@polkadot/types/ethereum/LookupSource.js

// Copyright 2017-2023 @polkadot/types authors & contributors
// SPDX-License-Identifier: Apache-2.0

import { AbstractBase } from '@polkadot/types-codec';
import { isBigInt, isBn, isHex, isNumber, isU8a, u8aConcat, u8aToBn, u8aToHex, u8aToU8a } from '@polkadot/util';
import { decodeAddress } from '@polkadot/util-crypto';
import { GenericAccountIndex } from "../generic/AccountIndex.js";
import { GenericEthereumAccountId } from "./AccountId.js";

// eslint-disable-next-line no-use-before-define

export const ACCOUNT_ID_PREFIX = new Uint8Array([0xff]);

/** @internal */
function decodeString(registry, value) {
  const decoded = decodeAddress(value);
  return decoded.length === 20 ? registry.createTypeUnsafe('EthereumAccountId', [decoded]) : registry.createTypeUnsafe('AccountIndex', [u8aToBn(decoded)]);
}

/** @internal */
function decodeU8a(registry, value) {
  // This allows us to instantiate an address with a raw publicKey. Do this first before
  // we checking the first byte, otherwise we may split an already-existent valid address
  if (value.length === 20) {
    return registry.createTypeUnsafe('EthereumAccountId', [value]);
  } else if (value[0] === 0xff) {
    return registry.createTypeUnsafe('EthereumAccountId', [value.subarray(1)]);
  }
  const [offset, length] = GenericAccountIndex.readLength(value);
  return registry.createTypeUnsafe('AccountIndex', [u8aToBn(value.subarray(offset, offset + length))]);
}
function decodeAddressOrIndex(registry, value) {
  return value instanceof GenericEthereumLookupSource ? value.inner : value instanceof GenericEthereumAccountId || value instanceof GenericAccountIndex ? value : isU8a(value) || Array.isArray(value) || isHex(value) ? decodeU8a(registry, u8aToU8a(value)) : isBn(value) || isNumber(value) || isBigInt(value) ? registry.createTypeUnsafe('AccountIndex', [value]) : decodeString(registry, value);
}

/**
 * @name GenericEthereumLookupSource
 * @description
 * A wrapper around an EthereumAccountId and/or AccountIndex that is encoded with a prefix.
 * Since we are dealing with underlying publicKeys (or shorter encoded addresses),
 * we extend from Base with an AccountId/AccountIndex wrapper. Basically the Address
 * is encoded as `[ <prefix-byte>, ...publicKey/...bytes ]` as per spec
 */
export class GenericEthereumLookupSource extends AbstractBase {
  constructor(registry, value = new Uint8Array()) {
    super(registry, decodeAddressOrIndex(registry, value));
  }

  /**
   * @description The length of the value when encoded as a Uint8Array
   */
  get encodedLength() {
    const rawLength = this._rawLength;
    return rawLength + (
    // for 1 byte AccountIndexes, we are not adding a specific prefix
    rawLength > 1 ? 1 : 0);
  }

  /**
   * @description The length of the raw value, either AccountIndex or AccountId
   */
  get _rawLength() {
    return this.inner instanceof GenericAccountIndex ? GenericAccountIndex.calcLength(this.inner) : this.inner.encodedLength;
  }

  /**
   * @description Returns a hex string representation of the value
   */
  toHex() {
    return u8aToHex(this.toU8a());
  }

  /**
   * @description Returns the base runtime type name for this instance
   */
  toRawType() {
    return 'Address';
  }

  /**
   * @description Encodes the value as a Uint8Array as per the SCALE specifications
   * @param isBare true when the value has none of the type-specific prefixes (internal)
   */
  toU8a(isBare) {
    const encoded = this.inner.toU8a().subarray(0, this._rawLength);
    return isBare ? encoded : u8aConcat(this.inner instanceof GenericAccountIndex ? GenericAccountIndex.writeLength(encoded) : ACCOUNT_ID_PREFIX, encoded);
  }
}