import { spawn } from 'node:child_process';
import { writeFileSync, mkdirSync } from 'node:fs';
import { join } from 'node:path';

const CHROME_PATH = 'C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe';
const USER_DATA = join(process.cwd(), '.chrome-test-profile');
const SCREENSHOT_DIR = join(process.cwd(), 'test-support', 'visual-evidence');

try {
  mkdirSync(SCREENSHOT_DIR, { recursive: true });
} catch {}

async function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

async function run() {
  console.log('[Browser Verification] Starting Chrome in headless mode...');
  const chrome = spawn(
    CHROME_PATH,
    [
      '--headless=new',
      '--remote-debugging-port=9222',
      '--disable-gpu',
      '--no-first-run',
      '--no-default-browser-check',
      `--user-data-dir=${USER_DATA}`,
      '--window-size=1280,960',
      'about:blank',
    ],
    { stdio: 'ignore' }
  );

  try {
    // Wait for Chrome remote debugging endpoint
    let versionData = null;
    for (let i = 0; i < 30; i++) {
      try {
        const res = await fetch('http://127.0.0.1:9222/json/version');
        if (res.ok) {
          versionData = await res.json();
          break;
        }
      } catch {}
      await sleep(200);
    }

    if (!versionData) {
      throw new Error('Failed to connect to Chrome DevTools endpoint on port 9222');
    }
    console.log('[Browser Verification] Connected to Chrome DevTools:', versionData.Browser);

    // Create a new target page
    const testUrl = process.env.REPLAY_TEST_URL || process.argv[2] || 'http://localhost:3008/account';
    const newTargetRes = await fetch(`http://127.0.0.1:9222/json/new?${encodeURIComponent(testUrl)}`, {
      method: 'PUT',
    });
    const target = await newTargetRes.json();
    console.log('[Browser Verification] Opened target page:', target.id);

    const ws = new WebSocket(target.webSocketDebuggerUrl);

    let messageId = 1;
    const callbacks = new Map();

    ws.onmessage = (event) => {
      const msg = JSON.parse(event.data);
      if (msg.id && callbacks.has(msg.id)) {
        const cb = callbacks.get(msg.id);
        callbacks.delete(msg.id);
        if (msg.error) {
          cb.reject(new Error(msg.error.message));
        } else {
          cb.resolve(msg.result);
        }
      }
    };

    await new Promise((resolve) => {
      ws.onopen = resolve;
    });

    const send = (method, params = {}) => {
      return new Promise((resolve, reject) => {
        const id = messageId++;
        callbacks.set(id, { resolve, reject });
        ws.send(JSON.stringify({ id, method, params }));
      });
    };

    await send('Page.enable');
    await send('Runtime.enable');

    console.log('[Browser Verification] Waiting for page load and Leaflet map rendering...');
    await sleep(2500);

    const evalJs = async (expr) => {
      const res = await send('Runtime.evaluate', {
        expression: expr,
        returnByValue: true,
        awaitPromise: true,
      });
      return res?.result?.value;
    };

    // 1. Verify modal title and elements
    const title = await evalJs('document.querySelector("h2")?.textContent');
    console.log('[Browser Verification] Modal Title:', title);

    const markerExists = await evalJs('!!document.querySelector(".rider-replay-marker")');
    console.log('[Browser Verification] Rider marker in DOM:', markerExists);

    const initialPos = await evalJs(`(() => {
      const el = document.querySelector(".rider-replay-marker");
      const arrow = document.querySelector(".rider-heading-arrow");
      return {
        markerTransform: el ? el.style.transform : null,
        arrowTransform: arrow ? arrow.style.transform : null,
      };
    })()`);
    console.log('[Browser Verification] Initial Marker State:', initialPos);

    // Capture screenshot: initial
    const snap1 = await send('Page.captureScreenshot', { format: 'png' });
    writeFileSync(join(SCREENSHOT_DIR, '01_initial_replay.png'), Buffer.from(snap1.data, 'base64'));
    console.log('[Browser Verification] Saved screenshot: 01_initial_replay.png');

    // 2. Click Play
    console.log('[Browser Verification] Clicking PLAY...');
    await evalJs('document.querySelector(\'[data-testid="play-pause-btn"]\')?.click()');
    await sleep(100);

    // Sample marker positions over 300 ms (approx 18 animation frames)
    console.log('[Browser Verification] Sampling marker positions in motion across animation frames...');
    const samples = [];
    for (let i = 0; i < 6; i++) {
      await sleep(50);
      const sample = await evalJs(`(() => {
        const el = document.querySelector(".rider-replay-marker");
        const arrow = document.querySelector(".rider-heading-arrow");
        const speed = document.querySelector(".text-3xl.font-extrabold")?.textContent;
        return {
          markerTransform: el ? el.style.transform : null,
          arrowTransform: arrow ? arrow.style.transform : null,
          speed,
        };
      })()`);
      samples.push(sample);
    }
    console.log('[Browser Verification] Recorded motion frames:');
    samples.forEach((s, idx) => console.log(`  Frame sample ${idx + 1}: ${s.markerTransform} | heading: ${s.arrowTransform} | speed: ${s.speed} mph`));

    // Verify intermediate sub-pixel movement occurred
    const uniqueTransforms = new Set(samples.map((s) => s.markerTransform));
    console.log(`[Browser Verification] Unique positions observed in 300ms: ${uniqueTransforms.size} / ${samples.length}`);
    if (uniqueTransforms.size > 1) {
      console.log('>>> SUCCESS: Marker smoothly animated across intermediate screen positions! <<<');
    } else {
      console.error('>>> FAIL: Marker did not move! <<<');
    }

    // Capture screenshot: in motion
    const snap2 = await send('Page.captureScreenshot', { format: 'png' });
    writeFileSync(join(SCREENSHOT_DIR, '02_motion_replay.png'), Buffer.from(snap2.data, 'base64'));
    console.log('[Browser Verification] Saved screenshot: 02_motion_replay.png');

    // 3. Click Pause
    console.log('[Browser Verification] Clicking PAUSE...');
    await evalJs('document.querySelector(\'[data-testid="play-pause-btn"]\')?.click()');
    const pausedState1 = await evalJs('document.querySelector(".rider-replay-marker")?.style.transform');
    console.log('[Browser Verification] Position immediately upon pause:', pausedState1);

    await sleep(500);
    const pausedState2 = await evalJs('document.querySelector(".rider-replay-marker")?.style.transform');
    console.log('[Browser Verification] Position 500ms after pause (checking drift):', pausedState2);

    if (pausedState1 === pausedState2) {
      console.log('>>> SUCCESS: Zero marker drift on pause! <<<');
    } else {
      console.error('>>> FAIL: Marker drifted while paused! <<<');
    }

    // Capture screenshot: paused
    const snap3 = await send('Page.captureScreenshot', { format: 'png' });
    writeFileSync(join(SCREENSHOT_DIR, '03_paused_replay.png'), Buffer.from(snap3.data, 'base64'));
    console.log('[Browser Verification] Saved screenshot: 03_paused_replay.png');

    // 4. Test Speed change to 2x and Resume
    console.log('[Browser Verification] Testing speed change to 2x and resume...');
    await evalJs(`(() => {
      const btn = Array.from(document.querySelectorAll("button")).find(b => b.textContent.trim() === "2x");
      btn?.click();
    })()`);
    await sleep(100);

    await evalJs('document.querySelector(\'[data-testid="play-pause-btn"]\')?.click()');
    await sleep(300);

    const speedSample = await evalJs('document.querySelector(".rider-replay-marker")?.style.transform');
    console.log('[Browser Verification] Position after 2x speed playback:', speedSample);

    // 5. Test Seek to exact point 100
    console.log('[Browser Verification] Testing timeline seek...');
    await evalJs(`(() => {
      const slider = document.querySelector('[data-testid="replay-timeline-slider"]');
      if (slider) {
        slider.value = '100';
        slider.dispatchEvent(new Event('change', { bubbles: true }));
      }
    })()`);
    await sleep(150);

    const seekPos = await evalJs(`(() => {
      const el = document.querySelector(".rider-replay-marker");
      const arrow = document.querySelector(".rider-heading-arrow");
      return {
        markerTransform: el ? el.style.transform : null,
        arrowTransform: arrow ? arrow.style.transform : null,
      };
    })()`);
    console.log('[Browser Verification] Position after seek to point 100:', seekPos);

    // Capture screenshot: seek
    const snap4 = await send('Page.captureScreenshot', { format: 'png' });
    writeFileSync(join(SCREENSHOT_DIR, '04_seek_replay.png'), Buffer.from(snap4.data, 'base64'));
    console.log('[Browser Verification] Saved screenshot: 04_seek_replay.png');

    ws.close();
  } finally {
    chrome.kill('SIGKILL');
    console.log('[Browser Verification] Chrome process terminated.');
  }
}

run().catch((err) => {
  console.error('[Browser Verification Error]:', err);
  process.exit(1);
});