// InstantAdPay — membership advertising with immutable on-chain settlement.
// Zero-dependency Node server (RM Circle pattern): static pages + JSON API,
// wallet sign-in (SIWE), live contract ledger, sponsor join links.
//
// Chain selection (Amoy rehearsal vs mainnet) lives in data/config.json —
// see chain.js. Wipe the volume's accounts/sessions + flip config = launch.
const http = require('http');
const fs = require('fs');
const path = require('path');
const { URL } = require('url');
const chain = require('./chain');
const auth = require('./auth');
const accounts = require('./accounts');

const PORT = Number(process.env.PORT || 3000);
const ROOT = __dirname;
const PUBLIC_DIR = path.join(ROOT, 'public');
const DATA_DIR = process.env.DATA_DIR || path.join(ROOT, 'data');
const ADMIN_PASSWORD = process.env.ADMIN_PASSWORD || 'changeme';
const IS_PROD = process.env.NODE_ENV === 'production';
const SITE_FILE = path.join(DATA_DIR, 'site.json');

fs.mkdirSync(DATA_DIR, { recursive: true });
chain.init({ onEvent: ev => pushFeed(ev) });
auth.init({ dataDir: DATA_DIR, chain, isProd: IS_PROD, site: 'instantadpay.com' });
accounts.init({ dataDir: DATA_DIR });

function siteConfig() {
  let saved = {};
  try { saved = JSON.parse(fs.readFileSync(SITE_FILE, 'utf8')); } catch (e) {}
  return Object.assign({
    siteName: 'InstantAdPay',
    tagline: 'Advertise and earn. Locked in code, not promises.',
    rehearsal: true // shows the testnet banner; flipped off at mainnet launch
  }, saved);
}

// ---- helpers ----
const MIME = { '.html': 'text/html; charset=utf-8', '.css': 'text/css', '.js': 'text/javascript',
  '.png': 'image/png', '.jpg': 'image/jpeg', '.svg': 'image/svg+xml', '.webp': 'image/webp',
  '.ico': 'image/x-icon', '.json': 'application/json', '.mp4': 'video/mp4', '.woff2': 'font/woff2' };
const CSP = "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; connect-src 'self'; font-src 'self' data:; form-action 'self'";
function baseHeaders(extra) {
  return Object.assign({ 'Content-Security-Policy': CSP, 'X-Content-Type-Options': 'nosniff',
    'Referrer-Policy': 'strict-origin-when-cross-origin' }, extra || {});
}
function json(res, code, obj, extra) {
  const body = JSON.stringify(obj);
  res.writeHead(code, baseHeaders(Object.assign({ 'Content-Type': 'application/json', 'Cache-Control': 'no-store' }, extra)));
  res.end(body);
}
function sendFile(res, file) {
  fs.readFile(file, (err, data) => {
    if (err) { res.writeHead(404, baseHeaders({ 'Content-Type': 'text/plain' })); return res.end('Not found'); }
    const ext = path.extname(file).toLowerCase();
    res.writeHead(200, baseHeaders({ 'Content-Type': MIME[ext] || 'application/octet-stream',
      'Cache-Control': ext === '.html' ? 'no-cache' : 'public, max-age=3600' }));
    res.end(data);
  });
}
function readBody(req) {
  return new Promise((resolve, reject) => {
    let d = ''; let n = 0;
    req.on('data', c => { n += c.length; if (n > 64 * 1024) { req.destroy(); reject(new Error('too big')); } d += c; });
    req.on('end', () => { try { resolve(d ? JSON.parse(d) : {}); } catch (e) { reject(e); } });
    req.on('error', reject);
  });
}
function parseCookies(req) {
  const out = {};
  for (const p of (req.headers.cookie || '').split(';')) {
    const i = p.indexOf('='); if (i > 0) out[p.slice(0, i).trim()] = decodeURIComponent(p.slice(i + 1).trim());
  }
  return out;
}
function isAdmin(req) {
  const h = req.headers.authorization || '';
  return h === 'Bearer ' + ADMIN_PASSWORD;
}

// ---- live feed (SSE) ----
const feedClients = new Set();
function pushFeed(ev) {
  const line = 'data: ' + JSON.stringify(ev) + '\n\n';
  for (const res of feedClients) { try { res.write(line); } catch (e) { feedClients.delete(res); } }
}

// ---- server ----
const server = http.createServer(async (req, res) => {
  try {
    const u = new URL(req.url, 'http://x');
    const p = u.pathname;

    // -- join links: /join/<sponsorId> — first-touch attribution cookie
    let m = /^\/join\/(\d{1,9})$/.exec(p);
    if (m && req.method === 'GET') {
      const sid = Number(m[1]);
      const cookies = parseCookies(req);
      const headers = { Location: '/' };
      if (!cookies['iap.sponsor']) {
        headers['Set-Cookie'] = `iap.sponsor=${sid}; Path=/; SameSite=Lax; Max-Age=${180 * 24 * 3600}${IS_PROD ? '; Secure' : ''}`;
      }
      res.writeHead(302, baseHeaders(headers));
      return res.end();
    }

    // -- public API
    if (p === '/api/config' && req.method === 'GET') {
      const c = chain.getConfig();
      return json(res, 200, Object.assign({ contract: c.contract, chainId: c.chainId,
        chainName: c.chainName, explorer: c.explorer, rpc: c.rpcs[0] }, siteConfig()));
    }
    if (p === '/api/catalog' && req.method === 'GET') {
      return json(res, 200, { products: await chain.catalog() });
    }
    if (p === '/api/feed' && req.method === 'GET') {
      return json(res, 200, { events: chain.recentEvents(Number(u.searchParams.get('n')) || 100) });
    }
    if (p === '/api/feed/live' && req.method === 'GET') {
      res.writeHead(200, baseHeaders({ 'Content-Type': 'text/event-stream', 'Cache-Control': 'no-store', Connection: 'keep-alive' }));
      res.write(': connected\n\n');
      feedClients.add(res);
      req.on('close', () => feedClients.delete(res));
      return;
    }
    if (p === '/api/sponsor' && req.method === 'GET') {
      const sid = Number(parseCookies(req)['iap.sponsor']) || 0;
      let sponsor = null;
      if (sid) { try { const mm = await chain.member(sid); if (mm.account !== '0x' + '0'.repeat(40)) sponsor = { id: sid }; } catch (e) {} }
      return json(res, 200, { sponsorId: sponsor ? sid : 0 });
    }
    if (p === '/api/stats' && req.method === 'GET') {
      let members = 0; try { members = await chain.memberCount(); } catch (e) {}
      return json(res, 200, { onchainMembers: members, siteAccounts: accounts.count() });
    }

    // -- accounts: email + password is the normal join path (wallet comes
    //    out only at purchase / payout-activation time and gets linked then)
    if (p === '/api/signup' && req.method === 'POST') {
      const b = await readBody(req);
      const sid = Number(parseCookies(req)['iap.sponsor']) || 0; // first-touch attribution
      const r = accounts.signup(b.email, b.password, sid);
      if (r.error) return json(res, 400, r);
      const token = auth.mintSession({ email: r.account.email });
      return json(res, 200, { ok: true, account: r.account }, { 'Set-Cookie': auth.sessionCookie(token) });
    }
    if (p === '/api/login' && req.method === 'POST') {
      const b = await readBody(req);
      const r = accounts.login(b.email, b.password);
      if (r.error) return json(res, 400, r);
      let memberId = 0;
      if (r.account.address) { try { memberId = await chain.memberIdByAccount(r.account.address); } catch (e) {} }
      const token = auth.mintSession({ email: r.account.email, address: r.account.address, memberId });
      return json(res, 200, { ok: true, account: r.account }, { 'Set-Cookie': auth.sessionCookie(token) });
    }

    // -- wallet auth: link-to-account when an email session exists, or
    //    wallet-first sign-in for crypto-native users
    if (p === '/api/auth/challenge' && req.method === 'POST') {
      const b = await readBody(req);
      const r = auth.makeChallenge(b.address);
      return json(res, r.error ? 400 : 200, r);
    }
    if (p === '/api/auth/verify' && req.method === 'POST') {
      const b = await readBody(req);
      const r = await auth.verifyChallenge(b.address, b.signature);
      if (r.error) return json(res, 400, r);
      let memberId = 0;
      try { memberId = await chain.memberIdByAccount(r.address); } catch (e) {}
      const s = auth.fromRequest(req);
      if (s && s.email) {
        const lr = accounts.linkWallet(s.email, r.address);
        if (lr.error) return json(res, 400, lr);
        auth.updateSession(s.token, { address: r.address, memberId });
        return json(res, 200, { ok: true, linked: true, address: r.address, memberId });
      }
      const acct = accounts.byAddress(r.address);
      const token = auth.mintSession({ email: acct ? acct.email : null, address: r.address, memberId });
      return json(res, 200, { ok: true, address: r.address, memberId },
        { 'Set-Cookie': auth.sessionCookie(token) });
    }
    if (p === '/api/auth/logout' && req.method === 'POST') {
      auth.logout(req);
      return json(res, 200, { ok: true }, { 'Set-Cookie': auth.clearCookie() });
    }
    if (p === '/api/me' && req.method === 'GET') {
      const s = auth.fromRequest(req);
      if (!s) return json(res, 200, { signedIn: false });
      const memberId = await auth.refreshMemberId(s);
      const acct = (s.email && accounts.byEmail(s.email)) || (s.address && accounts.byAddress(s.address)) || null;
      const out = { signedIn: true, email: s.email || (acct && acct.email) || null,
        address: s.address || (acct && acct.address) || null, memberId,
        sponsorId: (acct && acct.sponsorId) || Number(parseCookies(req)['iap.sponsor']) || 0 };
      if (memberId) {
        try {
          const mm = await chain.member(memberId);
          out.buyerCount = mm.buyerCount;
          out.onchainSponsorId = mm.sponsorId;
          out.credits = await chain.creditBalance(memberId, 0);
        } catch (e) { out.chainReadError = true; }
      }
      return json(res, 200, out);
    }

    if (p === '/api/my/activity' && req.method === 'GET') {
      const s = auth.fromRequest(req);
      if (!s) return json(res, 401, { error: 'Sign in first.' });
      const id = s.memberId || await auth.refreshMemberId(s);
      if (!id) return json(res, 200, { memberId: 0, earnings: [], purchases: [], referrals: [] });
      const evs = chain.recentEvents(600);
      return json(res, 200, {
        memberId: id,
        earnings: evs.filter(e => (e.type === 'TierPaid' && e.recipientId === id) || (e.type === 'AwardPaid' && e.toId === id)),
        purchases: evs.filter(e => e.type === 'Purchase' && e.buyerId === id),
        referrals: evs.filter(e => (e.type === 'MemberActivated' && e.sponsorId === id) || (e.type === 'BuyerCounted' && e.sponsorId === id))
      });
    }

    // -- admin (Bearer ADMIN_PASSWORD)
    if (p === '/api/admin/site' && req.method === 'PATCH') {
      if (!isAdmin(req)) return json(res, 401, { error: 'auth' });
      const b = await readBody(req);
      const cur = siteConfig();
      fs.writeFileSync(SITE_FILE, JSON.stringify(Object.assign(cur, b), null, 2));
      return json(res, 200, { ok: true, site: siteConfig() });
    }
    if (p === '/api/admin/chain' && req.method === 'PATCH') {
      if (!isAdmin(req)) return json(res, 401, { error: 'auth' });
      const b = await readBody(req);
      const file = path.join(DATA_DIR, 'config.json');
      let cur = {}; try { cur = JSON.parse(fs.readFileSync(file, 'utf8')); } catch (e) {}
      fs.writeFileSync(file, JSON.stringify(Object.assign(cur, b), null, 2));
      chain.reloadConfig();
      return json(res, 200, { ok: true, config: chain.getConfig() });
    }

    // -- pages
    if (req.method === 'GET') {
      if (p === '/') return sendFile(res, path.join(PUBLIC_DIR, 'index.html'));
      if (p === '/ledger') return sendFile(res, path.join(PUBLIC_DIR, 'ledger.html'));
      if (p === '/my') return sendFile(res, path.join(PUBLIC_DIR, 'my.html'));
      const safe = path.normalize(p).replace(/^([.\\/])+/, '');
      const file = path.join(PUBLIC_DIR, safe);
      if (file.startsWith(PUBLIC_DIR) && fs.existsSync(file) && fs.statSync(file).isFile()) return sendFile(res, file);
    }

    res.writeHead(404, baseHeaders({ 'Content-Type': 'text/plain' }));
    res.end('Not found');
  } catch (e) {
    console.error('request error', req.url, e.message);
    try { json(res, 500, { error: 'server error' }); } catch (_) {}
  }
});
server.listen(PORT, () => console.log(`InstantAdPay site on :${PORT} — chain: ${chain.getConfig().chainName}`));