Step1 - 레거시 코드 리팩토링

src/main/java/nextstep/common/domain/BaseEntity.java

@@ -0,0 +1,49 @@
+package nextstep.common.domain;
+
+import java.time.LocalDateTime;
+import java.util.Objects;
+
+public abstract class BaseEntity {
+    private Long id;
+    private LocalDateTime createdDate;
+    private LocalDateTime updatedDate;
+
+    protected BaseEntity(Long id) {
+        this(id, LocalDateTime.now(), LocalDateTime.now());
+    }
+
+    public BaseEntity(Long id, LocalDateTime createdDate, LocalDateTime updatedDate) {
+        this.id = id;
+        this.createdDate = createdDate;
+        this.updatedDate = updatedDate;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        BaseEntity that = (BaseEntity) o;
+        return Objects.equals(id, that.id)
+                && Objects.equals(createdDate, that.createdDate)
+                && Objects.equals(updatedDate, that.updatedDate);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, createdDate, updatedDate);
+    }
+
+    @Override
+    public String toString() {
+        return "BaseEntity{" +
+                "id=" + id +
+                ", createdDate=" + createdDate +
+                ", updatedDate=" + updatedDate +
+                '}';
+    }
+}

src/main/java/nextstep/common/domain/SoftDeletableBaseEntity.java

@@ -0,0 +1,56 @@
+package nextstep.common.domain;
+
+import java.time.LocalDateTime;
+import java.util.Objects;
+
+public abstract class SoftDeletableBaseEntity {
+    private Long id;
+    private boolean deleted;
+    private LocalDateTime createdDate;
+    private LocalDateTime updatedDate;
+
+    protected SoftDeletableBaseEntity(Long id) {
+        this(id, false, LocalDateTime.now(), LocalDateTime.now());
+    }
+
+    protected SoftDeletableBaseEntity(Long id, LocalDateTime createdAt, LocalDateTime updatedAt) {
+        this(id, false, createdAt, updatedAt);
+    }
+
+    protected SoftDeletableBaseEntity(Long id, boolean deleted, LocalDateTime createdDate,
+            LocalDateTime updatedDate) {
+        this.id = id;
+        this.deleted = deleted;
+        this.createdDate = createdDate;
+        this.updatedDate = updatedDate;
+    }
+
+    protected boolean isDeleted() {
+        return this.deleted;
+    }
+
+    public void updateDeleted() {
+        this.deleted = true;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        SoftDeletableBaseEntity that = (SoftDeletableBaseEntity) o;
+        return deleted == that.deleted
+                && Objects.equals(id, that.id)
+                && Objects.equals(createdDate, that.createdDate)
+                && Objects.equals(updatedDate, that.updatedDate);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, deleted, createdDate, updatedDate);
+    }
+}

src/main/java/nextstep/qna/domain/Answer.java

@@ -1,71 +1,58 @@
 package nextstep.qna.domain;
 
-import nextstep.qna.NotFoundException;
-import nextstep.qna.UnAuthorizedException;
-import nextstep.users.domain.NsUser;
-
 import java.time.LocalDateTime;
-
-public class Answer {
-    private Long id;
-
-    private NsUser writer;
-
+import nextstep.common.domain.SoftDeletableBaseEntity;
+import nextstep.qna.exception.unchecked.CannotDeleteException;
+import nextstep.qna.exception.unchecked.NotFoundException;
+import nextstep.qna.exception.unchecked.UnAuthorizedException;
+import nextstep.qna.exception.unchecked.WrongRequestException;
+
+public class Answer extends SoftDeletableBaseEntity {
+    private Long writerId;
     private Question question;
+    private BoardContent boardContent;
 
-    private String contents;
-
-    private boolean deleted = false;
-
-    private LocalDateTime createdDate = LocalDateTime.now();
-
-    private LocalDateTime updatedDate;
-
-    public Answer() {
+    public Answer(long writerId, Question question, String contents) {
+        this(null, writerId, question, contents);
     }
 
-    public Answer(NsUser writer, Question question, String contents) {
-        this(null, writer, question, contents);
-    }
-
-    public Answer(Long id, NsUser writer, Question question, String contents) {
-        this.id = id;
-        if(writer == null) {
+    public Answer(Long id, long writerId, Question question, String contents) {
+        super(id);
+        if (writerId <= 0L) {
             throw new UnAuthorizedException();
         }
 
-        if(question == null) {
+        if (question == null) {
             throw new NotFoundException();
         }
 
-        this.writer = writer;
+        this.writerId = writerId;
         this.question = question;
-        this.contents = contents;
+        this.boardContent = new BoardContent("" , contents);
     }
 
-    public Long getId() {
-        return id;
+    public boolean isDeleted() {
+        return super.isDeleted();
     }
 
-    public Answer setDeleted(boolean deleted) {
-        this.deleted = deleted;
-        return this;
-    }
+    public void putOnDelete(long requesterId) {
+        if (!isOwner(requesterId)) {
+            throw new CannotDeleteException("질문을 삭제할 권한이 없습니다.");
+        }
 
-    public boolean isDeleted() {
-        return deleted;
+        super.updateDeleted();
     }
 
-    public boolean isOwner(NsUser writer) {
-        return this.writer.equals(writer);
+    public boolean isOwner(long writerId) {
+        return this.writerId == writerId;
     }
 
-    public NsUser getWriter() {
-        return writer;
-    }
+    public DeleteHistory createAnswerDeleteHistory(LocalDateTime deletedDateTime) {
+        if (!isDeleted()) {
+            throw new WrongRequestException("삭제되지 않은 답변은 삭제이력을 생성할 수 없습니다.");
+        }
 
-    public String getContents() {
-        return contents;
+        return new DeleteHistory(ContentType.ANSWER, super.getId(), this.writerId, deletedDateTime);
     }
 
     public void toQuestion(Question question) {
@@ -74,6 +61,9 @@ public void toQuestion(Question question) {
 
     @Override
     public String toString() {
-        return "Answer [id=" + getId() + ", writer=" + writer + ", contents=" + contents + "]";
+        return "Answer [id=" + super.getId()
+                + ", writerId=" + writerId
+                + ", contents=" + boardContent
+                + "]";
     }
 }

src/main/java/nextstep/qna/domain/BoardContent.java

@@ -0,0 +1,19 @@
+package nextstep.qna.domain;
+
+public class BoardContent {
+    private String title;
+    private String contents;
+
+    public BoardContent(String title, String contents) {
+        this.title = title;
+        this.contents = contents;
+    }
+
+    @Override
+    public String toString() {
+        return "BoardContent{" +
+                "title='" + title + '\'' +
+                ", contents='" + contents + '\'' +
+                '}';
+    }
+}

src/main/java/nextstep/qna/domain/DeleteHistory.java

@@ -1,50 +1,53 @@
 package nextstep.qna.domain;
 
+import static java.util.Objects.*;
+
+import nextstep.common.domain.BaseEntity;
 import nextstep.users.domain.NsUser;
 
 import java.time.LocalDateTime;
 import java.util.Objects;
 
-public class DeleteHistory {
-    private Long id;
-
+public class DeleteHistory extends BaseEntity {
     private ContentType contentType;
-
     private Long contentId;
+    private Long deletedId;
 
-    private NsUser deletedBy;
-
-    private LocalDateTime createdDate = LocalDateTime.now();
-
-    public DeleteHistory() {
+    public DeleteHistory(ContentType contentType, Long contentId, Long deletedId, LocalDateTime createdDate) {
+        this(0L, contentType, contentId, deletedId, createdDate, null);
     }
 
-    public DeleteHistory(ContentType contentType, Long contentId, NsUser deletedBy, LocalDateTime createdDate) {
+    public DeleteHistory(Long id, ContentType contentType, Long contentId, Long deletedId, LocalDateTime createdDate, LocalDateTime updateDate) {
+        super(id, createdDate, updateDate);
         this.contentType = contentType;
         this.contentId = contentId;
-        this.deletedBy = deletedBy;
-        this.createdDate = createdDate;
+        this.deletedId = deletedId;
     }
 
     @Override
     public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
         DeleteHistory that = (DeleteHistory) o;
-        return Objects.equals(id, that.id) &&
-                contentType == that.contentType &&
-                Objects.equals(contentId, that.contentId) &&
-                Objects.equals(deletedBy, that.deletedBy);
+        return super.equals(o)
+                && contentType == that.contentType
+                && Objects.equals(contentId, that.contentId)
+                && Objects.equals(deletedId, that.deletedId);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(id, contentType, contentId, deletedBy);
+        return hash(super.hashCode(), contentType, contentId, deletedId);
     }
 
     @Override
     public String toString() {
-        return "DeleteHistory [id=" + id + ", contentType=" + contentType + ", contentId=" + contentId + ", deletedBy="
-                + deletedBy + ", createdDate=" + createdDate + "]";
+        return "DeleteHistory{" +
+                "id=" + super.toString() +
+                ", contentType=" + contentType +
+                ", contentId=" + contentId +
+                ", deletedId=" + deletedId +
+                '}';
     }
 }

src/main/java/nextstep/qna/domain/QnADomainService.java

@@ -0,0 +1,19 @@
+package nextstep.qna.domain;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+public class QnADomainService {
+
+    // TODO : 피드백 주신 부분 잘보았습니다.
+    //  저는 개인적으로 도메인 로직은 순수하게 유지하는게 가장 좋다고 생각합니다만.
+    //  스프링을 활용한 의존성주입이 필요한 예외적인 상황(불가피한 외부API 호출, 이메일 등등..)에서는 허용하고 사용해주는것도 좋다고 생각합니다.
+    //  다만 단계를 거쳐볼것 같아요. 1. 순수 객체 -> 2. 클래스 메서드(static) 집합 객체(=외부 bean 필요없이 캐싱 작업이 필요힌 경우) -> 3. 외부 bean이 불가피하게 필요한경우 bean & di
+    public List<DeleteHistory> deleteQuestion(
+            long requesterId, Question question, LocalDateTime fixedDeletedDateTime
+    ) {
+        question.putOnDelete(requesterId);
+
+        return question.bringAllDeleteHistories(fixedDeletedDateTime);
+    }
+}