[BE] issue122: 스터디 참여 기능

backend/src/main/java/com/woowacourse/moamoa/common/advice/CommonControllerAdvice.java

@@ -1,10 +1,12 @@
 package com.woowacourse.moamoa.common.advice;
 
-import com.woowacourse.moamoa.common.exception.UnauthorizedException;
+import static org.springframework.http.HttpStatus.UNAUTHORIZED;
+
 import com.woowacourse.moamoa.common.advice.response.ErrorResponse;
 import com.woowacourse.moamoa.common.exception.InvalidFormatException;
+import com.woowacourse.moamoa.common.exception.UnauthorizedException;
 import com.woowacourse.moamoa.study.domain.exception.InvalidPeriodException;
-import org.springframework.http.HttpStatus;
+import com.woowacourse.moamoa.study.service.exception.InvalidParticipationStudyException;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
@@ -14,14 +16,15 @@ public class CommonControllerAdvice {
 
     @ExceptionHandler({
             InvalidFormatException.class,
-            InvalidPeriodException.class
+            InvalidPeriodException.class,
+            InvalidParticipationStudyException.class
     })
     public ResponseEntity<ErrorResponse> handleBadRequest(final Exception e) {
         return ResponseEntity.badRequest().body(new ErrorResponse(e.getMessage()));
     }
 
     @ExceptionHandler
     public ResponseEntity<Void> handleUnauthorized(final UnauthorizedException e) {
-        return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
+        return ResponseEntity.status(UNAUTHORIZED).build();
     }
 }

backend/src/main/java/com/woowacourse/moamoa/study/controller/StudyController.java

@@ -1,31 +1,40 @@
 package com.woowacourse.moamoa.study.controller;
 
 import com.woowacourse.moamoa.auth.config.AuthenticationPrincipal;
-import com.woowacourse.moamoa.study.service.request.CreateStudyRequest;
 import com.woowacourse.moamoa.study.domain.Study;
-import com.woowacourse.moamoa.study.service.CreateStudyService;
+import com.woowacourse.moamoa.study.service.StudyService;
+import com.woowacourse.moamoa.study.service.request.CreatingStudyRequest;
 import java.net.URI;
 import javax.validation.Valid;
-import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 @RequiredArgsConstructor
-@Getter
+@RequestMapping("/api/studies")
 public class StudyController {
 
-    private final CreateStudyService createStudyService;
+    private final StudyService studyService;
 
-    @PostMapping("/api/studies")
+    @PostMapping
     public ResponseEntity<Void> createStudy(
             @AuthenticationPrincipal final Long githubId,
-            @Valid @RequestBody(required = false) final CreateStudyRequest createStudyRequest
+            @Valid @RequestBody(required = false) final CreatingStudyRequest creatingStudyRequest
     ) {
-        final Study study = createStudyService.createStudy(githubId, createStudyRequest);
+        final Study study = studyService.createStudy(githubId, creatingStudyRequest);
         return ResponseEntity.created(URI.create("/api/studies/" + study.getId())).build();
     }
+
+    @PostMapping("/{study-id}")
+    public ResponseEntity<Void> participateStudy(@AuthenticationPrincipal final Long githubId,
+                                                 @PathVariable("study-id") final Long studyId
+    ) {
+        studyService.participantStudy(githubId, studyId);
+        return ResponseEntity.ok().build();
+    }
 }

backend/src/main/java/com/woowacourse/moamoa/study/domain/Details.java

@@ -1,12 +1,19 @@
 package com.woowacourse.moamoa.study.domain;
 
+import static lombok.AccessLevel.PROTECTED;
+
+import com.woowacourse.moamoa.study.service.exception.InvalidParticipationStudyException;
 import java.util.Objects;
 import javax.persistence.Column;
 import javax.persistence.Embeddable;
+import lombok.NoArgsConstructor;
 
 @Embeddable
+@NoArgsConstructor(access = PROTECTED)
 public class Details {
 
+    private static final String CLOSE = "CLOSE";
+
     @Column(nullable = false)
     private String title;
 
@@ -22,9 +29,6 @@ public class Details {
     @Column(nullable = false)
     private String description;
 
-    protected Details() {
-    }
-
     public Details(final String title, final String excerpt, final String thumbnail, final String status,
                    final String description) {
         this.title = title;
@@ -34,6 +38,12 @@ public Details(final String title, final String excerpt, final String thumbnail,
         this.description = description;
     }
 
+    protected void checkStudyStatus() {
+        if (status.equals(CLOSE)) {
+            throw new InvalidParticipationStudyException();
+        }
+    }
+
     @Override
     public boolean equals(final Object o) {
         if (this == o) {

backend/src/main/java/com/woowacourse/moamoa/study/domain/Participant.java

@@ -2,10 +2,10 @@
 
 import static lombok.AccessLevel.PROTECTED;
 
-import java.util.Objects;
 import javax.persistence.Column;
 import javax.persistence.Embeddable;
 import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.ToString;
@@ -15,25 +15,9 @@
 @NoArgsConstructor(access = PROTECTED)
 @AllArgsConstructor
 @ToString
+@EqualsAndHashCode
 public class Participant {
 
     @Column(name = "member_id", nullable = false)
     private Long memberId;
-
-    @Override
-    public boolean equals(final Object o) {
-        if (this == o) {
-            return true;
-        }
-        if (o == null || getClass() != o.getClass()) {
-            return false;
-        }
-        final Participant that = (Participant) o;
-        return Objects.equals(memberId, that.memberId);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(memberId);
-    }
 }

backend/src/main/java/com/woowacourse/moamoa/study/domain/Participants.java

@@ -1,18 +1,24 @@
 package com.woowacourse.moamoa.study.domain;
 
+import static lombok.AccessLevel.PROTECTED;
+
+import com.woowacourse.moamoa.study.service.exception.InvalidParticipationStudyException;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
+import java.util.Set;
 import javax.persistence.CollectionTable;
 import javax.persistence.Column;
 import javax.persistence.ElementCollection;
 import javax.persistence.Embeddable;
-import javax.persistence.FetchType;
 import javax.persistence.JoinColumn;
+import lombok.NoArgsConstructor;
 import lombok.ToString;
 
 @Embeddable
 @ToString
+@NoArgsConstructor(access = PROTECTED)
 public class Participants {
 
     @Column(name = "current_member_count")
@@ -26,13 +32,10 @@ public class Participants {
 
     @ElementCollection
     @CollectionTable(name = "study_member", joinColumns = @JoinColumn(name = "study_id"))
-    private List<Participant> participants = new ArrayList<>();
-
-    protected Participants() {
-    }
+    private Set<Participant> participants = new HashSet<>();
 
     public Participants(final Integer size, final Integer max,
-                        final List<Participant> participants, Long ownerId) {
+                        final Set<Participant> participants, Long ownerId) {
         this.size = size;
         this.max = max;
         this.participants = participants;
@@ -43,8 +46,32 @@ public List<Participant> getParticipants() {
         return new ArrayList<>(participants);
     }
 
-    public static Participants createByMaxSizeAndOwnerId(final Integer maxSize, Long id) {
-        return new Participants(1, maxSize, new ArrayList<>(), id);
+    public static Participants createByMaxSizeAndOwnerId(final Integer maxSize, Long ownerId) {
+        return new Participants(1, maxSize, new HashSet<>(List.of(new Participant(ownerId))), ownerId);
+    }
+
+    protected void participate(final Participant participant) {
+        participants.add(participant);
+        this.size = this.size + 1;
+    }
+
+    public int getCurrentMemberSize() {
+        return size;
+    }
+
+    protected void checkParticipating(Long memberId) {
+        if (isInvalidMemberSize() || isAlreadyParticipation(memberId)) {
+            throw new InvalidParticipationStudyException();
+        }
+    }
+
+    private boolean isInvalidMemberSize() {
+        return max != null && max <= size;
+    }
+
+    private boolean isAlreadyParticipation(final Long memberId) {
+        final Participant participant = new Participant(memberId);
+        return Objects.equals(memberId, ownerId) || participants.contains(participant);
     }
 
     @Override
@@ -61,7 +88,7 @@ public boolean equals(final Object o) {
     }
 
     @Override
-    public int hashCode() {
+    public int hashCode()  {
         return Objects.hash(size, max, ownerId, participants);
     }
 }

backend/src/main/java/com/woowacourse/moamoa/study/domain/Period.java

@@ -1,13 +1,16 @@
 package com.woowacourse.moamoa.study.domain;
 
 import com.woowacourse.moamoa.study.domain.exception.InvalidPeriodException;
+import com.woowacourse.moamoa.study.service.exception.InvalidParticipationStudyException;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.util.Objects;
 import javax.persistence.Column;
 import javax.persistence.Embeddable;
+import lombok.Getter;
 
 @Embeddable
+@Getter
 public class Period {
 
     private LocalDate enrollmentEndDate;
@@ -21,16 +24,21 @@ public Period() {
     }
 
     public Period(final LocalDate enrollmentEndDate, final LocalDate startDate, final LocalDate endDate) {
-        if ((endDate != null && startDate.isAfter(endDate)) || (enrollmentEndDate != null && endDate != null && enrollmentEndDate.isAfter(endDate))) {
-            throw new InvalidPeriodException();
-        }
+        validatePeriod(enrollmentEndDate, startDate, endDate);
         this.enrollmentEndDate = enrollmentEndDate;
         this.startDate = startDate;
         this.endDate = endDate;
     }
 
     public boolean isBefore(final LocalDateTime createAt) {
-        return startDate.isBefore(createAt.toLocalDate()) || (enrollmentEndDate != null && enrollmentEndDate.isBefore(createAt.toLocalDate()));
+        return startDate.isBefore(createAt.toLocalDate()) || (enrollmentEndDate != null && enrollmentEndDate.isBefore(
+                createAt.toLocalDate()));
+    }
+
+    protected void checkParticipatingPeriod() {
+        if (enrollmentEndDate != null && enrollmentEndDate.isBefore(LocalDate.now())) {
+            throw new InvalidParticipationStudyException();
+        }
     }
 
     @Override
@@ -50,4 +58,18 @@ public boolean equals(final Object o) {
     public int hashCode() {
         return Objects.hash(enrollmentEndDate, startDate, endDate);
     }
+
+    private void validatePeriod(final LocalDate enrollmentEndDate, final LocalDate startDate, final LocalDate endDate) {
+        if (isImproperStudyDate(startDate, endDate) || isImproperEnrollmentEndDate(enrollmentEndDate, endDate)) {
+            throw new InvalidPeriodException();
+        }
+    }
+
+    private boolean isImproperStudyDate(final LocalDate startDate, final LocalDate endDate) {
+        return endDate != null && startDate.isAfter(endDate);
+    }
+
+    private boolean isImproperEnrollmentEndDate(final LocalDate enrollmentEndDate, final LocalDate endDate) {
+        return enrollmentEndDate != null && endDate != null && enrollmentEndDate.isAfter(endDate);
+    }
 }

backend/src/main/java/com/woowacourse/moamoa/study/domain/Study.java

@@ -3,6 +3,7 @@
 import static javax.persistence.GenerationType.IDENTITY;
 import static lombok.AccessLevel.PROTECTED;
 
+import com.woowacourse.moamoa.member.domain.Member;
 import com.woowacourse.moamoa.study.domain.exception.InvalidPeriodException;
 import java.time.LocalDateTime;
 import javax.persistence.Column;
@@ -56,6 +57,19 @@ public Study(final Long id, final Details details, final Participants participan
         validatePeriod(period);
     }
 
+    public void participate(final Member member) {
+        checkStudyParticipating(member.getId());
+
+        final Participant participant = new Participant(member.getId());
+        participants.participate(participant);
+    }
+
+    private void checkStudyParticipating(Long memberId) {
+        details.checkStudyStatus();
+        period.checkParticipatingPeriod();
+        participants.checkParticipating(memberId);
+    }
+
     private void validatePeriod(final Period period) {
         if (period.isBefore(createdAt)) {
             throw new InvalidPeriodException();