/* ProPresenter Timers — client part.

   The server part does all the ProPresenter talking and streams one merged
   state object here over SSE. Each tile renders whichever timers (and/or the
   LTC timecode) it has enabled, as auto-sized cards in a responsive grid.
   Which items a tile shows is per-tile state, picked in a "Timers ▾" header
   menu and persisted with the layout — the timer list is dynamic, so a
   static instanceSchema field can't list them (same approach as the ProdCom
   module's channels menu). Timers this tile has never seen default to
   enabled: only explicit un-ticks are stored. */

const LTC_KEY = '__ltc__';

export default function create({ root, moduleApi }) {
  let state = null;
  let feedOffline = false;
  let stream = null;
  let resizeObserver = null;
  let hiddenItems = new Set(moduleApi.instanceSettings.hiddenItems || []);

  // Which picker entry this tile was added as (the module's tiles() list):
  // '' or 'all' = every item, selectable via the Timers ▾ menu;
  // 'timer:<uuid>' or 'ltc' = exactly one card, no menu.
  const variant = String(moduleApi.variant || '');
  const soloKey = variant === 'ltc' ? LTC_KEY
    : variant.startsWith('timer:') ? variant.slice('timer:'.length)
      : '';
  /** Last name seen for a solo timer, so its card stays labeled if the
      timer is later deleted in ProPresenter. */
  let lastSoloName = '';

  /* ── DOM skeleton ───────────────────────────────────────────────── */

  root.innerHTML = `
    <div class="tm-wrap">
      <div class="tm-banner" hidden></div>
      <div class="tm-hint" hidden></div>
      <div class="tm-grid"></div>
    </div>`;

  const wrap = root.querySelector('.tm-wrap');
  const bannerEl = root.querySelector('.tm-banner');
  const hintEl = root.querySelector('.tm-hint');
  const gridEl = root.querySelector('.tm-grid');

  /** key (uuid or LTC_KEY) → { el, nameEl, timeEl, stateEl } */
  const cards = new Map();

  /* ── title-bar menu: pick which timers / LTC this tile shows ────── */

  let menuEl = null; // the open menu's element (filled on each open)
  const itemsMenu = soloKey ? null : moduleApi.header.addMenu({
    label: 'Timers ▾',
    title: 'Choose which timers this tile shows',
    build(menu) {
      menu.classList.add('tm-menu');
      menuEl = menu;
      rebuildMenu();
    },
  });

  function menuRows() {
    const rows = (state?.timers || []).map((t) => ({ key: t.uuid, name: t.name }));
    rows.push({ key: LTC_KEY, name: 'LTC timecode' });
    return rows;
  }

  function persistHidden() {
    moduleApi.saveInstanceSettings({ hiddenItems: [...hiddenItems] });
  }

  function toggleItem(key) {
    if (hiddenItems.has(key)) hiddenItems.delete(key);
    else hiddenItems.add(key);
    persistHidden();
    rebuildMenu();
    render();
  }

  function updateMenuLabel() {
    if (!itemsMenu) return;
    const rows = menuRows();
    const visible = rows.filter((r) => !hiddenItems.has(r.key)).length;
    itemsMenu.setLabel(visible === rows.length
      ? 'Timers ▾'
      : `Timers (${visible}/${rows.length}) ▾`);
  }

  function rebuildMenu() {
    updateMenuLabel();
    if (!menuEl) return; // menu not opened yet — the label is enough
    menuEl.innerHTML = '';
    const rows = menuRows();
    if (rows.length === 1) {
      const note = document.createElement('div');
      note.className = 'tm-menu-note';
      note.textContent = 'No timers discovered yet';
      menuEl.appendChild(note);
    }
    for (const row of rows) {
      const on = !hiddenItems.has(row.key);
      const item = document.createElement('button');
      item.className = 'tm-menu-item' + (on ? ' on' : '');
      item.setAttribute('role', 'menuitemcheckbox');
      item.setAttribute('aria-checked', String(on));
      const check = document.createElement('span');
      check.className = 'check';
      check.textContent = '✓';
      const name = document.createElement('span');
      name.className = 'name';
      name.textContent = row.name;
      item.append(check, name);
      item.addEventListener('click', (e) => {
        // keep the menu open: the rebuild detaches this item, which would
        // make the outside-click handler think we clicked outside
        e.stopPropagation();
        toggleItem(row.key);
      });
      menuEl.appendChild(item);
    }
  }

  /* ── state → cards ──────────────────────────────────────────────── */

  /** Map the API's state string onto our four looks. The spec's enum is
      stopped|running|complete|overrunning|overran, but its own response
      example says "overrun" — match the substring. */
  function classify(apiState) {
    const s = String(apiState || '').toLowerCase();
    if (s.includes('overr')) return 'overrun';
    if (s === 'running') return 'running';
    if (s === 'complete') return 'complete';
    return 'stopped';
  }

  const STATE_TEXT = { running: 'Running', stopped: 'Stopped', complete: 'Complete', overrun: 'Overrun' };

  /** Show the value the way ProPresenter reports it (sign included);
      only the ".00" hundredths some builds append are dropped for fit. */
  function displayTime(raw) {
    const s = String(raw || '').replace(/\.\d+$/, '');
    return s || '—';
  }

  function visibleItems() {
    const ltcState = state?.ltc || { supported: null, time: '', receiving: false };
    if (soloKey === LTC_KEY) return [{ key: LTC_KEY, ltc: ltcState }];
    if (soloKey) {
      const timer = (state?.timers || []).find((t) => t.uuid === soloKey);
      if (timer) {
        lastSoloName = timer.name;
        return [{ key: soloKey, timer }];
      }
      // The timer this tile was added for isn't in ProPresenter's list (yet,
      // or any more) — keep a clearly-labeled card up rather than erroring.
      return [{ key: soloKey, missing: true }];
    }
    const items = [];
    for (const t of state?.timers || []) {
      if (!hiddenItems.has(t.uuid)) items.push({ key: t.uuid, timer: t });
    }
    if (!hiddenItems.has(LTC_KEY)) items.push({ key: LTC_KEY, ltc: ltcState });
    return items;
  }

  function makeCard(item) {
    const el = document.createElement('div');
    el.className = 'tm-card' + (item.ltc ? ' tm-card-ltc' : '');
    const nameEl = document.createElement('div');
    nameEl.className = 'tm-name';
    const timeEl = document.createElement('div');
    timeEl.className = 'tm-time';
    const stateEl = document.createElement('div');
    stateEl.className = 'tm-state';
    if (item.ltc) {
      const badge = document.createElement('span');
      badge.className = 'tm-ltc-badge';
      badge.textContent = 'LTC';
      nameEl.append(badge, document.createTextNode('Timecode'));
    }
    el.append(nameEl, timeEl, stateEl);
    return { el, nameEl, timeEl, stateEl };
  }

  /** A solo tile whose timer vanished from ProPresenter's list. While the
      server is unreachable the list is merely unknown — the banner already
      says so, so only claim "not in ProPresenter" when actually connected. */
  function updateMissingCard(card) {
    card.nameEl.textContent = lastSoloName || 'Timer';
    card.timeEl.textContent = '—';
    if (state?.reachable) {
      card.stateEl.textContent = 'Not in ProPresenter';
      card.el.className = 'tm-card is-missing';
    } else {
      card.stateEl.textContent = '—';
      card.el.className = 'tm-card is-stopped';
    }
  }

  function updateTimerCard(card, timer) {
    card.nameEl.textContent = timer.name;
    card.timeEl.textContent = displayTime(timer.time);
    const kind = classify(timer.state);
    card.stateEl.textContent = timer.state ? (STATE_TEXT[kind] || timer.state) : '—';
    card.el.className = `tm-card is-${kind}`;
  }

  function updateLtcCard(card, ltc) {
    let mode;
    if (ltc.supported === false) {
      mode = 'unavailable';
      card.timeEl.textContent = '—';
      card.stateEl.textContent = 'Timecode not available on this ProPresenter';
    } else if (ltc.supported === null) {
      mode = 'waiting';
      card.timeEl.textContent = displayTime(ltc.time);
      card.stateEl.textContent = 'Waiting for ProPresenter…';
    } else if (ltc.receiving) {
      mode = 'receiving';
      card.timeEl.textContent = displayTime(ltc.time);
      card.stateEl.textContent = 'Receiving';
    } else {
      mode = 'nosignal';
      card.timeEl.textContent = displayTime(ltc.time);
      card.stateEl.textContent = 'No signal';
    }
    card.el.className = `tm-card tm-card-ltc is-ltc-${mode}`;
  }

  /* ── status dot + degraded banners ──────────────────────────────── */

  function renderStatus() {
    wrap.classList.toggle('is-stale', feedOffline || (state ? !state.reachable && state.enabled : false));
    if (feedOffline) {
      bannerEl.hidden = false;
      bannerEl.textContent = 'Not receiving updates from the ProdDash server.';
      moduleApi.setStatus('error', 'ProdDash server unreachable — reconnecting…');
      return;
    }
    if (!state) {
      bannerEl.hidden = true;
      moduleApi.setStatus('connecting', 'Connecting…');
      return;
    }
    if (!state.enabled) {
      bannerEl.hidden = true;
      moduleApi.setStatus('error', 'No ProPresenter host configured — set one in Admin');
      return;
    }
    if (!state.reachable) {
      bannerEl.hidden = false;
      bannerEl.textContent = 'ProPresenter unreachable — reconnecting…';
      moduleApi.setStatus('error', 'ProPresenter unreachable — reconnecting…');
      return;
    }
    bannerEl.hidden = true;
    moduleApi.setStatus('ok', 'Following ProPresenter timers');
  }

  /* ── main render: diff the card set, update in place ────────────── */

  function render() {
    renderStatus();
    rebuildMenu();

    let hint = '';
    if (state && !state.enabled) {
      hint = 'No ProPresenter connection — set the host and port in Admin.';
    }
    const items = hint ? [] : visibleItems();
    if (!hint && state?.reachable && !items.length) {
      hint = 'Nothing selected — pick timers in the Timers ▾ menu.';
    }
    hintEl.hidden = !hint;
    hintEl.textContent = hint;
    gridEl.hidden = Boolean(hint);
    if (hint) return;

    const wanted = new Set(items.map((i) => i.key));
    let structureChanged = false;
    for (const [key, card] of cards) {
      if (!wanted.has(key)) {
        card.el.remove();
        cards.delete(key);
        structureChanged = true;
      }
    }
    for (const item of items) {
      let card = cards.get(item.key);
      if (!card) {
        card = makeCard(item);
        cards.set(item.key, card);
        structureChanged = true;
      }
      if (item.ltc) updateLtcCard(card, item.ltc);
      else if (item.missing) updateMissingCard(card);
      else updateTimerCard(card, item.timer);
    }
    // Keep DOM order in step with the state's order (config-list order).
    const orderedEls = items.map((i) => cards.get(i.key).el);
    if (structureChanged || orderedEls.some((el, i) => gridEl.children[i] !== el)) {
      gridEl.replaceChildren(...orderedEls);
      fit();
    }
  }

  /* ── sizing: pick the column count that gives the biggest digits ── */

  function fit() {
    const n = Math.max(1, gridEl.childElementCount);
    const W = root.clientWidth;
    const H = root.clientHeight;
    if (!W || !H) return;
    const PAD = H < 120 ? 4 : 10;
    const GAP = H < 120 ? 5 : 8;
    const CARD_PAD = 12; // a card's own vertical padding + borders

    // For each column count, budget a card's full stack (name line, digits,
    // state line) and score by the digit size it affords ("-00:00:00" ≈ 9
    // tabular chars wide). Cards too short for three readable lines drop to
    // a compact look — no state text, the card color carries the state —
    // but any layout with a readable full stack beats every compact one.
    let best = null;
    for (let cols = 1; cols <= n; cols += 1) {
      const rows = Math.ceil(n / cols);
      const cw = (W - PAD * 2 - GAP * (cols - 1)) / cols - 18;
      const ch = (H - PAD * 2 - GAP * (rows - 1)) / rows - CARD_PAD;
      if (cw <= 0 || ch <= 0) continue;
      const meta = Math.max(9, Math.min(22, Math.floor(ch * 0.16)));
      const byWidth = (cw * 1.55) / 9;
      const full = Math.min(byWidth, ch - 2.6 * meta);
      const compact = Math.min(byWidth, ch - 1.3 * meta);
      const mode = full >= 14 ? 'full' : 'compact';
      const size = mode === 'full' ? full : compact;
      const score = (mode === 'full' ? 1000 : 0) + size;
      if (!best || score > best.score) best = { cols, meta, mode, size, cw, score };
    }
    if (!best) return;
    gridEl.style.gridTemplateColumns = `repeat(${best.cols}, 1fr)`;
    wrap.style.setProperty('--tm-pad', PAD + 'px');
    wrap.style.setProperty('--tm-gap', GAP + 'px');
    wrap.classList.toggle('tm-compact', best.mode === 'compact');
    const timeSize = Math.max(11, Math.floor(best.size));
    // LTC digits ("00:00:00:00") are ~11.5 tabular chars wide in the same cell.
    const ltcSize = Math.max(11, Math.floor(Math.min((best.cw * 1.55) / 11.5, best.size)));
    wrap.style.setProperty('--tm-time-size', timeSize + 'px');
    wrap.style.setProperty('--tm-ltc-size', ltcSize + 'px');
    wrap.style.setProperty('--tm-meta-size', best.meta + 'px');
  }

  /* ── live feed ──────────────────────────────────────────────────── */

  function connect() {
    stream = moduleApi.sse('/stream', {
      open() {
        feedOffline = false;
        render();
      },
      error() {
        // EventSource retries by itself (and the shell recreates closed
        // streams), but the tile must admit it is frozen meanwhile.
        feedOffline = true;
        render();
      },
      events: {
        state(ev) {
          try {
            state = JSON.parse(ev.data);
          } catch {
            return;
          }
          feedOffline = false;
          render();
        },
      },
    });
  }

  /* ── lifecycle ──────────────────────────────────────────────────── */

  return {
    start() {
      moduleApi.setStatus('connecting', 'Connecting…');
      // Instant paint from the snapshot, then live updates.
      moduleApi.fetch('/state')
        .then((res) => (res.ok ? res.json() : null))
        .then((body) => {
          if (body && body.state && !state) {
            state = body.state;
            render();
          }
        })
        .catch(() => { /* the stream will cover it */ });
      connect();

      let lastW = 0;
      let lastH = 0;
      resizeObserver = new ResizeObserver(() => {
        const w = Math.round(root.clientWidth);
        const h = Math.round(root.clientHeight);
        if (w === lastW && h === lastH) return;
        lastW = w;
        lastH = h;
        fit();
      });
      resizeObserver.observe(root);
      render();
    },
    stop() {
      stream?.close();
      stream = null;
      resizeObserver?.disconnect();
      resizeObserver = null;
      root.innerHTML = ''; // header controls are removed by the shell
    },
    onResize() {
      fit();
    },
  };
}