package main

import (
	"archive/zip"
	"bytes"
	"fmt"
	"io/ioutil"
)

func main() {

	data := []byte("00000000000000000000" +
		"00000000000000000000" +
		"00000000000000000000" +
		"00000000PK\x03\x0400000000" +
		"00000000000000\x03\x00\x1c\x0000" +
		"00000000000000000000" +
		"000000000asidhuasih " +
		"a\n sdjn osdn \nsdvs n" +
		"dv\nPK\x01\x020000000000000" +
		"00000000000\x03\x00\x18\x00\x00\x00000" +
		"00000000000000000000" +
		"0000000000000000PK\x01\x02" +
		"000000\x00\x000000OVET\"\x00\x00\x00" +
		"\"\x00\x00\x00\x03\x00\x18\x00\x00\x0000000000D\x00" +
		"\x00\x0000/000PK\x05\x06000000\x02\x00" +
		"0000\xa3\x00\x00\x00\x00\x00")
	z, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
	if err != nil {
		if z != nil {
			panic("non nil z")
		}
		return
	}
	var headers []*zip.FileHeader
	var contents [][]byte
	for _, f := range z.File {
		r, err := f.Open()
		if err != nil {
			continue
		}
		if f.UncompressedSize64 < 1e6 {
			c, err := ioutil.ReadAll(r)
			if err != nil {
				continue
			}
			if uint64(len(c)) != f.UncompressedSize64 {
				println("bad size:", len(c), f.UncompressedSize64)
				panic("bad size")
			}
			hdr := f.FileHeader
			headers = append(headers, &hdr)
			contents = append(contents, c)
		}
		r.Close()
	}
	if len(headers) == 0 {
		return
	}
	// Write a new archive with the same files.
	buf := new(bytes.Buffer)
	w := zip.NewWriter(buf)
	for i, h := range headers {
		w1, err := w.CreateHeader(h)
		if err != nil {
			panic(err)
		}
		xx:=len(contents[i])
		fmt.Println(xx)
		n, err := w1.Write(contents[i])
		if err != nil {
			panic(err)
		}
		if n != len(contents[i]) {
			panic("short write")
		}
	}
	err = w.Close()
	if err != nil {
		panic(err)
	}

}