package jnpf.dmsService;

import jnpf.base.UserInfo;
import jnpf.dmsEntity.operationlog.entity.DmsFileOperationLogEntity;
import jnpf.dmsEntity.operationlog.enums.DmsFileOperationType;
import jnpf.dmsEntity.operationlog.vo.DmsFileOperationLogItemVO;
import jnpf.dmsEntity.operationlog.vo.DmsFileOperationLogPageVO;
import jnpf.dmsEntity.permission.entity.DmsFileVersionEntity;
import jnpf.dmsEntity.permission.enums.DmsPermissionAction;
import jnpf.dmsEntity.permission.enums.DmsResourceType;
import jnpf.dmsMapper.DmsFileOperationLogMapper;
import jnpf.dmsMapper.DmsFileVersionMapper;
import jnpf.dmsPermission.DmsCurrentIdentity;
import jnpf.dmsPermission.DmsPermissionError;
import jnpf.dmsPermission.DmsPermissionException;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Collections;
import java.util.UUID;
import java.util.stream.Collectors;

@Service
@RequiredArgsConstructor
public class DmsFileOperationLogService {
    private static final int DEFAULT_PAGE_SIZE = 10;
    private static final int MAX_PAGE_SIZE = 50;
    private static final int MAX_KEYWORD_LENGTH = 100;

    private final DmsCurrentIdentity currentIdentity;
    private final DmsPermissionDecisionService decisionService;
    private final DmsFileVersionMapper fileVersionMapper;
    private final DmsFileOperationLogMapper operationLogMapper;

    public void recordUpload(UserInfo user, String tenantId, UUID documentId, UUID fileVersionId,
                             String fileName, String serviceId, String sourceId) {
        record(user, tenantId, documentId, fileVersionId, fileName, DmsFileOperationType.UPLOAD,
                "UPLOAD:" + serviceId + ":" + sourceId);
    }

    public void recordRevision(UserInfo user, String tenantId, UUID documentId, UUID fileVersionId,
                               String fileName, String serviceId, String sourceId) {
        record(user, tenantId, documentId, fileVersionId, fileName, DmsFileOperationType.REVISION,
                "REVISION:" + serviceId + ":" + sourceId);
    }

    public void recordView(UserInfo user, String tenantId, UUID documentId, UUID fileVersionId,
                           String fileName, UUID operationId) {
        record(user, tenantId, documentId, fileVersionId, fileName, DmsFileOperationType.VIEW,
                "VIEW:" + operationId);
    }

    public void recordDownload(UserInfo user, String tenantId, UUID documentId, UUID fileVersionId,
                               String fileName, UUID operationId) {
        record(user, tenantId, documentId, fileVersionId, fileName, DmsFileOperationType.DOWNLOAD,
                "DOWNLOAD:" + operationId);
    }

    @Transactional(readOnly = true)
    public DmsFileOperationLogPageVO page(UUID fileVersionId, String keyword,
                                          Integer requestedPage, Integer requestedSize) {
        UserInfo user = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(user);
        decisionService.requireAllowed(DmsResourceType.FILE_VERSION, fileVersionId,
                DmsPermissionAction.READ);
        DmsFileVersionEntity version = fileVersionMapper.selectByTenantAndId(tenantId, fileVersionId);
        if (version == null) {
            throw DmsPermissionException.of(DmsPermissionError.RESOURCE_NOT_FOUND,
                    "文件版本不存在");
        }

        String normalizedKeyword = normalizeKeyword(keyword);
        int currentPage = requestedPage == null || requestedPage < 1 ? 1 : requestedPage;
        int pageSize = requestedSize == null || requestedSize < 1
                ? DEFAULT_PAGE_SIZE : Math.min(requestedSize, MAX_PAGE_SIZE);
        long offset = (long) (currentPage - 1) * pageSize;
        long total = operationLogMapper.countByDocument(tenantId, version.getDocumentId(),
                normalizedKeyword);

        DmsFileOperationLogPageVO result = new DmsFileOperationLogPageVO();
        result.setCurrentPage(currentPage);
        result.setPageSize(pageSize);
        result.setTotal(total);
        if (offset >= total) {
            result.setList(Collections.<DmsFileOperationLogItemVO>emptyList());
            return result;
        }
        result.setList(operationLogMapper.selectByDocument(tenantId, version.getDocumentId(),
                        normalizedKeyword, pageSize, offset).stream()
                .map(this::toItem)
                .collect(Collectors.toList()));
        return result;
    }

    private void record(UserInfo user, String tenantId, UUID documentId, UUID fileVersionId,
                        String fileName, DmsFileOperationType type, String operationKey) {
        String operatorName = displayName(user);
        DmsFileOperationLogEntity log = new DmsFileOperationLogEntity();
        log.setTenantId(tenantId.trim());
        log.setDocumentId(documentId);
        log.setFileVersionId(fileVersionId);
        log.setOperationCode(type.name());
        log.setOperationKey(operationKey);
        log.setOperatorUserId(user.getUserId().trim());
        log.setOperatorName(operatorName);
        log.setFileName(fileName.trim());
        log.setOperationContent("用户" + operatorName + type.getActionText() + "：" + fileName.trim());
        operationLogMapper.insertIgnore(log);
    }

    private DmsFileOperationLogItemVO toItem(DmsFileOperationLogEntity entity) {
        DmsFileOperationLogItemVO result = new DmsFileOperationLogItemVO();
        result.setId(entity.getId());
        result.setOperationCode(entity.getOperationCode());
        result.setOperationContent(entity.getOperationContent());
        result.setOccurredAt(entity.getOccurredAt());
        return result;
    }

    private String displayName(UserInfo user) {
        String userName = trimToNull(user.getUserName());
        if (userName != null) {
            return userName;
        }
        String account = trimToNull(user.getUserAccount());
        return account != null ? account : user.getUserId().trim();
    }

    private String normalizeKeyword(String keyword) {
        String normalized = trimToNull(keyword);
        if (normalized != null && normalized.length() > MAX_KEYWORD_LENGTH) {
            throw DmsPermissionException.of(DmsPermissionError.INVALID_REQUEST,
                    "日志搜索关键字不能超过 " + MAX_KEYWORD_LENGTH + " 个字符");
        }
        return normalized;
    }

    private String trimToNull(String value) {
        return value == null || value.trim().isEmpty() ? null : value.trim();
    }
}