/* ProPresenter Look — client part.

   The server part polls ProPresenter and streams the live audience look
   here over SSE; the tile only renders. The look's name fills the tile so
   it reads from across the booth, flashes once when it changes, and stays
   on screen dimmed — marked "last known" — while ProPresenter is
   unreachable. */

export default function create({ root, moduleApi }) {
  let view = null;
  let feedOffline = false;
  let stream = null;
  let resizeObserver = null;
  let flashTimer = null;
  let lastName = null;

  root.innerHTML = `
    <div class="pl-screen">
      <header class="pl-top">
        <div class="pl-heading">Look</div>
        <div class="pl-live"><span class="pl-live-dot"></span><span class="pl-live-text">Connecting…</span></div>
      </header>
      <div class="pl-name-box"><div class="pl-name is-waiting">Connecting…</div></div>
      <footer class="pl-meta">
        <span class="pl-tag" hidden>Modified</span>
        <span class="pl-since" hidden></span>
      </footer>
    </div>`;

  const screenEl = root.querySelector('.pl-screen');
  const topEl = root.querySelector('.pl-top');
  const headingEl = root.querySelector('.pl-heading');
  const liveEl = root.querySelector('.pl-live');
  const liveTextEl = root.querySelector('.pl-live-text');
  const nameBox = root.querySelector('.pl-name-box');
  const nameEl = root.querySelector('.pl-name');
  const metaEl = root.querySelector('.pl-meta');
  const tagEl = root.querySelector('.pl-tag');
  const sinceEl = root.querySelector('.pl-since');

  const on = (key) => moduleApi.instanceSettings[key] !== false;

  function timeText(ms) {
    return new Date(ms).toLocaleTimeString([], { hour: 'numeric', minute: '2-digit' });
  }

  /** Biggest font size at which the name fits its box without breaking a word. */
  function fitName() {
    const MIN = 11;
    const boxHeight = nameBox.clientHeight;
    const boxWidth = nameBox.clientWidth;
    nameEl.style.overflowWrap = 'normal';
    if (boxHeight < MIN || !boxWidth) {
      nameEl.style.fontSize = `${MIN}px`;
      return;
    }
    const fits = (size) => {
      nameEl.style.fontSize = `${size}px`;
      return nameEl.scrollWidth <= nameBox.clientWidth + 1 && nameEl.scrollHeight <= nameBox.clientHeight + 1;
    };
    let lo = MIN;
    let hi = Math.max(MIN, Math.floor(boxHeight));
    let best = MIN;
    while (lo <= hi) {
      const mid = (lo + hi) >> 1;
      if (fits(mid)) { best = mid; lo = mid + 1; } else { hi = mid - 1; }
    }
    nameEl.style.fontSize = `${best}px`;
    // One word too long even at MIN: let it break rather than overflow.
    if (best === MIN && nameEl.scrollWidth > nameBox.clientWidth + 1) nameEl.style.overflowWrap = 'anywhere';
  }

  function flash() {
    screenEl.classList.remove('is-changed');
    void screenEl.offsetWidth; // restart the animation
    screenEl.classList.add('is-changed');
    clearTimeout(flashTimer);
    flashTimer = setTimeout(() => screenEl.classList.remove('is-changed'), 2600);
  }

  function setStatus() {
    if (feedOffline) {
      moduleApi.setStatus('error', 'ProdDash server unreachable — reconnecting…');
    } else if (!view) {
      moduleApi.setStatus('connecting', 'Connecting…');
    } else if (!view.configured) {
      moduleApi.setStatus('error', 'No ProPresenter host configured — set one in Admin');
    } else if (view.reachable) {
      moduleApi.setStatus('ok', `Live look: ${view.look ? view.look.name : '—'}`);
    } else if (!view.updatedAt && !view.lastError) {
      moduleApi.setStatus('connecting', 'Reaching ProPresenter…');
    } else {
      moduleApi.setStatus('error', `ProPresenter unreachable${view.lastError ? ` (${view.lastError})` : ''} — reconnecting…`);
    }
  }

  function render() {
    setStatus();
    const offline = feedOffline || Boolean(view && view.configured && !view.reachable && (view.updatedAt || view.lastError));
    const look = view && view.look;

    screenEl.classList.toggle('is-offline', offline);
    headingEl.hidden = !on('showHeading');
    liveEl.hidden = !on('showLive') && !offline; // losing the feed always shows
    topEl.hidden = headingEl.hidden && liveEl.hidden;

    liveEl.classList.toggle('is-live', !offline && Boolean(view && view.reachable));
    liveEl.classList.toggle('is-down', offline);
    if (feedOffline) liveTextEl.textContent = 'ProdDash offline';
    else if (offline) liveTextEl.textContent = look ? 'Unreachable · last known' : 'Unreachable';
    else if (view && view.reachable) liveTextEl.textContent = 'Live';
    else liveTextEl.textContent = 'Connecting…';

    let name;
    let waiting = false;
    if (look) {
      name = look.name;
    } else if (view && !view.configured) {
      name = 'Set up in Admin';
      waiting = true;
    } else if (offline) {
      name = 'ProPresenter unreachable';
      waiting = true;
    } else {
      name = 'Connecting…';
      waiting = true;
    }
    nameEl.textContent = name;
    nameEl.classList.toggle('is-waiting', waiting);

    if (look && lastName !== null && lastName !== `${look.name}|${look.modified}`) flash();
    if (look) lastName = `${look.name}|${look.modified}`;

    tagEl.hidden = !(look && look.modified);
    const since = look && view.changedAt && on('showSince');
    sinceEl.hidden = !since;
    if (since) sinceEl.textContent = `since ${timeText(view.changedAt)}`;
    metaEl.hidden = tagEl.hidden && sinceEl.hidden;

    fitName();
  }

  function connect() {
    stream = moduleApi.sse('/stream', {
      open() {
        feedOffline = false;
        render();
      },
      error() {
        feedOffline = true;
        render();
      },
      events: {
        state(e) {
          try {
            view = JSON.parse(e.data);
          } catch {
            return;
          }
          feedOffline = false;
          render();
        },
      },
    });
  }

  return {
    start() {
      render();
      moduleApi.fetch('/state')
        .then((r) => (r.ok ? r.json() : null))
        .then((body) => {
          if (body && body.state && !view) {
            view = body.state;
            render();
          }
        })
        .catch(() => {});
      connect();
      resizeObserver = new ResizeObserver(() => fitName());
      resizeObserver.observe(nameBox);
    },
    stop() {
      if (stream) stream.close();
      stream = null;
      if (resizeObserver) resizeObserver.disconnect();
      resizeObserver = null;
      clearTimeout(flashTimer);
      root.innerHTML = '';
    },
  };
}