const assert = require('node:assert/strict');
const path = require('node:path');
const { randomUUID } = require('node:crypto');
const { mkdtempSync, mkdirSync } = require('node:fs');
const { createRequire } = require('node:module');
const root = path.resolve(__dirname, '../..');
const clientRequire = createRequire(path.join(root, 'client/package.json'));
const { chromium, expect } = clientRequire('@playwright/test');

// D1 diagnostic: the company-representative authorization dialog pages its
// lender list (30 per page). With the target lender on page 3, compare the old
// test loop (response-only wait) with a loop that waits for the option list to
// change, under CPU throttling that models a loaded host. Synthetic data only.
async function authorizationDialog(page) {
  await page.getByRole('tab', { name: '公司代表授权', exact: true }).click({ timeout: 30000 });
  await page.getByRole('button', { name: '登记公司代表授权范围', exact: true }).click();
  const dialog = page.getByRole('dialog');
  await expect(dialog.getByLabel('授权出借人').locator('option').nth(1)).toBeAttached({ timeout: 30000 });
  return dialog;
}
const optionValues = (dialog) => dialog.getByLabel('授权出借人').locator('option').evaluateAll((os) => os.map((o) => o.value).join(','));

// The original loop from company-loan-employee-browser.cjs (before D1).
async function oldLoop(page, dialog, targetId, timeout) {
  for (let i = 0; !(await dialog.getByLabel('授权出借人').locator(`option[value="${targetId}"]`).count()); i++) {
    assert.ok(i < 20);
    await Promise.all([page.waitForResponse((r) => r.url().includes('/loan-lenders?page='), { timeout }),
      dialog.getByRole('button', { name: '下一页出借人', exact: true }).click({ timeout })]);
  }
}

// Wait for the rendered options to change after each page step (works for
// network responses and cache hits alike).
async function stepTo(dialog, direction) {
  const before = await optionValues(dialog);
  const button = dialog.getByRole('button', { name: direction === 'next' ? '下一页出借人' : '上一页出借人', exact: true });
  await expect(button).toBeEnabled({ timeout: 10000 });
  await button.click();
  // The list empties while a page loads; only a loaded, different page counts.
  await expect.poll(async () => { const now = await optionValues(dialog); return now.split(',').length > 1 && now !== before; },
    { timeout: 15000 }).toBe(true);
}
async function newLoop(dialog, targetId) {
  const target = dialog.getByLabel('授权出借人').locator(`option[value="${targetId}"]`);
  while (await dialog.getByRole('button', { name: '上一页出借人', exact: true }).isEnabled()) await stepTo(dialog, 'previous');
  for (let i = 0; !(await target.count()); i++) { assert.ok(i < 20, 'target lender not found on any page'); await stepTo(dialog, 'next'); }
}

module.exports = async function paginationDiagnostic(h) {
  const { app, prisma, call, finance, manager, password, config, verifiedLender, confirmedLoan } = h;
  const checks = [];
  // Fillers are eligible for the dialog (verified, linked to their own employee),
  // so the target is reached only by real paging, with or without a server filter.
  for (let n = 0; n < 64; n++) {
    const staff = await h.actor(['employee']);
    await verifiedLender(`合成翻页-${String(n).padStart(2, '0')}`, staff.id, '5');
  }
  const target = await verifiedLender('合成翻页-目标', manager.id, '3');
  const loan = await confirmedLoan(target.id, '100.00', '合成翻页目标借款');
  // Explicit exclusions prove that filtering is applied before pagination and
  // count, including the current finance actor and an unverified linked lender.
  const own = await verifiedLender('合成翻页-本人排除', finance.id, '4');
  const unverified = await call(finance, 'POST', '/loan-lenders', { legalEntityId: h.company.id, name: '合成翻页-未核实排除',
    bankInstitutionId: h.bank.id, bankName: '合成', bankAccount: '9'.repeat(16), accountName: '合成翻页-未核实排除', requestKey: randomUUID() });
  // The dialog pages the server-filtered list of lenders it can offer.
  const pages = [];
  for (let p = 1; ; p++) {
    const r = await call(finance, 'GET', `/loan-lenders?page=${p}&pageSize=30&eligible=related_authority`);
    assert.ok(r.items.every((i) => i.identityStatus === 'verified' && i.employeeId && i.employeeId !== finance.id), 'filter returns only offerable lenders');
    pages.push(r.items.map((i) => i.id)); if (p * 30 >= r.total) break;
  }
  const all = await call(finance, 'GET', '/loan-lenders?page=1&pageSize=30');
  await call(finance, 'GET', '/loan-lenders?page=1&pageSize=30&eligible=other', undefined, 400);
  for (const who of [manager, h.ordinary]) await call(who, 'GET', '/loan-lenders?eligible=related_authority', undefined, 403);
  assert.ok(!pages.flat().includes(own.id) && !pages.flat().includes(unverified.id));
  assert.equal(pages.flat().length, 65, 'eligible total excludes unlinked, unverified and self lenders');
  checks.push(`eligible_filter_total_${pages.flat().length}_of_${all.total}`);
  const targetPage = pages.findIndex((ids) => ids.includes(target.id)) + 1;
  assert.ok(targetPage >= 3, `target lender must be on page 3 or later, observed ${targetPage}`);
  checks.push(`target_on_page_${targetPage}_of_${pages.length}`);

  const browser = await chromium.launch({ headless: true, args: ['--disable-background-networking'] });
  const origin = await app.listen({ host: '127.0.0.1', port: 0 });
  const base = path.join(root, 'artifacts/qa-flow/loan-browser-diagnostics-20261010/authorization-pagination'); mkdirSync(base, { recursive: true });
  const output = mkdtempSync(path.join(base, 'run-'));
  const oldOrigin = config.appOrigin; config.appOrigin = origin;
  const results = [];
  const record = (entry) => { results.push(entry); console.log(JSON.stringify({ stage: 'loan_authorization_pagination_step', ...entry })); };
  try {
    for (const mode of ['desktop', 'mobile']) {
      const context = await browser.newContext({ viewport: mode === 'mobile' ? { width: 390, height: 844 } : { width: 1440, height: 1000 }, serviceWorkers: 'block' });
      await context.route('**/*', (route) => route.request().url().startsWith(`${origin}/`) ? route.continue() : route.abort());
      await context.tracing.start({ screenshots: true, snapshots: true });
      const page = await context.newPage();
      const requests = [];
      page.on('request', (r) => { if (r.url().includes('/loan-lenders?page=')) requests.push(new URL(r.url()).searchParams.get('page')); });
      try {
        await page.goto(`${origin}/login?redirect=${encodeURIComponent(`${mode === 'mobile' ? '/mobile' : ''}/company-loans`)}`);
        await page.getByTestId('login-identifier').fill(finance.email); await page.getByTestId('login-password').fill(password);
        await page.getByTestId('login-submit').click(); await expect(page.getByRole('heading', { name: '公司借款', exact: true })).toBeVisible();
        const cdp = await context.newCDPSession(page);

        // 0. Counterexample before any paging (only page 1 cached): page 2 is answered
        // with page 1's data, so the list never changes and the new wait must fail.
        let dialog = await authorizationDialog(page);
        await page.route('**/api/loan-lenders?page=*', (route) => {
          const url = new URL(route.request().url()); url.searchParams.set('page', '1');
          return route.continue({ url: url.toString() });
        });
        await stepTo(dialog, 'next').then(() => { throw new Error('a page that never changes must not satisfy the wait'); },
          (error) => { assert.ok(/toBe|Timeout|expect/i.test(String(error.message)), String(error.message).slice(0, 200)); });
        await page.unroute('**/api/loan-lenders?page=*');
        record({ mode, step: 'unchanged_page_counterexample', outcome: 'new wait fails as required' });
        await page.keyboard.press('Escape'); await expect(page.getByRole('dialog')).toHaveCount(0);
        await page.reload(); await expect(page.getByRole('heading', { name: '公司借款', exact: true })).toBeVisible({ timeout: 30000 });
        requests.length = 0;

        // 1. Old loop under a loaded host: does it reproduce the timeout?
        await cdp.send('Emulation.setCPUThrottlingRate', { rate: 20 });
        dialog = await authorizationDialog(page);
        let oldOutcome = 'pass';
        try { await oldLoop(page, dialog, target.id, 8000); } catch (error) { oldOutcome = error.name === 'TimeoutError' ? 'timeout' : `error:${error.name}`; }
        const landed = await dialog.getByLabel('授权出借人').locator(`option[value="${target.id}"]`).count();
        await page.keyboard.press('Escape'); await expect(page.getByRole('dialog')).toHaveCount(0);
        record({ mode, step: 'old_loop_throttled', outcome: oldOutcome, targetVisibleAfter: landed > 0, requests: [...requests] });

        // 2. Reopen: which lender page does the dialog start on?
        requests.length = 0;
        dialog = await authorizationDialog(page);
        const firstPage = (await optionValues(dialog)).split(',').filter(Boolean);
        const startsOnPage = pages.findIndex((ids) => ids.some((id) => firstPage.includes(id))) + 1;
        record({ mode, step: 'reopen_start_page', startsOnPage });
        assert.equal(startsOnPage, 1, 'reopening the dialog starts from the first lender page');
        assert.deepEqual(firstPage, pages[0], 'reopening renders precisely the first page');

        // 3. New loop, throttled, including returning to page 1 first.
        await newLoop(dialog, target.id);
        assert.equal(await dialog.getByLabel('授权出借人').locator(`option[value="${target.id}"]`).count(), 1);
        assert.deepEqual((await optionValues(dialog)).split(',').filter(Boolean), pages[targetPage - 1]);
        // 4. Cache: step back and forward again; the forward step may be served from cache.
        const beforeCache = requests.length;
        await stepTo(dialog, 'previous');
        assert.deepEqual((await optionValues(dialog)).split(',').filter(Boolean), pages[targetPage - 2]);
        await stepTo(dialog, 'next');
        assert.deepEqual((await optionValues(dialog)).split(',').filter(Boolean), pages[targetPage - 1]);
        record({ mode, step: 'new_loop_throttled_with_cache', outcome: 'pass', requestsDuringBackForward: requests.length - beforeCache });
        await cdp.send('Emulation.setCPUThrottlingRate', { rate: 1 });

        // The third-page target must be usable, not merely visible. Finance
        // proposes this scope and its designated representative confirms it.
        await dialog.getByLabel('授权出借人').selectOption(target.id);
        await dialog.getByRole('checkbox', { name: new RegExp(loan.loanNo) }).check();
        await dialog.getByLabel('代表权及授权范围依据').fill('合成第三页目标公司代表权及借款范围');
        const proposed = page.waitForResponse(r => new URL(r.url()).pathname === '/api/loan-related-authorizations' && r.request().method() === 'POST');
        await dialog.getByRole('button', { name: '确认', exact: true }).click();
        const proposalResponse = await proposed; assert.equal(proposalResponse.status(), 200);
        const authorizationId = (await proposalResponse.json()).data.id;
        await expect(dialog).not.toBeVisible();
        const representative = await browser.newContext({ viewport: mode === 'mobile' ? { width: 390, height: 844 } : { width: 1440, height: 1000 }, serviceWorkers: 'block' });
        try {
          await representative.route('**/*', route => route.request().url().startsWith(`${origin}/`) ? route.continue() : route.abort());
          const rp = await representative.newPage();
          await rp.goto(`${origin}/login?redirect=${encodeURIComponent(`${mode === 'mobile' ? '/mobile' : ''}/company-loans`)}`);
          await rp.getByTestId('login-identifier').fill(manager.email); await rp.getByTestId('login-password').fill(password);
          await rp.getByTestId('login-submit').click(); await expect(rp.getByRole('heading', { name: '公司借款', exact: true })).toBeVisible();
          await rp.getByRole('button', { name: '代表公司确认授权范围', exact: true }).click();
          const rd = rp.getByRole('dialog'); await expect(rd).toContainText(loan.loanNo);
          await rd.getByLabel('确认或停止的理由').fill('合成本人核对第三页借款及公司代表范围');
          const confirmed = rp.waitForResponse(r => new URL(r.url()).pathname === `/api/loan-related-authorizations/${authorizationId}/actions` && r.request().method() === 'POST');
          await rd.getByRole('button', { name: '确认', exact: true }).click();
          assert.equal((await confirmed).status(), 200); await expect(rd).not.toBeVisible();
        } finally { await representative.close(); }
        const saved = await prisma.loanRelatedAuthorization.findUniqueOrThrow({ where: { id: authorizationId }, include: { events: true, loans: true } });
        assert.equal(saved.approver_id, manager.id); assert.equal(saved.proposed_by, finance.id);
        assert.deepEqual(saved.loans.map(r => r.loan_id), [loan.id]);
        assert.ok(saved.events.some(r => r.action === 'confirm' && r.actor_id === manager.id));
        assert.ok(await prisma.auditLog.count({ where: { action: 'LOAN_RELATED_AUTHORIZATION_DECIDED', target_id: authorizationId } }));
        assert.equal(await prisma.loanRepayment.count({ where: { lender_id: target.id } }), 0);
        record({ mode, step: 'third_page_scope_proposed_and_confirmed', outcome: 'pass', zeroRepayments: true });

        checks.push(`${mode}_pagination_diagnosed`);
      } finally {
        await context.tracing.stop({ path: path.join(output, `trace-${mode}.zip`) });
        await page.screenshot({ path: path.join(output, `final-${mode}.png`), fullPage: true }).catch(() => {});
        await context.close();
      }
    }
  } finally { config.appOrigin = oldOrigin; await browser.close(); }
  assert.ok(loan.id);
  console.log(JSON.stringify({ stage: 'loan_authorization_pagination_diagnostic', status: 'PASS', checks, results, output: path.relative(root, output) }));
  return results;
};