import { AbstractBalanceAndProxyAllowanceFetcher } from '@0xproject/order-utils';
import { BlockParamLiteral } from '@0xproject/types';
import { BigNumber } from '@0xproject/utils';
import * as _ from 'lodash';
import { TokenWrapper } from '../contract_wrappers/token_wrapper';
/**
* Copy on read store for balances/proxyAllowances of tokens/accounts
*/
export class BalanceAndProxyAllowanceLazyStore implements AbstractBalanceAndProxyAllowanceFetcher {
private _tokenWrapper: TokenWrapper;
private _defaultBlock: BlockParamLiteral;
private _balance: {
[tokenAddress: string]: {
[userAddress: string]: BigNumber;
};
};
private _proxyAllowance: {
[tokenAddress: string]: {
[userAddress: string]: BigNumber;
};
};
constructor(token: TokenWrapper, defaultBlock: BlockParamLiteral) {
this._tokenWrapper = token;
this._defaultBlock = defaultBlock;
this._balance = {};
this._proxyAllowance = {};
}
public async getBalanceAsync(tokenAddress: string, userAddress: string): Promise<BigNumber> {
if (_.isUndefined(this._balance[tokenAddress]) || _.isUndefined(this._balance[tokenAddress][userAddress])) {
const methodOpts = {
defaultBlock: this._defaultBlock,
};
const balance = await this._tokenWrapper.getBalanceAsync(tokenAddress, userAddress, methodOpts);
this.setBalance(tokenAddress, userAddress, balance);
}
const cachedBalance = this._balance[tokenAddress][userAddress];
return cachedBalance;
}
public setBalance(tokenAddress: string, userAddress: string, balance: BigNumber): void {
if (_.isUndefined(this._balance[tokenAddress])) {
this._balance[tokenAddress] = {};
}
this._balance[tokenAddress][userAddress] = balance;
}
public deleteBalance(tokenAddress: string, userAddress: string): void {
if (!_.isUndefined(this._balance[tokenAddress])) {
delete this._balance[tokenAddress][userAddress];
if (_.isEmpty(this._balance[tokenAddress])) {
delete this._balance[tokenAddress];
}
}
}
public async getProxyAllowanceAsync(tokenAddress: string, userAddress: string): Promise<BigNumber> {
if (
_.isUndefined(this._proxyAllowance[tokenAddress]) ||
_.isUndefined(this._proxyAllowance[tokenAddress][userAddress])
) {
const methodOpts = {
defaultBlock: this._defaultBlock,
};
const proxyAllowance = await this._tokenWrapper.getProxyAllowanceAsync(
tokenAddress,
userAddress,
methodOpts,
);
this.setProxyAllowance(tokenAddress, userAddress, proxyAllowance);
}
const cachedProxyAllowance = this._proxyAllowance[tokenAddress][userAddress];
return cachedProxyAllowance;
}
public setProxyAllowance(tokenAddress: string, userAddress: string, proxyAllowance: BigNumber): void {
if (_.isUndefined(this._proxyAllowance[tokenAddress])) {
this._proxyAllowance[tokenAddress] = {};
}
this._proxyAllowance[tokenAddress][userAddress] = proxyAllowance;
}
public deleteProxyAllowance(tokenAddress: string, userAddress: string): void {
if (!_.isUndefined(this._proxyAllowance[tokenAddress])) {
delete this._proxyAllowance[tokenAddress][userAddress];
if (_.isEmpty(this._proxyAllowance[tokenAddress])) {
delete this._proxyAllowance[tokenAddress];
}
}
}
public deleteAll(): void {
this._balance = {};
this._proxyAllowance = {};
}
}