feat(guestbook, luckydraw): 방명록 및 방명록 연계 추첨 기능 추가

src/main/java/inha/gdgoc/domain/guestbook/controller/GuestbookController.java

@@ -0,0 +1,80 @@
+package inha.gdgoc.domain.guestbook.controller;
+
+import inha.gdgoc.domain.guestbook.controller.message.GuestbookMessage;
+import inha.gdgoc.domain.guestbook.dto.request.GuestbookCreateRequest;
+import inha.gdgoc.domain.guestbook.dto.request.LuckyDrawRequest;
+import inha.gdgoc.domain.guestbook.dto.response.GuestbookEntryResponse;
+import inha.gdgoc.domain.guestbook.dto.response.LuckyDrawWinnerResponse;
+import inha.gdgoc.domain.guestbook.service.GuestbookService;
+import inha.gdgoc.global.dto.response.ApiResponse;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.access.prepost.PreAuthorize;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+import java.util.Map;
+
+@RestController
+@RequestMapping("/api/v1/guestbook")
+@RequiredArgsConstructor
+@PreAuthorize("hasAnyRole('ORGANIZER','ADMIN')")
+public class GuestbookController {
+
+    private final GuestbookService service;
+
+    /* ===== helpers ===== */
+    private static ResponseEntity<ApiResponse<Map<String, Object>, Void>> okUpdated(String msg, long updated) {
+        return ResponseEntity.ok(ApiResponse.ok(msg, Map.of("updated", updated)));
+    }
+
+    /* ===== 방명록: 등록(자동 응모) ===== */
+    // 운영진 PC에서 손목밴드 번호 + 이름 입력 → 저장 + 자동 응모 상태로 들어감
+    @PostMapping("/entries")
+    public ResponseEntity<ApiResponse<GuestbookEntryResponse, Void>> createEntry(@Valid @RequestBody GuestbookCreateRequest req) {
+        GuestbookEntryResponse saved = service.register(req.wristbandSerial(), req.name());
+        return ResponseEntity.ok(ApiResponse.ok(GuestbookMessage.ENTRY_CREATED_SUCCESS, saved));
+    }
+
+    /* ===== 방명록: 목록 ===== */
+    @GetMapping("/entries")
+    public ResponseEntity<ApiResponse<List<GuestbookEntryResponse>, Void>> listEntries() {
+        var result = service.listEntries();
+        return ResponseEntity.ok(ApiResponse.ok(GuestbookMessage.ENTRY_LIST_RETRIEVED_SUCCESS, result));
+    }
+
+    /* ===== 방명록: 단건 조회(필요하면) ===== */
+    @GetMapping("/entries/{entryId}")
+    public ResponseEntity<ApiResponse<GuestbookEntryResponse, Void>> getEntry(@PathVariable Long entryId) {
+        return ResponseEntity.ok(ApiResponse.ok(GuestbookMessage.ENTRY_RETRIEVED_SUCCESS, service.get(entryId)));
+    }
+
+    /* ===== 방명록: 삭제(운영 중 실수 입력 정정용) ===== */
+    @DeleteMapping("/entries/{entryId}")
+    public ResponseEntity<ApiResponse<Map<String, Object>, Void>> deleteEntry(@PathVariable Long entryId) {
+        service.delete(entryId);
+        return okUpdated(GuestbookMessage.ENTRY_DELETED_SUCCESS, 1L);
+    }
+
+    /* ===== 럭키드로우: 추첨 ===== */
+    // 요청 예시: { "count": 3, "excludeWinnerIds": [1,2] } 같은 확장도 가능
+    @PostMapping("/lucky-draw")
+    public ResponseEntity<ApiResponse<List<LuckyDrawWinnerResponse>, Void>> drawWinners(@Valid @RequestBody LuckyDrawRequest req) {
+        List<LuckyDrawWinnerResponse> winners = service.draw(req);
+        return ResponseEntity.ok(ApiResponse.ok(GuestbookMessage.LUCKY_DRAW_SUCCESS, winners));
+    }
+
+    /* ===== 럭키드로우: 당첨자 목록 ===== */
+    @GetMapping("/lucky-draw/winners")
+    public ResponseEntity<ApiResponse<List<LuckyDrawWinnerResponse>, Void>> listWinners() {
+        return ResponseEntity.ok(ApiResponse.ok(GuestbookMessage.WINNER_LIST_RETRIEVED_SUCCESS, service.listWinners()));
+    }
+
+    /* ===== 럭키드로우: 리셋(테스트/리허설용) ===== */
+    @PostMapping("/lucky-draw/reset")
+    public ResponseEntity<ApiResponse<Map<String, Object>, Void>> resetWinners() {
+        long updated = service.resetWinners();
+        return okUpdated(GuestbookMessage.WINNER_RESET_SUCCESS, updated);
+    }
+}

src/main/java/inha/gdgoc/domain/guestbook/controller/message/GuestbookMessage.java

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+package inha.gdgoc.domain.guestbook.controller.message;
+
+public class GuestbookMessage {
+
+    public static final String ENTRY_CREATED_SUCCESS = "방명록 작성이 완료되었습니다.";
+    public static final String ENTRY_RETRIEVED_SUCCESS = "방명록 단건 조회에 성공했습니다.";
+    public static final String ENTRY_LIST_RETRIEVED_SUCCESS = "방명록 목록 조회에 성공했습니다.";
+    public static final String ENTRY_DELETED_SUCCESS = "방명록 삭제에 성공했습니다.";
+
+    public static final String LUCKY_DRAW_SUCCESS = "럭키드로우 추첨이 완료되었습니다.";
+    public static final String WINNER_LIST_RETRIEVED_SUCCESS = "당첨자 목록 조회에 성공했습니다.";
+    public static final String WINNER_RESET_SUCCESS = "당첨자 초기화가 완료되었습니다.";
+}

src/main/java/inha/gdgoc/domain/guestbook/dto/request/GuestbookCreateRequest.java

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+package inha.gdgoc.domain.guestbook.dto.request;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+public record GuestbookCreateRequest(@NotBlank @Size(max = 32) String wristbandSerial,
+                                     @NotBlank @Size(max = 50) String name) {
+
+}

src/main/java/inha/gdgoc/domain/guestbook/dto/request/LuckyDrawRequest.java

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+package inha.gdgoc.domain.guestbook.dto.request;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import jakarta.validation.constraints.Max;
+import jakarta.validation.constraints.Min;
+
+public record LuckyDrawRequest(@Min(1) @Max(50) int count) {
+
+    @JsonCreator
+    public LuckyDrawRequest(@JsonProperty("count") Integer count) {
+        this((count == null) ? 1 : count);
+    }
+}

src/main/java/inha/gdgoc/domain/guestbook/dto/response/GuestbookEntryResponse.java

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+package inha.gdgoc.domain.guestbook.dto.response;
+
+import inha.gdgoc.domain.guestbook.entity.GuestbookEntry;
+
+import java.time.LocalDateTime;
+
+public record GuestbookEntryResponse(Long id, String wristbandSerial, String name, LocalDateTime createdAt,
+                                     LocalDateTime wonAt) {
+
+    public static GuestbookEntryResponse from(GuestbookEntry e) {
+        return new GuestbookEntryResponse(e.getId(), e.getWristbandSerial(), e.getName(), e.getCreatedAt(), e.getWonAt());
+    }
+}

src/main/java/inha/gdgoc/domain/guestbook/dto/response/LuckyDrawWinnerResponse.java

@@ -0,0 +1,12 @@
+package inha.gdgoc.domain.guestbook.dto.response;
+
+import inha.gdgoc.domain.guestbook.entity.GuestbookEntry;
+
+import java.time.LocalDateTime;
+
+public record LuckyDrawWinnerResponse(Long id, String wristbandSerial, String name, LocalDateTime wonAt) {
+
+    public static LuckyDrawWinnerResponse from(GuestbookEntry e) {
+        return new LuckyDrawWinnerResponse(e.getId(), e.getWristbandSerial(), e.getName(), e.getWonAt());
+    }
+}

src/main/java/inha/gdgoc/domain/guestbook/entity/GuestbookEntry.java

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+package inha.gdgoc.domain.guestbook.entity;
+
+import jakarta.persistence.*;
+import lombok.Getter;
+
+import java.time.LocalDateTime;
+
+@Getter
+@Entity
+@Table(name = "guestbook_entry", indexes = {@Index(name = "idx_guestbook_created_at", columnList = "createdAt")})
+public class GuestbookEntry {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "wristband_serial", nullable = false, unique = true, length = 32)
+    private String wristbandSerial; // 손목밴드 일련번호(키)
+
+    @Column(nullable = false, length = 50)
+    private String name;
+
+    @Column(nullable = false, updatable = false)
+    private final LocalDateTime createdAt = LocalDateTime.now();
+
+    private LocalDateTime wonAt; // 당첨 시각 (null이면 미당첨)
+
+    protected GuestbookEntry() {}
+
+    public GuestbookEntry(String wristbandSerial, String name) {
+        this.wristbandSerial = wristbandSerial;
+        this.name = name;
+    }
+
+    public boolean isWon() {return wonAt != null;}
+
+    public void markWon() {this.wonAt = LocalDateTime.now();}
+}

src/main/java/inha/gdgoc/domain/guestbook/repository/GuestbookRepository.java

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+package inha.gdgoc.domain.guestbook.repository;
+
+import inha.gdgoc.domain.guestbook.entity.GuestbookEntry;
+import jakarta.persistence.LockModeType;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+
+import java.util.List;
+
+public interface GuestbookRepository extends JpaRepository<GuestbookEntry, Long> {
+
+    boolean existsByWristbandSerial(String wristbandSerial);
+
+    // 목록
+    List<GuestbookEntry> findAllByOrderByCreatedAtDesc();
+
+    // 당첨 전 후보(락)
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("select g from GuestbookEntry g where g.wonAt is null")
+    List<GuestbookEntry> findAllByWonAtIsNullForUpdate();
+
+    // 당첨자 목록
+    List<GuestbookEntry> findAllByWonAtIsNotNullOrderByWonAtAsc();
+
+    // 리셋 (wonAt = null)
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("update GuestbookEntry g set g.wonAt = null where g.wonAt is not null")
+    long clearAllWinners();
+}

src/main/java/inha/gdgoc/domain/guestbook/service/GuestbookService.java

@@ -0,0 +1,99 @@
+package inha.gdgoc.domain.guestbook.service;
+
+import inha.gdgoc.domain.guestbook.dto.request.LuckyDrawRequest;
+import inha.gdgoc.domain.guestbook.dto.response.GuestbookEntryResponse;
+import inha.gdgoc.domain.guestbook.dto.response.LuckyDrawWinnerResponse;
+import inha.gdgoc.domain.guestbook.entity.GuestbookEntry;
+import inha.gdgoc.domain.guestbook.repository.GuestbookRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+@Service
+@Transactional
+@RequiredArgsConstructor
+public class GuestbookService {
+
+    private final GuestbookRepository repo;
+
+    /* ===== 등록 ===== */
+    public GuestbookEntryResponse register(String wristbandSerial, String name) {
+        wristbandSerial = wristbandSerial == null ? "" : wristbandSerial.trim();
+        name = name == null ? "" : name.trim();
+
+        if (wristbandSerial.isBlank() || name.isBlank()) {
+            throw new IllegalArgumentException("wristbandSerial and name are required");
+        }
+        if (repo.existsByWristbandSerial(wristbandSerial)) {
+            throw new DuplicateWristbandSerialException();
+        }
+
+        GuestbookEntry saved = repo.save(new GuestbookEntry(wristbandSerial, name));
+        return GuestbookEntryResponse.from(saved);
+    }
+
+    /* ===== 목록 ===== */
+    @Transactional(readOnly = true)
+    public List<GuestbookEntryResponse> listEntries() {
+        return repo.findAllByOrderByCreatedAtDesc().stream().map(GuestbookEntryResponse::from).toList();
+    }
+
+    /* ===== 단건 ===== */
+    @Transactional(readOnly = true)
+    public GuestbookEntryResponse get(Long id) {
+        return repo.findById(id).map(GuestbookEntryResponse::from).orElseThrow(NotFoundException::new);
+    }
+
+    /* ===== 삭제 ===== */
+    public void delete(Long id) {
+        repo.deleteById(id);
+    }
+
+    /* ===== 추첨 ===== */
+    public List<LuckyDrawWinnerResponse> draw(LuckyDrawRequest req) {
+        int count = req.count();
+
+        List<GuestbookEntry> pool = repo.findAllByWonAtIsNullForUpdate();
+        if (pool.size() < count) {
+            throw new NoCandidatesException();
+        }
+
+        Collections.shuffle(pool);
+
+        List<LuckyDrawWinnerResponse> winners = new ArrayList<>();
+        for (int i = 0; i < count; i++) {
+            GuestbookEntry e = pool.get(i);
+            e.markWon();
+            winners.add(LuckyDrawWinnerResponse.from(e));
+        }
+        return winners;
+    }
+
+    /* ===== 당첨자 목록 ===== */
+    @Transactional(readOnly = true)
+    public List<LuckyDrawWinnerResponse> listWinners() {
+        return repo.findAllByWonAtIsNotNullOrderByWonAtAsc().stream().map(LuckyDrawWinnerResponse::from).toList();
+    }
+
+    /* ===== 리셋 ===== */
+    public long resetWinners() {
+        return repo.clearAllWinners();
+    }
+
+    /* ===== exceptions ===== */
+    public static class DuplicateWristbandSerialException extends RuntimeException {
+
+    }
+
+    public static class NoCandidatesException extends RuntimeException {
+
+    }
+
+    public static class NotFoundException extends RuntimeException {
+
+    }
+}