package nep11 import ( "fmt" "math/big" "github.com/google/uuid" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/neorpc/result" "github.com/nspcc-dev/neo-go/pkg/rpcclient/unwrap" "github.com/nspcc-dev/neo-go/pkg/util" ) // DivisibleReader is a reader interface for divisible NEP-11 contract. type DivisibleReader struct { BaseReader } // DivisibleWriter is a state-changing interface for divisible NEP-11 contract. // It's mostly useful not directly, but as a reusable layer for higher-level // structures. type DivisibleWriter struct { BaseWriter } // Divisible is a full reader interface for divisible NEP-11 contract. type Divisible struct { DivisibleReader DivisibleWriter } // OwnerIterator is used for iterating over OwnerOf (for divisible NFTs) results. type OwnerIterator struct { client Invoker session uuid.UUID iterator result.Iterator } // NewDivisibleReader creates an instance of DivisibleReader for a contract // with the given hash using the given invoker. func NewDivisibleReader(invoker Invoker, hash util.Uint160) *DivisibleReader { return &DivisibleReader{*NewBaseReader(invoker, hash)} } // NewDivisible creates an instance of Divisible for a contract // with the given hash using the given actor. func NewDivisible(actor Actor, hash util.Uint160) *Divisible { return &Divisible{*NewDivisibleReader(actor, hash), DivisibleWriter{BaseWriter{hash, actor}}} } // OwnerOf returns returns an iterator that allows to walk through all owners of // the given token. It depends on the server to provide proper session-based // iterator, but can also work with expanded one. func (t *DivisibleReader) OwnerOf(token []byte) (*OwnerIterator, error) { sess, iter, err := unwrap.SessionIterator(t.invoker.Call(t.hash, "ownerOf", token)) if err != nil { return nil, err } return &OwnerIterator{t.invoker, sess, iter}, nil } // OwnerOfExpanded uses the same NEP-11 method as OwnerOf, but can be useful if // the server used doesn't support sessions and doesn't expand iterators. It // creates a script that will get num of result items from the iterator right in // the VM and return them to you. It's only limited by VM stack and GAS available // for RPC invocations. func (t *DivisibleReader) OwnerOfExpanded(token []byte, num int) ([]util.Uint160, error) { return unwrap.ArrayOfUint160(t.invoker.CallAndExpandIterator(t.hash, "ownerOf", num, token)) } // BalanceOfD is a BalanceOf for divisible NFTs, it returns the amount of token // owned by a particular account. func (t *DivisibleReader) BalanceOfD(owner util.Uint160, token []byte) (*big.Int, error) { return unwrap.BigInt(t.invoker.Call(t.hash, "balanceOf", owner, token)) } // TransferD is a divisible version of (*Base).Transfer, allowing to transfer a // part of NFT. It creates and sends a transaction that performs a `transfer` // method call using the given parameters and checks for this call result, // failing the transaction if it's not true. The returned values are transaction // hash, its ValidUntilBlock value and an error if any. func (t *DivisibleWriter) TransferD(from util.Uint160, to util.Uint160, amount *big.Int, id []byte, data interface{}) (util.Uint256, uint32, error) { script, err := t.transferScript(from, to, amount, id, data) if err != nil { return util.Uint256{}, 0, err } return t.actor.SendRun(script) } // TransferDTransaction is a divisible version of (*Base).TransferTransaction, // allowing to transfer a part of NFT. It creates a transaction that performs a // `transfer` method call using the given parameters and checks for this call // result, failing the transaction if it's not true. This transaction is signed, // but not sent to the network, instead it's returned to the caller. func (t *DivisibleWriter) TransferDTransaction(from util.Uint160, to util.Uint160, amount *big.Int, id []byte, data interface{}) (*transaction.Transaction, error) { script, err := t.transferScript(from, to, amount, id, data) if err != nil { return nil, err } return t.actor.MakeRun(script) } // TransferDUnsigned is a divisible version of (*Base).TransferUnsigned, // allowing to transfer a part of NFT. It creates a transaction that performs a // `transfer` method call using the given parameters and checks for this call // result, failing the transaction if it's not true. This transaction is not // signed and just returned to the caller. func (t *DivisibleWriter) TransferDUnsigned(from util.Uint160, to util.Uint160, amount *big.Int, id []byte, data interface{}) (*transaction.Transaction, error) { script, err := t.transferScript(from, to, amount, id, data) if err != nil { return nil, err } return t.actor.MakeUnsignedRun(script, nil) } // Next returns the next set of elements from the iterator (up to num of them). // It can return less than num elements in case iterator doesn't have that many // or zero elements if the iterator has no more elements or the session is // expired. func (v *OwnerIterator) Next(num int) ([]util.Uint160, error) { items, err := v.client.TraverseIterator(v.session, &v.iterator, num) if err != nil { return nil, err } res := make([]util.Uint160, len(items)) for i := range items { b, err := items[i].TryBytes() if err != nil { return nil, fmt.Errorf("element %d is not a byte string: %w", i, err) } u, err := util.Uint160DecodeBytesBE(b) if err != nil { return nil, fmt.Errorf("element %d is not a uint160: %w", i, err) } res[i] = u } return res, nil } // Terminate closes the iterator session used by OwnerIterator (if it's // session-based). func (v *OwnerIterator) Terminate() error { if v.iterator.ID == nil { return nil } return v.client.TerminateSession(v.session) }