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import { assetDataUtils } from '@0xproject/order-utils';
import { AssetProxyId } from '@0xproject/types';
import { BigNumber, errorUtils } from '@0xproject/utils';
import * as _ from 'lodash';
import { AbstractAssetWrapper } from './abstract_asset_wrapper';
import { constants } from './constants';
import { ERC20Wrapper } from './erc20_wrapper';
import { ERC721Wrapper } from './erc721_wrapper';
interface ProxyIdToAssetWrappers {
[proxyId: string]: AbstractAssetWrapper;
}
/**
* This class abstracts away the differences between ERC20 and ERC721 tokens so that
* the logic that uses it does not need to care what standard a token belongs to.
*/
export class AssetWrapper {
private readonly _proxyIdToAssetWrappers: ProxyIdToAssetWrappers;
constructor(assetWrappers: AbstractAssetWrapper[]) {
this._proxyIdToAssetWrappers = {};
_.each(assetWrappers, assetWrapper => {
const proxyId = assetWrapper.getProxyId();
this._proxyIdToAssetWrappers[proxyId] = assetWrapper;
});
}
public async getBalanceAsync(userAddress: string, assetData: string): Promise<BigNumber> {
const proxyId = assetDataUtils.decodeAssetProxyId(assetData);
switch (proxyId) {
case AssetProxyId.ERC20: {
const erc20Wrapper = this._proxyIdToAssetWrappers[proxyId] as ERC20Wrapper;
const balance = await erc20Wrapper.getBalanceAsync(userAddress, assetData);
return balance;
}
case AssetProxyId.ERC721: {
const assetWrapper = this._proxyIdToAssetWrappers[proxyId] as ERC721Wrapper;
const assetProxyData = assetDataUtils.decodeERC721AssetData(assetData);
const isOwner = await assetWrapper.isOwnerAsync(
userAddress,
assetProxyData.tokenAddress,
assetProxyData.tokenId,
);
const balance = isOwner ? new BigNumber(1) : new BigNumber(0);
return balance;
}
default:
throw errorUtils.spawnSwitchErr('proxyId', proxyId);
}
}
public async setBalanceAsync(userAddress: string, assetData: string, desiredBalance: BigNumber): Promise<void> {
const proxyId = assetDataUtils.decodeAssetProxyId(assetData);
switch (proxyId) {
case AssetProxyId.ERC20: {
const erc20Wrapper = this._proxyIdToAssetWrappers[proxyId] as ERC20Wrapper;
await erc20Wrapper.setBalanceAsync(userAddress, assetData, desiredBalance);
return;
}
case AssetProxyId.ERC721: {
if (!desiredBalance.eq(0) && !desiredBalance.eq(1)) {
throw new Error(`Balance for ERC721 token can only be set to 0 or 1. Got: ${desiredBalance}`);
}
const erc721Wrapper = this._proxyIdToAssetWrappers[proxyId] as ERC721Wrapper;
const assetProxyData = assetDataUtils.decodeERC721AssetData(assetData);
const doesTokenExist = erc721Wrapper.doesTokenExistAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
);
if (!doesTokenExist && desiredBalance.eq(1)) {
await erc721Wrapper.mintAsync(assetProxyData.tokenAddress, assetProxyData.tokenId, userAddress);
return;
} else if (!doesTokenExist && desiredBalance.eq(0)) {
return; // noop
}
const tokenOwner = await erc721Wrapper.ownerOfAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
);
if (userAddress !== tokenOwner && desiredBalance.eq(1)) {
await erc721Wrapper.transferFromAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
tokenOwner,
userAddress,
);
} else if (tokenOwner === userAddress && desiredBalance.eq(0)) {
// Transfer token to someone else
const userAddresses = await (erc721Wrapper as any)._web3Wrapper.getAvailableAddressesAsync();
const nonOwner = _.find(userAddresses, a => a !== userAddress);
await erc721Wrapper.transferFromAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
tokenOwner,
nonOwner,
);
return;
} else if (
(userAddress !== tokenOwner && desiredBalance.eq(0)) ||
(tokenOwner === userAddress && desiredBalance.eq(1))
) {
return; // noop
}
break;
}
default:
throw errorUtils.spawnSwitchErr('proxyId', proxyId);
}
}
public async getProxyAllowanceAsync(userAddress: string, assetData: string): Promise<BigNumber> {
const proxyId = assetDataUtils.decodeAssetProxyId(assetData);
switch (proxyId) {
case AssetProxyId.ERC20: {
const erc20Wrapper = this._proxyIdToAssetWrappers[proxyId] as ERC20Wrapper;
const allowance = await erc20Wrapper.getProxyAllowanceAsync(userAddress, assetData);
return allowance;
}
case AssetProxyId.ERC721: {
const assetWrapper = this._proxyIdToAssetWrappers[proxyId] as ERC721Wrapper;
const erc721ProxyData = assetDataUtils.decodeERC721AssetData(assetData);
const isProxyApprovedForAll = await assetWrapper.isProxyApprovedForAllAsync(
userAddress,
erc721ProxyData.tokenAddress,
);
if (isProxyApprovedForAll) {
return constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS;
}
const isProxyApproved = await assetWrapper.isProxyApprovedAsync(
erc721ProxyData.tokenAddress,
erc721ProxyData.tokenId,
);
const allowance = isProxyApproved ? new BigNumber(1) : new BigNumber(0);
return allowance;
}
default:
throw errorUtils.spawnSwitchErr('proxyId', proxyId);
}
}
public async setProxyAllowanceAsync(
userAddress: string,
assetData: string,
desiredAllowance: BigNumber,
): Promise<void> {
const proxyId = assetDataUtils.decodeAssetProxyId(assetData);
switch (proxyId) {
case AssetProxyId.ERC20: {
const erc20Wrapper = this._proxyIdToAssetWrappers[proxyId] as ERC20Wrapper;
await erc20Wrapper.setAllowanceAsync(userAddress, assetData, desiredAllowance);
return;
}
case AssetProxyId.ERC721: {
if (
!desiredAllowance.eq(0) &&
!desiredAllowance.eq(1) &&
!desiredAllowance.eq(constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS)
) {
throw new Error(
`Allowance for ERC721 token can only be set to 0, 1 or 2^256-1. Got: ${desiredAllowance}`,
);
}
const erc721Wrapper = this._proxyIdToAssetWrappers[proxyId] as ERC721Wrapper;
const assetProxyData = assetDataUtils.decodeERC721AssetData(assetData);
const doesTokenExist = await erc721Wrapper.doesTokenExistAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
);
if (!doesTokenExist) {
throw new Error(
`Cannot setProxyAllowance on non-existent token: ${assetProxyData.tokenAddress} ${
assetProxyData.tokenId
}`,
);
}
const isProxyApprovedForAll = await erc721Wrapper.isProxyApprovedForAllAsync(
userAddress,
assetProxyData.tokenAddress,
);
if (!isProxyApprovedForAll && desiredAllowance.eq(constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS)) {
const isApproved = true;
await erc721Wrapper.approveProxyForAllAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
isApproved,
);
} else if (isProxyApprovedForAll && desiredAllowance.eq(0)) {
const isApproved = false;
await erc721Wrapper.approveProxyForAllAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
isApproved,
);
} else if (isProxyApprovedForAll && desiredAllowance.eq(constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS)) {
return; // Noop
}
const isProxyApproved = await erc721Wrapper.isProxyApprovedAsync(
assetProxyData.tokenAddress,
assetProxyData.tokenId,
);
if (!isProxyApproved && desiredAllowance.eq(1)) {
await erc721Wrapper.approveProxyAsync(assetProxyData.tokenAddress, assetProxyData.tokenId);
} else if (isProxyApproved && desiredAllowance.eq(0)) {
// Remove approval
await erc721Wrapper.approveAsync(
constants.NULL_ADDRESS,
assetProxyData.tokenAddress,
assetProxyData.tokenId,
);
} else if (
(!isProxyApproved && desiredAllowance.eq(0)) ||
(isProxyApproved && desiredAllowance.eq(1))
) {
return; // noop
}
break;
}
default:
throw errorUtils.spawnSwitchErr('proxyId', proxyId);
}
}
}
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