import { DhanFeed, DhanEnv, ExchangeSegment } from 'dhan-ts';

const config = {
  accessToken: process.env.DHAN_ACCESS_TOKEN!,
  clientId: process.env.DHAN_CLIENT_ID!,
  env: DhanEnv.PROD,
};

const feed = new DhanFeed(config);

// 20-level market depth
const depth20Feed = feed.marketDepthFeed20;

// 200-level market depth
const depth200Feed = feed.marketDepthFeed200;

async connect(): Promise<void>

subscribe(instruments: Instrument[]): void

const instruments = [
  [ExchangeSegment.NSE_EQ, "1333"], // Reliance
];

await depth20Feed.connect();
depth20Feed.subscribe(instruments);

depth20Feed.on('data', (data) => {
  console.log('Bid levels:', data.bids.length);
  console.log('Ask levels:', data.asks.length);

  // Display top 5 levels
  data.bids.slice(0, 5).forEach((level, i) => {
    console.log(`Bid ${i + 1}: ${level.quantity} @ ₹${level.price} (${level.orders} orders)`);
  });

  data.asks.slice(0, 5).forEach((level, i) => {
    console.log(`Ask ${i + 1}: ${level.quantity} @ ₹${level.price} (${level.orders} orders)`);
  });
});

unsubscribe(instruments: Instrument[]): void

close(): void

depth20Feed.on('data', (data: MarketDepthData) => {
  console.log('Exchange:', data.exchangeSegment);
  console.log('Security ID:', data.securityId);
  console.log('Bids:', data.bids);
  console.log('Asks:', data.asks);
});

depth20Feed.on('error', (error: Error) => {
  console.error('Error:', error);
});

depth20Feed.on('disconnected', (data: DisconnectionResponse) => {
  console.log('Disconnected:', data.reason);
});

interface MarketDepthData {
  exchangeSegment: number;
  securityId: number;
  bids: DepthLevel[];
  asks: DepthLevel[];
}

interface DepthLevel {
  price: number;
  quantity: number;
  orders: number;
}

function displayOrderBook(data: MarketDepthData) {
  console.clear();
  console.log('=== ORDER BOOK ===');
  console.log(`Security: ${data.securityId}\n`);

  console.log('ASKS (Sell Orders)');
  console.log('Price\t\tQty\tOrders');
  data.asks.reverse().slice(0, 10).forEach(level => {
    console.log(`${level.price}\t${level.quantity}\t${level.orders}`);
  });

  console.log('\n--- SPREAD ---\n');

  console.log('BIDS (Buy Orders)');
  console.log('Price\t\tQty\tOrders');
  data.bids.slice(0, 10).forEach(level => {
    console.log(`${level.price}\t${level.quantity}\t${level.orders}`);
  });
}

depth20Feed.on('data', displayOrderBook);

depth20Feed.on('data', (data) => {
  const totalBidQty = data.bids.reduce((sum, level) => sum + level.quantity, 0);
  const totalAskQty = data.asks.reduce((sum, level) => sum + level.quantity, 0);

  const bidValue = data.bids.reduce((sum, level) =>
    sum + (level.quantity * level.price), 0
  );
  const askValue = data.asks.reduce((sum, level) =>
    sum + (level.quantity * level.price), 0
  );

  console.log(`Total Bid Qty: ${totalBidQty}`);
  console.log(`Total Ask Qty: ${totalAskQty}`);
  console.log(`Bid Value: ₹${bidValue.toFixed(2)}`);
  console.log(`Ask Value: ₹${askValue.toFixed(2)}`);
  console.log(`Buy Pressure: ${((totalBidQty / (totalBidQty + totalAskQty)) * 100).toFixed(2)}%`);
});

depth20Feed.on('data', (data) => {
  const bestBid = data.bids[0];
  const bestAsk = data.asks[0];

  if (bestBid && bestAsk) {
    const spread = bestAsk.price - bestBid.price;
    const spreadBps = (spread / bestBid.price) * 10000;

    console.log(`Spread: ₹${spread} (${spreadBps.toFixed(2)} bps)`);

    if (spreadBps > 50) {
      console.log('⚠️ Wide spread detected - low liquidity');
    }
  }
});

function calculateVWAP(levels: DepthLevel[], side: 'bid' | 'ask'): number {
  let totalValue = 0;
  let totalQty = 0;

  levels.forEach(level => {
    totalValue += level.price * level.quantity;
    totalQty += level.quantity;
  });

  return totalQty > 0 ? totalValue / totalQty : 0;
}

depth20Feed.on('data', (data) => {
  const bidVWAP = calculateVWAP(data.bids, 'bid');
  const askVWAP = calculateVWAP(data.asks, 'ask');

  console.log(`Bid VWAP: ₹${bidVWAP.toFixed(2)}`);
  console.log(`Ask VWAP: ₹${askVWAP.toFixed(2)}`);
});

depth20Feed.on('data', (data) => {
  const bidQty = data.bids.reduce((sum, l) => sum + l.quantity, 0);
  const askQty = data.asks.reduce((sum, l) => sum + l.quantity, 0);

  const imbalance = (bidQty - askQty) / (bidQty + askQty);

  if (imbalance > 0.3) {
    console.log('🔵 Strong buying pressure');
  } else if (imbalance < -0.3) {
    console.log('🔴 Strong selling pressure');
  } else {
    console.log('⚪ Balanced order book');
  }
});