/**
* Whale Alert Stream — GET /api/v1/stream/whales
* Real-time large Bitcoin transactions.
* Query: ?min=100 (minimum BTC threshold, default 100)
* Price: $0.01 USDC
*/
import { NextRequest } from 'next/server';
import { pollWhaleEvents, formatSSE, formatHeartbeat } from '@/lib/events';
import { sanitizeInt } from '@/lib/validation';
export const runtime = 'nodejs';
export const dynamic = 'force-dynamic';
export async function GET(request: NextRequest) {
const { searchParams } = new URL(request.url);
const minBtc = sanitizeInt(searchParams.get('min'), 100, 1, 100000);
const encoder = new TextEncoder();
const POLL_INTERVAL = 20_000;
const HEARTBEAT_INTERVAL = 30_000;
const MAX_DURATION = 300_000;
const seenTxids = new Set<string>();
const stream = new ReadableStream({
async start(controller) {
const startTime = Date.now();
let heartbeatTimer: ReturnType<typeof setInterval> | null = null;
let pollTimer: ReturnType<typeof setInterval> | null = null;
controller.enqueue(encoder.encode(`event: connected\ndata: ${JSON.stringify({ message: 'Whale alert stream connected', minBtc, channel: 'whale_tx' })}\n\n`));
heartbeatTimer = setInterval(() => {
try { controller.enqueue(encoder.encode(formatHeartbeat())); }
catch { cleanup(); }
}, HEARTBEAT_INTERVAL);
pollTimer = setInterval(async () => {
if (Date.now() - startTime > MAX_DURATION) {
controller.enqueue(encoder.encode(`event: timeout\ndata: ${JSON.stringify({ message: 'Stream max duration reached. Reconnect.' })}\n\n`));
cleanup();
return;
}
try {
const events = await pollWhaleEvents(minBtc);
for (const event of events) {
const txid = (event.data as any).txid;
if (txid && seenTxids.has(txid)) continue;
if (txid) seenTxids.add(txid);
controller.enqueue(encoder.encode(formatSSE(event)));
}
// Cap seen set size
if (seenTxids.size > 500) {
const arr = Array.from(seenTxids);
for (let i = 0; i < 250; i++) seenTxids.delete(arr[i]);
}
} catch { /* silent */ }
}, POLL_INTERVAL);
function cleanup() {
if (heartbeatTimer) clearInterval(heartbeatTimer);
if (pollTimer) clearInterval(pollTimer);
try { controller.close(); } catch {}
}
request.signal.addEventListener('abort', cleanup);
},
});
return new Response(stream, {
headers: {
'Content-Type': 'text/event-stream',
'Cache-Control': 'no-cache, no-store',
'Connection': 'keep-alive',
'X-Accel-Buffering': 'no',
// CORS + security (middleware can't inject on custom Response)
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Methods': 'GET, OPTIONS',
'X-Content-Type-Options': 'nosniff',
},
});
}
