.User;
 import java.util.List;
-import java.util.stream.Collectors;
+import java.util.function.Function;
 
 public class PostDtoAssembler {
 
     private PostDtoAssembler() {
     }
 
-    public static List<PostResponseDto> assembleFrom(AppUser appUser, List<Post> posts) {
+    public static List<PostResponseDto> assembleFrom(
+        User requestUser,
+        boolean isGuest,
+        List<Post> posts
+    ) {
         return posts.stream()
-            .map(post -> convertFrom(post, appUser))
-            .collect(Collectors.toList());
+            .map(post -> convertFrom(requestUser, isGuest, post))
+            .collect(toList());
+    }
+
+    private static PostResponseDto convertFrom(User requestUser, boolean isGuest, Post post) {
+        List<String> tags = createTagsFrom(post);
+        List<CommentResponseDto> comments = createCommentResponsesFrom(post);
+
+        return PostResponseDto.builder()
+            .id(post.getId())
+            .imageUrls(post.getImageUrls())
+            .githubRepoUrl(post.getGithubRepoUrl())
+            .content(post.getContent())
+            .authorName(post.getAuthorName())
+            .profileImageUrl(post.getAuthorProfileImage())
+            .likesCount(post.getLikeCounts())
+            .tags(tags)
+            .createdAt(post.getCreatedAt())
+            .updatedAt(post.getUpdatedAt())
+            .comments(comments)
+            .isLiked(isLikedBy(requestUser, post, isGuest))
+            .build();
     }
 
-    private static PostResponseDto convertFrom(Post post, AppUser appUser) {
-        User postWriter = post.getUser();
-        List<String> tags = post.getTags()
+    private static List<CommentResponseDto> createCommentResponsesFrom(Post post) {
+        return post.getComments()
             .stream()
-            .map(Tag::getName)
-            .collect(Collectors.toList());
-        List<CommentResponse> comments = post.getComments()
+            .map(toCommentResponse())
+            .collect(toList());
+    }
+
+    private static Function<Comment, CommentResponseDto> toCommentResponse() {
+        return comment -> CommentResponseDto.builder()
+            .id(comment.getId())
+            .profileImageUrl(comment.getProfileImageUrl())
+            .authorName(comment.getAuthorName())
+            .content(comment.getContent())
+            .isLiked(false)
+            .build();
+    }
+
+    private static List<String> createTagsFrom(Post post) {
+        return post.getTags()
             .stream()
-            .map(CommentResponse::from)
-            .collect(Collectors.toList());
-
-        if (appUser.isGuest()) {
-            return new PostResponseDto(post.getId(), post.getImageUrls(), post.getGithubRepoUrl(),
-                post.getContent(), postWriter.getName(), postWriter.getImage(),
-                post.getLikeCounts(),
-                tags, post.getCreatedAt(), post.getUpdatedAt(), comments, null);
+            .map(Tag::getName)
+            .collect(toList());
+    }
+
+    private static Boolean isLikedBy(User requestUser, Post post, boolean isGuest) {
+        if (isGuest) {
+            return null;
         }
 
-        return new PostResponseDto(post.getId(), post.getImageUrls(), post.getGithubRepoUrl(),
-            post.getContent(), postWriter.getName(), postWriter.getImage(),
-            post.getLikeCounts(),
-            tags, post.getCreatedAt(), post.getUpdatedAt(), comments, post.isLikedBy(appUser.getUsername()));
+        return post.isLikedBy(requestUser);
     }
 }

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/application/PostFeedService.java

@@ -0,0 +1,82 @@
+package com.woowacourse.pickgit.post.application;
+
+import com.woowacourse.pickgit.exception.authentication.UnauthorizedException;
+import com.woowacourse.pickgit.exception.user.UserNotFoundException;
+import com.woowacourse.pickgit.post.application.dto.request.HomeFeedRequestDto;
+import com.woowacourse.pickgit.post.application.dto.response.PostResponseDto;
+import com.woowacourse.pickgit.post.domain.Post;
+import com.woowacourse.pickgit.post.domain.repository.PostRepository;
+import com.woowacourse.pickgit.user.domain.User;
+import com.woowacourse.pickgit.user.domain.UserRepository;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@Transactional(readOnly = true)
+public class PostFeedService {
+
+    private final PostRepository postRepository;
+    private final UserRepository userRepository;
+
+    public PostFeedService(PostRepository postRepository, UserRepository userRepository) {
+        this.postRepository = postRepository;
+        this.userRepository = userRepository;
+    }
+
+    public List<PostResponseDto> homeFeed(HomeFeedRequestDto homeFeedRequestDto) {
+        return readFeed(homeFeedRequestDto, Optional.empty());
+    }
+
+    public List<PostResponseDto> myFeed(HomeFeedRequestDto homeFeedRequestDto) {
+        String userName = homeFeedRequestDto.getRequestUserName();
+
+        if (Objects.isNull(userName)) {
+            throw new UnauthorizedException();
+        }
+
+        return readFeed(homeFeedRequestDto, Optional.of(userName));
+    }
+
+    public List<PostResponseDto> userFeed(HomeFeedRequestDto homeFeedRequestDto, String userName) {
+        return readFeed(homeFeedRequestDto, Optional.of(userName));
+    }
+
+    private List<PostResponseDto> readFeed(
+        HomeFeedRequestDto homeFeedRequestDto,
+        Optional<String> userName
+    ) {
+        var page = homeFeedRequestDto.getPage().intValue();
+        var limit = homeFeedRequestDto.getLimit().intValue();
+        var requestUserName = homeFeedRequestDto.getRequestUserName();
+        var isGuest = homeFeedRequestDto.isGuest();
+
+        Pageable pageable = PageRequest.of(page, limit);
+        List<Post> result = getPostsBy(userName, pageable);
+
+        User requestUser = findUserByName(requestUserName);
+
+        return PostDtoAssembler.assembleFrom(requestUser, isGuest, result);
+    }
+
+    private List<Post> getPostsBy(Optional<String> userName, Pageable pageable) {
+        return userName
+            .map(this::findUserByName)
+            .map(target -> postRepository.findAllPostsByUser(target, pageable))
+            .orElse(postRepository.findAllPosts(pageable));
+    }
+
+    private User findUserByName(String userName) {
+        if(Objects.isNull(userName)) {
+            return null;
+        }
+
+        return userRepository
+            .findByBasicProfile_Name(userName)
+            .orElseThrow(UserNotFoundException::new);
+    }
+}