package client

import (
	"errors"
	"fmt"

	"git.frostfs.info/TrueCloudLab/frostfs-contract/commonclient"
	"github.com/nspcc-dev/neo-go/pkg/core/state"
	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
	"github.com/nspcc-dev/neo-go/pkg/rpcclient/actor"
	"github.com/nspcc-dev/neo-go/pkg/rpcclient/unwrap"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
	"github.com/nspcc-dev/neo-go/pkg/vm/vmstate"
	"github.com/nspcc-dev/neo-go/pkg/wallet"
)

type (
	Client struct {
		act      *actor.Actor
		acc      *wallet.Account
		contract util.Uint160
	}

	Options struct {
		// todo add proxy params
	}
)

type (
	Subject struct {
		PrimaryKey     *keys.PublicKey
		AdditionalKeys keys.PublicKeys
		Namespace      string
		Name           string
		KV             map[string]string
	}

	SubjectExtended struct {
		PrimaryKey     *keys.PublicKey
		AdditionalKeys keys.PublicKeys
		Namespace      string
		Name           string
		KV             map[string]string
		Groups         []*Group
	}

	Namespace struct {
		Name string
	}

	NamespaceExtended struct {
		Name          string
		GroupsCount   int64
		SubjectsCount int64
	}

	Group struct {
		Name      string
		Namespace string
	}

	GroupExtended struct {
		Name          string
		Namespace     string
		SubjectsCount int64
	}
)

const (
	SubjectIAMPathKey      = "iam-path"
	SubjectCreatedTimeKey  = "ctime"
	SubjectModifiedTimeKey = "mtime"
)

const iteratorBatchSize = 100

const (
	addOwnerMethod    = "addOwner"
	deleteOwnerMethod = "deleteOwner"
	listOwnersMethod  = "listOwners"

	versionMethod = "version"

	createSubjectMethod       = "createSubject"
	getSubjectMethod          = "getSubject"
	getSubjectExtendedMethod  = "getSubjectExtended"
	listSubjectsMethod        = "listSubjects"
	addSubjectKeyMethod       = "addSubjectKey"
	removeSubjectKeyMethod    = "removeSubjectKey"
	getSubjectByKeyMethod     = "getSubjectByKey"
	getSubjectKeyByNameMethod = "getSubjectKeyByName"
	setSubjectKVMethod        = "setSubjectKV"
	setSubjectNameMethod      = "setSubjectName"
	deleteSubjectKVMethod     = "deleteSubjectKV"
	deleteSubjectMethod       = "deleteSubject"

	createNamespaceMethod            = "createNamespace"
	getNamespaceMethod               = "getNamespace"
	getNamespaceExtendedMethod       = "getNamespaceExtended"
	listNamespacesMethod             = "listNamespaces"
	addSubjectToNamespaceMethod      = "addSubjectToNamespace"
	removeSubjectFromNamespaceMethod = "removeSubjectFromNamespace"
	listNamespaceSubjectsMethod      = "listNamespaceSubjects"

	createGroupMethod            = "createGroup"
	getGroupMethod               = "getGroup"
	getGroupExtendedMethod       = "getGroupExtended"
	listGroupsMethod             = "listGroups"
	addSubjectToGroupMethod      = "addSubjectToGroup"
	removeSubjectFromGroupMethod = "removeSubjectFromGroup"
	listGroupSubjectsMethod      = "listGroupSubjects"
	deleteGroupMethod            = "deleteGroup"
)

// New creates a new Client. Options can be nil.
func New(ra actor.RPCActor, acc *wallet.Account, contract util.Uint160, _ *Options) (*Client, error) {
	act, err := actor.NewSimple(ra, acc)
	if err != nil {
		return nil, fmt.Errorf("init actor: %w", err)
	}

	return &Client{
		act:      act,
		acc:      acc,
		contract: contract,
	}, nil
}

// StartTx inits transaction.
func (c Client) StartTx() *commonclient.Transaction {
	return commonclient.NewTransaction(c.contract)
}

// SendTx sends provided transaction to blockchain.
func (c Client) SendTx(txn *commonclient.Transaction) (tx util.Uint256, vub uint32, err error) {
	txBytes, err := txn.Bytes()
	if err != nil {
		return util.Uint256{}, 0, err
	}

	return c.act.SendRun(txBytes)
}

// Version returns version of contract.
func (c Client) Version() (int64, error) {
	return unwrap.Int64(c.act.Call(c.contract, versionMethod))
}

// AddOwner adds new address that can perform write operations on contract.
// Must be invoked by committee.
func (c Client) AddOwner(owner util.Uint160) (tx util.Uint256, vub uint32, err error) {
	method, args := c.AddOwnerCall(owner)
	return c.act.SendCall(c.contract, method, args...)
}

// AddOwnerCall provides args for AddOwner to use in commonclient.Transaction.
func (c Client) AddOwnerCall(owner util.Uint160) (method string, args []any) {
	return addOwnerMethod, []any{owner}
}

// DeleteOwner removes address from list of that can perform write operations on contract.
// Must be invoked by committee.
func (c Client) DeleteOwner(owner util.Uint160) (tx util.Uint256, vub uint32, err error) {
	method, args := c.DeleteOwnerCall(owner)
	return c.act.SendCall(c.contract, method, args...)
}

// DeleteOwnerCall provides args for DeleteOwner to use in commonclient.Transaction.
func (c Client) DeleteOwnerCall(owner util.Uint160) (method string, args []any) {
	return deleteOwnerMethod, []any{owner}
}

// ListOwners returns list of address that can perform write operations on contract.
func (c Client) ListOwners() ([]util.Uint160, error) {
	return unwrapArrayOfUint160(commonclient.ReadIteratorItems(c.act, iteratorBatchSize, c.contract, listOwnersMethod))
}

// CreateSubject creates new subject using public key.
// Must be invoked by contract owner.
func (c Client) CreateSubject(key *keys.PublicKey) (tx util.Uint256, vub uint32, err error) {
	method, args := c.CreateSubjectCall(key)
	return c.act.SendCall(c.contract, method, args...)
}

// CreateSubjectCall provides args for CreateSubject to use in commonclient.Transaction.
func (c Client) CreateSubjectCall(key *keys.PublicKey) (method string, args []any) {
	return createSubjectMethod, []any{key.Bytes()}
}

// GetSubject gets subject by address.
func (c Client) GetSubject(addr util.Uint160) (*Subject, error) {
	items, err := unwrap.Array(c.act.Call(c.contract, getSubjectMethod, addr))
	if err != nil {
		return nil, err
	}

	return parseSubject(items)
}

// GetSubjectExtended gets extended subject by address.
func (c Client) GetSubjectExtended(addr util.Uint160) (*SubjectExtended, error) {
	items, err := unwrap.Array(c.act.Call(c.contract, getSubjectExtendedMethod, addr))
	if err != nil {
		return nil, err
	}

	return parseSubjectExtended(items)
}

// ListSubjects gets all subjects.
func (c Client) ListSubjects() ([]util.Uint160, error) {
	return unwrapArrayOfUint160(commonclient.ReadIteratorItems(c.act, iteratorBatchSize, c.contract, listSubjectsMethod))
}

// AddSubjectKey adds extra public key to subject.
// Must be invoked by contract owner.
func (c Client) AddSubjectKey(addr util.Uint160, key *keys.PublicKey) (tx util.Uint256, vub uint32, err error) {
	method, args := c.AddSubjectKeyCall(addr, key)
	return c.act.SendCall(c.contract, method, args...)
}

// AddSubjectKeyCall provides args for AddSubjectKey to use in commonclient.Transaction.
func (c Client) AddSubjectKeyCall(addr util.Uint160, key *keys.PublicKey) (method string, args []any) {
	return addSubjectKeyMethod, []any{addr, key.Bytes()}
}

// RemoveSubjectKey removes extra public key from subject.
// Must be invoked by contract owner.
func (c Client) RemoveSubjectKey(addr util.Uint160, key *keys.PublicKey) (tx util.Uint256, vub uint32, err error) {
	method, args := c.RemoveSubjectKeyCall(addr, key)
	return c.act.SendCall(c.contract, method, args...)
}

// RemoveSubjectKeyCall provides args for RemoveSubjectKey to use in commonclient.Transaction.
func (c Client) RemoveSubjectKeyCall(addr util.Uint160, key *keys.PublicKey) (method string, args []any) {
	return removeSubjectKeyMethod, []any{addr, key.Bytes()}
}

// SetSubjectKV updates subject kv map.
// Must be invoked by contract owner.
// You can use some predefined key constants: SubjectLoginKey, SubjectIAMPathKey, SubjectCreatedTimeKey, SubjectModifiedTimeKey.
func (c Client) SetSubjectKV(addr util.Uint160, key, val string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.SetSubjectKVCall(addr, key, val)
	return c.act.SendCall(c.contract, method, args...)
}

// SetSubjectKVCall provides args for SetSubjectLogin to use in commonclient.Transaction.
func (c Client) SetSubjectKVCall(addr util.Uint160, key, val string) (method string, args []any) {
	return setSubjectKVMethod, []any{addr, key, val}
}

// SetSubjectName updates subject name.
// Must be invoked by contract owner.
func (c Client) SetSubjectName(addr util.Uint160, name string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.SetSubjectNameCall(addr, name)
	return c.act.SendCall(c.contract, method, args...)
}

// SetSubjectNameCall provides args for SetSubjectLogin to use in commonclient.Transaction.
func (c Client) SetSubjectNameCall(addr util.Uint160, name string) (method string, args []any) {
	return setSubjectNameMethod, []any{addr, name}
}

// DeleteSubjectKV removes subject kv map.
// Must be invoked by contract owner.
func (c Client) DeleteSubjectKV(addr util.Uint160, key string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.DeleteSubjectKVCall(addr, key)
	return c.act.SendCall(c.contract, method, args...)
}

// DeleteSubjectKVCall provides args for SetSubjectLogin to use in commonclient.Transaction.
func (c Client) DeleteSubjectKVCall(addr util.Uint160, key string) (method string, args []any) {
	return deleteSubjectKVMethod, []any{addr, key}
}

// GetSubjectByKey gets subject by its primary or additional keys.
func (c Client) GetSubjectByKey(key *keys.PublicKey) (*Subject, error) {
	items, err := unwrap.Array(c.act.Call(c.contract, getSubjectByKeyMethod, key.Bytes()))
	if err != nil {
		return nil, err
	}

	return parseSubject(items)
}

// GetSubjectKeyByName gets subject public key by its name (namespace scope).
func (c Client) GetSubjectKeyByName(namespace, subjectName string) (*keys.PublicKey, error) {
	return unwrap.PublicKey(c.act.Call(c.contract, getSubjectKeyByNameMethod, namespace, subjectName))
}

// DeleteSubject delete subject and removes it from related namespaces and groups.
// Must be invoked by contract owner.
func (c Client) DeleteSubject(addr util.Uint160) (tx util.Uint256, vub uint32, err error) {
	method, args := c.DeleteSubjectCall(addr)
	return c.act.SendCall(c.contract, method, args...)
}

// DeleteSubjectCall provides args for DeleteSubject to use in commonclient.Transaction.
func (c Client) DeleteSubjectCall(addr util.Uint160) (method string, args []any) {
	return deleteSubjectMethod, []any{addr}
}

// CreateNamespace create new namespace.
// Must be invoked by contract owner.
func (c Client) CreateNamespace(namespace string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.CreateNamespaceCall(namespace)
	return c.act.SendCall(c.contract, method, args...)
}

// CreateNamespaceCall provides args for CreateNamespace to use in commonclient.Transaction.
func (c Client) CreateNamespaceCall(namespace string) (method string, args []any) {
	return createNamespaceMethod, []any{namespace}
}

// GetNamespace gets namespace.
func (c Client) GetNamespace(namespace string) (*Namespace, error) {
	items, err := unwrap.Array(c.act.Call(c.contract, getNamespaceMethod, namespace))
	if err != nil {
		return nil, err
	}

	return parseNamespace(items)
}

// GetNamespaceExtended gets extended namespace.
func (c Client) GetNamespaceExtended(namespace string) (*NamespaceExtended, error) {
	items, err := unwrap.Array(c.act.Call(c.contract, getNamespaceExtendedMethod, namespace))
	if err != nil {
		return nil, err
	}

	return parseNamespaceExtended(items)
}

// ListNamespaces gets all namespaces.
func (c Client) ListNamespaces() ([]*Namespace, error) {
	items, err := commonclient.ReadIteratorItems(c.act, iteratorBatchSize, c.contract, listNamespacesMethod)
	if err != nil {
		return nil, err
	}

	return parseNamespaces(items)
}

// AddSubjectToNamespace adds a subject to namespace.
// Must be invoked by contract owner.
func (c Client) AddSubjectToNamespace(addr util.Uint160, namespace string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.AddSubjectToNamespaceCall(addr, namespace)
	return c.act.SendCall(c.contract, method, args...)
}

// AddSubjectToNamespaceCall provides args for AddSubjectToNamespace to use in commonclient.Transaction.
func (c Client) AddSubjectToNamespaceCall(addr util.Uint160, namespace string) (method string, args []any) {
	return addSubjectToNamespaceMethod, []any{addr, namespace}
}

// RemoveSubjectFromNamespace removes a subject from namespace.
// Must be invoked by contract owner.
func (c Client) RemoveSubjectFromNamespace(addr util.Uint160) (tx util.Uint256, vub uint32, err error) {
	method, args := c.RemoveSubjectFromNamespaceCall(addr)
	return c.act.SendCall(c.contract, method, args...)
}

// RemoveSubjectFromNamespaceCall provides args for RemoveSubjectFromNamespace to use in commonclient.Transaction.
func (c Client) RemoveSubjectFromNamespaceCall(addr util.Uint160) (method string, args []any) {
	return removeSubjectFromNamespaceMethod, []any{addr}
}

// ListNamespaceSubjects gets all subjects from namespace.
func (c Client) ListNamespaceSubjects(namespace string) ([]util.Uint160, error) {
	return unwrapArrayOfUint160(commonclient.ReadIteratorItems(c.act, iteratorBatchSize, c.contract, listNamespaceSubjectsMethod, namespace))
}

// CreateGroup creates a new group in specific namespace.
// Must be invoked by contract owner.
func (c Client) CreateGroup(namespace, group string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.CreateGroupCall(namespace, group)
	return c.act.SendCall(c.contract, method, args...)
}

// CreateGroupCall provides args for CreateGroup to use in commonclient.Transaction.
func (c Client) CreateGroupCall(namespace, group string) (method string, args []any) {
	return createGroupMethod, []any{namespace, group}
}

// GetGroup gets group.
func (c Client) GetGroup(namespace, group string) (*Group, error) {
	items, err := unwrap.Array(c.act.Call(c.contract, getGroupMethod, namespace, group))
	if err != nil {
		return nil, err
	}

	return parseGroup(items)
}

// GetGroupExtended gets extended group.
func (c Client) GetGroupExtended(namespace, group string) (*GroupExtended, error) {
	items, err := unwrap.Array(c.act.Call(c.contract, getGroupExtendedMethod, namespace, group))
	if err != nil {
		return nil, err
	}

	return parseGroupExtended(items)
}

// ListGroups gets all groups in specific namespace.
func (c Client) ListGroups(namespace string) ([]*Group, error) {
	items, err := commonclient.ReadIteratorItems(c.act, iteratorBatchSize, c.contract, listGroupsMethod, namespace)
	if err != nil {
		return nil, err
	}

	return parseGroups(items)
}

// AddSubjectToGroup adds a new subject to group.
// Must be invoked by contract owner.
func (c Client) AddSubjectToGroup(addr util.Uint160, group string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.AddSubjectToGroupCall(addr, group)
	return c.act.SendCall(c.contract, method, args...)
}

// AddSubjectToGroupCall provides args for AddSubjectToGroup to use in commonclient.Transaction.
func (c Client) AddSubjectToGroupCall(addr util.Uint160, group string) (method string, args []any) {
	return addSubjectToGroupMethod, []any{addr, group}
}

// RemoveSubjectFromGroup removes subject from group.
// Must be invoked by contract owner.
func (c Client) RemoveSubjectFromGroup(addr util.Uint160, namespace, group string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.RemoveSubjectFromGroupCall(addr, namespace, group)
	return c.act.SendCall(c.contract, method, args...)
}

// RemoveSubjectFromGroupCall provides args for RemoveSubjectFromGroup to use in commonclient.Transaction.
func (c Client) RemoveSubjectFromGroupCall(addr util.Uint160, namespace, group string) (method string, args []any) {
	return removeSubjectFromGroupMethod, []any{addr, namespace, group}
}

// ListGroupSubjects gets all subjects in specific group.
func (c Client) ListGroupSubjects(namespace, group string) ([]util.Uint160, error) {
	return unwrapArrayOfUint160(commonclient.ReadIteratorItems(c.act, iteratorBatchSize, c.contract, listGroupSubjectsMethod, namespace, group))
}

// DeleteGroup deletes group.
// Must be invoked by contract owner.
func (c Client) DeleteGroup(namespace, group string) (tx util.Uint256, vub uint32, err error) {
	method, args := c.DeleteGroupCall(namespace, group)
	return c.act.SendCall(c.contract, method, args...)
}

// DeleteGroupCall provides args for DeleteGroup to use in commonclient.Transaction.
func (c Client) DeleteGroupCall(namespace, group string) (method string, args []any) {
	return deleteGroupMethod, []any{namespace, group}
}

// ListNonEmptyNamespaces gets namespaces that contain at least one subject.
func (c Client) ListNonEmptyNamespaces() ([]string, error) {
	namespaces, err := c.ListNamespaces()
	if err != nil {
		return nil, err
	}

	var res []string

	for _, namespace := range namespaces {
		nsExt, err := c.GetNamespaceExtended(namespace.Name)
		if err != nil {
			return nil, err
		}

		if nsExt.SubjectsCount > 0 {
			res = append(res, nsExt.Name)
		}
	}

	return res, nil
}

// Wait invokes underlying wait method on actor.Actor.
func (c Client) Wait(tx util.Uint256, vub uint32, err error) (*state.AppExecResult, error) {
	return c.act.Wait(tx, vub, err)
}

// ListNonEmptyGroups gets groups that contain at least one subject.
func (c Client) ListNonEmptyGroups(namespace string) ([]string, error) {
	groups, err := c.ListGroups(namespace)
	if err != nil {
		return nil, err
	}

	var res []string

	for _, group := range groups {
		groupExt, err := c.GetGroupExtended(namespace, group.Name)
		if err != nil {
			return nil, err
		}

		if groupExt.SubjectsCount > 0 {
			res = append(res, groupExt.Name)
		}
	}

	return res, nil
}

func unwrapArrayOfUint160(items []stackitem.Item, err error) ([]util.Uint160, error) {
	if err != nil {
		return nil, err
	}

	return unwrap.ArrayOfUint160(makeValidRes(stackitem.NewArray(items)))
}

func makeValidRes(item stackitem.Item) (*result.Invoke, error) {
	return &result.Invoke{
		Stack: []stackitem.Item{item},
		State: vmstate.Halt.String(),
	}, nil
}

func parseSubject(structArr []stackitem.Item) (*Subject, error) {
	if len(structArr) < 5 {
		return nil, errors.New("invalid response subject struct")
	}

	var (
		err  error
		subj Subject
	)

	subj.PrimaryKey, err = unwrap.PublicKey(makeValidRes(structArr[0]))
	if err != nil {
		return nil, err
	}

	if !structArr[1].Equals(stackitem.Null{}) {
		subj.AdditionalKeys, err = unwrap.ArrayOfPublicKeys(makeValidRes(structArr[1]))
		if err != nil {
			return nil, err
		}
	}

	if !structArr[2].Equals(stackitem.Null{}) {
		subj.Namespace, err = unwrap.UTF8String(makeValidRes(structArr[2]))
		if err != nil {
			return nil, err
		}
	}

	if !structArr[2].Equals(stackitem.Null{}) {
		subj.Name, err = unwrap.UTF8String(makeValidRes(structArr[3]))
		if err != nil {
			return nil, err
		}
	}

	subj.KV, err = parseMap(structArr[4])
	if err != nil {
		return nil, err
	}

	return &subj, nil
}

func parseSubjectExtended(structArr []stackitem.Item) (*SubjectExtended, error) {
	if len(structArr) < 6 {
		return nil, errors.New("invalid response subject extended struct")
	}

	var (
		err  error
		subj SubjectExtended
	)

	subj.PrimaryKey, err = unwrap.PublicKey(makeValidRes(structArr[0]))
	if err != nil {
		return nil, err
	}

	if !structArr[1].Equals(stackitem.Null{}) {
		subj.AdditionalKeys, err = unwrap.ArrayOfPublicKeys(makeValidRes(structArr[1]))
		if err != nil {
			return nil, err
		}
	}

	nsBytes, err := structArr[2].TryBytes()
	if err != nil {
		return nil, err
	}
	subj.Namespace = string(nsBytes)

	nameBytes, err := structArr[3].TryBytes()
	if err != nil {
		return nil, err
	}
	subj.Name = string(nameBytes)

	subj.KV, err = parseMap(structArr[4])
	if err != nil {
		return nil, err
	}

	if !structArr[5].Equals(stackitem.Null{}) {
		groupItems, ok := structArr[5].Value().([]stackitem.Item)
		if !ok {
			return nil, fmt.Errorf("invalid groups field")
		}

		subj.Groups, err = parseGroups(groupItems)
		if err != nil {
			return nil, err
		}
	}

	return &subj, nil
}

func parseMap(item stackitem.Item) (map[string]string, error) {
	if item.Equals(stackitem.Null{}) {
		return nil, nil
	}

	metaMap, err := unwrap.Map(makeValidRes(item))
	if err != nil {
		return nil, err
	}

	meta, ok := metaMap.Value().([]stackitem.MapElement)
	if !ok {
		return nil, errors.New("invalid map type")
	}

	res := make(map[string]string, len(meta))
	for _, element := range meta {
		key, err := element.Key.TryBytes()
		if err != nil {
			return nil, err
		}
		val, err := element.Value.TryBytes()
		if err != nil {
			return nil, err
		}
		res[string(key)] = string(val)
	}

	return res, nil
}

func parseNamespace(structArr []stackitem.Item) (*Namespace, error) {
	if len(structArr) < 1 {
		return nil, errors.New("invalid response namespace struct")
	}

	name, err := structArr[0].TryBytes()
	if err != nil {
		return nil, err
	}

	return &Namespace{Name: string(name)}, nil
}

func parseNamespaceExtended(structArr []stackitem.Item) (*NamespaceExtended, error) {
	if len(structArr) < 3 {
		return nil, errors.New("invalid response namespace extended struct")
	}

	name, err := structArr[0].TryBytes()
	if err != nil {
		return nil, err
	}

	groupCount, err := structArr[1].TryInteger()
	if err != nil {
		return nil, err
	}

	subjectCount, err := structArr[2].TryInteger()
	if err != nil {
		return nil, err
	}

	return &NamespaceExtended{
		Name:          string(name),
		GroupsCount:   groupCount.Int64(),
		SubjectsCount: subjectCount.Int64(),
	}, nil
}

func parseNamespaces(items []stackitem.Item) ([]*Namespace, error) {
	var err error
	res := make([]*Namespace, len(items))

	for i := 0; i < len(items); i++ {
		arr, ok := items[i].Value().([]stackitem.Item)
		if !ok {
			return nil, fmt.Errorf("invalid namespace type")
		}
		res[i], err = parseNamespace(arr)
		if err != nil {
			return nil, err
		}
	}

	return res, nil
}

func parseGroup(structArr []stackitem.Item) (*Group, error) {
	if len(structArr) < 2 {
		return nil, errors.New("invalid response group struct")
	}

	name, err := structArr[0].TryBytes()
	if err != nil {
		return nil, err
	}

	namespace, err := structArr[1].TryBytes()
	if err != nil {
		return nil, err
	}

	return &Group{
		Name:      string(name),
		Namespace: string(namespace),
	}, nil
}

func parseGroupExtended(structArr []stackitem.Item) (*GroupExtended, error) {
	if len(structArr) < 3 {
		return nil, errors.New("invalid response group extended struct")
	}

	name, err := structArr[0].TryBytes()
	if err != nil {
		return nil, err
	}

	namespace, err := structArr[1].TryBytes()
	if err != nil {
		return nil, err
	}

	subjectCount, err := structArr[2].TryInteger()
	if err != nil {
		return nil, err
	}

	return &GroupExtended{
		Name:          string(name),
		Namespace:     string(namespace),
		SubjectsCount: subjectCount.Int64(),
	}, nil
}

func parseGroups(items []stackitem.Item) ([]*Group, error) {
	var err error
	res := make([]*Group, len(items))

	for i := 0; i < len(items); i++ {
		arr, ok := items[i].Value().([]stackitem.Item)
		if !ok {
			return nil, fmt.Errorf("invalid group type")
		}
		res[i], err = parseGroup(arr)
		if err != nil {
			return nil, err
		}
	}

	return res, nil
}