import ccxt, { binance, Exchange, okx, type OHLCV } from "ccxt";
import { Command } from "commander";
import { createObjectCsvWriter } from "csv-writer";
import { parse } from "date-fns";
import ProgressBar from "progress";

async function fetchOHLCV(
  exchangeId: string,
  symbol: string,
  timeframe: string,
  since: number,
  until: number,
  outputPath: string,
) {
  const ExchangeClass = (ccxt as { [key: string]: any })[exchangeId];
  if (!ExchangeClass) {
    throw new Error(`Exchange ${exchangeId} not supported`);
  }

  const defaultLimit = 500;
  const exchange: Exchange = new ExchangeClass();
  const progressBar = new ProgressBar(
    "Fetching data [:bar] :percent :elapseds",
    {
      total: until - since,
      width: 40,
    },
  );

  let allOHLCV: OHLCV[] = [];
  let currentSince = since;

  while (true) {
    const ohlcv = await exchange.fetchOHLCV(
      symbol,
      timeframe,
      currentSince,
      defaultLimit,
    );

    const lastTimestamp = ohlcv[ohlcv.length - 1][0];
    if (lastTimestamp == undefined) {
      throw new Error(`last timestamp undefined`);
    }

    const increment = lastTimestamp - currentSince;
    progressBar.tick(increment);

    currentSince = lastTimestamp + 1;
    allOHLCV = allOHLCV.concat(ohlcv);

    if (lastTimestamp >= until) break;
  }

  const records = allOHLCV.map((candle) => {
    const [timestamp, open, high, low, close, volume] = candle;
    return {
      open,
      high,
      low,
      close,
      volume,
      timestamp,
    };
  });

  const csvWriter = createObjectCsvWriter({
    path: outputPath,
    header: [
      { id: "open", title: "open" },
      { id: "high", title: "high" },
      { id: "low", title: "low" },
      { id: "close", title: "close" },
      { id: "volume", title: "volume" },
      { id: "timestamp", title: "timestamp" },
    ],
  });

  await csvWriter.writeRecords(records);

  console.log(`Total fetched: ${allOHLCV.length}, saved to ${outputPath}`);
}

// Use commander to handle command-line arguments
const cli = new Command();
cli.description("CLI tool for fetching trading data from exchanges.");
cli
  .requiredOption("-e, --exchange <exchange>", "Exchange, e.g., binance")
  .requiredOption(
    "-s, --symbol <symbol>",
    "Trading pair symbol, e.g., BTC/USDT",
  )
  .requiredOption(
    "-t, --timeframe <timeframe>",
    "Timeframe, e.g., 1m, 5m, 1h, 1d",
  )
  .requiredOption("--since <since>", "Start time (format: 2024-07-01 00:00:00)")
  .requiredOption("--until <until>", "End time (format: 2024-07-18 23:59:59)")
  .requiredOption("-o, --output <outputPath>", "Path to save the CSV file");
cli.parse(process.argv);

const options = cli.opts();
const since = parse(options.since, "yyyy-MM-dd HH:mm:ss", new Date()).getTime();
const until = parse(options.until, "yyyy-MM-dd HH:mm:ss", new Date()).getTime();

try {
  await fetchOHLCV(
    options.exchange,
    options.symbol,
    options.timeframe,
    since,
    until,
    options.output,
  );
} catch (err) {
  console.error("Error:", err);
}