feat: 오늘의 질문 도메인 구현

commitlint.config.js

@@ -17,6 +17,7 @@ module.exports = {
             "auth",
             "user",
             "ai",
+            "report",
             "friend",
             "notify",
             "infra",
@@ -104,6 +105,9 @@ module.exports = {
                     ai: {
                         description: '🤖 AI 처리 (예: 벡터 검색, OpenAI API, 모델 응답 로직)'
                     },
+                    report: {
+                        description: '📔 리포트 도메인 (예: 리포트 생성, 조회, 관리)'
+                    },
                     friend: {
                         description: '👥 친구 도메인 (예: 친구 신청, 수락, 목록 관리)'
                     },

src/main/java/com/devkor/ifive/nadab/domain/question/api/QuestionController.java

@@ -0,0 +1,87 @@
+package com.devkor.ifive.nadab.domain.question.api;
+
+import com.devkor.ifive.nadab.domain.question.api.dto.response.DailyQuestionResponse;
+import com.devkor.ifive.nadab.domain.question.application.QuestionCommandService;
+import com.devkor.ifive.nadab.global.core.response.ApiResponseDto;
+import com.devkor.ifive.nadab.global.core.response.ApiResponseEntity;
+import com.devkor.ifive.nadab.global.security.principal.UserPrincipal;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.access.prepost.PreAuthorize;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@Tag(name = "질문 API", description = "오늘의 질문 관련 API")
+@RestController
+@RequestMapping("${api_prefix}/question")
+@RequiredArgsConstructor
+public class QuestionController {
+
+    private final QuestionCommandService questionCommandService;
+
+    @GetMapping
+    @PreAuthorize("isAuthenticated()")
+    @Operation(
+            summary = "오늘의 질문 조회",
+            description = "오늘의 질문을 조회합니다.",
+            security = @SecurityRequirement(name = "bearerAuth"),
+            responses = {
+                    @ApiResponse(
+                            responseCode = "200",
+                            description = "성공",
+                            content = @Content(schema = @Schema(implementation = DailyQuestionResponse.class), mediaType = "application/json")
+                    ),
+                    @ApiResponse(
+                            responseCode = "401",
+                            description = "사용자 인증 실패",
+                            content = @Content
+                    )
+            }
+    )
+    public ResponseEntity<ApiResponseDto<DailyQuestionResponse>> getDailyQuestion(
+            @AuthenticationPrincipal UserPrincipal principal
+    ) {
+        DailyQuestionResponse response = questionCommandService.getOrCreateTodayQuestion(principal.getId());
+        return ApiResponseEntity.ok(response);
+    }
+
+    @PostMapping("/reroll")
+    @PreAuthorize("isAuthenticated()")
+    @Operation(
+            summary = "새로운 질문 받기",
+            description = "오늘의 질문을 새로 받습니다. 하루에 한 번만 가능합니다.",
+            security = @SecurityRequirement(name = "bearerAuth"),
+            responses = {
+                    @ApiResponse(
+                            responseCode = "200",
+                            description = "성공",
+                            content = @Content(schema = @Schema(implementation = DailyQuestionResponse.class), mediaType = "application/json")
+                    ),
+                    @ApiResponse(
+                            responseCode = "401",
+                            description = "사용자 인증 실패",
+                            content = @Content
+                    ),
+                    @ApiResponse(
+                            responseCode = "409",
+                            description = "오늘의 질문은 하루에 한 번만 새로 받을 수 있습니다.",
+                            content = @Content
+                    )
+            }
+    )
+    public ResponseEntity<ApiResponseDto<DailyQuestionResponse>> rerollDailyQuestion(
+            @AuthenticationPrincipal UserPrincipal principal
+    ) {
+        DailyQuestionResponse response = questionCommandService.rerollTodayQuestion(principal.getId());
+        return ApiResponseEntity.ok(response);
+    }
+}

src/main/java/com/devkor/ifive/nadab/domain/question/api/dto/response/DailyQuestionResponse.java

@@ -0,0 +1,28 @@
+package com.devkor.ifive.nadab.domain.question.api.dto.response;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@Schema(description = "오늘의 질문 응답")
+public record DailyQuestionResponse(
+        @Schema(description = "질문 ID")
+        Long questionId,
+
+        @Schema(description = "질문 텍스트")
+        String questionText,
+
+        @Schema(description = "공감 가이드 텍스트")
+        String empathyGuide,
+
+        @Schema(description = "힌트 가이드 텍스트")
+        String hintGuide,
+
+        @Schema(description = "도입 질문 가이드 텍스트")
+        String leadingQuestionGuide,
+
+        @Schema(description = "사용자가 오늘의 질문에 답변했는지 여부")
+        boolean answered,
+
+        @Schema(description = "사용자가 새로운 질문 받기를 했는지 여부")
+        boolean rerollUsed
+) {
+}

src/main/java/com/devkor/ifive/nadab/domain/question/application/QuestionCommandService.java

@@ -0,0 +1,144 @@
+package com.devkor.ifive.nadab.domain.question.application;
+
+import com.devkor.ifive.nadab.domain.question.api.dto.response.DailyQuestionResponse;
+import com.devkor.ifive.nadab.domain.question.application.helper.DailyQuestionSelector;
+import com.devkor.ifive.nadab.domain.question.application.helper.QuestionLevelPolicy;
+import com.devkor.ifive.nadab.domain.question.application.helper.WeightedInterestPicker;
+import com.devkor.ifive.nadab.domain.question.core.entity.DailyQuestion;
+import com.devkor.ifive.nadab.domain.question.core.entity.UserDailyQuestion;
+import com.devkor.ifive.nadab.domain.question.core.repository.UserDailyQuestionRepository;
+import com.devkor.ifive.nadab.domain.report.core.repository.AnswerEntryRepository;
+import com.devkor.ifive.nadab.domain.user.core.entity.User;
+import com.devkor.ifive.nadab.domain.user.core.repository.InterestRepository;
+import com.devkor.ifive.nadab.domain.user.core.repository.UserInterestRepository;
+import com.devkor.ifive.nadab.domain.user.core.repository.UserRepository;
+import com.devkor.ifive.nadab.global.exception.BadRequestException;
+import com.devkor.ifive.nadab.global.exception.ConflictException;
+import com.devkor.ifive.nadab.global.exception.NotFoundException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.*;
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+@Transactional
+public class QuestionCommandService {
+
+    private static final ZoneId KST = ZoneId.of("Asia/Seoul");
+
+    private final UserRepository userRepository;
+    private final UserDailyQuestionRepository userDailyQuestionRepository;
+    private final UserInterestRepository userInterestRepository;
+    private final InterestRepository interestRepository;
+    private final AnswerEntryRepository answerEntryRepository;
+
+    private final QuestionLevelPolicy questionLevelPolicy;
+    private final WeightedInterestPicker weightedInterestPicker;
+    private final DailyQuestionSelector dailyQuestionSelector;
+
+    public DailyQuestionResponse getOrCreateTodayQuestion(Long userId) {
+        LocalDate today = LocalDate.now(KST);
+
+        User user = userRepository.findById(userId)
+                .orElseThrow(() -> new NotFoundException("사용자를 찾을 수 없습니다. id: " + userId));
+
+        UserDailyQuestion udq = userDailyQuestionRepository.findByUserIdAndDate(userId, today)
+                .orElseGet(() -> this.createTodayQuestion(userId, today));
+
+        DailyQuestion question = udq.getDailyQuestion();
+
+        boolean answered = answerEntryRepository.existsActiveAnswer(userId, question.getId());
+
+        return new DailyQuestionResponse(
+                question.getId(),
+                question.getQuestionText(),
+                question.getEmpathyGuide(),
+                question.getHintGuide(),
+                question.getLeadingQuestionGuide(),
+                answered,
+                udq.isRerollUsed()
+        );
+    }
+
+    /**
+     * 오늘 첫 질문 생성:
+     * - UserInterest의 interest_id 질문들 중 랜덤 1개
+     * - 가입 2주 미만은 level = 1만
+     * - 이미 답변한 질문은 제외
+     */
+    public UserDailyQuestion createTodayQuestion(Long userId, LocalDate todayKst) {
+        // 동시성: 여러 요청이 동시에 들어오면 UNIQUE(user_id, date)로 한 번만 성공해야 함
+        // -> insert 시도 후 unique 위반이면 다시 조회해서 반환
+        try {
+            User user = userRepository.findById(userId)
+                    .orElseThrow(() -> new NotFoundException("사용자를 찾을 수 없습니다. id: " + userId));
+
+            Long userInterestId = userInterestRepository.findInterestIdByUserId(userId)
+                    .orElseThrow(() -> new NotFoundException("사용자의 관심 주제를 찾을 수 없습니다. id: " + userId));
+
+            Integer levelOnly = questionLevelPolicy.levelOnlyFor(user, OffsetDateTime.now());
+
+            DailyQuestion picked = dailyQuestionSelector.pickFirst(user.getId(), userInterestId, levelOnly);
+
+            UserDailyQuestion udq = UserDailyQuestion.create(user, todayKst, picked);
+            return userDailyQuestionRepository.save(udq);
+
+        } catch (DataIntegrityViolationException e) {
+            // 이미 생성됨(경합 상황)
+            return userDailyQuestionRepository.findByUserIdAndDate(userId, todayKst)
+                    .orElseThrow(() -> e);
+        }
+    }
+
+    /**
+     * 리롤:
+     * - reroll_used = false일 때만 허용
+     * - 관심사 가중치 랜덤: 내 interest 50%, 나머지 interest는 동등 분배
+     * - 선택된 interest 내에서 랜덤 질문 (단, 현재 질문 제외)
+     * - 가입 2주 미만이면 level = 1만
+     * - 이미 답변한 질문은 제외
+     */
+    public DailyQuestionResponse rerollTodayQuestion(Long userId) {
+        LocalDate today = LocalDate.now(KST);
+
+        UserDailyQuestion udq = userDailyQuestionRepository.findByUserIdAndDate(userId, today)
+                .orElseThrow(() -> new ConflictException("오늘의 첫 질문이 아직 생성되지 않았습니다."));
+
+        if (udq.isRerollUsed()) {
+            throw new BadRequestException("오늘의 질문은 하루에 한 번만 새로 받을 수 있습니다.");
+        }
+
+        User user = udq.getUser();
+
+        Long userInterestId = userInterestRepository.findInterestIdByUserId(userId)
+                .orElseThrow(() -> new NotFoundException("유저 관심 주제가 없습니다. id: " + userId));
+
+        List<Long> allInterestIds = interestRepository.findAllIds();
+        Long selectedInterestId = weightedInterestPicker.pickForReroll(userInterestId, allInterestIds);
+
+        Integer levelOnly = questionLevelPolicy.levelOnlyFor(user, OffsetDateTime.now());
+
+        DailyQuestion newQ = dailyQuestionSelector.pickReroll(
+                user.getId(),
+                selectedInterestId,
+                udq.getDailyQuestion().getId(),
+                levelOnly
+        );
+
+        udq.rerollTo(newQ);
+
+        return new DailyQuestionResponse(
+                newQ.getId(),
+                newQ.getQuestionText(),
+                newQ.getEmpathyGuide(),
+                newQ.getHintGuide(),
+                newQ.getLeadingQuestionGuide(),
+                false,
+                true
+        );
+    }
+}

src/main/java/com/devkor/ifive/nadab/domain/question/application/helper/DailyQuestionSelector.java

@@ -0,0 +1,29 @@
+package com.devkor.ifive.nadab.domain.question.application.helper;
+
+import com.devkor.ifive.nadab.domain.question.core.entity.DailyQuestion;
+import com.devkor.ifive.nadab.domain.question.core.repository.DailyQuestionRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.stereotype.Component;
+
+
+@Component
+@RequiredArgsConstructor
+public class DailyQuestionSelector {
+
+    private final DailyQuestionRepository dailyQuestionRepository;
+
+    public DailyQuestion pickFirst(Long userId, Long interestId, Integer levelOnly) {
+        return dailyQuestionRepository.findRandomByInterestExcludingAnswered(userId, interestId, levelOnly, PageRequest.of(0, 1))
+                .stream()
+                .findFirst()
+                .orElseThrow(() -> new IllegalStateException("조건에 맞는 질문이 없습니다."));
+    }
+
+    public DailyQuestion pickReroll(Long userId, Long interestId, Long excludeQuestionId, Integer levelOnly) {
+        return dailyQuestionRepository.findRandomByInterestExcludingAnsweredAndExcludingId(userId, interestId, excludeQuestionId, levelOnly, PageRequest.of(0, 1))
+                .stream()
+                .findFirst()
+                .orElseThrow(() -> new IllegalStateException("리롤 가능한 질문이 없습니다."));
+    }
+}

src/main/java/com/devkor/ifive/nadab/domain/question/application/helper/QuestionLevelPolicy.java

@@ -0,0 +1,25 @@
+package com.devkor.ifive.nadab.domain.question.application.helper;
+
+import com.devkor.ifive.nadab.domain.user.core.entity.User;
+import org.springframework.stereotype.Component;
+
+import java.time.OffsetDateTime;
+
+/**
+ * 질문 작성 시, 사용자 레벨에 따른 정책을 적용하는 헬퍼 클래스
+ * - 신규 사용자(가입 후 14일 이내)는 레벨 1 질문만 작성 가능
+ */
+@Component
+public class QuestionLevelPolicy {
+
+    private static final int NEWBIE_DAYS = 14;
+    private static final int NEWBIE_LEVEL_ONLY = 1;
+
+    public Integer levelOnlyFor(User user, OffsetDateTime now) {
+        OffsetDateTime registeredAt = user.getRegisteredAt();
+        if (registeredAt == null) return null;
+
+        boolean isNewbie = registeredAt.isAfter(now.minusDays(NEWBIE_DAYS));
+        return isNewbie ? NEWBIE_LEVEL_ONLY : null;
+    }
+}

src/main/java/com/devkor/ifive/nadab/domain/question/application/helper/WeightedInterestPicker.java

@@ -0,0 +1,37 @@
+package com.devkor.ifive.nadab.domain.question.application.helper;
+
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * 가중치 기반으로 관심사를 선택하는 헬퍼 클래스
+ * - 사용자의 기존 관심사에 더 높은 가중치(0.5)를 부여하여 재선택
+ * - 나머지 관심사들은 균등하게 나머지 가중치(0.5)를 분배
+ */
+@Component
+public class WeightedInterestPicker {
+
+    public Long pickForReroll(Long userInterestId, List<Long> allInterestIds) {
+        if (allInterestIds == null || allInterestIds.isEmpty()) {
+            throw new IllegalStateException("interest 목록이 비어있습니다.");
+        }
+        if (allInterestIds.size() == 1) {
+            return allInterestIds.get(0);
+        }
+
+        double userWeight = 0.5d;
+        double othersWeightEach = 0.5d / (allInterestIds.size() - 1);
+
+        double r = ThreadLocalRandom.current().nextDouble(0.0, 1.0);
+        double acc = 0.0;
+
+        for (Long id : allInterestIds) {
+            double w = id.equals(userInterestId) ? userWeight : othersWeightEach;
+            acc += w;
+            if (r <= acc) return id;
+        }
+        return allInterestIds.get(allInterestIds.size() - 1); // float 오차 방지
+    }
+}