import { test, expect, chromium } from '@playwright/test';
import { execFileSync } from 'node:child_process';
import { mkdtempSync, rmSync } from 'node:fs';
import { tmpdir } from 'node:os';
import path from 'node:path';
import { PROBE_SCRIPT } from '../lib/probe';
import { throttle } from '../lib/cdp';
import { append } from '../lib/results';

const BUSY = 'file://' + path.resolve(__dirname, '../fixtures/busy.html');
const PERF_DIR = path.resolve(__dirname, '../..');

test('probe detects long task', async ({ page }) => {
  await page.addInitScript(PROBE_SCRIPT);
  await page.goto(BUSY);
  await page.evaluate(() => (window as any).__perf.start());
  await page.click('#busy');
  const m = await page.evaluate(() => (window as any).__perf.stop());
  expect(m.long_task_n).toBeGreaterThanOrEqual(1);
  expect(m.long_task_ms).toBeGreaterThanOrEqual(100);
  expect(m.frame_n).toBeGreaterThan(0);
  expect(m.duration_ms).toBeGreaterThan(0);
});

test('throttle slows script', async ({ page }) => {
  await page.goto(BUSY);
  const loop = () => page.evaluate(() => {
    const t = performance.now();
    let x = 0;
    for (let i = 0; i < 3e7; i++) x += i % 7;
    return performance.now() - t + x * 0;
  });
  await throttle(page, 1);
  const base = await loop();
  await throttle(page, 4);
  const slow = await loop();
  expect(slow).toBeGreaterThanOrEqual(2 * base);
});

test('fresh context isolation', async ({ browser }) => {
  const a = await browser.newContext();
  const pa = await a.newPage();
  await pa.goto(BUSY);
  await pa.evaluate(() => localStorage.setItem('k', 'v'));
  const b = await browser.newContext();
  const pb = await b.newPage();
  await pb.goto(BUSY);
  expect(await pb.evaluate(() => localStorage.getItem('k'))).toBeNull();
  await a.close();
  await b.close();
});

test('results format', async () => {
  const tmp = mkdtempSync(path.join(tmpdir(), 'perf-'));
  const runDir = path.join(tmp, `harness-${Date.now()}`);
  process.env.PERF_RESULTS_DIR = runDir;
  append({
    scenario: 'harness', target: 'prod', role: 'admin', scale: 1, cpu_rate: 1, repeat: 0,
    metrics: { long_task_ms: 123.4 }, artifacts: [],
  });
  const py = path.join(PERF_DIR, '.venv/bin/python');
  const out = execFileSync(py, ['-m', 'perfkit.aggregate', runDir], { cwd: PERF_DIR }).toString().trim();
  const summary = JSON.parse(execFileSync('cat', [path.join(out, 'summary.json')]).toString());
  expect(summary.groups).toHaveLength(1);
  expect(summary.groups[0].n).toBe(1);
  rmSync(tmp, { recursive: true, force: true });
  rmSync(out, { recursive: true, force: true });
});