import { keccak256 } from "ethereumjs-util";

import { getPackageJson } from "../../../util/packageInfo";
import { MethodNotFoundError } from "../errors";
import { rpcData, validateParams } from "../input";
import { bufferToRpcData } from "../output";

// tslint:disable only-buidler-error

export class Web3Module {
  public async processRequest(
    method: string,
    params: any[] = []
  ): Promise<any> {
    switch (method) {
      case "web3_clientVersion":
        return this._clientVersionAction(...this._clientVersionParams(params));

      case "web3_sha3":
        return this._sha3Action(...this._sha3Params(params));
    }

    throw new MethodNotFoundError(`Method ${method} not found`);
  }

  // web3_clientVersion

  private _clientVersionParams(params: any[]): [] {
    return validateParams(params);
  }

  private async _clientVersionAction(): Promise<string> {
    // TODO: This is a temporal fix because of https://github.com/OpenZeppelin/openzeppelin-test-helpers/pull/73
    return "EthereumJS TestRPC/v2.8.0/ethereum-js";

    // const buidlerPackage = await getPackageJson();
    // const ethereumjsVMPackage = require("@nomiclabs/ethereumjs-vm/package.json");
    // return `BuidlerEVM/${buidlerPackage.version}/ethereumjs-vm/${ethereumjsVMPackage.version}`;
  }

  // web3_sha3

  private _sha3Params(params: any[]): [Buffer] {
    return validateParams(params, rpcData);
  }

  private async _sha3Action(buffer: Buffer): Promise<string> {
    return bufferToRpcData(keccak256(buffer));
  }
}