import { IExtrinsic } from '@polkadot/types/types';
import { compactToU8a, stringToU8a } from '@polkadot/util';
import { blake2AsHex } from '@polkadot/util-crypto';
import BN from 'bn.js';
import fs from 'fs';
import { decodeAddress } from '@polkadot/keyring';
import { Seat } from '@constantinople/types/council';

export class Utils {
  private static LENGTH_ADDRESS = 32 + 1; // publicKey + prefix
  private static LENGTH_ERA = 2; // assuming mortals
  private static LENGTH_SIGNATURE = 64; // assuming ed25519 or sr25519
  private static LENGTH_VERSION = 1; // 0x80 & version

  public static calcTxLength = (extrinsic?: IExtrinsic | null, nonce?: BN): BN => {
    return new BN(
      Utils.LENGTH_VERSION +
        Utils.LENGTH_ADDRESS +
        Utils.LENGTH_SIGNATURE +
        Utils.LENGTH_ERA +
        compactToU8a(nonce || 0).length +
        (extrinsic ? extrinsic.encodedLength : 0)
    );
  };

  /** hash(accountId + salt) */
  public static hashVote(accountId: string, salt: string): string {
    const accountU8a = decodeAddress(accountId);
    const saltU8a = stringToU8a(salt);
    const voteU8a = new Uint8Array(accountU8a.length + saltU8a.length);
    voteU8a.set(accountU8a);
    voteU8a.set(saltU8a, accountU8a.length);

    const hash = blake2AsHex(voteU8a, 256);
    // console.log('Vote hash:', hash, 'for', { accountId, salt });
    return hash;
  }

  public static wait(ms: number): Promise<void> {
    return new Promise(resolve => setTimeout(resolve, ms));
  }

  public static getTotalStake(seat: Seat): BN {
    return new BN(+seat.stake.toString() + seat.backers.reduce((a, baker) => a + +baker.stake.toString(), 0));
  }

  public static readRuntimeFromFile(path: string): string {
    return '0x' + fs.readFileSync(path).toString('hex');
  }
}