package jnpf.dmsService;

import jnpf.base.UserInfo;
import jnpf.dmsEntity.permission.entity.DmsDocumentEntity;
import jnpf.dmsEntity.permission.entity.DmsFileVersionEntity;
import jnpf.dmsEntity.permission.entity.DmsFolderEntity;
import jnpf.dmsEntity.permission.entity.DmsPermissionResourceEntity;
import jnpf.dmsEntity.permission.enums.DmsPermissionAction;
import jnpf.dmsEntity.permission.enums.DmsResourceType;
import jnpf.dmsEntity.permission.form.DocumentCreateForm;
import jnpf.dmsEntity.permission.form.FileVersionCreateForm;
import jnpf.dmsEntity.permission.form.FolderCreateForm;
import jnpf.dmsEntity.permission.form.FolderCreateUserForm;
import jnpf.dmsEntity.permission.vo.DmsPermissionResourceVO;
import jnpf.dmsIntegration.audit.DmsAuditAdapter;
import jnpf.dmsMapper.DmsDocumentMapper;
import jnpf.dmsMapper.DmsFileVersionMapper;
import jnpf.dmsMapper.DmsFolderMapper;
import jnpf.dmsMapper.DmsPermissionResourceMapper;
import jnpf.dmsPermission.DmsCurrentIdentity;
import jnpf.dmsPermission.DmsPermissionError;
import jnpf.dmsPermission.DmsPermissionException;
import lombok.RequiredArgsConstructor;
import org.springframework.dao.DuplicateKeyException;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Locale;
import java.util.Objects;
import java.util.UUID;

@Service
@RequiredArgsConstructor
public class DmsResourceService {
    private static final String WEB_FOLDER_REGISTRAR = "jnpf-dms-web";
    private static final String WEB_FOLDER_SOURCE_PREFIX = "web-folder:";

    private final DmsCurrentIdentity currentIdentity;
    private final DmsPermissionDecisionService decisionService;
    private final DmsFolderMapper folderMapper;
    private final DmsDocumentMapper documentMapper;
    private final DmsFileVersionMapper fileVersionMapper;
    private final DmsPermissionResourceMapper resourceMapper;
    private final DmsPermissionGrantService permissionGrantService;
    private final DmsAuditAdapter auditAdapter;

    @Transactional
    public DmsPermissionResourceVO createFolder(FolderCreateUserForm form) {
        UserInfo user = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(user);
        if (form.getParentId() == null) {
            throw DmsPermissionException.of(DmsPermissionError.INVALID_RESOURCE_PARENT,
                    "网页端只能在已有 Folder 下创建子目录");
        }
        decisionService.requireAllowed(DmsResourceType.FOLDER, form.getParentId(),
                DmsPermissionAction.CREATE);

        String sourceId = WEB_FOLDER_SOURCE_PREFIX + form.getSourceId().trim();
        String name = form.getName().trim();
        resourceMapper.lockSource(tenantId, "SYSTEM", sourceId);
        DmsPermissionResourceEntity existingRegistry = resourceMapper.selectBySource(
                tenantId, "SYSTEM", sourceId);
        if (existingRegistry != null) {
            DmsPermissionResourceVO existing = existingWebFolder(tenantId, user.getUserId(), form.getParentId(), name,
                    sourceId, existingRegistry);
            permissionGrantService.ensureFolderCreatorCreatePermission(
                    tenantId, existingRegistry.getId(), user.getUserId());
            return existing;
        }

        UUID folderId = resourceMapper.nextUuidV7();
        DmsFolderEntity folder = new DmsFolderEntity();
        folder.setId(folderId);
        folder.setTenantId(tenantId);
        folder.setParentId(form.getParentId());
        folder.setName(name);
        folder.setCreatedBy(user.getUserId());
        try {
            folderMapper.insert(folder);
            insertRegistry(tenantId, folderId, DmsResourceType.FOLDER, sourceId,
                    WEB_FOLDER_REGISTRAR);
            permissionGrantService.ensureFolderCreatorCreatePermission(
                    tenantId, folderId, user.getUserId());
        } catch (DuplicateKeyException ex) {
            throw conflict("Folder ID 或 source_id 已被其他资源占用", ex);
        }
        auditAdapter.dataChange("CREATE", "网页创建 DMS 子目录", "dms_folders",
                folderId.toString(), null, null);
        return requireView(tenantId, folderId);
    }

    @Transactional
    public DmsPermissionResourceVO createFolder(FolderCreateForm form, String serviceId) {
        UserInfo user = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(user);
        validateFolderMode(form);
        if (form.getParentId() != null) {
            decisionService.requireAllowed(DmsResourceType.FOLDER, form.getParentId(), DmsPermissionAction.CREATE);
        }
        DmsFolderEntity desired = new DmsFolderEntity();
        desired.setId(form.getId());
        desired.setTenantId(tenantId);
        desired.setParentId(form.getParentId());
        desired.setName(form.getName().trim());
        desired.setCreatedBy(user.getUserId());

        DmsPermissionResourceVO existing = existingFolder(desired, form.getSourceId(), serviceId);
        if (existing != null) {
            return existing;
        }
        try {
            folderMapper.insert(desired);
            insertRegistry(tenantId, form.getId(), DmsResourceType.FOLDER,
                    form.getSourceId(), serviceId);
        } catch (DuplicateKeyException ex) {
            throw conflict("Folder ID、父级、名称或 source_id 已被其他资源占用", ex);
        }
        auditAdapter.dataChange("CREATE", "创建 DMS Folder", "dms_folders", form.getId().toString(),
                null, null);
        return requireView(tenantId, form.getId());
    }

    @Transactional
    public DmsPermissionResourceVO createDocument(DocumentCreateForm form, String serviceId) {
        UserInfo user = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(user);
        decisionService.requireAllowed(DmsResourceType.FOLDER, form.getFolderId(), DmsPermissionAction.CREATE);
        DmsDocumentEntity desired = new DmsDocumentEntity();
        desired.setId(form.getId());
        desired.setTenantId(tenantId);
        desired.setFolderId(form.getFolderId());
        desired.setName(form.getName().trim());
        desired.setCreatedBy(user.getUserId());

        DmsPermissionResourceVO existing = existingDocument(desired, form.getSourceId(), serviceId);
        if (existing != null) {
            return existing;
        }
        try {
            documentMapper.insert(desired);
            insertRegistry(tenantId, form.getId(), DmsResourceType.DOCUMENT,
                    form.getSourceId(), serviceId);
        } catch (DuplicateKeyException ex) {
            throw conflict("Document ID、所属 Folder 或 source_id 冲突", ex);
        }
        auditAdapter.dataChange("CREATE", "创建 DMS Document", "dms_documents", form.getId().toString(),
                null, null);
        return requireView(tenantId, form.getId());
    }

    @Transactional
    public DmsPermissionResourceVO createFileVersion(FileVersionCreateForm form, String serviceId) {
        UserInfo user = currentIdentity.requireUser();
        String tenantId = currentIdentity.tenantId(user);
        decisionService.requireAllowed(DmsResourceType.DOCUMENT, form.getDocumentId(), DmsPermissionAction.UPDATE);
        DmsFileVersionEntity desired = new DmsFileVersionEntity();
        desired.setId(form.getId());
        desired.setTenantId(tenantId);
        desired.setDocumentId(form.getDocumentId());
        desired.setVersionNo(form.getVersionNo());
        desired.setFileName(form.getFileName().trim());
        desired.setMimeType(trimToNull(form.getMimeType()));
        desired.setSizeBytes(form.getSizeBytes());
        desired.setChecksumSha256(form.getChecksumSha256() == null ? null
                : form.getChecksumSha256().toLowerCase(Locale.ROOT));
        desired.setCreatedBy(user.getUserId());

        DmsPermissionResourceVO existing = existingFileVersion(desired, form.getSourceId(), serviceId);
        if (existing != null) {
            return existing;
        }
        try {
            fileVersionMapper.insert(desired);
            insertRegistry(tenantId, form.getId(), DmsResourceType.FILE_VERSION,
                    form.getSourceId(), serviceId);
        } catch (DuplicateKeyException ex) {
            throw conflict("FileVersion ID、版本号或 source_id 冲突", ex);
        }
        auditAdapter.dataChange("CREATE", "创建 DMS FileVersion", "dms_file_versions",
                form.getId().toString(), null, null);
        return requireView(tenantId, form.getId());
    }

    private DmsPermissionResourceVO existingFolder(DmsFolderEntity desired, String sourceId, String serviceId) {
        DmsFolderEntity actual = folderMapper.selectByTenantAndId(desired.getTenantId(), desired.getId());
        DmsPermissionResourceEntity registry = existingRegistry(desired.getTenantId(), desired.getId(), sourceId);
        if (actual == null && registry == null) {
            return null;
        }
        if (actual == null || registry == null || !Objects.equals(actual.getParentId(), desired.getParentId())
                || !Objects.equals(actual.getName(), desired.getName())
                || !sameRegistry(registry, DmsResourceType.FOLDER, sourceId, serviceId)) {
            throw conflict("Folder 创建重试内容与原请求不一致", null);
        }
        return requireView(desired.getTenantId(), desired.getId());
    }

    private DmsPermissionResourceVO existingWebFolder(String tenantId, String userId, UUID parentId,
                                                       String name, String sourceId,
                                                       DmsPermissionResourceEntity registry) {
        DmsFolderEntity folder = folderMapper.selectByTenantAndId(tenantId, registry.getId());
        if (folder == null
                || !DmsResourceType.FOLDER.name().equals(registry.getResourceType())
                || !"SYSTEM".equals(registry.getSourceType())
                || !sourceId.equals(registry.getSourceId())
                || !WEB_FOLDER_REGISTRAR.equals(registry.getRegisteredBy())
                || !userId.equals(folder.getCreatedBy())
                || !Objects.equals(parentId, folder.getParentId())
                || !name.equals(folder.getName())) {
            throw conflict("source_id 已存在，但子目录创建内容与原请求不一致", null);
        }
        return requireView(tenantId, registry.getId());
    }

    private DmsPermissionResourceVO existingDocument(DmsDocumentEntity desired, String sourceId, String serviceId) {
        DmsDocumentEntity actual = documentMapper.selectByTenantAndId(desired.getTenantId(), desired.getId());
        DmsPermissionResourceEntity registry = existingRegistry(desired.getTenantId(), desired.getId(), sourceId);
        if (actual == null && registry == null) {
            return null;
        }
        if (actual == null || registry == null || !Objects.equals(actual.getFolderId(), desired.getFolderId())
                || !Objects.equals(actual.getName(), desired.getName())
                || !sameRegistry(registry, DmsResourceType.DOCUMENT, sourceId, serviceId)) {
            throw conflict("Document 创建重试内容与原请求不一致", null);
        }
        return requireView(desired.getTenantId(), desired.getId());
    }

    private DmsPermissionResourceVO existingFileVersion(DmsFileVersionEntity desired, String sourceId,
                                                         String serviceId) {
        DmsFileVersionEntity actual = fileVersionMapper.selectByTenantAndId(desired.getTenantId(), desired.getId());
        DmsPermissionResourceEntity registry = existingRegistry(desired.getTenantId(), desired.getId(), sourceId);
        if (actual == null && registry == null) {
            return null;
        }
        if (actual == null || registry == null
                || !Objects.equals(actual.getDocumentId(), desired.getDocumentId())
                || !Objects.equals(actual.getVersionNo(), desired.getVersionNo())
                || !Objects.equals(actual.getFileName(), desired.getFileName())
                || !Objects.equals(actual.getMimeType(), desired.getMimeType())
                || !Objects.equals(actual.getSizeBytes(), desired.getSizeBytes())
                || !equalsIgnoreCase(actual.getChecksumSha256(), desired.getChecksumSha256())
                || !sameRegistry(registry, DmsResourceType.FILE_VERSION, sourceId, serviceId)) {
            throw conflict("FileVersion 创建重试内容与原请求不一致", null);
        }
        return requireView(desired.getTenantId(), desired.getId());
    }

    private DmsPermissionResourceEntity existingRegistry(String tenantId, UUID id, String sourceId) {
        DmsPermissionResourceEntity byId = resourceMapper.selectByTenantAndId(tenantId, id);
        DmsPermissionResourceEntity bySource = resourceMapper.selectBySource(tenantId, "SYSTEM", sourceId.trim());
        if (bySource != null && !id.equals(bySource.getId())) {
            throw conflict("source_id 已绑定到另一个权限资源", null);
        }
        return byId;
    }

    private boolean sameRegistry(DmsPermissionResourceEntity registry, DmsResourceType type,
                                 String sourceId, String serviceId) {
        return type.name().equals(registry.getResourceType())
                && "SYSTEM".equals(registry.getSourceType())
                && sourceId.trim().equals(registry.getSourceId())
                && serviceId.equals(registry.getRegisteredBy());
    }

    private void insertRegistry(String tenantId, UUID id, DmsResourceType type, String sourceId,
                                String serviceId) {
        DmsPermissionResourceEntity registry = new DmsPermissionResourceEntity();
        registry.setId(id);
        registry.setTenantId(tenantId);
        registry.setResourceType(type.name());
        registry.setSourceType("SYSTEM");
        registry.setSourceId(sourceId.trim());
        registry.setRegisteredBy(serviceId);
        resourceMapper.insert(registry);
    }

    private DmsPermissionResourceVO requireView(String tenantId, UUID id) {
        DmsPermissionResourceVO view = resourceMapper.selectView(tenantId, id);
        if (view == null) {
            throw DmsPermissionException.of(DmsPermissionError.RESOURCE_NOT_FOUND,
                    "权限资源创建后无法读取: " + id);
        }
        return view;
    }

    private void validateFolderMode(FolderCreateForm form) {
        if (form.isRootInitialization() != (form.getParentId() == null)) {
            throw DmsPermissionException.of(DmsPermissionError.INVALID_RESOURCE_PARENT,
                    "仅 rootInitialization=true 的 Folder 可以不提供 parentId");
        }
    }

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

    private boolean equalsIgnoreCase(String left, String right) {
        return left == null ? right == null : right != null && left.equalsIgnoreCase(right);
    }

    private DmsPermissionException conflict(String message, Throwable cause) {
        DmsPermissionException exception = DmsPermissionException.of(DmsPermissionError.SOURCE_CONFLICT, message);
        if (cause != null) {
            exception.initCause(cause);
        }
        return exception;
    }
}