1단계 - 레거시 코드 리팩터링

README.md

@@ -6,4 +6,18 @@
 * 모든 피드백을 완료하면 다음 단계를 도전하고 앞의 과정을 반복한다.
 
 ## 온라인 코드 리뷰 과정
-* [텍스트와 이미지로 살펴보는 온라인 코드 리뷰 과정](https://github.com/next-step/nextstep-docs/tree/master/codereview)
+* [텍스트와 이미지로 살펴보는 온라인 코드 리뷰 과정](https://github.com/next-step/nextstep-docs/tree/master/codereview)
+
+---
+
+## 기능 목록
+
+### 질문 삭제하기
+
+- 질문자 = 로그인 사용자 아니면 삭제 불가 
+- 답변 중 다른 사람이 쓴 답변이 있으면 삭제 불가 
+- 답변이 없으면 삭제 가능 
+- 질문자와 답변자가 모두 동일하면 삭제 가능 
+- 삭제되면 질문 상태 변경 
+- 삭제되면 모든 답변 상태 변경 
+- 삭제 이력 생성됨

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

@@ -1,67 +1,39 @@
 package nextstep.qna.domain;
 
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+import nextstep.qna.CannotDeleteException;
 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;
+public class Answer extends SoftDeletableBaseEntity {
 
     private Question question;
 
     private String contents;
 
-    private boolean deleted = false;
-
-    private LocalDateTime createdDate = LocalDateTime.now();
-
-    private LocalDateTime updatedDate;
-
-    public Answer() {
-    }
-
     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) {
-            throw new UnAuthorizedException();
-        }
-
-        if(question == null) {
-            throw new NotFoundException();
-        }
-
-        this.writer = writer;
+        super(id, writer);
         this.question = question;
         this.contents = contents;
     }
 
-    public Long getId() {
-        return id;
-    }
-
-    public Answer setDeleted(boolean deleted) {
-        this.deleted = deleted;
-        return this;
-    }
-
-    public boolean isDeleted() {
-        return deleted;
-    }
+    public static Answer create(NsUser writer, Question question, String contents) {
+        if (writer == null) {
+            throw new UnAuthorizedException();
+        }
 
-    public boolean isOwner(NsUser writer) {
-        return this.writer.equals(writer);
-    }
+        if (question == null) {
+            throw new NotFoundException();
+        }
 
-    public NsUser getWriter() {
-        return writer;
+        return new Answer(null, writer, question, contents);
     }
 
     public String getContents() {
@@ -72,8 +44,22 @@ public void toQuestion(Question question) {
         this.question = question;
     }
 
+    public void delete(NsUser user) throws CannotDeleteException {
+        if (!isOwner(user)) {
+            throw new CannotDeleteException("다른 사람이 쓴 답변이 있어 삭제할 수 없습니다.");
+        }
+        markAsDeleted();
+    }
+
+    public List<DeleteHistory> toDeleteHistories() {
+        List<DeleteHistory> deleteHistories = new ArrayList<>();
+        deleteHistories.add(
+                new DeleteHistory(ContentType.ANSWER, getId(), getWriter(), LocalDateTime.now()));
+        return deleteHistories;
+    }
+
     @Override
     public String toString() {
-        return "Answer [id=" + getId() + ", writer=" + writer + ", contents=" + contents + "]";
+        return "Answer [id=" + getId() + ", writer=" + getWriter() + ", contents=" + contents + "]";
     }
 }

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

@@ -0,0 +1,44 @@
+package nextstep.qna.domain;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import nextstep.qna.CannotDeleteException;
+import nextstep.users.domain.NsUser;
+
+public class Answers {
+
+    private final List<Answer> answers;
+
+    public Answers(Answer... answers) {
+        this(new ArrayList<>(Arrays.asList(answers)));
+    }
+
+    public Answers(List<Answer> answers) {
+        this.answers = answers;
+    }
+
+    public List<Answer> answers() {
+        return Collections.unmodifiableList(new ArrayList<>(answers));
+    }
+
+    public void add(Answer answer) {
+        answers.add(answer);
+    }
+
+    public void delete(NsUser user) throws CannotDeleteException {
+        for (Answer answer : answers) {
+            answer.delete(user);
+        }
+    }
+
+    public List<DeleteHistory> toDeleteHistories() throws CannotDeleteException {
+        List<DeleteHistory> deleteHistories = new ArrayList<>();
+        for (Answer answer : answers) {
+            deleteHistories.addAll(answer.toDeleteHistories());
+        }
+        return deleteHistories;
+    }
+
+}

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

@@ -0,0 +1,11 @@
+package nextstep.qna.domain;
+
+import java.time.LocalDateTime;
+
+public abstract class BaseTimeEntity {
+
+    private LocalDateTime createdDate = LocalDateTime.now();
+
+    private LocalDateTime updatedDate;
+
+}

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

@@ -1,92 +1,60 @@
 package nextstep.qna.domain;
 
-import nextstep.users.domain.NsUser;
-
 import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.List;
+import nextstep.qna.CannotDeleteException;
+import nextstep.users.domain.NsUser;
 
-public class Question {
-    private Long id;
-
-    private String title;
-
-    private String contents;
-
-    private NsUser writer;
-
-    private List<Answer> answers = new ArrayList<>();
-
-    private boolean deleted = false;
-
-    private LocalDateTime createdDate = LocalDateTime.now();
-
-    private LocalDateTime updatedDate;
+public class Question extends SoftDeletableBaseEntity {
+    private QuestionContent content;
 
-    public Question() {
-    }
+    private Answers answers = new Answers();
 
-    public Question(NsUser writer, String title, String contents) {
-        this(0L, writer, title, contents);
+    public Question(NsUser writer, QuestionContent content) {
+        this(0L, writer, content);
     }
 
-    public Question(Long id, NsUser writer, String title, String contents) {
-        this.id = id;
-        this.writer = writer;
-        this.title = title;
-        this.contents = contents;
-    }
-
-    public Long getId() {
-        return id;
+    public Question(Long id, NsUser writer, QuestionContent content) {
+        super(id, writer);
+        this.content = content;
     }
 
     public String getTitle() {
-        return title;
-    }
-
-    public Question setTitle(String title) {
-        this.title = title;
-        return this;
+        return content.title();
     }
 
     public String getContents() {
-        return contents;
-    }
-
-    public Question setContents(String contents) {
-        this.contents = contents;
-        return this;
-    }
-
-    public NsUser getWriter() {
-        return writer;
+        return content.contents();
     }
 
     public void addAnswer(Answer answer) {
         answer.toQuestion(this);
         answers.add(answer);
     }
 
-    public boolean isOwner(NsUser loginUser) {
-        return writer.equals(loginUser);
-    }
-
-    public Question setDeleted(boolean deleted) {
-        this.deleted = deleted;
-        return this;
+    public Answers getAnswers() {
+        return answers;
     }
 
-    public boolean isDeleted() {
-        return deleted;
+    public void delete(NsUser user) throws CannotDeleteException {
+        if (!isOwner(user)) {
+            throw new CannotDeleteException("질문을 삭제할 권한이 없습니다.");
+        }
+        markAsDeleted();
+        answers.delete(user);
     }
 
-    public List<Answer> getAnswers() {
-        return answers;
+    public List<DeleteHistory> toDeleteHistories() throws CannotDeleteException {
+        List<DeleteHistory> deleteHistories = new ArrayList<>();
+        deleteHistories.add(
+                new DeleteHistory(ContentType.QUESTION, getId(), getWriter(), LocalDateTime.now()));
+        deleteHistories.addAll(answers.toDeleteHistories());
+        return deleteHistories;
     }
 
     @Override
     public String toString() {
-        return "Question [id=" + getId() + ", title=" + title + ", contents=" + contents + ", writer=" + writer + "]";
+        return "Question [id=" + getId() + ", content=" + content + ", writer=" + getWriter() + "]";
     }
 }

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

@@ -0,0 +1,28 @@
+package nextstep.qna.domain;
+
+public class QuestionContent {
+
+    private final String title;
+
+    private final String contents;
+
+    public QuestionContent(String title, String contents) {
+        this.title = title;
+        this.contents = contents;
+    }
+
+    public String title() {
+        return title;
+    }
+
+    public String contents() {
+        return contents;
+    }
+
+    @Override
+    public String toString() {
+        return "QuestionContent{" +
+                ", title=" + title + ", contents=" + contents +
+                '}';
+    }
+}

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

@@ -0,0 +1,38 @@
+package nextstep.qna.domain;
+
+import nextstep.users.domain.NsUser;
+
+public abstract class SoftDeletableBaseEntity extends BaseTimeEntity {
+
+    private Long id;
+
+    private NsUser writer;
+
+    private boolean deleted = false;
+
+    protected SoftDeletableBaseEntity(Long id, NsUser writer) {
+        this.id = id;
+        this.writer = writer;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public NsUser getWriter() {
+        return writer;
+    }
+
+    protected void markAsDeleted() {
+        this.deleted = true;
+    }
+
+    public boolean isOwner(NsUser loginUser) {
+        return writer.equals(loginUser);
+    }
+
+    public boolean isDeleted() {
+        return deleted;
+    }
+
+}