package request import ( "bytes" "encoding/base64" "encoding/hex" "encoding/json" "errors" "fmt" "strconv" "strings" "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/smartcontract" "github.com/nspcc-dev/neo-go/pkg/util" ) type ( // Param represents a param either passed to // the server or to send to a server using // the client. Param struct { Type paramType Value interface{} } paramType int // FuncParam represents a function argument parameter used in the // invokefunction RPC method. FuncParam struct { Type smartcontract.ParamType `json:"type"` Value Param `json:"value"` } // BlockFilter is a wrapper structure for block event filter. The only // allowed filter is primary index. BlockFilter struct { Primary int `json:"primary"` } // TxFilter is a wrapper structure for transaction event filter. It // allows to filter transactions by senders and signers. TxFilter struct { Sender *util.Uint160 `json:"sender,omitempty"` Signer *util.Uint160 `json:"signer,omitempty"` } // NotificationFilter is a wrapper structure representing filter used for // notifications generated during transaction execution. Notifications can // be filtered by contract hash and by name. NotificationFilter struct { Contract *util.Uint160 `json:"contract,omitempty"` Name *string `json:"name,omitempty"` } // ExecutionFilter is a wrapper structure used for transaction execution // events. It allows to choose failing or successful transactions based // on their VM state. ExecutionFilter struct { State string `json:"state"` } ) // These are parameter types accepted by RPC server. const ( defaultT paramType = iota StringT NumberT ArrayT FuncParamT BlockFilterT TxFilterT NotificationFilterT ExecutionFilterT Signer ) var errMissingParameter = errors.New("parameter is missing") func (p Param) String() string { return fmt.Sprintf("%v", p.Value) } // GetString returns string value of the parameter. func (p *Param) GetString() (string, error) { if p == nil { return "", errMissingParameter } str, ok := p.Value.(string) if !ok { return "", errors.New("not a string") } return str, nil } // GetBoolean returns boolean value of the parameter. func (p *Param) GetBoolean() bool { if p == nil { return false } switch p.Type { case NumberT: return p.Value != 0 case StringT: return p.Value != "" default: return true } } // GetInt returns int value of te parameter. func (p *Param) GetInt() (int, error) { if p == nil { return 0, errMissingParameter } i, ok := p.Value.(int) if ok { return i, nil } else if s, ok := p.Value.(string); ok { return strconv.Atoi(s) } return 0, errors.New("not an integer") } // GetArray returns a slice of Params stored in the parameter. func (p *Param) GetArray() ([]Param, error) { if p == nil { return nil, errMissingParameter } a, ok := p.Value.([]Param) if !ok { return nil, errors.New("not an array") } return a, nil } // GetUint256 returns 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 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 } if len(s) == 2*util.Uint160Size+2 && s[0] == '0' && s[1] == 'x' { s = s[2:] } return util.Uint160DecodeStringLE(s) } // GetUint160FromAddress returns 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 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 current parameter as a function call parameter. func (p *Param) GetFuncParam() (FuncParam, error) { if p == nil { return FuncParam{}, errMissingParameter } fp, ok := p.Value.(FuncParam) if !ok { return FuncParam{}, errors.New("not a function parameter") } return fp, nil } // GetBytesHex returns []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 []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) } // GetSigner returns transaction.Signer value of the parameter. func (p Param) GetSigner() (transaction.Signer, error) { c, ok := p.Value.(transaction.Signer) if !ok { return transaction.Signer{}, errors.New("not a signer") } return c, nil } // GetSigners returns a slice of transaction.Signer with global scope from // array of Uint160 or array of serialized transaction.Signer stored in the // parameter. func (p Param) GetSigners() ([]transaction.Signer, error) { hashes, err := p.GetArray() if err != nil { return nil, err } signers := make([]transaction.Signer, 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.Global, } } if err != nil { for i, h := range hashes { signers[i], err = h.GetSigner() if err != nil { return nil, err } } } return signers, nil } // UnmarshalJSON implements json.Unmarshaler interface. func (p *Param) UnmarshalJSON(data []byte) error { var s string var num float64 // To unmarshal correctly we need to pass pointers into the decoder. var attempts = [...]Param{ {NumberT, &num}, {StringT, &s}, {FuncParamT, &FuncParam{}}, {BlockFilterT, &BlockFilter{}}, {TxFilterT, &TxFilter{}}, {NotificationFilterT, &NotificationFilter{}}, {ExecutionFilterT, &ExecutionFilter{}}, {Signer, &transaction.Signer{}}, {ArrayT, &[]Param{}}, } if bytes.Equal(data, []byte("null")) { p.Type = defaultT return nil } for _, cur := range attempts { r := bytes.NewReader(data) jd := json.NewDecoder(r) jd.DisallowUnknownFields() if err := jd.Decode(cur.Value); err == nil { p.Type = cur.Type // But we need to store actual values, not pointers. switch val := cur.Value.(type) { case *float64: p.Value = int(*val) case *string: p.Value = *val case *FuncParam: p.Value = *val case *BlockFilter: p.Value = *val case *TxFilter: p.Value = *val case *NotificationFilter: p.Value = *val case *ExecutionFilter: if (*val).State == "HALT" || (*val).State == "FAULT" { p.Value = *val } else { continue } case *transaction.Signer: p.Value = *val case *[]Param: p.Value = *val } return nil } } return errors.New("unknown type") }