frostfs-s3-lifecycler/internal/resolver/resolver.go

package resolver

import (
	"errors"
	"fmt"
	"strings"

	"git.frostfs.info/TrueCloudLab/frostfs-contract/nns"
	"git.frostfs.info/TrueCloudLab/frostfs-s3-lifecycler/internal/morph"
	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)

// ResolveContractHash determine contract hash by resolving NNS name.
func ResolveContractHash(cli *morph.Client, contractHash string) (util.Uint160, error) {
	if hash, err := util.Uint160DecodeStringLE(contractHash); err == nil {
		return hash, nil
	}

	if strings.Count(contractHash, ".") != 1 {
		return util.Uint160{}, fmt.Errorf("invalid contract name: '%s'", contractHash)
	}

	nnsContract, err := cli.Client().NNSHash()
	if err != nil {
		return util.Uint160{}, fmt.Errorf("get NNS contract hash: %w", err)
	}

	return invokeResolve(cli, nnsContract, contractHash)
}

func invokeResolve(cli *morph.Client, nnsContract util.Uint160, contractHash string) (util.Uint160, error) {
	items, err := cli.Client().TestInvoke(nnsContract, "resolve", contractHash, int64(nns.TXT))
	if err != nil {
		return util.Uint160{}, fmt.Errorf("contract invocation: %w", err)
	}
	if len(items) != 1 {
		return util.Uint160{}, fmt.Errorf("stack has %d items", len(items))
	}

	if _, ok := items[0].(stackitem.Null); !ok {
		arr, ok := items[0].Value().([]stackitem.Item)
		if !ok {
			// unexpected for types from stackitem package
			return util.Uint160{}, errors.New("invalid cast to stack item slice")
		}

		for i := range arr {
			recordValue, err := arr[i].TryBytes()
			if err != nil {
				return util.Uint160{}, fmt.Errorf("convert array item to byte slice: %w", err)
			}

			strRecordValue := string(recordValue)
			scriptHash, err := address.StringToUint160(strRecordValue)
			if err == nil {
				return scriptHash, nil
			}
			scriptHash, err = util.Uint160DecodeStringLE(strRecordValue)
			if err == nil {
				return scriptHash, nil
			}
		}
	}

	return util.Uint160{}, errors.New("record not found")
}