import { DataItem, MethodAbi } from 'ethereum-types';
import * as ethUtil from 'ethereumjs-util';
import * as _ from 'lodash';
import { AbstractDataTypes, DataType, DataTypeFactory } from '../abstract_data_types';
import * as Constants from '../utils/constants';
import { DecodingRules, EncodingRules } from '../utils/rules';
import { Tuple } from './tuple';
export class Method extends AbstractDataTypes.Set {
private readonly _methodSignature: string;
private readonly _methodSelector: string;
private readonly _returnDataType: DataType;
public constructor(abi: MethodAbi, dataTypeFactory: DataTypeFactory) {
const methodDataItem = { type: 'method', name: abi.name, components: abi.inputs };
super(methodDataItem, dataTypeFactory);
this._methodSignature = this._computeSignature();
this._methodSelector = this._computeSelector();
const returnDataItem: DataItem = { type: 'tuple', name: abi.name, components: abi.outputs };
this._returnDataType = new Tuple(returnDataItem, this.getFactory());
}
public encode(value: any, rules?: EncodingRules): string {
const calldata = super.encode(value, rules, this._methodSelector);
return calldata;
}
public decode(calldata: string, rules?: DecodingRules): any[] | object {
const value = super.decode(calldata, rules, this._methodSelector);
return value;
}
public encodeReturnValues(value: any, rules?: EncodingRules): string {
const returnData = this._returnDataType.encode(value, rules);
return returnData;
}
public decodeReturnValues(returndata: string, rules?: DecodingRules): any {
const returnValues = this._returnDataType.decode(returndata, rules);
return returnValues;
}
public getSignature(): string {
return this._methodSignature;
}
public getSelector(): string {
return this._methodSelector;
}
private _computeSignature(): string {
const memberSignature = this._computeSignatureOfMembers();
const methodSignature = `${this.getDataItem().name}${memberSignature}`;
return methodSignature;
}
private _computeSelector(): string {
const signature = this._computeSignature();
const selector = ethUtil.bufferToHex(
ethUtil.toBuffer(
ethUtil
.sha3(signature)
.slice(Constants.HEX_SELECTOR_BYTE_OFFSET_IN_CALLDATA, Constants.HEX_SELECTOR_LENGTH_IN_BYTES),
),
);
return selector;
}
}