import { render } from 'preact';
import { readBootstrap } from './bootstrap';
import { App } from './App';
import { createT } from './i18n';
import { WidgetApi } from './widget-api';
import './styles.css';

// Input-mode detector for hover styling. CSS gates `:hover` and
// `:focus-visible` rules on `:root[data-input="mouse"]` because Capacitor's
// Android Chromium WebView synthesises `:hover` on the focused element
// after a tap and never clears it until the next interaction elsewhere —
// without the gate, every tap leaves a sticky hover state on the tapped
// card («card greys out after tap and only un-greys when you tap a
// different button»).
//
// Truth comes from `pointerdown.pointerType`. The capture-phase listener
// runs in the same task as any post-tap `:hover` synthesis, so a touch
// tap on Android lands in 'touch' mode in the same render frame as the
// synthesised hover would paint.
//
// Initial mode is plain 'mouse' — matchMedia-based guessing was tried and
// dropped: every interaction-media query is mis-reported on at least one
// shipping device (see git history for the survey). Defaulting to 'mouse'
// is strictly no worse on any device: a desktop user gets hover from frame
// zero, and a touch user cannot trigger `:hover` before tapping — by the
// time the first tap fires, our listener has already moved the attribute
// to 'touch'.
const setInputMode = (mode: 'touch' | 'mouse'): void => {
  document.documentElement.dataset.input = mode;
};
setInputMode('mouse');
window.addEventListener(
  'pointerdown',
  (event) => {
    setInputMode(event.pointerType === 'mouse' ? 'mouse' : 'touch');
  },
  { passive: true, capture: true }
);

const root = document.getElementById('app');
if (!root) {
  throw new Error('#app root element missing — index.html out of sync');
}

const result = readBootstrap(window.location.search);

if (!result.ok) {
  // Either someone opened the widget URL directly (no host params), or a
  // host bug failed to provide them. Either way render a self-contained
  // diagnostic instead of going silent. Bootstrap failed before we could
  // read clientLanguage from the URL, so let createT fall back to
  // navigator.language.
  const t = createT();
  render(
    <div class="app">
      <div class="error-banner">
        <strong>{t('bootstrap.failed')}</strong>
        {t('bootstrap.missing-params', { names: result.missing.join(', ') })}{' '}
        {t('bootstrap.embedded-only', { route: '/bots/telegram' })}
      </div>
    </div>,
    root
  );
} else {
  // Apply initial theme synchronously so the first paint isn't flashed
  // through the wrong palette.
  document.documentElement.dataset.theme = result.bootstrap.theme;

  // Instantiate the WidgetApi BEFORE the first render. The constructor
  // attaches the `window.addEventListener('message', ...)` listener
  // synchronously, so by the time the host's ClientWidgetApi fires its
  // capabilities request on iframe `load` we're already listening. On a
  // cached-bundle remount the request can race ahead of any useEffect —
  // construction at module-load closes that window.
  const api = new WidgetApi(result.bootstrap);
  render(<App bootstrap={result.bootstrap} api={api} />, root);
}
