package params import ( "bytes" "encoding/base64" "encoding/hex" "encoding/json" "errors" "fmt" "math/big" "strconv" "strings" "github.com/google/uuid" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/encoding/address" "github.com/nspcc-dev/neo-go/pkg/neorpc" "github.com/nspcc-dev/neo-go/pkg/smartcontract" "github.com/nspcc-dev/neo-go/pkg/util" ) type ( // Param represents a param either passed to // the server or to be sent to a server using // the client. Param struct { json.RawMessage cache interface{} } // FuncParam represents a function argument parameter used in the // invokefunction RPC method. FuncParam struct { Type smartcontract.ParamType `json:"type"` Value Param `json:"value"` } ) var ( jsonNullBytes = []byte("null") jsonFalseBytes = []byte("false") jsonTrueBytes = []byte("true") errMissingParameter = errors.New("parameter is missing") errNotAString = errors.New("not a string") errNotAnInt = errors.New("not an integer") errNotABool = errors.New("not a boolean") errNotAnArray = errors.New("not an array") ) func (p Param) String() string { str, _ := p.GetString() return str } // GetStringStrict returns a string value of the parameter. func (p *Param) GetStringStrict() (string, error) { if p == nil { return "", errMissingParameter } if p.IsNull() { return "", errNotAString } if p.cache == nil { var s string err := json.Unmarshal(p.RawMessage, &s) if err != nil { return "", errNotAString } p.cache = s } if s, ok := p.cache.(string); ok { return s, nil } return "", errNotAString } // GetString returns a string value of the parameter or tries to cast the parameter to a string value. func (p *Param) GetString() (string, error) { if p == nil { return "", errMissingParameter } if p.IsNull() { return "", errNotAString } if p.cache == nil { var s string err := json.Unmarshal(p.RawMessage, &s) if err == nil { p.cache = s } else { var i int64 err = json.Unmarshal(p.RawMessage, &i) if err == nil { p.cache = i } else { var b bool err = json.Unmarshal(p.RawMessage, &b) if err == nil { p.cache = b } else { return "", errNotAString } } } } switch t := p.cache.(type) { case string: return t, nil case int64: return strconv.FormatInt(t, 10), nil case bool: if t { return "true", nil } return "false", nil default: return "", errNotAString } } // GetBooleanStrict returns boolean value of the parameter. func (p *Param) GetBooleanStrict() (bool, error) { if p == nil { return false, errMissingParameter } if bytes.Equal(p.RawMessage, jsonTrueBytes) { p.cache = true return true, nil } if bytes.Equal(p.RawMessage, jsonFalseBytes) { p.cache = false return false, nil } return false, errNotABool } // GetBoolean returns a boolean value of the parameter or tries to cast the parameter to a bool value. func (p *Param) GetBoolean() (bool, error) { if p == nil { return false, errMissingParameter } if p.IsNull() { return false, errNotABool } var b bool if p.cache == nil { err := json.Unmarshal(p.RawMessage, &b) if err == nil { p.cache = b } else { var s string err = json.Unmarshal(p.RawMessage, &s) if err == nil { p.cache = s } else { var i int64 err = json.Unmarshal(p.RawMessage, &i) if err == nil { p.cache = i } else { return false, errNotABool } } } } switch t := p.cache.(type) { case bool: return t, nil case string: return t != "", nil case int64: return t != 0, nil default: return false, errNotABool } } // GetIntStrict returns an int value of the parameter if the parameter is an integer. func (p *Param) GetIntStrict() (int, error) { if p == nil { return 0, errMissingParameter } if p.IsNull() { return 0, errNotAnInt } value, err := p.fillIntCache() if err != nil { return 0, err } if i, ok := value.(int64); ok && i == int64(int(i)) { return int(i), nil } return 0, errNotAnInt } func (p *Param) fillIntCache() (interface{}, error) { if p.cache != nil { return p.cache, nil } // We could also try unmarshalling to uint64, but JSON reliably supports numbers // up to 53 bits in size. var i int64 err := json.Unmarshal(p.RawMessage, &i) if err == nil { p.cache = i return i, nil } var s string err = json.Unmarshal(p.RawMessage, &s) if err == nil { p.cache = s return s, nil } var b bool err = json.Unmarshal(p.RawMessage, &b) if err == nil { p.cache = b return b, nil } return nil, errNotAnInt } // GetInt returns an int value of the parameter or tries to cast the parameter to an int value. func (p *Param) GetInt() (int, error) { if p == nil { return 0, errMissingParameter } if p.IsNull() { return 0, errNotAnInt } value, err := p.fillIntCache() if err != nil { return 0, err } switch t := value.(type) { case int64: if t == int64(int(t)) { return int(t), nil } return 0, errNotAnInt case string: return strconv.Atoi(t) case bool: if t { return 1, nil } return 0, nil default: panic("unreachable") } } // GetBigInt returns a big-integer value of the parameter. func (p *Param) GetBigInt() (*big.Int, error) { if p == nil { return nil, errMissingParameter } if p.IsNull() { return nil, errNotAnInt } value, err := p.fillIntCache() if err != nil { return nil, err } switch t := value.(type) { case int64: return big.NewInt(t), nil case string: bi, ok := new(big.Int).SetString(t, 10) if !ok { return nil, errNotAnInt } return bi, nil case bool: if t { return big.NewInt(1), nil } return new(big.Int), nil default: panic("unreachable") } } // GetArray returns a slice of Params stored in the parameter. func (p *Param) GetArray() ([]Param, error) { if p == nil { return nil, errMissingParameter } if p.IsNull() { return nil, errNotAnArray } if p.cache == nil { a := []Param{} err := json.Unmarshal(p.RawMessage, &a) if err != nil { return nil, errNotAnArray } p.cache = a } if a, ok := p.cache.([]Param); ok { return a, nil } return nil, errNotAnArray } // GetUint256 returns a Uint256 value of the parameter. func (p *Param) GetUint256() (util.Uint256, error) { s, err := p.GetString() if err != nil { return util.Uint256{}, err } return util.Uint256DecodeStringLE(strings.TrimPrefix(s, "0x")) } // GetUint160FromHex returns a Uint160 value of the parameter encoded in hex. func (p *Param) GetUint160FromHex() (util.Uint160, error) { s, err := p.GetString() if err != nil { return util.Uint160{}, err } return util.Uint160DecodeStringLE(strings.TrimPrefix(s, "0x")) } // GetUint160FromAddress returns a Uint160 value of the parameter that was // supplied as an address. func (p *Param) GetUint160FromAddress() (util.Uint160, error) { s, err := p.GetString() if err != nil { return util.Uint160{}, err } return address.StringToUint160(s) } // GetUint160FromAddressOrHex returns a Uint160 value of the parameter that was // supplied either as raw hex or as an address. func (p *Param) GetUint160FromAddressOrHex() (util.Uint160, error) { u, err := p.GetUint160FromHex() if err == nil { return u, err } return p.GetUint160FromAddress() } // GetFuncParam returns the current parameter as a function call parameter. func (p *Param) GetFuncParam() (FuncParam, error) { if p == nil { return FuncParam{}, errMissingParameter } // This one doesn't need to be cached, it's used only once. fp := FuncParam{} err := json.Unmarshal(p.RawMessage, &fp) return fp, err } // GetBytesHex returns a []byte value of the parameter if // it is a hex-encoded string. func (p *Param) GetBytesHex() ([]byte, error) { s, err := p.GetString() if err != nil { return nil, err } return hex.DecodeString(s) } // GetBytesBase64 returns a []byte value of the parameter if // it is a base64-encoded string. func (p *Param) GetBytesBase64() ([]byte, error) { s, err := p.GetString() if err != nil { return nil, err } return base64.StdEncoding.DecodeString(s) } // GetSignerWithWitness returns a neorpc.SignerWithWitness value of the parameter. func (p *Param) GetSignerWithWitness() (neorpc.SignerWithWitness, error) { // This one doesn't need to be cached, it's used only once. c := neorpc.SignerWithWitness{} err := json.Unmarshal(p.RawMessage, &c) if err != nil { return neorpc.SignerWithWitness{}, fmt.Errorf("not a signer: %w", err) } return c, nil } // GetSignersWithWitnesses returns a slice of SignerWithWitness with CalledByEntry // scope from an array of Uint160 or an array of serialized transaction.Signer stored // in the parameter. func (p Param) GetSignersWithWitnesses() ([]transaction.Signer, []transaction.Witness, error) { hashes, err := p.GetArray() if err != nil { return nil, nil, err } signers := make([]transaction.Signer, len(hashes)) witnesses := make([]transaction.Witness, len(hashes)) // try to extract hashes first for i, h := range hashes { var u util.Uint160 u, err = h.GetUint160FromHex() if err != nil { break } signers[i] = transaction.Signer{ Account: u, Scopes: transaction.CalledByEntry, } } if err != nil { for i, h := range hashes { signerWithWitness, err := h.GetSignerWithWitness() if err != nil { return nil, nil, err } signers[i] = signerWithWitness.Signer witnesses[i] = signerWithWitness.Witness } } return signers, witnesses, nil } // IsNull returns whether the parameter represents JSON nil value. func (p *Param) IsNull() bool { return bytes.Equal(p.RawMessage, jsonNullBytes) } // GetUUID returns UUID from parameter. func (p *Param) GetUUID() (uuid.UUID, error) { s, err := p.GetString() if err != nil { return uuid.UUID{}, err } id, err := uuid.Parse(s) if err != nil { return uuid.UUID{}, fmt.Errorf("not a valid UUID: %w", err) } return id, nil }