qingsongping-AIDevelop/mydreamjob-server/src/main/java/com/mydreamjob/resume/ResumeVersionService.java

package com.mydreamjob.resume;

import com.mydreamjob.common.exception.BusinessException;
import com.mydreamjob.common.exception.ErrorCode;
import com.mydreamjob.profile.ProfileService;
import com.mydreamjob.profile.storage.ResumeFilenameSanitizer;
import com.mydreamjob.profile.storage.ResumeStorageService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.dao.DataIntegrityViolationException;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.transaction.support.TransactionSynchronization;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.web.multipart.MultipartFile;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * 简历版本管理 Service
 *
 * <p>权限：仅简历本人（JWT 身份）可操作，身份一律不信任请求参数。
 * 文件校验复用 {@link ProfileService#validateResumeFile}，存储复用 {@link ResumeStorageService}。
 */
@Slf4j
@Service
@RequiredArgsConstructor
public class ResumeVersionService {

    private static final int MAX_NAME_LENGTH = 120;
    private static final int MAX_VERSION_NO_RETRY = 3;

    private final ResumeVersionRepository resumeVersionRepository;
    private final ResumeExportTaskRepository exportTaskRepository;
    private final ResumeStorageService resumeStorageService;
    private final ResumeVersionWriter versionWriter;
    private final ProfileService profileService;

    // ── 创建 ──────────────────────────────────────────────────

    /**
     * 创建简历版本（默认非默认）。版本号每用户递增（max+1），
     * 并发冲突由 {@link ResumeVersionWriter} 独立事务重试（冲突只回滚单次尝试）。
     * 外层事务为角色校验提供持久化上下文（worker 线程无 OSIV）。
     *
     * <p>孤儿文件防护：版本行由 {@code REQUIRES_NEW} 独立事务写入——
     * 写入成功即独立提交，外层事务回滚不会让版本行消失，文件始终被引用；
     * 写入失败（重试耗尽或异常）时版本行不存在，由下方 catch 清理已保存的新文件。
     * 因此创建流程不存在"外层回滚导致文件孤儿"的问题。
     */
    @Transactional
    public ResumeVersion createVersion(Long userId, String name, MultipartFile file) {
        profileService.assertStudentRole(userId);
        validateName(name);
        profileService.validateResumeFile(file);

        String storagePath = resumeStorageService.store(userId, file);
        try {
            for (int attempt = 0; attempt < MAX_VERSION_NO_RETRY; attempt++) {
                try {
                    return versionWriter.saveNewVersion(userId, normalizeName(name), storagePath,
                            ResumeFilenameSanitizer.forDownload(file.getOriginalFilename(), "resume"),
                            file.getContentType(), file.getSize());
                } catch (DataIntegrityViolationException e) {
                    // uk_resume_versions_user_no 并发冲突 → 短退避后重试
                    log.info("Resume version_no conflict for user {}, retry {}/{}", userId, attempt + 1, MAX_VERSION_NO_RETRY);
                    try {
                        Thread.sleep(20L); // 等待并发胜者提交，重读时能看到其版本号
                    } catch (InterruptedException ie) {
                        Thread.currentThread().interrupt();
                        throw new BusinessException(ErrorCode.BAD_REQUEST, "failed to assign resume version number");
                    }
                }
            }
            throw new BusinessException(ErrorCode.BAD_REQUEST, "failed to assign resume version number");
        } catch (RuntimeException e) {
            // 数据库写入最终失败（重试耗尽或异常）→ 清理已保存但未被引用的新文件，避免孤儿文件
            log.warn("Resume version create failed, cleaning orphan file: {}", storagePath);
            resumeStorageService.delete(storagePath);
            throw e;
        }
    }

    // ── 查询 ──────────────────────────────────────────────────

    /** 本人 ACTIVE 版本列表，version_no 倒序 */
    public List<ResumeVersion> listVersions(Long userId) {
        profileService.assertStudentRole(userId);
        return resumeVersionRepository.findByUserIdAndStatusOrderByVersionNoDesc(userId, ResumeVersion.STATUS_ACTIVE);
    }

    /** 本人版本详情（ACTIVE） */
    public ResumeVersion getVersion(Long userId, Long versionId) {
        profileService.assertStudentRole(userId);
        ResumeVersion version = requireOwnActiveVersion(userId, versionId);
        return version;
    }

    // ── 修改 ──────────────────────────────────────────────────

    /**
     * 修改版本：可选重命名 + 可选替换文件。
     *
     * <p>文件一致性：先保存新文件 → 更新数据库 → 事务提交后删除旧文件。
     * 保存新文件后注册 {@link TransactionSynchronization}：
     * <ul>
     *   <li>afterCommit：旧文件未被 PENDING/RUNNING 导出任务引用时才删除；</li>
     *   <li>afterCompletion(非 COMMITTED)：事务回滚（含提交阶段失败）时清理本次刚保存的新文件，
     *       防止孤儿文件；绝不删除旧文件（数据库仍引用旧文件）。</li>
     * </ul>
     * 立即异常（repository.save 抛错）仅在非事务上下文（单元测试）直接清理新文件，
     * 事务上下文中统一由 afterCompletion 处理，避免重复删除。
     */
    @Transactional
    public ResumeVersion updateVersion(Long userId, Long versionId, String name, MultipartFile file) {
        profileService.assertStudentRole(userId);
        validateName(name);
        ResumeVersion version = requireOwnActiveVersion(userId, versionId);

        if (name != null) {
            version.setName(normalizeName(name));
        }
        String oldStoragePath = version.getFileStoragePath();
        String newStoragePath = null;
        boolean syncRegistered = false;
        if (file != null && !file.isEmpty()) {
            profileService.validateResumeFile(file);
            // 1) 先保存新文件（绝不在保存前删除旧文件）
            newStoragePath = resumeStorageService.store(userId, file);
            version.setFileStoragePath(newStoragePath);
            version.setFileName(ResumeFilenameSanitizer.forDownload(file.getOriginalFilename(), "resume"));
            version.setContentType(file.getContentType());
            version.setFileSize(file.getSize());
            // 2) 注册事务回调：提交后删旧文件；回滚时清理新文件
            syncRegistered = registerFileLifecycleSynchronization(oldStoragePath, newStoragePath);
        }
        try {
            // 3) 更新数据库记录
            version = resumeVersionRepository.save(version);
        } catch (RuntimeException e) {
            // 立即失败：仅在未注册事务回调（非事务上下文/单元测试）时直接清理新文件；
            // 事务上下文中由 afterCompletion(非 COMMITTED) 统一清理，避免重复删除。
            if (newStoragePath != null && !syncRegistered) {
                log.warn("Resume version update failed, cleaning new file: {}", newStoragePath);
                resumeStorageService.delete(newStoragePath);
            }
            throw e;
        }
        if (newStoragePath != null && oldStoragePath != null && !syncRegistered) {
            // 非事务上下文（单元测试）：无 afterCommit 回调，立即执行旧文件清理
            deleteOldFileIfUnreferenced(oldStoragePath);
        }
        return version;
    }

    // ── 删除 ──────────────────────────────────────────────────

    /**
     * 删除版本（硬删除）。前置：非默认版本；无 PENDING/RUNNING 导出任务。
     *
     * <p>文件一致性：先完成数据库删除，仅在事务成功提交后删除存储文件；
     * 数据库删除失败时不得删除原文件。
     */
    @Transactional
    public void deleteVersion(Long userId, Long versionId) {
        profileService.assertStudentRole(userId);
        ResumeVersion version = requireOwnActiveVersion(userId, versionId);
        if (version.isDefault()) {
            throw new BusinessException(ErrorCode.DEFAULT_RESUME_DELETE_NOT_ALLOWED);
        }
        if (exportTaskRepository.existsByResumeVersionIdAndStatusIn(versionId,
                List.of(ResumeExportTask.STATUS_PENDING, ResumeExportTask.STATUS_RUNNING))) {
            throw new BusinessException(ErrorCode.RESUME_EXPORT_IN_PROGRESS);
        }
        // 1) 先完成数据库删除
        resumeVersionRepository.delete(version);
        // 2) 事务提交后再删除存储文件（提交失败则文件保留）
        deleteFileAfterCommit(version.getFileStoragePath());
    }

    // ── 设置默认 ──────────────────────────────────────────────

    /**
     * 设为默认：同事务内清空旧默认并设置新默认；已默认幂等；并发冲突 409。
     */
    @Transactional
    public ResumeVersion setDefault(Long userId, Long versionId) {
        profileService.assertStudentRole(userId);
        ResumeVersion version = requireOwnActiveVersion(userId, versionId);
        if (version.isDefault()) {
            return version; // 幂等
        }
        resumeVersionRepository.findFirstByUserIdAndDefaultKey(userId, ResumeVersion.DEFAULT_KEY)
                .ifPresent(old -> old.setDefaultKey(null));
        version.setDefaultKey(ResumeVersion.DEFAULT_KEY);
        try {
            return resumeVersionRepository.save(version);
        } catch (DataIntegrityViolationException e) {
            // uk_resume_versions_default 并发冲突：两个版本同时被设为默认
            throw new BusinessException(ErrorCode.DUPLICATE_DEFAULT_RESUME);
        }
    }

    // ── 视图 ──────────────────────────────────────────────────

    public Map<String, Object> toView(ResumeVersion version) {
        Map<String, Object> v = new HashMap<>();
        v.put("id", version.getId());
        v.put("name", version.getName());
        v.put("versionNo", version.getVersionNo());
        v.put("fileName", version.getFileName());
        v.put("contentType", version.getContentType());
        v.put("fileSize", version.getFileSize());
        v.put("default", version.isDefault());
        v.put("status", version.getStatus());
        v.put("createdAt", version.getCreatedAt());
        v.put("updatedAt", version.getUpdatedAt());
        return v;
    }

    public List<Map<String, Object>> toViewList(List<ResumeVersion> versions) {
        return versions.stream().map(this::toView).collect(Collectors.toList());
    }

    // ── 私有 ──────────────────────────────────────────────────

    private ResumeVersion requireOwnActiveVersion(Long userId, Long versionId) {
        // 先按 id 查询：不存在或非 ACTIVE → 404；存在但属于他人 → 403；本人 → 继续
        ResumeVersion version = resumeVersionRepository.findById(versionId)
                .orElseThrow(() -> new BusinessException(ErrorCode.RESUME_VERSION_NOT_FOUND));
        if (!ResumeVersion.STATUS_ACTIVE.equals(version.getStatus())) {
            throw new BusinessException(ErrorCode.RESUME_VERSION_NOT_FOUND);
        }
        if (!version.getUserId().equals(userId)) {
            throw new BusinessException(ErrorCode.FORBIDDEN);
        }
        return version;
    }

    private void validateName(String name) {
        if (name != null && name.trim().length() > MAX_NAME_LENGTH) {
            throw new BusinessException(ErrorCode.BAD_REQUEST,
                    "name must be at most " + MAX_NAME_LENGTH + " characters");
        }
    }

    private String normalizeName(String name) {
        if (name == null) return null;
        String trimmed = name.trim();
        return trimmed.isEmpty() ? null : trimmed;
    }

    /**
     * 注册文件生命周期事务回调（替换版本文件场景）：
     * <ul>
     *   <li>afterCommit：旧文件未被 PENDING/RUNNING 导出任务引用时删除；</li>
     *   <li>afterCompletion(非 COMMITTED)：清理本次刚保存的新文件（覆盖提交阶段失败导致的外层回滚），
     *       绝不删除旧文件（数据库仍引用旧文件）。</li>
     * </ul>
     * 返回是否注册成功；非事务上下文（单元测试）返回 false，由调用方即时清理。
     */
    private boolean registerFileLifecycleSynchronization(String oldStoragePath, String newStoragePath) {
        if (!TransactionSynchronizationManager.isSynchronizationActive()) {
            return false;
        }
        TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
            @Override
            public void afterCommit() {
                deleteOldFileIfUnreferenced(oldStoragePath);
            }

            @Override
            public void afterCompletion(int status) {
                if (status != TransactionSynchronization.STATUS_COMMITTED && newStoragePath != null) {
                    log.warn("Resume version update rolled back, cleaning new file: {}", newStoragePath);
                    resumeStorageService.delete(newStoragePath);
                }
            }
        });
        return true;
    }

    /** 旧文件未被进行中的导出任务引用时删除（保持导出快照一致） */
    private void deleteOldFileIfUnreferenced(String oldStoragePath) {
        if (oldStoragePath == null) return;
        boolean referenced = exportTaskRepository.existsBySourceStoragePathAndStatusIn(oldStoragePath,
                List.of(ResumeExportTask.STATUS_PENDING, ResumeExportTask.STATUS_RUNNING));
        if (!referenced) {
            resumeStorageService.delete(oldStoragePath);
        }
    }

    /**
     * 事务成功提交后删除存储文件；非事务上下文（单元测试）直接删除。
     * 数据库失败/回滚时不会执行删除，保证文件与数据库一致。
     */
    private void deleteFileAfterCommit(String storagePath) {
        if (storagePath == null) return;
        if (TransactionSynchronizationManager.isSynchronizationActive()) {
            TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
                @Override
                public void afterCommit() {
                    resumeStorageService.delete(storagePath);
                }
            });
        } else {
            resumeStorageService.delete(storagePath);
        }
    }
}