#!/usr/bin/env node
/**
 * spv-p2p-headersync-chipnet.mjs — Phase 1a end-to-end demo.
 *
 * Anchors at a real chipnet checkpoint (from test/fixtures/spv-chipnet.json)
 * and pulls all headers up to the live tip via getheaders/headers from
 * ≥1 chipnet peer, feeding the existing HeaderChain (PoW + link + anchor
 * validated on every append).
 *
 * Proves the transport-independent core actually walks the chain end-to-end,
 * not just handshakes. Runs against real network — not part of vitest.
 */
// Run via tsx so the TS imports resolve without a build step:
//   node --import tsx scripts/spv-p2p-headersync-chipnet.mjs
// or: npx tsx scripts/spv-p2p-headersync-chipnet.mjs
import dns from 'node:dns/promises';
import { NETWORKS } from '../shells/app/src/core/spv/p2p/wire.ts';
import { NodeNetTransport } from '../shells/app/src/core/spv/p2p/transport-node.ts';
import { syncHeaders } from '../shells/app/src/core/spv/p2p/header-sync.ts';

// Real chipnet checkpoint from test/fixtures/spv-chipnet.json (2026-07-26).
// syncHeaders() re-derives the hash from headerHex and passes it into
// HeaderChain, which pins the anchor.
const ANCHOR = {
  height:    315684,
  headerHex: '0000002021cd2665f2a91a793add02d2722b3103ef24a6d796d79244c125be4b00000000029c1f97ee4286151c0440ee3f35cfbbe9369a7998b938aa96b6ed48c78c87050d26616a15b66a1c12b6850c',
};

async function resolveSeeds(seeds, per = 3) {
  const out = new Set();
  for (const s of seeds) {
    try {
      const ips = await dns.resolve4(s);
      for (const ip of ips.slice(0, per)) out.add(ip);
    } catch { /* seed unreachable, skip */ }
  }
  return [...out];
}

async function main() {
  console.log(`Phase 1a end-to-end — chipnet header sync from checkpoint ${ANCHOR.height}\n`);
  const hosts = await resolveSeeds(NETWORKS.chipnet.seeds, 3);
  console.log(`Resolved ${hosts.length} chipnet peers: ${hosts.join(', ')}\n`);
  if (hosts.length === 0) { console.error('no peers resolved'); process.exit(1); }

  const t0 = Date.now();
  const result = await syncHeaders({
    transport:  new NodeNetTransport(),
    network:    NETWORKS.chipnet,
    anchor:     ANCHOR,
    peerHosts:  hosts,
    minPeers:   Math.min(2, hosts.length),
    maxHeaders: 5000,
    onProgress: ({ height, peers, batch }) => console.log(`  batch ${batch}: height=${height} peers-live=${peers}`),
    onDropped:  (host, reason) => console.log(`  ✗ dropped ${host}: ${reason}`),
  });
  const dt = Date.now() - t0;

  console.log(`\n✅ synced ${result.chain.height - ANCHOR.height} headers in ${dt} ms`);
  console.log(`   tip height        = ${result.chain.height}`);
  console.log(`   tip hash          = ${result.chain.tip?.hash}`);
  console.log(`   cumulative work   = ${result.chain.tip?.cumWork.toString()}`);
  console.log(`   leader            = ${result.syncedFromHost}`);
  console.log(`   peers handshook   = ${result.peersHandshook.length}  spread=${result.tipSpread}`);
  for (const p of result.peersHandshook) console.log(`     • ${p.host}  ${p.userAgent}  h=${p.startHeight}`);
  console.log(`   batches           = ${result.batches}`);
}

main().catch((e) => { console.error('FAILED:', e?.message ?? e); if (e?.stack) console.error(e.stack); process.exit(1); });