import {
AssetProxyId,
ERC20AssetData,
ERC721AssetData,
MultiAssetData,
MultiAssetDataWithRecursiveDecoding,
SingleAssetData,
} from '@0x/types';
import { AbiEncoder, BigNumber } from '@0x/utils';
import * as _ from 'lodash';
import { constants } from './constants';
const encodingRules: AbiEncoder.EncodingRules = { shouldOptimize: true };
const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
export const assetDataUtils = {
/**
* Encodes an ERC20 token address into a hex encoded assetData string, usable in the makerAssetData or
* takerAssetData fields in a 0x order.
* @param tokenAddress The ERC20 token address to encode
* @return The hex encoded assetData string
*/
encodeERC20AssetData(tokenAddress: string): string {
const abiEncoder = new AbiEncoder.Method(constants.ERC20_METHOD_ABI);
const args = [tokenAddress];
const assetData = abiEncoder.encode(args, encodingRules);
return assetData;
},
/**
* Decodes an ERC20 assetData hex string into it's corresponding ERC20 tokenAddress & assetProxyId
* @param assetData Hex encoded assetData string to decode
* @return An object containing the decoded tokenAddress & assetProxyId
*/
decodeERC20AssetData(assetData: string): ERC20AssetData {
assetDataUtils.assertIsERC20AssetData(assetData);
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
const abiEncoder = new AbiEncoder.Method(constants.ERC20_METHOD_ABI);
const decodedAssetData = abiEncoder.decode(assetData, decodingRules);
return {
assetProxyId,
// TODO(abandeali1): fix return types for `AbiEncoder.Method.decode` so that we can remove type assertion
tokenAddress: (decodedAssetData as any).tokenContract,
};
},
/**
* Encodes an ERC721 token address into a hex encoded assetData string, usable in the makerAssetData or
* takerAssetData fields in a 0x order.
* @param tokenAddress The ERC721 token address to encode
* @param tokenId The ERC721 tokenId to encode
* @return The hex encoded assetData string
*/
encodeERC721AssetData(tokenAddress: string, tokenId: BigNumber): string {
const abiEncoder = new AbiEncoder.Method(constants.ERC721_METHOD_ABI);
const args = [tokenAddress, tokenId];
const assetData = abiEncoder.encode(args, encodingRules);
return assetData;
},
/**
* Decodes an ERC721 assetData hex string into it's corresponding ERC721 tokenAddress, tokenId & assetProxyId
* @param assetData Hex encoded assetData string to decode
* @return An object containing the decoded tokenAddress, tokenId & assetProxyId
*/
decodeERC721AssetData(assetData: string): ERC721AssetData {
assetDataUtils.assertIsERC721AssetData(assetData);
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
const abiEncoder = new AbiEncoder.Method(constants.ERC721_METHOD_ABI);
const decodedAssetData = abiEncoder.decode(assetData, decodingRules);
return {
assetProxyId,
// TODO(abandeali1): fix return types for `AbiEncoder.Method.decode` so that we can remove type assertion
tokenAddress: (decodedAssetData as any).tokenContract,
tokenId: (decodedAssetData as any).tokenId,
};
},
/**
* Encodes assetData for multiple AssetProxies into a single hex encoded assetData string, usable in the makerAssetData or
* takerAssetData fields in a 0x order.
* @param amounts Amounts of each asset that correspond to a single unit within an order.
* @param nestedAssetData assetData strings that correspond to a valid assetProxyId.
* @return The hex encoded assetData string
*/
encodeMultiAssetData(amounts: BigNumber[], nestedAssetData: string[]): string {
if (amounts.length !== nestedAssetData.length) {
throw new Error(
`Invalid MultiAsset arguments. Expected length of 'amounts' (${
amounts.length
}) to equal length of 'nestedAssetData' (${nestedAssetData.length})`,
);
}
_.forEach(nestedAssetData, assetDataElement => assetDataUtils.validateAssetDataOrThrow(assetDataElement));
const abiEncoder = new AbiEncoder.Method(constants.MULTI_ASSET_METHOD_ABI);
const args = [amounts, nestedAssetData];
const assetData = abiEncoder.encode(args, encodingRules);
return assetData;
},
/**
* Decodes a MultiAsset assetData hex string into it's corresponding amounts and nestedAssetData
* @param assetData Hex encoded assetData string to decode
* @return An object containing the decoded amounts and nestedAssetData
*/
decodeMultiAssetData(assetData: string): MultiAssetData {
assetDataUtils.assertIsMultiAssetData(assetData);
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
const abiEncoder = new AbiEncoder.Method(constants.MULTI_ASSET_METHOD_ABI);
const decodedAssetData = abiEncoder.decode(assetData, decodingRules);
// TODO(abandeali1): fix return types for `AbiEncoder.Method.decode` so that we can remove type assertion
const amounts = (decodedAssetData as any).amounts;
const nestedAssetData = (decodedAssetData as any).nestedAssetData;
if (amounts.length !== nestedAssetData.length) {
throw new Error(
`Invalid MultiAsset assetData. Expected length of 'amounts' (${
amounts.length
}) to equal length of 'nestedAssetData' (${nestedAssetData.length})`,
);
}
return {
assetProxyId,
amounts,
nestedAssetData,
};
},
/**
* Decodes a MultiAsset assetData hex string into it's corresponding amounts and decoded nestedAssetData elements (all nested elements are flattened)
* @param assetData Hex encoded assetData string to decode
* @return An object containing the decoded amounts and nestedAssetData
*/
decodeMultiAssetDataRecursively(assetData: string): MultiAssetDataWithRecursiveDecoding {
const decodedAssetData = assetDataUtils.decodeMultiAssetData(assetData);
const amounts: any[] = [];
const decodedNestedAssetData = _.map(
decodedAssetData.nestedAssetData as string[],
(nestedAssetDataElement, index) => {
const decodedNestedAssetDataElement = assetDataUtils.decodeAssetDataOrThrow(nestedAssetDataElement);
if (decodedNestedAssetDataElement.assetProxyId === AssetProxyId.MultiAsset) {
const recursivelyDecodedAssetData = assetDataUtils.decodeMultiAssetDataRecursively(
nestedAssetDataElement,
);
amounts.push(
_.map(recursivelyDecodedAssetData.amounts, amountElement =>
amountElement.times(decodedAssetData.amounts[index]),
),
);
return recursivelyDecodedAssetData.nestedAssetData;
} else {
amounts.push(decodedAssetData.amounts[index]);
return decodedNestedAssetDataElement as SingleAssetData;
}
},
);
const flattenedAmounts = _.flattenDeep(amounts);
const flattenedDecodedNestedAssetData = _.flattenDeep(decodedNestedAssetData);
return {
assetProxyId: decodedAssetData.assetProxyId,
amounts: flattenedAmounts,
// tslint:disable-next-line:no-unnecessary-type-assertion
nestedAssetData: flattenedDecodedNestedAssetData as SingleAssetData[],
};
},
/**
* Decode and return the assetProxyId from the assetData
* @param assetData Hex encoded assetData string to decode
* @return The assetProxyId
*/
decodeAssetProxyId(assetData: string): AssetProxyId {
if (assetData.length < constants.SELECTOR_CHAR_LENGTH_WITH_PREFIX) {
throw new Error(
`Could not decode assetData. Expected length of encoded data to be at least 10. Got ${
assetData.length
}`,
);
}
const assetProxyId = assetData.slice(0, constants.SELECTOR_CHAR_LENGTH_WITH_PREFIX);
if (
assetProxyId !== AssetProxyId.ERC20 &&
assetProxyId !== AssetProxyId.ERC721 &&
assetProxyId !== AssetProxyId.MultiAsset
) {
throw new Error(`Invalid assetProxyId: ${assetProxyId}`);
}
return assetProxyId;
},
/**
* Checks if the decoded asset data is valid ERC20 data
* @param decodedAssetData The decoded asset data to check
*/
isERC20AssetData(decodedAssetData: SingleAssetData | MultiAssetData): decodedAssetData is ERC20AssetData {
return decodedAssetData.assetProxyId === AssetProxyId.ERC20;
},
/**
* Checks if the decoded asset data is valid ERC721 data
* @param decodedAssetData The decoded asset data to check
*/
isERC721AssetData(decodedAssetData: SingleAssetData | MultiAssetData): decodedAssetData is ERC721AssetData {
return decodedAssetData.assetProxyId === AssetProxyId.ERC721;
},
/**
* Checks if the decoded asset data is valid MultiAsset data
* @param decodedAssetData The decoded asset data to check
*/
isMultiAssetData(decodedAssetData: SingleAssetData | MultiAssetData): decodedAssetData is MultiAssetData {
return decodedAssetData.assetProxyId === AssetProxyId.MultiAsset;
},
/**
* Throws if the length or assetProxyId are invalid for the ERC20Proxy.
* @param assetData Hex encoded assetData string
*/
assertIsERC20AssetData(assetData: string): void {
if (assetData.length < constants.ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
throw new Error(
`Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${
constants.ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
}. Got ${assetData.length}`,
);
}
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
if (assetProxyId !== AssetProxyId.ERC20) {
throw new Error(
`Could not decode ERC20 assetData. Expected assetProxyId to be ERC20 (${
AssetProxyId.ERC20
}), but got ${assetProxyId}`,
);
}
},
/**
* Throws if the length or assetProxyId are invalid for the ERC721Proxy.
* @param assetData Hex encoded assetData string
*/
assertIsERC721AssetData(assetData: string): void {
if (assetData.length < constants.ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
throw new Error(
`Could not decode ERC721 assetData. Expected length of encoded data to be at least ${
constants.ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
}. Got ${assetData.length}`,
);
}
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
if (assetProxyId !== AssetProxyId.ERC721) {
throw new Error(
`Could not decode ERC721 assetData. Expected assetProxyId to be ERC721 (${
AssetProxyId.ERC721
}), but got ${assetProxyId}`,
);
}
},
/**
* Throws if the length or assetProxyId are invalid for the MultiAssetProxy.
* @param assetData Hex encoded assetData string
*/
assertIsMultiAssetData(assetData: string): void {
if (assetData.length < constants.MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
throw new Error(
`Could not decode MultiAsset assetData. Expected length of encoded data to be at least ${
constants.MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
}. Got ${assetData.length}`,
);
}
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
if (assetProxyId !== AssetProxyId.MultiAsset) {
throw new Error(
`Could not decode MultiAsset assetData. Expected assetProxyId to be MultiAsset (${
AssetProxyId.MultiAsset
}), but got ${assetProxyId}`,
);
}
},
/**
* Throws if the length or assetProxyId are invalid for the corresponding AssetProxy.
* @param assetData Hex encoded assetData string
*/
validateAssetDataOrThrow(assetData: string): void {
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
switch (assetProxyId) {
case AssetProxyId.ERC20:
assetDataUtils.assertIsERC20AssetData(assetData);
break;
case AssetProxyId.ERC721:
assetDataUtils.assertIsERC721AssetData(assetData);
break;
case AssetProxyId.MultiAsset:
assetDataUtils.assertIsMultiAssetData(assetData);
break;
default:
throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
}
},
/**
* Decode any assetData into it's corresponding assetData object
* @param assetData Hex encoded assetData string to decode
* @return Either a ERC20 or ERC721 assetData object
*/
decodeAssetDataOrThrow(assetData: string): SingleAssetData | MultiAssetData {
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
switch (assetProxyId) {
case AssetProxyId.ERC20:
const erc20AssetData = assetDataUtils.decodeERC20AssetData(assetData);
return erc20AssetData;
case AssetProxyId.ERC721:
const erc721AssetData = assetDataUtils.decodeERC721AssetData(assetData);
return erc721AssetData;
case AssetProxyId.MultiAsset:
const multiAssetData = assetDataUtils.decodeMultiAssetData(assetData);
return multiAssetData;
default:
throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
}
},
};
