package libnmdc

import (
	"encoding/base32"
	"errors"

	"github.com/cxmcc/tiger"
)

func tth(input []byte) (string, error) {
	if len(input) > 1024 {
		return "", errors.New("TTH content exceeded 1024 bytes")
	}

	leafHash := tiger.New()

	//buff := make([]byte, 1024)
	//leafHash.Write([]byte("\x00"))
	//copy(buff[1:], []byte(input))
	//leafHash.Write(buff)
	//fmt.Printf("%#v\n", buff)

	leafHash.Write([]byte("\x00" + string(input)))
	leafHashBytes := leafHash.Sum(nil)

	rootHash := tiger.New()
	//rootHash.Write([]byte("\x01"))
	//rootHash.Write(leafHashBytes)
	rootHash.Write([]byte("\x01" + string(leafHashBytes)))
	rootHashBytes := rootHash.Sum(nil)

	/*
	   * The Tiger Hash function, modified to prepend the specified byte to the input
	    * data. This is useful for the THEX algorithm which prepends a 0x00 to leaf
	    * nodes and 0x01 to the hash nodes.
	    **/

	// Definitely StdEncoding
	return base32.StdEncoding.EncodeToString(rootHashBytes), nil
}