MyCrypto/common/libs/contracts/index.ts

import AbiFunction, { IUserSendParams, ISendParams } from './ABIFunction';
import { IFullWallet } from 'libs/wallet/IWallet';
import { RPCNode } from 'libs/nodes';
import { ContractOutputMappings } from './types';
import { Wei } from 'libs/units';

const ABIFUNC_METHOD_NAMES = [
  'encodeInput',
  'decodeInput',
  'decodeOutput',
  'call'
];

export interface ISetConfigForTx {
  wallet: IFullWallet;
  nodeLib: RPCNode;
  chainId: number;
  gasPrice: Wei;
}

enum ABIMethodTypes {
  FUNC = 'function'
}

export type TContract = typeof Contract;

export default class Contract {
  public static setConfigForTx = (
    contract: Contract,
    { wallet, nodeLib, chainId, gasPrice }: ISetConfigForTx
  ): Contract =>
    contract
      .setWallet(wallet)
      .setNode(nodeLib)
      .setChainId(chainId)
      .setGasPrice(gasPrice);

  public static getFunctions = (contract: Contract) =>
    Object.getOwnPropertyNames(contract).reduce(
      (accu, currContractMethodName) => {
        const currContractMethod = contract[currContractMethodName];
        const methodNames = Object.getOwnPropertyNames(currContractMethod);

        const isFunc = ABIFUNC_METHOD_NAMES.reduce(
          (isAbiFunc, currAbiFuncMethodName) =>
            isAbiFunc && methodNames.includes(currAbiFuncMethodName),
          true
        );
        return isFunc
          ? { ...accu, [currContractMethodName]: currContractMethod }
          : accu;
      },
      {}
    );

  public address: string;
  public abi;
  private wallet: IFullWallet;
  private gasPrice: Wei;
  private chainId: number;
  private node: RPCNode;

  constructor(abi, outputMappings: ContractOutputMappings = {}) {
    this.assignABIFuncs(abi, outputMappings);
  }

  public at = (addr: string) => {
    this.address = addr;
    return this;
  };

  public setWallet = (w: IFullWallet) => {
    this.wallet = w;
    return this;
  };

  public setGasPrice = (gasPrice: Wei) => {
    this.gasPrice = gasPrice;
    return this;
  };

  public setChainId = (chainId: number) => {
    this.chainId = chainId;
    return this;
  };
  public setNode = (node: RPCNode) => {
    //TODO: caching
    this.node = node;
    return this;
  };

  private assignABIFuncs = (abi, outputMappings: ContractOutputMappings) => {
    abi.forEach(currentABIMethod => {
      const { name, type } = currentABIMethod;
      if (type === ABIMethodTypes.FUNC) {
        //only grab the functions we need
        const {
          encodeInput,
          decodeInput,
          decodeOutput,
          call,
          send,
          constant,
          outputs,
          inputs
        } = new AbiFunction(currentABIMethod, outputMappings[name]);

        const proxiedCall = new Proxy(call, {
          apply: this.applyTrapForCall
        });

        const proxiedSend = new Proxy(send, { apply: this.applyTrapForSend });

        const funcToAssign = {
          [name]: {
            encodeInput,
            decodeInput,
            decodeOutput,
            call: proxiedCall,
            send: proxiedSend,
            constant,
            outputs,
            inputs
          }
        };
        Object.assign(this, funcToAssign);
      }
    });
  };

  private applyTrapForCall = (target, _, argumentsList) => {
    return target(
      //TODO: pass object instead
      ...(argumentsList.length > 0 ? argumentsList : [null]),
      this.node,
      this.address
    );
  };

  private applyTrapForSend = (
    target: (sendParams: ISendParams) => void,
    _,
    [userSendParams]: [IUserSendParams]
  ) => {
    return target({
      chainId: this.chainId,
      gasPrice: this.gasPrice,
      to: this.address,
      nodeLib: this.node,
      wallet: this.wallet,
      ...userSendParams
    });
  };
}