package hashleaf

import (
	"crypto/ed25519"
	"fmt"

	"git.sigsum.org/sigsum-go/pkg/hex"
	"git.sigsum.org/sigsum-go/pkg/types"
	"git.sigsum.org/sigsum-tools-go/internal/util"
)

func Main(_ []string, optPriv string, optShardHint uint64) error {
	data, err := util.BytesFromStdin()
	if err != nil {
		return fmt.Errorf("sign: %v", err)
	}
	priv, err := util.SignerFromHex(optPriv)
	if err != nil {
		return fmt.Errorf("sign: %v", err)
	}
	stm := types.Statement{
		ShardHint: optShardHint,
		Checksum:  *types.HashFn(data),
	}
	sig, err := stm.Sign(priv)
	if err != nil {
		fmt.Errorf("sign: %v", err)
	}
	leaf := types.Leaf{
		Statement: stm,
		Signature: *sig,
		KeyHash:   *types.HashFn(priv.Public().(ed25519.PublicKey)[:]),
	}
	lh := types.LeafHash(leaf.ToBinary())

	fmt.Printf("%s\n", hex.Serialize(lh[:]))
	return nil
}