Feat: 요약 및 문제 생성 API 구현 (#32)

* Rename: AI Task 도메인 이름 변경

- llm 으로 변경

* Refactor: LLM 도메인 애플리케이션 계층과 프레젠테이션 계층 응답 분리

* Feat: LLM 작업 진행 상태 확인 기능 구현

* Feat: 요약 및 문제 결과 조회 기능 구현

* Feat: 요약 및 문제 생성 기능 구현

- AI 서버와 통신하는 부분 제외하고 기능 구현
- 임시 UUID 를 통해 task 저장

* Feat: LLM 서버 콜백 기능 구현

- LLM 서버가 API 콜을 통해 페이지별 요약 및 문제 내용 전달
- task id 를 통해 조회하여 요약 내용과 문제 내용 업데이트

* Refactor: 변수 이름 변경

- 필드명 카멜케이스로 변경

* Refactor: 통일성 없는 부분 수정

- 필드명 변경
- 변수 추출

* Refactor: 예외 종류, 메서드 네이밍 변경

- LLMQueryService 예외 타입 변경
- SummaryAndProblemUpdateResponse 메서드 네이밍 변경

* Refactor: LLMQueryService 응답과 LLMController 응답 분리

src/main/java/notai/llm/application/LLMQueryService.java

@@ -0,0 +1,110 @@
+package notai.llm.application;
+
+import lombok.RequiredArgsConstructor;
+import notai.common.exception.type.BadRequestException;
+import notai.common.exception.type.InternalServerErrorException;
+import notai.common.exception.type.NotFoundException;
+import notai.document.domain.DocumentRepository;
+import notai.llm.application.result.LLMResultsResult;
+import notai.llm.application.result.LLMResultsResult.LLMContent;
+import notai.llm.application.result.LLMResultsResult.LLMResult;
+import notai.llm.application.result.LLMStatusResult;
+import notai.llm.domain.TaskStatus;
+import notai.llm.query.LLMQueryRepository;
+import notai.problem.query.ProblemQueryRepository;
+import notai.problem.query.result.ProblemPageContentResult;
+import notai.summary.query.SummaryQueryRepository;
+import notai.summary.query.result.SummaryPageContentResult;
+import org.springframework.stereotype.Service;
+
+import java.util.Collections;
+import java.util.List;
+
+import static notai.llm.domain.TaskStatus.COMPLETED;
+import static notai.llm.domain.TaskStatus.IN_PROGRESS;
+
+@Service
+@RequiredArgsConstructor
+public class LLMQueryService {
+
+    private final LLMQueryRepository llmQueryRepository;
+    private final DocumentRepository documentRepository;
+    private final SummaryQueryRepository summaryQueryRepository;
+    private final ProblemQueryRepository problemQueryRepository;
+
+    public LLMStatusResult fetchTaskStatus(Long documentId) {
+        checkDocumentExists(documentId);
+        List<Long> summaryIds = getSummaryIds(documentId);
+        List<TaskStatus> taskStatuses = getTaskStatuses(summaryIds);
+
+        int totalPages = summaryIds.size();
+        int completedPages = Collections.frequency(taskStatuses, COMPLETED);
+
+        if (totalPages == completedPages) {
+            return LLMStatusResult.of(documentId, COMPLETED, totalPages, completedPages);
+        }
+        return LLMStatusResult.of(documentId, IN_PROGRESS, totalPages, completedPages);
+    }
+
+    public LLMResultsResult findTaskResult(Long documentId) {
+        checkDocumentExists(documentId);
+        List<SummaryPageContentResult> summaryResults = getSummaryPageContentResults(documentId);
+        List<ProblemPageContentResult> problemResults = getProblemPageContentResults(documentId);
+        checkSummaryAndProblemCountsEqual(summaryResults, problemResults);
+
+        List<LLMResult> results = summaryResults.stream().map(summaryResult -> {
+            LLMContent content = LLMContent.of(
+                    summaryResult.content(),
+                    findProblemContentByPageNumber(problemResults, summaryResult.pageNumber())
+            );
+            return LLMResult.of(summaryResult.pageNumber(), content);
+        }).toList();
+
+        return LLMResultsResult.of(documentId, results);
+    }
+
+    private void checkDocumentExists(Long documentId) {
+        if (!documentRepository.existsById(documentId)) {
+            throw new NotFoundException("해당 강의자료를 찾을 수 없습니다.");
+        }
+    }
+
+    private static void checkSummaryAndProblemCountsEqual(
+            List<SummaryPageContentResult> summaryResults, List<ProblemPageContentResult> problemResults
+    ) {
+        if (summaryResults.size() != problemResults.size()) {
+            throw new InternalServerErrorException("AI 요약 및 문제 생성 중에 문제가 발생했습니다."); // 요약 개수와 문제 개수가 불일치
+        }
+    }
+
+    private List<Long> getSummaryIds(Long documentId) {
+        List<Long> summaryIds = summaryQueryRepository.getSummaryIdsByDocumentId(documentId);
+        if (summaryIds.isEmpty()) {
+            throw new BadRequestException("AI 기능을 요청한 기록이 없습니다.");
+        }
+        return summaryIds;
+    }
+
+    private List<TaskStatus> getTaskStatuses(List<Long> summaryIds) {
+        return summaryIds.stream().map(llmQueryRepository::getTaskStatusBySummaryId).toList();
+    }
+
+    private List<SummaryPageContentResult> getSummaryPageContentResults(Long documentId) {
+        List<SummaryPageContentResult> summaryResults = summaryQueryRepository.getPageNumbersAndContentByDocumentId(
+                documentId);
+        if (summaryResults.isEmpty()) {
+            throw new NotFoundException("AI 기능을 요청한 기록이 없습니다.");
+        }
+        return summaryResults;
+    }
+
+    private List<ProblemPageContentResult> getProblemPageContentResults(Long documentId) {
+        return problemQueryRepository.getPageNumbersAndContentByDocumentId(documentId);
+    }
+
+    private String findProblemContentByPageNumber(List<ProblemPageContentResult> results, int pageNumber) {
+        return results.stream().filter(result -> result.pageNumber() == pageNumber).findFirst().map(
+                ProblemPageContentResult::content).orElseThrow(() -> new InternalServerErrorException(
+                "AI 요약 및 문제 생성 중에 문제가 발생했습니다.")); // 요약 페이지와 문제 페이지가 불일치
+    }
+}

src/main/java/notai/llm/application/LLMService.java

@@ -0,0 +1,76 @@
+package notai.llm.application;
+
+import lombok.RequiredArgsConstructor;
+import notai.common.exception.type.NotFoundException;
+import notai.document.domain.Document;
+import notai.document.domain.DocumentRepository;
+import notai.llm.application.command.LLMSubmitCommand;
+import notai.llm.application.command.SummaryAndProblemUpdateCommand;
+import notai.llm.application.result.LLMSubmitResult;
+import notai.llm.domain.LLM;
+import notai.llm.domain.LLMRepository;
+import notai.problem.domain.Problem;
+import notai.problem.domain.ProblemRepository;
+import notai.summary.domain.Summary;
+import notai.summary.domain.SummaryRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDateTime;
+import java.util.UUID;
+
+/**
+ * SummaryService 와 ExamService 는 엔티티와 관련된 로직만 처리하고
+ * AI 요약 및 문제 생성 요청은 여기서 처리하는 식으로 생각했습니다.
+ * AI 서버와의 통신은 별도 클래스에서 처리합니다.
+ */
+@Service
+@Transactional
+@RequiredArgsConstructor
+public class LLMService {
+
+    private final LLMRepository llmRepository;
+    private final DocumentRepository documentRepository;
+    private final SummaryRepository summaryRepository;
+    private final ProblemRepository problemRepository;
+
+    public LLMSubmitResult submitTask(LLMSubmitCommand command) {
+        // TODO: document 개발 코드 올려주시면, getById 로 수정
+        Document foundDocument =
+                documentRepository.findById(command.documentId()).orElseThrow(() -> new NotFoundException(""));
+
+        command.pages().forEach(pageNumber -> {
+            UUID taskId = sendRequestToAIServer();
+            Summary summary = new Summary(foundDocument, pageNumber);
+            Problem problem = new Problem(foundDocument, pageNumber);
+
+            LLM taskRecord = new LLM(taskId, summary, problem);
+            llmRepository.save(taskRecord);
+        });
+
+        return LLMSubmitResult.of(command.documentId(), LocalDateTime.now());
+    }
+
+    public Integer updateSummaryAndProblem(SummaryAndProblemUpdateCommand command) {
+        LLM taskRecord = llmRepository.getById(command.taskId());
+        Summary foundSummary = summaryRepository.getById(taskRecord.getSummary().getId());
+        Problem foundProblem = problemRepository.getById(taskRecord.getProblem().getId());
+
+        taskRecord.completeTask();
+        foundSummary.updateContent(command.summary());
+        foundProblem.updateContent(command.problem());
+
+        llmRepository.save(taskRecord);
+        summaryRepository.save(foundSummary);
+        problemRepository.save(foundProblem);
+
+        return command.pageNumber();
+    }
+
+    /**
+     * 임시 값 반환, 추후 AI 서버에서 작업 단위 UUID 가 반환됨.
+     */
+    private UUID sendRequestToAIServer() {
+        return UUID.randomUUID();
+    }
+}

src/main/java/notai/llm/application/command/LLMSubmitCommand.java

@@ -0,0 +1,10 @@
+package notai.llm.application.command;
+
+import java.util.List;
+
+public record LLMSubmitCommand(
+        Long documentId,
+        List<Integer> pages
+) {
+
+}

src/main/java/notai/llm/application/command/SummaryAndProblemUpdateCommand.java

@@ -0,0 +1,11 @@
+package notai.llm.application.command;
+
+import java.util.UUID;
+
+public record SummaryAndProblemUpdateCommand(
+        UUID taskId,
+        Integer pageNumber,
+        String summary,
+        String problem
+) {
+}

src/main/java/notai/llm/application/result/LLMResultsResult.java

@@ -0,0 +1,31 @@
+package notai.llm.application.result;
+
+import java.util.List;
+
+public record LLMResultsResult(
+        Long documentId,
+        Integer totalPages,
+        List<LLMResult> results
+) {
+    public static LLMResultsResult of(Long documentId, List<LLMResult> results) {
+        return new LLMResultsResult(documentId, results.size(), results);
+    }
+
+    public record LLMResult(
+            Integer pageNumber,
+            LLMContent content
+    ) {
+        public static LLMResult of(Integer pageNumber, LLMContent content) {
+            return new LLMResult(pageNumber, content);
+        }
+    }
+
+    public record LLMContent(
+            String summary,
+            String problem
+    ) {
+        public static LLMContent of(String summary, String problem) {
+            return new LLMContent(summary, problem);
+        }
+    }
+}

src/main/java/notai/llm/application/result/LLMStatusResult.java

@@ -0,0 +1,14 @@
+package notai.llm.application.result;
+
+import notai.llm.domain.TaskStatus;
+
+public record LLMStatusResult(
+        Long documentId,
+        TaskStatus overallStatus,
+        Integer totalPages,
+        Integer completedPages
+) {
+    public static LLMStatusResult of(Long documentId, TaskStatus overallStatus, Integer totalPages, Integer completedPages) {
+        return new LLMStatusResult(documentId, overallStatus, totalPages, completedPages);
+    }
+}

src/main/java/notai/llm/application/result/LLMSubmitResult.java

@@ -0,0 +1,12 @@
+package notai.llm.application.result;
+
+import java.time.LocalDateTime;
+
+public record LLMSubmitResult(
+        Long documentId,
+        LocalDateTime createdAt
+) {
+    public static LLMSubmitResult of(Long documentId, LocalDateTime createdAt) {
+        return new LLMSubmitResult(documentId, createdAt);
+    }
+}