package service

import (
	"fmt"

	"dd_fiber_api/internal/document"
	"dd_fiber_api/internal/document/dao"
	"dd_fiber_api/pkg/snowflake"
)

// DocumentService 文档管理服务
type DocumentService struct {
	folderDAO *dao.FolderDAO
	fileDAO   *dao.FileDAO
}

// NewDocumentService 创建 DocumentService
func NewDocumentService(folderDAO *dao.FolderDAO, fileDAO *dao.FileDAO) *DocumentService {
	return &DocumentService{folderDAO: folderDAO, fileDAO: fileDAO}
}

// ListFolders 列出所有文件夹
func (s *DocumentService) ListFolders() ([]*document.DocFolder, error) {
	return s.folderDAO.List()
}

// CreateFolder 创建文件夹
func (s *DocumentService) CreateFolder(req *document.CreateFolderRequest) (*document.DocFolder, error) {
	id := snowflake.GetInstance().NextIDString()
	f := &document.DocFolder{
		ID:        id,
		Name:      req.Name,
		SortOrder: req.SortOrder,
	}
	if err := s.folderDAO.Create(f); err != nil {
		return nil, err
	}
	return s.folderDAO.GetByID(id)
}

// UpdateFolder 更新文件夹
func (s *DocumentService) UpdateFolder(req *document.UpdateFolderRequest) error {
	f, err := s.folderDAO.GetByID(req.ID)
	if err != nil || f == nil {
		return fmt.Errorf("文件夹不存在")
	}
	f.Name = req.Name
	f.SortOrder = req.SortOrder
	return s.folderDAO.Update(f)
}

// DeleteFolder 删除文件夹（同时删除其下文件记录）
func (s *DocumentService) DeleteFolder(id string) error {
	_ = s.fileDAO.DeleteByFolderID(id)
	return s.folderDAO.Delete(id)
}

// ListFiles 列出文件夹下的文件
func (s *DocumentService) ListFiles(folderID string) ([]*document.DocFile, error) {
	return s.fileDAO.ListByFolderID(folderID)
}

// CreateFile 创建文档记录
func (s *DocumentService) CreateFile(req *document.CreateFileRequest) (*document.DocFile, error) {
	if req.FolderID == "" || req.FileURL == "" {
		return nil, fmt.Errorf("folder_id 和 file_url 必填")
	}
	folder, err := s.folderDAO.GetByID(req.FolderID)
	if err != nil || folder == nil {
		return nil, fmt.Errorf("文件夹不存在")
	}
	id := snowflake.GetInstance().NextIDString()
	name := req.Name
	if name == "" {
		name = req.FileName
	}
	f := &document.DocFile{
		ID:       id,
		FolderID: req.FolderID,
		Name:     name,
		FileName: req.FileName,
		FileURL:  req.FileURL,
		FileSize: req.FileSize,
		MimeType: req.MimeType,
	}
	if err := s.fileDAO.Create(f); err != nil {
		return nil, err
	}
	return s.fileDAO.GetByID(id)
}

// UpdateFile 更新文档（名称）
func (s *DocumentService) UpdateFile(req *document.UpdateFileRequest) error {
	f, err := s.fileDAO.GetByID(req.ID)
	if err != nil || f == nil {
		return fmt.Errorf("文档不存在")
	}
	f.Name = req.Name
	return s.fileDAO.Update(f)
}

// DeleteFile 删除文档记录
func (s *DocumentService) DeleteFile(id string) error {
	return s.fileDAO.Delete(id)
}