// E2E for the per-node Reach page (#/nodes/<pubkey>/reach).
// Defaults to localhost:3000 — NEVER point at prod (AGENTS.md). CI sets BASE_URL.
const { chromium } = require('playwright');
const BASE = process.env.BASE_URL || 'http://localhost:3000';

async function getJson(page, url) {
  const resp = await page.request.get(url);
  if (!resp.ok()) throw new Error('GET ' + url + ' → HTTP ' + resp.status());
  return resp.json();
}

(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();

  // A repeater is most likely to have reach data (it relays).
  const nodes = await getJson(page, BASE + '/api/nodes?role=repeater&limit=1');
  if (!nodes.nodes || !nodes.nodes.length) {
    console.log('node-reach E2E SKIP (no repeater in dataset)');
    await browser.close();
    return;
  }
  const pk = nodes.nodes[0].public_key;

  // 1. The endpoint returns the documented shape.
  const reach = await getJson(page, BASE + '/api/nodes/' + pk + '/reach?days=7');
  for (const k of ['node', 'window', 'reliable_tokens', 'importance', 'links', 'direct_observers']) {
    if (!(k in reach)) throw new Error('reach response missing key: ' + k);
  }
  if (!Array.isArray(reach.links)) throw new Error('reach.links must be an array');

  // 2. The page renders.
  await page.goto(BASE + '/#/nodes/' + pk + '/reach');
  await page.waitForSelector('.nq-head', { timeout: 20000 });
  if (!(await page.locator('h2', { hasText: 'Reach' }).count())) {
    throw new Error('Reach header missing');
  }

  // 3. If this node is identifiable, exercise the table, toggles and links.
  if (reach.reliable_tokens.length && (await page.locator('#nqRows').count())) {
    await page.waitForSelector('#nqIncoming');
    await page.waitForSelector('#nqOutgoing');

    // Derive the EXACT expected row counts from the API so the toggles are
    // verified, not just "didn't shrink" (tautology). Base shows two-way only;
    // incoming adds we-only links; +outgoing adds the rest (= all links).
    const twoWayExp = reach.links.filter(l => l.bidir).length;
    const weOnlyExp = reach.links.filter(l => !l.bidir && l.we_hear > 0 && l.they_hear === 0).length;
    const allExp = reach.links.length;

    const base = await page.locator('#nqRows tr').count();
    if (base !== twoWayExp) throw new Error(`base rows ${base} != two-way ${twoWayExp}`);
    await page.check('#nqIncoming');
    const withIncoming = await page.locator('#nqRows tr').count();
    if (withIncoming !== twoWayExp + weOnlyExp) {
      throw new Error(`incoming rows ${withIncoming} != two-way+we-only ${twoWayExp + weOnlyExp}`);
    }
    await page.check('#nqOutgoing');
    const withBoth = await page.locator('#nqRows tr').count();
    if (withBoth !== allExp) throw new Error(`both-toggles rows ${withBoth} != all links ${allExp}`);

    // Neighbour rows link to a node detail page.
    if (await page.locator('#nqRows a.nq-link').count()) {
      const href = await page.locator('#nqRows a.nq-link').first().getAttribute('href');
      if (!href || !href.startsWith('#/nodes/')) throw new Error('neighbour link malformed: ' + href);
    }

    // Leaflet puts .leaflet-container on the element you hand L.map(), so the
    // class lands on #nqMap itself. The old selector had a space in it and so
    // waited for a DESCENDANT carrying the class, which never exists: that is
    // why this suite timed out here every time it was run.
    //
    // The condition is the node's own coordinates, not a link's:
    // public/node-reach.js calls NodeReachMap.render only when n.lat != null,
    // so a node with positioned neighbours but no position of its own has no
    // map to wait for.
    if (reach.node && reach.node.lat != null && reach.node.lon != null) {
      await page.waitForSelector('#nqMap.leaflet-container', { timeout: 10000 });
    }
  }

  // 4. A busy server (429 + Retry-After) is retried by the reach page itself:
  // a "retrying" hint, then the report, with no error. The reach requests are
  // answered by a route so the server does not have to be made busy.
  const reachPath = '/api/nodes/' + pk + '/reach';
  async function withReachRoute(answer, fn) {
    const p = await browser.newPage();
    const seen = { n: 0, at: [] };
    await p.route((url) => new URL(url).pathname === reachPath, async (route) => {
      seen.n++;
      seen.at.push(Date.now());
      const a = await answer(seen.n);
      if (a === 'pass') return route.continue();
      return route.fulfill(a);
    });
    try { await fn(p, seen); } finally { await p.close(); }
  }
  const busy = { status: 429, headers: { 'Retry-After': '1', 'Content-Type': 'application/json' },
    body: JSON.stringify({ error: 'reach is busy computing other reports', retryAfter: 1 }) };

  await withReachRoute((n) => (n <= 2 ? busy : 'pass'), async (p, seen) => {
    await p.goto(BASE + '/#/nodes/' + pk + '/reach');
    await p.waitForSelector('.nq-busy', { timeout: 10000 });
    const hint = await p.locator('.nq-busy').textContent();
    if (!hint.includes('retrying in 1 s')) throw new Error('busy hint text: ' + hint);
    await p.waitForSelector('.nq-head', { timeout: 20000 });
    if (await p.locator('.nq-error').count()) throw new Error('error shown after a successful retry');
    if (seen.n !== 3) throw new Error('reach requests ' + seen.n + ' != 3 (2 busy + 1 served)');
    // Two waits of Retry-After: 1 s each between the first and third request.
    const gap = seen.at[2] - seen.at[0];
    if (gap < 1800) throw new Error('retries did not wait for Retry-After: ' + gap + ' ms for two retries');
  });

  // 5. A server that stays busy: 5 retries, then the error.
  await withReachRoute(() => busy, async (p, seen) => {
    await p.goto(BASE + '/#/nodes/' + pk + '/reach');
    await p.waitForSelector('.nq-error', { timeout: 20000 });
    const msg = await p.locator('.nq-error').textContent();
    if (!msg.includes('API 429')) throw new Error('give-up error text: ' + msg);
    if (seen.n !== 6) throw new Error('reach requests ' + seen.n + ' != 6 (1 + 5 retries)');
  });

  // 6. Leaving the page while it waits stops the retries.
  await withReachRoute(() => busy, async (p, seen) => {
    await p.goto(BASE + '/#/nodes/' + pk + '/reach');
    await p.waitForSelector('.nq-busy', { timeout: 10000 });
    const atLeave = seen.n;
    await p.evaluate(() => { location.hash = '#/nodes'; });
    await p.waitForTimeout(2500);
    if (seen.n !== atLeave) throw new Error('reach retried after leaving the page: ' + atLeave + ' → ' + seen.n);
  });

  // 6b. Leaving while the request is still in flight: the late 429 must not
  // start a retry or write the hint into the page that replaced this one.
  await withReachRoute(async () => { await new Promise((r) => setTimeout(r, 1000)); return busy; }, async (p, seen) => {
    await p.goto(BASE + '/#/nodes/' + pk + '/reach');
    await p.waitForFunction(() => document.querySelector('.nq-load') !== null, null, { timeout: 10000 });
    await p.evaluate(() => { location.hash = '#/nodes'; });
    await p.waitForTimeout(2500);
    if (await p.locator('.nq-busy').count()) throw new Error('busy hint written after leaving the page');
    if (seen.n !== 1) throw new Error('reach retried after leaving mid-request: ' + seen.n + ' requests');
  });

  // 7. Other errors are not retried.
  await withReachRoute(() => ({ status: 500, body: '{"error":"reach computation failed"}', headers: { 'Retry-After': '1' } }), async (p, seen) => {
    await p.goto(BASE + '/#/nodes/' + pk + '/reach');
    await p.waitForSelector('.nq-error', { timeout: 10000 });
    await p.waitForTimeout(1500);
    if (seen.n !== 1) throw new Error('a 500 was retried: ' + seen.n + ' requests');
  });

  console.log('node-reach E2E OK');
  await browser.close();
})().catch((e) => { console.error(e); process.exit(1); });