package jnpf.dmsService;

import jnpf.audit.sdk.annotation.AuditLog;
import jnpf.base.UserInfo;
import jnpf.dmsEntity.permission.entity.DmsFileVersionEntity;
import jnpf.dmsEntity.permission.enums.DmsPersonalFolderType;
import jnpf.dmsEntity.permission.form.DmsPersonalFolderBorrowForm;
import jnpf.dmsEntity.permission.form.DmsPersonalFolderDownloadForm;
import jnpf.dmsEntity.permission.form.DmsPersonalFolderFavoriteForm;
import jnpf.dmsEntity.permission.form.DmsPersonalFolderFileForm;
import jnpf.dmsEntity.permission.enums.DmsPermissionAction;
import jnpf.dmsEntity.permission.enums.DmsResourceType;
import jnpf.dmsEntity.permission.vo.DmsPersonalFolderAddResultVO;
import jnpf.dmsEntity.permission.vo.DmsPersonalFolderFileVO;
import jnpf.dmsEntity.permission.vo.DmsPersonalFolderVO;
import jnpf.dmsEntity.print.form.DmsWorkflowPrintFilesGrantForm;
import jnpf.dmsEntity.print.vo.DmsWorkflowPrintFilesGrantResultVO;
import jnpf.dmsMapper.DmsPersonalFolderMapper;
import jnpf.dmsPermission.DmsCurrentIdentity;
import jnpf.dmsPermission.DmsFileSearchPolicy;
import jnpf.dmsPermission.DmsPermissionError;
import jnpf.dmsPermission.DmsPermissionException;
import jnpf.dmsPermission.DmsPermissionExecutionContext;
import jnpf.dmsPermission.DmsPermissionGuard;
import jnpf.dmsPermission.DmsPermissionOperation;
import jnpf.dmsPermission.DmsPermissionProperties;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;
import java.util.TreeMap;
import java.util.UUID;
import java.util.stream.Collectors;

@Service
@RequiredArgsConstructor
public class DmsPersonalFolderService {
    private static final String BORROW_PERMISSION_SOURCE_PREFIX = "personal-folder-borrow:";
    private static final String DOWNLOAD_PERMISSION_SOURCE_PREFIX = "personal-folder-download:";
    private static final String PRINT_PERMISSION_SOURCE_PREFIX = "workflow-print-files:";

    private final DmsCurrentIdentity currentIdentity;
    private final DmsPermissionProperties properties;
    private final DmsPersonalFolderMapper personalFolderMapper;
    private final DmsPermissionGrantService permissionGrantService;
    private final DmsPermissionGuard permissionGuard;

    public List<DmsPersonalFolderVO> folders() {
        currentIdentity.requireUser();
        return Arrays.stream(DmsPersonalFolderType.values())
                .map(type -> new DmsPersonalFolderVO(type.name(), type.getLabel()))
                .collect(Collectors.toList());
    }

    @Transactional(readOnly = true)
    public List<DmsPersonalFolderFileVO> files(String folderType, String keyword, Integer pageSize) {
        UserInfo user = currentIdentity.requireUser();
        DmsPersonalFolderType type = folderType(folderType);
        String normalizedKeyword = DmsFileSearchPolicy.normalizeKeyword(keyword);
        return personalFolderMapper.selectFiles(
                currentIdentity.tenantId(user),
                user.getUserId().trim(),
                type.name(),
                normalizedKeyword,
                pageSize(pageSize));
    }

    @Transactional(rollbackFor = Exception.class)
    @AuditLog(action = "ADD_FAVORITE_SNAPSHOT", label = "收藏文件加入个人文件夹",
            bizModule = "DMS", bizType = "DMS_PERSONAL_FOLDER", bizCodeExpr = "",
            bizCodeRequired = false, targetTable = "dms_personal_folder_items",
            targetIdExpr = "#p0.fileVersionId",
            extraExpr = "{'documentId': #p0.documentId, 'operationId': #p0.operationId}")
    public DmsPersonalFolderAddResultVO addFavoriteSnapshot(
            DmsPersonalFolderFavoriteForm form) {
        UserInfo user = currentIdentity.requireUser();
        if (form == null || form.getDocumentId() == null || form.getFileVersionId() == null
                || form.getOperationId() == null) {
            throw invalidRequest("收藏文件ID、文件版本ID和操作ID不能为空");
        }
        String tenantId = currentIdentity.tenantId(user);
        String userId = user.getUserId().trim();
        DmsPersonalFolderFileForm.FileRelation relation =
                new DmsPersonalFolderFileForm.FileRelation();
        relation.setDocumentId(form.getDocumentId());
        relation.setFileVersionId(form.getFileVersionId());
        validateRelations(tenantId, Collections.singletonList(relation));

        DmsPermissionExecutionContext context = new DmsPermissionExecutionContext();
        context.setResourceType(DmsResourceType.FILE_VERSION);
        context.setResourceId(form.getFileVersionId());
        context.setActionCode(DmsPermissionAction.READ);
        context.setOperationId(form.getOperationId());
        int added = permissionGuard.execute(context, new DmsPermissionOperation<Integer>() {
            @Override
            public Integer execute() {
                return insertFavoriteSnapshot();
            }

            @Override
            public Integer replay() {
                return insertFavoriteSnapshot();
            }

            private int insertFavoriteSnapshot() {
                return personalFolderMapper.insertFavoriteSnapshot(
                        tenantId, userId, form.getDocumentId(), form.getFileVersionId());
            }
        });
        return new DmsPersonalFolderAddResultVO(1, added);
    }

    @Transactional(rollbackFor = Exception.class)
    @AuditLog(action = "ADD_BORROW_SNAPSHOT", label = "借阅文件加入个人文件夹",
            bizModule = "DMS", bizType = "DMS_PERSONAL_FOLDER", bizCodeExpr = "",
            bizCodeRequired = false, targetTable = "dms_personal_folder_items",
            targetIdExpr = "#p0.files[0].fileVersionId",
            targetIdsExpr = "#p0.files.![fileVersionId]",
            extraExpr = "{'userId': #p0.userId, 'serviceId': #p1, 'files': #p0.files}")
    public DmsPersonalFolderAddResultVO addBorrowSnapshots(
            DmsPersonalFolderBorrowForm form, String serviceId) {
        UserInfo currentUser = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(currentUser);
        String userId = requiredText(form == null ? null : form.getUserId(), "借阅用户ID不能为空");
        List<DmsPersonalFolderFileForm.FileRelation> files = distinctFiles(form, "借阅");
        validateRelations(tenantId, files);
        grantBorrowReadPermissions(tenantId, userId, files, serviceId);
        int added = personalFolderMapper.insertBorrowSnapshots(tenantId, userId, files);
        return new DmsPersonalFolderAddResultVO(form.getFiles().size(), added);
    }

    @Transactional(rollbackFor = Exception.class)
    @AuditLog(action = "ADD_DOWNLOAD_SNAPSHOT", label = "下载文件加入个人文件夹",
            bizModule = "DMS", bizType = "DMS_PERSONAL_FOLDER", bizCodeExpr = "",
            bizCodeRequired = false, targetTable = "dms_personal_folder_items",
            targetIdExpr = "#p0.files[0].fileVersionId",
            targetIdsExpr = "#p0.files.![fileVersionId]",
            extraExpr = "{'userId': #p0.userId, 'serviceId': #p1, 'files': #p0.files}")
    public DmsPersonalFolderAddResultVO addDownloadSnapshots(
            DmsPersonalFolderDownloadForm form, String serviceId) {
        UserInfo currentUser = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(currentUser);
        String userId = requiredText(form == null ? null : form.getUserId(), "下载用户ID不能为空");
        List<DmsPersonalFolderFileForm.FileRelation> files = distinctFiles(form, "下载");
        validateRelations(tenantId, files);
        grantDownloadPermissions(tenantId, userId, files, serviceId, form.getRequestId());
        int added = personalFolderMapper.insertDownloadSnapshots(tenantId, userId, files);
        return new DmsPersonalFolderAddResultVO(form.getFiles().size(), added);
    }

    @Transactional(rollbackFor = Exception.class)
    public DmsWorkflowPrintFilesGrantResultVO grantPrintPermissions(
            DmsWorkflowPrintFilesGrantForm form, String serviceId) {
        UserInfo currentUser = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(currentUser);
        String userId = requiredText(form == null ? null : form.getUserId(), "打印用户ID不能为空");
        List<DmsPersonalFolderFileForm.FileRelation> files = distinctFiles(form, "打印");
        validateRelations(tenantId, files);
        grantPrintPermissions(tenantId, userId, files, serviceId);
        return new DmsWorkflowPrintFilesGrantResultVO(form.getFiles().size(), files.size());
    }

    private List<DmsPersonalFolderFileForm.FileRelation> distinctFiles(
            DmsPersonalFolderFileForm form, String actionLabel) {
        if (form == null || form.getFiles() == null || form.getFiles().isEmpty()) {
            throw invalidRequest(actionLabel + "文件不能为空");
        }
        if (form.getFiles().size() > 200) {
            throw invalidRequest("单次最多添加200个" + actionLabel + "文件");
        }
        Map<UUID, DmsPersonalFolderFileForm.FileRelation> byVersion = new LinkedHashMap<>();
        Map<UUID, UUID> versionByDocument = new LinkedHashMap<>();
        for (DmsPersonalFolderFileForm.FileRelation file : form.getFiles()) {
            if (file == null || file.getDocumentId() == null || file.getFileVersionId() == null) {
                throw invalidRequest(actionLabel + "文件ID和文件版本ID不能为空");
            }
            DmsPersonalFolderFileForm.FileRelation normalized = copyWithValidatedValidity(file);
            UUID previousVersion = versionByDocument.putIfAbsent(
                    normalized.getDocumentId(), normalized.getFileVersionId());
            if (previousVersion != null && !previousVersion.equals(normalized.getFileVersionId())) {
                throw invalidRequest("同一文件不能关联多个" + actionLabel + "版本：" + normalized.getDocumentId());
            }
            DmsPersonalFolderFileForm.FileRelation previous = byVersion.putIfAbsent(
                    normalized.getFileVersionId(), normalized);
            if (previous != null && !Objects.equals(
                    previous.getValidTo(), normalized.getValidTo())) {
                throw invalidRequest("同一文件版本不能设置多个" + actionLabel + "有效期："
                        + normalized.getFileVersionId());
            }
        }
        return new ArrayList<>(byVersion.values());
    }

    private DmsPersonalFolderFileForm.FileRelation copyWithValidatedValidity(
            DmsPersonalFolderFileForm.FileRelation file) {
        DmsPersonalFolderFileForm.FileRelation normalized =
                new DmsPersonalFolderFileForm.FileRelation();
        normalized.setDocumentId(file.getDocumentId());
        normalized.setFileVersionId(file.getFileVersionId());
        normalized.setValidTo(optionalFuture(file.getValidTo()));
        return normalized;
    }

    private void grantBorrowReadPermissions(
            String tenantId, String userId,
            List<DmsPersonalFolderFileForm.FileRelation> files, String serviceId) {
        Map<Long, List<DmsPersonalFolderFileForm.FileRelation>> filesByValidity = groupByValidity(files);
        for (Map.Entry<Long, List<DmsPersonalFolderFileForm.FileRelation>> entry
                : filesByValidity.entrySet()) {
            Date validTo = entry.getKey() == null ? null : new Date(entry.getKey());
            List<UUID> fileVersionIds = versionIds(entry.getValue());
            permissionGrantService.ensureWorkflowBorrowReadPermissions(
                    tenantId, permissionSourceId(BORROW_PERMISSION_SOURCE_PREFIX, userId,
                            fileVersionIds, validTo), userId,
                    fileVersionIds, validTo, serviceId, Collections.emptyList());
        }
    }

    private void grantDownloadPermissions(
            String tenantId, String userId,
            List<DmsPersonalFolderFileForm.FileRelation> files, String serviceId, String requestId) {
        Map<Long, List<DmsPersonalFolderFileForm.FileRelation>> filesByValidity = groupByValidity(files);
        for (Map.Entry<Long, List<DmsPersonalFolderFileForm.FileRelation>> entry
                : filesByValidity.entrySet()) {
            Date validTo = entry.getKey() == null ? null : new Date(entry.getKey());
            List<UUID> fileVersionIds = versionIds(entry.getValue());
            List<jnpf.dmsEntity.permission.entity.DmsFilePermissionEntity> permissions =
                    permissionGrantService.ensureWorkflowDownloadPermissions(
                    tenantId, permissionSourceId(DOWNLOAD_PERMISSION_SOURCE_PREFIX,
                            requestId == null || requestId.trim().isEmpty()
                                    ? userId : userId + "|request:" + requestId.trim(),
                            fileVersionIds, validTo), userId,
                    fileVersionIds, validTo, serviceId, Collections.emptyList());
            if (permissions != null) {
                for (DmsPersonalFolderFileForm.FileRelation file : entry.getValue()) {
                    permissions.stream().filter(permission -> file.getFileVersionId().equals(permission.getResourceId()))
                            .findFirst().ifPresent(permission -> file.setValidTo(permission.getValidTo()));
                }
            }
        }
    }

    private void grantPrintPermissions(
            String tenantId, String userId,
            List<DmsPersonalFolderFileForm.FileRelation> files, String serviceId) {
        Map<Long, List<DmsPersonalFolderFileForm.FileRelation>> filesByValidity = groupByValidity(files);
        for (Map.Entry<Long, List<DmsPersonalFolderFileForm.FileRelation>> entry
                : filesByValidity.entrySet()) {
            Date validTo = entry.getKey() == null ? null : new Date(entry.getKey());
            List<UUID> fileVersionIds = versionIds(entry.getValue());
            permissionGrantService.ensureWorkflowPrintPermissions(
                    tenantId, permissionSourceId(PRINT_PERMISSION_SOURCE_PREFIX, userId,
                            fileVersionIds, validTo), userId,
                    fileVersionIds, validTo, serviceId, Collections.emptyList());
        }
    }

    private Map<Long, List<DmsPersonalFolderFileForm.FileRelation>> groupByValidity(
            List<DmsPersonalFolderFileForm.FileRelation> files) {
        Map<Long, List<DmsPersonalFolderFileForm.FileRelation>> filesByValidity =
                new TreeMap<>(Comparator.nullsLast(Long::compareTo));
        for (DmsPersonalFolderFileForm.FileRelation file : files) {
            Long validTo = file.getValidTo() == null ? null : file.getValidTo().getTime();
            filesByValidity.computeIfAbsent(validTo, ignored -> new ArrayList<>())
                    .add(file);
        }
        return filesByValidity;
    }

    private List<UUID> versionIds(List<DmsPersonalFolderFileForm.FileRelation> files) {
        return files.stream().map(DmsPersonalFolderFileForm.FileRelation::getFileVersionId)
                .collect(Collectors.toList());
    }

    private void validateRelations(
            String tenantId, List<DmsPersonalFolderFileForm.FileRelation> files) {
        List<UUID> versionIds = files.stream()
                .map(DmsPersonalFolderFileForm.FileRelation::getFileVersionId)
                .collect(Collectors.toList());
        List<DmsFileVersionEntity> readableVersions = personalFolderMapper
                .selectReadableVersions(tenantId, versionIds);
        if (readableVersions == null) {
            readableVersions = new ArrayList<>();
        }
        Map<UUID, DmsFileVersionEntity> versions = readableVersions.stream()
                .collect(Collectors.toMap(DmsFileVersionEntity::getId, value -> value));
        for (DmsPersonalFolderFileForm.FileRelation file : files) {
            DmsFileVersionEntity version = versions.get(file.getFileVersionId());
            if (version == null) {
                throw DmsPermissionException.of(DmsPermissionError.RESOURCE_NOT_FOUND,
                        "文件版本不存在或不可用：" + file.getFileVersionId());
            }
            if (!file.getDocumentId().equals(version.getDocumentId())) {
                throw invalidRequest("文件与文件版本关联不一致：" + file.getFileVersionId());
            }
        }
    }

    private DmsPersonalFolderType folderType(String value) {
        try {
            return DmsPersonalFolderType.valueOf(value == null ? "" : value.trim().toUpperCase(Locale.ROOT));
        } catch (IllegalArgumentException ex) {
            throw DmsPermissionException.of(DmsPermissionError.INVALID_REQUEST,
                    "个人文件夹类型无效");
        }
    }

    private int pageSize(Integer requested) {
        int value = requested == null ? properties.getDefaultPageSize() : requested;
        if (value < 1 || value > properties.getMaxPageSize()) {
            throw DmsPermissionException.of(DmsPermissionError.INVALID_REQUEST,
                    "pageSize 必须在 1 到 " + properties.getMaxPageSize() + " 之间");
        }
        return value;
    }

    private String requiredText(String value, String message) {
        if (value == null || value.trim().isEmpty()) {
            throw invalidRequest(message);
        }
        return value.trim();
    }

    private Date optionalFuture(Date value) {
        if (value == null) {
            return null;
        }
        Date copy = new Date(value.getTime());
        if (!copy.after(new Date())) {
            throw invalidRequest("有效期必须晚于当前时间");
        }
        return copy;
    }

    private String permissionSourceId(String prefix, String userId,
                                      List<UUID> fileVersionIds, Date validTo) {
        List<UUID> sortedIds = new ArrayList<>(fileVersionIds);
        sortedIds.sort(Comparator.comparing(UUID::toString));
        String validity = validTo == null ? "PERMANENT" : Long.toString(validTo.getTime());
        String canonical = userId + "|" + validity + "|" + sortedIds.stream()
                .map(UUID::toString).collect(Collectors.joining(","));
        UUID fingerprint = UUID.nameUUIDFromBytes(canonical.getBytes(StandardCharsets.UTF_8));
        return prefix + fingerprint;
    }

    private DmsPermissionException invalidRequest(String message) {
        return DmsPermissionException.of(DmsPermissionError.INVALID_REQUEST, message);
    }
}