"""Render and smoke-check the delivered local HTML using a temporary headless browser."""
from pathlib import Path
import base64
import json
import shutil
import subprocess
import tempfile
import time
import urllib.request
import websocket

ASSETS = Path(__file__).resolve().parent
ROOT = ASSETS.parent
PAGE = ROOT / 'Week7_Stata代码详解.html'
browser = Path(r'C:\Program Files\Google\Chrome\Application\chrome.exe')
profile = Path(tempfile.mkdtemp(prefix='browser_profile_', dir=ASSETS)).resolve()
stderr = (ASSETS / 'browser_stderr.log').open('w', encoding='utf-8')
process = subprocess.Popen([
    str(browser), '--headless=new', '--disable-gpu', '--no-sandbox', '--disable-gpu-sandbox', '--no-first-run',
    '--no-default-browser-check', '--disable-extensions', '--disable-sync',
    '--disable-background-networking', '--disable-component-update',
    '--remote-debugging-port=0', '--user-data-dir=' + str(profile), 'about:blank'
], stdout=subprocess.DEVNULL, stderr=stderr, creationflags=subprocess.CREATE_NO_WINDOW)
socket = None
errors = []
events = []
seq = 0


def command(method, params=None):
    global seq
    seq += 1
    message_id = seq
    socket.send(json.dumps({'id': message_id, 'method': method, 'params': params or {}}))
    while True:
        response = json.loads(socket.recv())
        if response.get('method') == 'Runtime.exceptionThrown':
            errors.append(response['params'])
        if response.get('method'):
            events.append(response)
        if response.get('id') == message_id:
            if 'error' in response:
                raise RuntimeError(response['error'])
            return response.get('result', {})


def evaluate(expression):
    response = command('Runtime.evaluate', {'expression': expression, 'returnByValue': True, 'awaitPromise': True})
    if 'exceptionDetails' in response:
        raise RuntimeError(response['exceptionDetails'])
    return response.get('result', {}).get('value')


def settle():
    evaluate('new Promise(resolve=>requestAnimationFrame(()=>requestAnimationFrame(resolve)))')


def screenshot(name):
    settle()
    result = command('Page.captureScreenshot', {'format': 'png', 'captureBeyondViewport': False})
    (ASSETS / name).write_bytes(base64.b64decode(result['data']))


try:
    port_file = profile / 'DevToolsActivePort'
    deadline = time.monotonic() + 25
    while not port_file.exists() and time.monotonic() < deadline:
        if process.poll() is not None:
            raise RuntimeError('Browser exited before opening DevTools')
        time.sleep(.1)
    port = port_file.read_text().splitlines()[0]
    opener = urllib.request.build_opener(urllib.request.ProxyHandler({}))
    with opener.open(f'http://127.0.0.1:{port}/json/list', timeout=5) as response:
        targets = json.load(response)
    target = next(item for item in targets if item['type'] == 'page')
    socket = websocket.create_connection(target['webSocketDebuggerUrl'], timeout=20, suppress_origin=True)
    command('Page.enable')
    command('Runtime.enable')
    command('Page.addScriptToEvaluateOnNewDocument', {'source': 'window.matchMediaOriginal=window.matchMedia;'})
    command('Emulation.setDeviceMetricsOverride', {'width': 1440, 'height': 1000, 'deviceScaleFactor': 1, 'mobile': False})
    command('Page.navigate', {'url': PAGE.as_uri()})
    deadline = time.monotonic() + 20
    while time.monotonic() < deadline:
        if evaluate('document.readyState') == 'complete':
            break
        time.sleep(.1)
    evaluate('document.fonts.ready.then(()=>true)')
    evaluate("document.documentElement.style.scrollBehavior='auto'; true")
    checks = evaluate('''(()=>({
      title:document.title,
      sections:document.querySelectorAll('main section').length,
      codeBlocks:document.querySelectorAll('.code-block').length,
      anchorsValid:[...document.querySelectorAll('a[href^="#"]')].every(a=>document.getElementById(a.hash.slice(1))),
      imageLoaded:[...document.images].every(i=>i.complete && i.naturalWidth>0),
      viewport:innerWidth, documentWidth:document.documentElement.scrollWidth,
      externalResources:performance.getEntriesByType('resource').filter(r=>/^https?:/.test(r.name)).length,
      codeTextMatches:[...document.querySelectorAll('.code-block')].every(b=>[...b.querySelectorAll('.src')].map(s=>s.textContent).join('\\n')===new TextDecoder().decode(Uint8Array.from(atob(b.dataset.source),c=>c.charCodeAt(0))))
    }))()''')
    assert checks['sections'] == 20
    assert checks['codeBlocks'] == 17
    assert checks['anchorsValid'] and checks['imageLoaded'] and checks['codeTextMatches']
    assert checks['externalResources'] == 0
    assert checks['documentWidth'] <= checks['viewport']
    screenshot('preview_desktop.png')
    evaluate("document.getElementById('audit').scrollIntoView(); true")
    screenshot('preview_code.png')
    evaluate("document.querySelector('#plot figure').scrollIntoView(); true")
    screenshot('preview_figure.png')
    # Exercise the print event without launching a print UI.
    evaluate("window.__printClicked=false; window.print=()=>{window.__printClicked=true};document.getElementById('print-btn').click();true")
    assert evaluate('window.__printClicked') is True
    # Clipboard is mocked to verify payload; browser permission itself is not asserted.
    evaluate("window.__copiedText=null;Object.defineProperty(navigator,'clipboard',{configurable:true,value:{writeText:async text=>{window.__copiedText=text}}});document.querySelector('.copy-btn').click();true")
    settle()
    copied = evaluate('window.__copiedText')
    assert copied == '\n'.join((ROOT / 'week7_analysis.do').read_text(encoding='utf-8-sig').splitlines()[:8])
    evaluate("document.getElementById('copy-status').textContent='';true")
    command('Emulation.setDeviceMetricsOverride', {'width': 390, 'height': 844, 'deviceScaleFactor': 1, 'mobile': True})
    evaluate('scrollTo({top:0,behavior:"instant"});true')
    settle()
    mobile = evaluate('({viewport:innerWidth,documentWidth:document.documentElement.scrollWidth,mobileNav:getComputedStyle(document.querySelector(".mobile-nav")).display,sidebar:getComputedStyle(document.querySelector(".sidebar")).display})')
    assert mobile['documentWidth'] <= mobile['viewport']
    assert mobile['mobileNav'] != 'none' and mobile['sidebar'] == 'none'
    screenshot('preview_mobile.png')
    evaluate('document.querySelector(".mobile-nav summary").click();true')
    assert evaluate('document.querySelector(".mobile-nav").open') is True
    evaluate('''document.querySelector(".mobile-nav a[href='#reshape']").click();true''')
    settle()
    assert evaluate('document.querySelector(".mobile-nav").open') is False
    assert evaluate('location.hash') == '#reshape'
    screenshot('preview_mobile_code.png')
    # Check the long plot command fits in its code container at narrow width.
    narrow = evaluate('''(()=>{const b=document.querySelector('#plot .code-block');return {width:b.clientWidth,scrollWidth:b.scrollWidth,viewport:innerWidth,documentWidth:document.documentElement.scrollWidth}})()''')
    assert narrow['scrollWidth'] <= narrow['width'] + 1
    assert narrow['documentWidth'] <= narrow['viewport']
    # Emulate print CSS to check navigation and action buttons disappear.
    command('Emulation.setEmulatedMedia', {'media': 'print'})
    assert evaluate('getComputedStyle(document.querySelector(".back-top")).display') == 'none'
    command('Emulation.setEmulatedMedia', {'media': ''})
    assert not errors, errors
    result = {'status': 'passed', 'desktop': checks, 'mobile': mobile, 'long_code_mobile': narrow,
              'runtime_exceptions': errors, 'copy_payload_verified_with_mock_clipboard': True,
              'print_action_verified_with_mock_handler': True, 'mobile_navigation_verified': True,
              'print_css_verified': True,
              'screenshots': ['preview_desktop.png', 'preview_code.png', 'preview_figure.png', 'preview_mobile.png', 'preview_mobile_code.png']}
    (ASSETS / 'browser_verification.json').write_text(json.dumps(result, ensure_ascii=False, indent=2), encoding='utf-8')
    print(json.dumps(result, ensure_ascii=True, indent=2))
finally:
    if socket:
        try:
            command('Browser.close')
        except Exception:
            pass
        socket.close()
    try:
        process.wait(timeout=8)
    except subprocess.TimeoutExpired:
        process.terminate()
        process.wait(timeout=5)
    stderr.close()
    # Delete only the unique profile created by this script, inside its own assets directory.
    assert profile.parent == ASSETS.resolve() and profile.name.startswith('browser_profile_')
    shutil.rmtree(profile, ignore_errors=True)