package archive_test

import (
    "archive/tar"
    "fmt"
    "io"
    "io/ioutil"
    "os"
    "os/exec"
    "path"
    "testing"
)

func TestArchive(t *testing.T) {
    const tarName = "test.tar"
    tmpDir, err := ioutil.TempDir("", "test-src")
    defer os.RemoveAll(tmpDir)
    if err != nil {
        panic(err)
    }

    for i, currCase := range []struct {
        filePath string
    }{
        // ok
        {filePath: "0/1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30/file.txt"},
        // ok
        {filePath: "0/1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30/31/32/33/file.txt"},
        // fails: path len = 101 characters
        {filePath: "0/1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30/31/32/333/file.txt"},
        // fails
        {filePath: "0/1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30/31/32/33/34/35/36/37/38/39/40/file.txt"},
        // fails
        {filePath: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000/file.txt"},
    } {
        srcDir, err := ioutil.TempDir(tmpDir, fmt.Sprintf("case-%d-input-", i))
        if err != nil {
            panic(err)
        }

        srcFile := path.Join(srcDir, currCase.filePath)
        err = os.MkdirAll(path.Dir(srcFile), 0755)
        if err != nil {
            panic(err)
        }

        err = ioutil.WriteFile(srcFile, []byte("Hello, world!"), 0644)
        if err != nil {
            panic(err)
        }

        outDir, err := ioutil.TempDir(tmpDir, fmt.Sprintf("case-%d-output-", i))
        if err != nil {
            panic(err)
        }

        tarPath := path.Join(outDir, tarName)

        func() {
            out, err := os.Create(tarPath)
            if err != nil {
                panic(err)
            }
            defer out.Close()

            tarWriter := tar.NewWriter(out)
            defer tarWriter.Close()

            srcInfo, err := os.Stat(srcFile)
            if err != nil {
                panic(err)
            }

            header, err := tar.FileInfoHeader(srcInfo, srcFile)
            if err != nil {
                panic(err)
            }
            header.Name = currCase.filePath

            // Adding these lines fixes the issue (both lines required)-------
            //header.Uid = 0
            //header.Gid = 0
            // ---------------------------------------------------------------

            err = tarWriter.WriteHeader(header)
            if err != nil {
                panic(err)
            }

            if header.Typeflag == tar.TypeReg {
                file, err := os.Open(srcFile)
                if err != nil {
                    panic(err)
                }
                defer file.Close()

                _, err = io.CopyN(tarWriter, file, srcInfo.Size())
                if err != nil {
                    panic(err)
                }
            }
        }()

        // expand using 'tar' command
        cmd := exec.Command("tar", "-C", outDir, "-xf", tarName)
        cmd.Dir = outDir
        output, err := cmd.CombinedOutput()
        if err != nil {
            t.Errorf("Case %d: command %v failed: %s", i, cmd.Args, string(output))
        }

        // long file in tar should be expanded properly
        _, err = os.Stat(path.Join(outDir, currCase.filePath))
        if err != nil {
            t.Errorf("Case %d: file did not exist at path %s", i, path.Join(outDir, currCase.filePath))
        }

        // stray file should not exist
        _, err = os.Stat(path.Join(outDir, "file.txt"))
        if err == nil {
            t.Errorf("Case %d: unexpected file at %s", i, path.Join(outDir, "file.txt"))
        }
    }
}