4 files changed, 95 insertions, 9 deletions
diff --git a/packages/contracts/src/abstract/abstract_asset_wrapper.ts b/packages/contracts/src/abstract/abstract_asset_wrapper.ts
new file mode 100644
index 000000000..d7ab58fea
--- /dev/null
+++ b/packages/contracts/src/abstract/abstract_asset_wrapper.ts
@@ -0,0 +1,10 @@
+import { BigNumber } from '@0xproject/utils';
+
+export abstract class AbstractAssetWrapper {
+    public abstract getProxyId(): number;
+    public abstract async setBalancesAndAllowancesAsync(): Promise<void>;
+    public abstract async getBalanceAsync(owner: string, assetData: string): Promise<BigNumber>;
+    public abstract async getProxyAllowanceAsync(owner: string, assetData: string): Promise<BigNumber>;
+    public abstract getTokenOwnerAddresses(): string[];
+    public abstract getTokenAddresses(): string[];
+}
diff --git a/packages/contracts/src/utils/asset_wrapper.ts b/packages/contracts/src/utils/asset_wrapper.ts
new file mode 100644
index 000000000..4c345aa30
--- /dev/null
+++ b/packages/contracts/src/utils/asset_wrapper.ts
@@ -0,0 +1,32 @@
+import { assetProxyUtils } from '@0xproject/order-utils';
+import { BigNumber } from '@0xproject/utils';
+import * as _ from 'lodash';
+
+import { AbstractAssetWrapper } from '../abstract/abstract_asset_wrapper';
+
+interface ProxyIdToAssetWrappers {
+    [proxyId: number]: AbstractAssetWrapper;
+}
+
+export class AssetWrapper {
+    private _proxyIdToAssetWrappers: ProxyIdToAssetWrappers;
+    constructor(assetWrappers: AbstractAssetWrapper[]) {
+        this._proxyIdToAssetWrappers = {};
+        _.each(assetWrappers, assetWrapper => {
+            const proxyId = assetWrapper.getProxyId();
+            this._proxyIdToAssetWrappers[proxyId] = assetWrapper;
+        });
+    }
+    public async getBalanceAsync(owner: string, assetData: string): Promise<BigNumber> {
+        const proxyId = assetProxyUtils.decodeAssetDataId(assetData);
+        const assetWrapper = this._proxyIdToAssetWrappers[proxyId];
+        const balance = await assetWrapper.getBalanceAsync(owner, assetData);
+        return balance;
+    }
+    public async getProxyAllowanceAsync(owner: string, assetData: string): Promise<BigNumber> {
+        const proxyId = assetProxyUtils.decodeAssetDataId(assetData);
+        const assetWrapper = this._proxyIdToAssetWrappers[proxyId];
+        const balance = await assetWrapper.getProxyAllowanceAsync(owner, assetData);
+        return balance;
+    }
+}
diff --git a/packages/contracts/src/utils/erc20_wrapper.ts b/packages/contracts/src/utils/erc20_wrapper.ts
index fc42fbff2..2d367ae1c 100644
--- a/packages/contracts/src/utils/erc20_wrapper.ts
+++ b/packages/contracts/src/utils/erc20_wrapper.ts
@@ -1,3 +1,4 @@
+import { assetProxyUtils } from '@0xproject/order-utils';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import { Provider } from 'ethereum-types';
@@ -18,6 +19,7 @@ export class ERC20Wrapper {
     private _provider: Provider;
     private _dummyTokenContracts: DummyERC20TokenContract[];
     private _proxyContract?: ERC20ProxyContract;
+    private _proxyIdIfExists?: number;
     constructor(provider: Provider, tokenOwnerAddresses: string[], contractOwnerAddress: string) {
         this._dummyTokenContracts = [];
         this._web3Wrapper = new Web3Wrapper(provider);
@@ -50,8 +52,13 @@ export class ERC20Wrapper {
             this._provider,
             txDefaults,
         );
+        this._proxyIdIfExists = await this._proxyContract.getProxyId.callAsync();
         return this._proxyContract;
     }
+    public getProxyId(): number {
+        this._validateProxyContractExistsOrThrow();
+        return this._proxyIdIfExists as number;
+    }
     public async setBalancesAndAllowancesAsync(): Promise<void> {
         this._validateDummyTokenContractsExistOrThrow();
         this._validateProxyContractExistsOrThrow();
@@ -76,24 +83,28 @@ export class ERC20Wrapper {
             }
         }
     }
-    public async getBalanceAsync(owner: string, token: string): Promise<BigNumber> {
-        const tokenContractIfExists = _.find(this._dummyTokenContracts, c => c.address === token);
+    public async getBalanceAsync(owner: string, assetData: string): Promise<BigNumber> {
+        const erc20ProxyData = assetProxyUtils.decodeERC20AssetData(assetData);
+        const tokenAddress = erc20ProxyData.tokenAddress;
+        const tokenContractIfExists = _.find(this._dummyTokenContracts, c => c.address === tokenAddress);
         if (_.isUndefined(tokenContractIfExists)) {
-            throw new Error(`Token: ${token} was not deployed through ERC20Wrapper`);
+            throw new Error(`Token: ${tokenAddress} was not deployed through ERC20Wrapper`);
         }
         const balance = new BigNumber(await tokenContractIfExists.balanceOf.callAsync(owner));
         return balance;
     }
-    public async getProxyAllowanceAsync(owner: string, token: string): Promise<BigNumber> {
+    public async getProxyAllowanceAsync(owner: string, assetData: string): Promise<BigNumber> {
+        const erc20ProxyData = assetProxyUtils.decodeERC20AssetData(assetData);
+        const tokenAddress = erc20ProxyData.tokenAddress;
         this._validateProxyContractExistsOrThrow();
-        const tokenContractIfExists = _.find(this._dummyTokenContracts, c => c.address === token);
+        const tokenContractIfExists = _.find(this._dummyTokenContracts, c => c.address === tokenAddress);
         if (_.isUndefined(tokenContractIfExists)) {
-            throw new Error(`Token: ${token} was not deployed through ERC20Wrapper`);
+            throw new Error(`Token: ${tokenAddress} was not deployed through ERC20Wrapper`);
         }
-        const balance = new BigNumber(
+        const allowance = new BigNumber(
             await tokenContractIfExists.allowance.callAsync(owner, (this._proxyContract as ERC20ProxyContract).address),
         );
-        return balance;
+        return allowance;
     }
     public async getBalancesAsync(): Promise<ERC20BalancesByOwner> {
         this._validateDummyTokenContractsExistOrThrow();
diff --git a/packages/contracts/src/utils/erc721_wrapper.ts b/packages/contracts/src/utils/erc721_wrapper.ts
index b20d9acd2..6a6f10fa7 100644
--- a/packages/contracts/src/utils/erc721_wrapper.ts
+++ b/packages/contracts/src/utils/erc721_wrapper.ts
@@ -1,4 +1,4 @@
-import { generatePseudoRandomSalt } from '@0xproject/order-utils';
+import { assetProxyUtils, generatePseudoRandomSalt } from '@0xproject/order-utils';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import { Provider } from 'ethereum-types';
@@ -19,6 +19,7 @@ export class ERC721Wrapper {
     private _provider: Provider;
     private _dummyTokenContracts: DummyERC721TokenContract[];
     private _proxyContract?: ERC721ProxyContract;
+    private _proxyIdIfExists?: number;
     private _initialTokenIdsByOwner: ERC721TokenIdsByOwner = {};
     constructor(provider: Provider, tokenOwnerAddresses: string[], contractOwnerAddress: string) {
         this._web3Wrapper = new Web3Wrapper(provider);
@@ -47,8 +48,13 @@ export class ERC721Wrapper {
             this._provider,
             txDefaults,
         );
+        this._proxyIdIfExists = await this._proxyContract.getProxyId.callAsync();
         return this._proxyContract;
     }
+    public getProxyId(): number {
+        this._validateProxyContractExistsOrThrow();
+        return this._proxyIdIfExists as number;
+    }
     public async setBalancesAndAllowancesAsync(): Promise<void> {
         this._validateDummyTokenContractsExistOrThrow();
         this._validateProxyContractExistsOrThrow();
@@ -85,6 +91,33 @@ export class ERC721Wrapper {
             }
         }
     }
+    public async getBalanceAsync(owner: string, assetData: string): Promise<BigNumber> {
+        const erc721ProxyData = assetProxyUtils.decodeERC721AssetData(assetData);
+        const tokenAddress = erc721ProxyData.tokenAddress;
+        const tokenContractIfExists = _.find(this._dummyTokenContracts, c => c.address === tokenAddress);
+        if (_.isUndefined(tokenContractIfExists)) {
+            throw new Error(`Token: ${tokenAddress} was not deployed through ERC20Wrapper`);
+        }
+        const tokenId = erc721ProxyData.tokenId;
+        const tokenOwner = await tokenContractIfExists.ownerOf.callAsync(tokenId);
+        const balance = tokenOwner === owner ? new BigNumber(1) : new BigNumber(0);
+        return balance;
+    }
+    public async getProxyAllowanceAsync(owner: string, assetData: string): Promise<BigNumber> {
+        const erc721ProxyData = assetProxyUtils.decodeERC721AssetData(assetData);
+        const tokenAddress = erc721ProxyData.tokenAddress;
+        this._validateProxyContractExistsOrThrow();
+        const tokenContractIfExists = _.find(this._dummyTokenContracts, c => c.address === tokenAddress);
+        if (_.isUndefined(tokenContractIfExists)) {
+            throw new Error(`Token: ${tokenAddress} was not deployed through ERC20Wrapper`);
+        }
+        const operator = (this._proxyContract as ERC721ProxyContract).address;
+        const didApproveAll = await tokenContractIfExists.isApprovedForAll.callAsync(owner, operator);
+        const tokenId = erc721ProxyData.tokenId;
+        const allowedAddress = await tokenContractIfExists.getApproved.callAsync(tokenId);
+        const allowance = allowedAddress === operator || didApproveAll ? new BigNumber(1) : new BigNumber(0);
+        return allowance;
+    }
     public async getBalancesAsync(): Promise<ERC721TokenIdsByOwner> {
         this._validateDummyTokenContractsExistOrThrow();
         this._validateBalancesAndAllowancesSetOrThrow();