package dirhash

import (
	"archive/zip"
	"crypto/sha256"
	"encoding/base64"
	"errors"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"sort"
	"strings"
)

// DefaultHash is the default hash function used in new go.sum entries.
var DefaultHash Hash = Hash1

// A Hash is a directory hash function.
// It accepts a list of files along with a function that opens the content of each file.

     */
    @Override
    @Internal
    public Date getDate() {
        return date != null ? date : defaultDate();
    }

    @Nullable
    private Date defaultDate() {
        final File file = getFile();
        if (file == null) {
            return null;
        }

        final long modified = file.lastModified();

// an error and does not write ziphashfile.
func hashZip(mod module.Version, zipfile, ziphashfile string) (err error) {
	hash, err := dirhash.HashZip(zipfile, dirhash.DefaultHash)
	if err != nil {
		return err
	}
	if err := checkModSum(mod, hash); err != nil {
		return err
	}
	hf, err := lockedfile.Create(ziphashfile)
	if err != nil {
		return err
	}