package service

import (
	"context"
	"mime/multipart"
	"os"
	"path/filepath"
	"server/internal/db"
	"server/internal/db/sqlc"
	"server/internal/model/common"
	"server/internal/model/response"
	"server/internal/pkg/httputil"

	gonanoid "github.com/matoous/go-nanoid/v2"
)

type SysFileService struct {
	store *db.Store
}

func NewSysFileService(store *db.Store) *SysFileService {
	return &SysFileService{
		store: store,
	}
}

// MakeSavedDir 创建目录并返回
func MakeSavedDir(folder string) (string, error) {
	rootDir, err := os.Getwd()

	if err != nil {
		return "", err
	}

	uploadDir := filepath.Join(rootDir, "uploads", folder)

	if err = os.MkdirAll(uploadDir, 0755); err != nil {
		return "", err
	}

	return uploadDir, nil
}

func (s *SysFileService) ListPage(ctx context.Context, p *common.Pagination) ([]sqlc.File, int64, error) {
	params := sqlc.GetFilesParams{
		Limit:  p.PageSize,
		Offset: (p.Page - 1) * p.PageSize,
	}

	total, err := s.store.CountFiles(ctx)

	if err != nil {
		return nil, 0, err
	}

	list, err := s.store.GetFiles(ctx, params)

	if err != nil {
		return nil, 0, err
	}

	return response.ToFiles(list), total, nil
}

func (s *SysFileService) Upload(ctx context.Context, folder string, file *multipart.FileHeader) (*sqlc.CreateFileRow, error) {
	// 生成文件名
	fileID, err := gonanoid.New()
	if err != nil {
		return nil, err
	}

	savedDir, err := MakeSavedDir(folder)
	if err != nil {
		return nil, err
	}

	fileExt := filepath.Ext(file.Filename)
	filename := fileID + fileExt
	filePath := filepath.Join(folder, filename)
	// 用于保存文件
	savedPath := filepath.Join(savedDir, filename)

	// 打开上传的文件
	src, err := file.Open()
	if err != nil {
		return nil, err
	}
	defer src.Close()

	// 创建目标文件
	dst, err := os.Create(savedPath)
	if err != nil {
		return nil, err
	}
	defer dst.Close()

	// 复制文件内容
	if _, err = dst.ReadFrom(src); err != nil {
		return nil, err
	}

	params := sqlc.CreateFileParams{
		FileName:     filename,
		FilePath:     filePath,
		OriginalName: file.Filename,
		FolderName:   folder,
		MimeType:     file.Header.Get("Content-Type"),
		FileSize:     file.Size,
	}

	result, err := s.store.CreateFile(ctx, params)
	if err != nil {
		return nil, err
	}

	result.FilePath = httputil.BuildFileUrl(&result.FilePath)

	return &result, nil
}