import { fetchAsync } from '@0x/utils'; import * as R from 'ramda'; import { Connection } from 'typeorm'; export interface TradingPair { fromSymbol: string; toSymbol: string; latestSavedTime: number; } const COINLIST_API = 'https://min-api.cryptocompare.com/data/all/coinlist?BuiltOn=7605'; interface CryptoCompareCoinListResp { Data: Map; } interface CryptoCompareCoin { Symbol: string; BuiltOn: string; SmartContractAddress: string; } const TO_CURRENCIES = ['USD', 'EUR', 'ETH', 'USDT']; const ETHEREUM_IDENTIFIER = '7605'; const HTTP_OK_STATUS = 200; /** * Get trading pairs with latest scraped time for OHLCV records * @param conn a typeorm Connection to postgres */ export async function fetchOHLCVTradingPairsAsync( conn: Connection, source: string, earliestBackfillTime: number, ): Promise { // fetch existing ohlcv records const latestTradingPairs: Array<{ from_symbol: string; to_symbol: string; latest: string; }> = await conn.query(`SELECT MAX(end_time) as latest, from_symbol, to_symbol FROM raw.ohlcv_external GROUP BY from_symbol, to_symbol;`); const latestTradingPairsIndex: { [fromSym: string]: { [toSym: string]: number } } = {}; latestTradingPairs.forEach(pair => { const latestIndex: { [toSym: string]: number } = latestTradingPairsIndex[pair.from_symbol] || {}; latestIndex[pair.to_symbol] = parseInt(pair.latest, 10); // tslint:disable-line:custom-no-magic-numbers latestTradingPairsIndex[pair.from_symbol] = latestIndex; }); // get token symbols used by Crypto Compare const allCoinsResp = await fetchAsync(COINLIST_API); if (allCoinsResp.status !== HTTP_OK_STATUS) { return []; } const allCoins: CryptoCompareCoinListResp = await allCoinsResp.json(); const erc20CoinsIndex: Map = new Map(); Object.entries(allCoins.Data).forEach(pair => { const [symbol, coinData] = pair; if (coinData.BuiltOn === ETHEREUM_IDENTIFIER && coinData.SmartContractAddress !== 'N/A') { erc20CoinsIndex.set(coinData.SmartContractAddress.toLowerCase(), symbol); } }); // fetch all tokens that are traded on 0x const rawTokenAddresses: Array<{ tokenaddress: string }> = await conn.query( `SELECT DISTINCT(maker_token_address) as tokenaddress FROM raw.exchange_fill_events UNION SELECT DISTINCT(taker_token_address) as tokenaddress FROM raw.exchange_fill_events`, ); const tokenAddresses = R.pluck('tokenaddress', rawTokenAddresses); // join token addresses with CC symbols const allTokenSymbols: string[] = tokenAddresses .map(tokenAddress => erc20CoinsIndex.get(tokenAddress.toLowerCase()) || '') .filter(x => x); // generate list of all tokens with time of latest existing record OR default earliest time const allTradingPairCombinations: TradingPair[] = R.chain(sym => { return TO_CURRENCIES.map(fiat => { return { fromSymbol: sym, toSymbol: fiat, latestSavedTime: R.path([sym, fiat], latestTradingPairsIndex) || earliestBackfillTime, }; }); }, allTokenSymbols); return allTradingPairCombinations; }