"fmt"
	"hash"
	"io"
)

// Tagger is the interface that wraps the basic ETag method.
type Tagger interface {
	ETag() ETag
}

type wrapReader struct {
	io.Reader
	Tagger
}

var _ Tagger = wrapReader{} // compiler check

// ETag returns the ETag of the underlying Tagger.
func (r wrapReader) ETag() ETag {
	if r.Tagger == nil {
		return nil
	}
	return r.Tagger.ETag()
}

func (r *Reader) ActualSize() int64 { return r.actualSize }

// ETag returns the ETag computed by an underlying etag.Tagger.
// If the underlying io.Reader does not implement etag.Tagger
// it returns nil.
func (r *Reader) ETag() etag.ETag {
	if t, ok := r.src.(etag.Tagger); ok {
		return t.ETag()
	}
	return nil
}

// MD5Current returns the MD5 checksum of the content

Anis Elleuch <******@****.***>
Frederick F. Kautz IV <******@****.***> <******@****.***>
Harshavardhana <******@****.***> <******@****.***>
Harshavardhana <******@****.***> <badger@gitter.im>
Harshavardhana <******@****.***>
Krishna Srinivas <******@****.***> <******@****.***>
Matthew Farrellee <******@****.***>

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package etag

import (
	"context"
	"io"
	"net/http"
	"strings"
	"testing"
)

var _ Tagger = Wrap(nil, nil).(Tagger) // runtime check that wrapReader implements Tagger

var parseTests = []struct {
	String     string
	ETag       ETag
	ShouldFail bool
}{

	it := gcs.client.Bucket(gcs.Bucket).Objects(ctx, &storage.Query{
		Delimiter: "/",
		Prefix:    gcs.Prefix,
		Versions:  false,
	})
	pager := iterator.NewPager(it, 1, "")
	gcsObjects := make([]*storage.ObjectAttrs, 0)
	_, err := pager.NextPage(&gcsObjects)
	if err != nil {
		return false, gcsToObjectError(err, gcs.Bucket, gcs.Prefix)
	}
	if len(gcsObjects) > 0 {
		return true, nil
	}

//	}
//	ETag = ETag.Format()
func (e ETag) Format() ETag {
	if !e.IsEncrypted() {
		return e
	}
	return e[len(e)-16:]
}

var _ Tagger = ETag{} // compiler check

// ETag returns the ETag itself.
//
// By providing this method ETag implements
// the Tagger interface.
func (e ETag) ETag() ETag { return e }

// FromContentMD5 decodes and returns the Content-MD5