package exporter

import (
	"archive/zip"
	"compress/flate"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
	"time"
)

// ZipFiles 将分片文件打包为压缩zip并返回路径与大小，同时清理源xlsx分片文件
func ZipFiles(jobID uint64, files []string) (string, int64) {
	baseDir := "storage/export"
	_ = os.MkdirAll(baseDir, 0755)
	zipPath := filepath.Join(baseDir, fmt.Sprintf("job_%d_%d.zip", jobID, time.Now().Unix()))
	zf, err := os.Create(zipPath)
	if err != nil {
		return zipPath, 0
	}
	defer zf.Close()
	zw := zip.NewWriter(zf)
	// 注册 DEFLATE 压缩器
	zw.RegisterCompressor(zip.Deflate, func(out io.Writer) (io.WriteCloser, error) {
		w, err := flate.NewWriter(out, flate.DefaultCompression)
		if err != nil {
			return nil, err
		}
		return w, nil
	})
	for _, p := range files {
		f, err := os.Open(p)
		if err != nil {
			continue
		}
		// 创建压缩文件头，指定使用 DEFLATE 压缩
		w, err := zw.CreateHeader(&zip.FileHeader{
			Name:   filepath.Base(p),
			Method: zip.Deflate, // 使用 DEFLATE 压缩
		})
		if err != nil {
			f.Close()
			continue
		}
		_, _ = io.Copy(w, f)
		f.Close()
	}
	_ = zw.Close()
	st, err := os.Stat(zipPath)
	if err != nil {
		return zipPath, 0
	}
	// 清理xlsx分片文件以节省空间
	for _, fp := range files {
		if strings.HasSuffix(strings.ToLower(fp), ".xlsx") {
			_ = os.Remove(fp)
		}
	}
	return zipPath, st.Size()
}