import { Address } from "@celo/utils/lib/address";
import invariant from "tiny-invariant";
import { TransactionReceipt } from "web3-core";
import { Contract, ContractOptions } from "web3-eth-contract";
import { AbiItem } from "web3-utils";

import { Wallet } from "../wallet";

type MethodSignature = (...params: any[]) => {
  call: (
    config: any,
    callback?: (err: any, result: any) => void
  ) => Promise<any>;
  send: (
    config: any,
    callback?: (err: any, result: any) => void
  ) => Promise<TransactionReceipt>;
  estimateGas: (
    config: any,
    callback?: (err: any, gasAmount: number) => void
  ) => Promise<number>;
  encodeABI: () => string;
};

interface MethodsType {
  [method: string]: MethodSignature;
}

// Wrap the send function to route through the wallet object
function wrapSend(
  method: MethodSignature,
  wallet: Wallet,
  contractAddress: Address
): MethodSignature {
  return (...params: any[]) => {
    const result = method(...params);
    const send = async (
      config: any,
      callback?: (err: any, result: any) => void
    ) => {
      const abi = result.encodeABI();
      const gas = await result.estimateGas({ from: wallet.address, ...config });

      try {
        const receipt = await wallet.signAndSendTransaction([
          {
            to: contractAddress,
            data: abi,
            from: wallet.address,
            gas,
          },
        ]);
        if (callback) callback(null, receipt);
        return receipt;
      } catch (e) {
        if (callback) callback(e, null);
        invariant(false, e as unknown as string);
      }
    };
    return {
      ...result,
      send,
    };
  };
}

export class NodeContract extends Contract {
  constructor(
    abi: AbiItem[],
    private address: string,
    private wallet: Wallet,
    options?: ContractOptions
  ) {
    super(abi, address, options);
    this.methods = Object.entries(super.methods).reduce(
      (accum: MethodsType, [method, func]) => ({
        ...accum,
        [method]: wrapSend(func as MethodSignature, this.wallet, this.address),
      }),
      {}
    );
  }
}