'use strict';

// Shared sign-in flow for the E2E specs (todos 37/38). Drives the real
// user-run stack only: landing -> /oauth/start -> d-OAuth login (with the
// one-time forced password change + TOTP enrollment on a fresh user) ->
// /consent approve -> BFF dashboard. Never starts a server, never mocks.
//
// The TOTP code generator is injected (`totpCode(secret) -> code`) so the
// specs can lazily require the pinned `otplib` only when the flow runs;
// --list and the readiness probe never touch it.

const crypto = require('node:crypto');

const { saveSpecFields } = require('./helpers');

function newPassword() {
  return crypto.randomBytes(15).toString('base64url');
}

async function submitFirstForm(page) {
  const btn = page.locator('form button[type="submit"], form input[type="submit"], form button:not([type])');
  if ((await btn.count()) > 0) {
    await btn.first().click();
  } else {
    await page.locator('form').first().evaluate((form) => form.submit());
  }
}

async function extractTotpSecret(page) {
  const text = await page.locator('body').innerText();
  const uriMatch = text.match(/secret=([A-Z2-7]{16,})/);
  if (uriMatch) {
    return uriMatch[1].replace(/=+$/, '');
  }
  const href = await page.locator('a[href^="otpauth://"]').first().getAttribute('href').catch(() => null);
  if (href) {
    const secret = new URL(href).searchParams.get('secret');
    if (secret) {
      return secret.replace(/=+$/, '');
    }
  }
  throw new Error('could not capture the TOTP secret from /login/totp/setup (shown once)');
}

async function fillLoginForm(page, fixture, totpCode) {
  await page.locator('[name="email"]').fill(fixture.email);
  await page.locator('[name="password"]').fill(fixture.password);
  const codeField = page.locator('[name="code"]');
  if ((await codeField.count()) > 0) {
    if (!fixture.totp_secret) {
      throw new Error('login shows a code field but the fixture has no totp_secret');
    }
    await codeField.fill(totpCode(fixture.totp_secret));
  }
  await submitAndSettle(page);
}

function msUntilNextTotpStep() {
  return 30_000 - (Date.now() % 30_000) + 2000;
}

// Honor the AS throttle: prefer its Retry-After delay, else 60s, clamped to
// 5s..300s so a missing or absurd header cannot stall or spin the suite.
function retryAfterMs(resp) {
  const raw = resp.headers()['retry-after'];
  const secs = Number.parseInt(Array.isArray(raw) ? raw[0] : raw, 10);
  if (Number.isFinite(secs)) {
    return Math.min(300_000, Math.max(5_000, secs * 1000));
  }
  return 60_000;
}

async function waitForUrlSettled(page, timeoutMs = 15000) {
  const deadline = Date.now() + timeoutMs;
  let last = page.url();
  let stableSince = Date.now();
  for (;;) {
    await page.waitForTimeout(500);
    const now = page.url();
    if (now !== last) {
      last = now;
      stableSince = Date.now();
    } else if (Date.now() - stableSince >= 1000) {
      return;
    }
    if (Date.now() > deadline) {
      return;
    }
  }
}

async function submitAndSettle(page) {
  await submitFirstForm(page);
  await page.waitForLoadState('domcontentloaded');
  await waitForUrlSettled(page);
}

async function approveConsent(page, requestId, csrf) {
  const url = `${new URL(page.url()).origin}/consent`;
  for (let attempt = 1; attempt <= 2; attempt += 1) {
    const resp = await page.request.post(url, {
      form: { request_id: requestId, csrf, decision: 'approve' },
    });
    if (resp.ok()) {
      return;
    }
    const body = await resp.text().catch(() => '');
    const limited = resp.status() === 429 || body.includes('rate_limited');
    if (limited && attempt < 2) {
      await page.waitForTimeout(retryAfterMs(resp));
      continue;
    }
    if (limited) {
      throw new Error(`BLOCKED: AS rate-limited on POST ${url} (attempt ${attempt}): ${body.slice(0, 200)}`);
    }
    throw new Error(`consent approve failed: ${resp.status()} at ${resp.url()}: ${body.slice(0, 200)}`);
  }
}

async function gotoWithRetry(page, url) {
  let lastError;
  for (let attempt = 0; attempt < 3; attempt++) {
    try {
      await page.goto(url, { timeout: 30_000 });
      return;
    } catch (err) {
      lastError = err;
      if (!/net::ERR_|ECONNREFUSED|ETIMEDOUT/.test(err.message)) {
        throw err;
      }
      await page.waitForTimeout(1000);
    }
  }
  throw lastError;
}

async function ensureLoggedIn(page, fixture, totpCode, rateLimitRetried = false) {
  await gotoWithRetry(page, '/oauth/start');
  await page.waitForLoadState('domcontentloaded');
  if ((await page.locator('[name="email"]').count()) > 0) {
    await page.waitForTimeout(msUntilNextTotpStep());
    await fillLoginForm(page, fixture, totpCode);
    if (page.url().includes('/login')) {
      const body = await page.locator('body').innerText().catch(() => '');
      if (body.includes('rate_limited')) {
        if (rateLimitRetried) {
          throw new Error(`BLOCKED: AS rate-limited at ${page.url()}: ${body.slice(0, 200)}`);
        }
        await page.waitForTimeout(60_000);
        return ensureLoggedIn(page, fixture, totpCode, true);
      }
      throw new Error(`login did not leave /login at ${page.url()}: ${body.slice(0, 200)}`);
    }
  }
  if (page.url().includes('/login/change-password')) {
    const next = newPassword();
    await page.locator('[name="new_password"]').fill(next);
    await page.locator('[name="confirm"]').fill(next);
    fixture.password = next;
    await submitAndSettle(page);
  }
  if (page.url().includes('/login/totp/setup')) {
    fixture.totp_secret = await extractTotpSecret(page);
    saveSpecFields(fixture);
    const origin = new URL(page.url()).origin;
    await page.goto(`${origin}/login/totp/confirm`);
    await page.waitForLoadState('domcontentloaded');
  }
  if (page.url().includes('/login/totp/confirm') || page.url().includes('/login/totp')) {
    await page.locator('[name="code"]').fill(totpCode(fixture.totp_secret));
    await submitAndSettle(page);
  }
  // Approve via the context API client, not an in-page click: this Chromium
  // build aborts following the approval 302 (https AS -> http BFF callback,
  // net::ERR_ABORTED, proven by netlog: 302 received then CANCELLED with no
  // follow-up request). Same endpoint, same cookies, same form fields.
  if (page.url().includes('/consent')) {
    const requestId = await page.locator('[name="request_id"]').inputValue();
    const csrf = await page.locator('[name="csrf"]').inputValue();
    await approveConsent(page, requestId, csrf);
  }
  const check = await page.request.get('/api/session').catch(() => null);
  if (!check || check.status() !== 200) {
    const body = await page.locator('body').innerText().catch(() => '');
    const hasForm = (await page.locator('[name="email"]').count()) > 0;
    throw new Error(
      `no BFF session after sign-in (page at ${page.url()}, session status ${check ? check.status() : 'request failed'}, hasLoginForm=${hasForm}): ${body.slice(0, 200)}`,
    );
  }
}

async function awaitSession(page, timeoutMs = 15000) {
  const deadline = Date.now() + timeoutMs;
  let lastStatus = 0;
  for (;;) {
    const res = await page.request.get('/api/session');
    lastStatus = res.status();
    if (res.status() === 200) {
      return await res.json();
    }
    if (Date.now() > deadline) {
      throw new Error(`timed out waiting for /api/session 200 (last status ${lastStatus})`);
    }
    await page.waitForTimeout(500);
  }
}

module.exports = { ensureLoggedIn, awaitSession, submitFirstForm, extractTotpSecret, newPassword };