(function () {
  var cfg = window.EB_CONCIERGE || {};
  var botId = cfg.botId;
  var apiBase = (cfg.apiBase || '').replace(/\/$/, '');
  if (!botId || !apiBase) {
    // eslint-disable-next-line no-console
    console.error('[EventBuzz Concierge] Missing window.EB_CONCIERGE.botId or apiBase');
    return;
  }

  var storageKey = 'ebc_session_' + botId;
  var sessionId = null;
  // A page refresh starts a new chat unless ?session=<WebChatSession id> is present.
  // Remove IDs saved by older widget builds so participant identity is never
  // silently restored from localStorage.
  try { localStorage.removeItem(storageKey); } catch {}

  function readSessionRefFromUrl() {
    try {
      var params = new URLSearchParams(window.location.search || '');
      return String(params.get('session') || params.get('sessionId') || cfg.sessionId || '').trim();
    } catch (e) {
      return String(cfg.sessionId || '').trim();
    }
  }

  var resumeSessionRef = readSessionRefFromUrl();

  function el(tag, attrs, children) {
    var n = document.createElement(tag);
    if (attrs) for (var k in attrs) n.setAttribute(k, attrs[k]);
    if (children) children.forEach(function (c) { n.appendChild(typeof c === 'string' ? document.createTextNode(c) : c); });
    return n;
  }

  function addCssOnce() {
    if (document.getElementById('ebc-css')) return;
    var link = el('link', { id: 'ebc-css', rel: 'stylesheet', href: apiBase.replace(/\/api$/, '') + '/embed/concierge-widget.css?v=5' });
    document.head.appendChild(link);
  }

  addCssOnce();

  var root = el('div', { id: 'eventbuzz-concierge-root', 'data-eventbuzz-concierge': 'root' });
  var launcher = el('button', { class: 'ebc-launcher', type: 'button', 'aria-label': 'Chat with event concierge' }, ['Chat']);
  var panel = el('div', { class: 'ebc-panel', role: 'dialog', 'aria-label': 'Event concierge chat' });
  var header = el('div', { class: 'ebc-header' });
  var title = el('div', { class: 'ebc-title' }, ['Event Concierge']);
  var headerActions = el('div', { class: 'ebc-header-actions' });
  var endBtn = el('button', { class: 'ebc-end', type: 'button', 'aria-label': 'End chat' }, ['End chat']);
  var closeBtn = el('button', { class: 'ebc-close', type: 'button', 'aria-label': 'Close' }, ['×']);
  header.appendChild(title);
  headerActions.appendChild(endBtn);
  headerActions.appendChild(closeBtn);
  header.appendChild(headerActions);

  var messages = el('div', { class: 'ebc-messages' });
  var error = el('div', { class: 'ebc-error' }, ['']);
  var inputBar = el('div', { class: 'ebc-inputbar' });
  var input = el('input', { class: 'ebc-input', placeholder: 'Ask a question…', maxlength: '800' });
  var sendBtn = el('button', { class: 'ebc-send', type: 'button' }, ['Send']);
  inputBar.appendChild(input);
  inputBar.appendChild(sendBtn);

  panel.appendChild(header);
  panel.appendChild(messages);
  panel.appendChild(error);
  panel.appendChild(inputBar);
  root.appendChild(launcher);
  root.appendChild(panel);
  document.body.appendChild(root);

  function ensureOnTop() {
    if (!root.parentNode) {
      document.body.appendChild(root);
      return;
    }
    if (document.body.lastElementChild !== root) {
      document.body.appendChild(root);
    }
  }

  ensureOnTop();
  if (typeof MutationObserver !== 'undefined') {
    var topTimer = null;
    var observer = new MutationObserver(function () {
      if (topTimer) return;
      topTimer = setTimeout(function () {
        topTimer = null;
        ensureOnTop();
      }, 50);
    });
    observer.observe(document.body, { childList: true });
  } else {
    setInterval(ensureOnTop, 1000);
  }

  function setError(msg) {
    if (!msg) {
      error.style.display = 'none';
      error.textContent = '';
      return;
    }
    error.style.display = 'block';
    error.textContent = msg;
  }

  function parseNumberedRecommendations(text) {
    var source = String(text || '').trim();
    var markerPattern = /(?:^|\s)(\d{1,2})[.)]\s+/g;
    var markers = [];
    var match;

    while ((match = markerPattern.exec(source)) !== null) {
      markers.push({
        number: match[1],
        markerStart: match.index,
        contentStart: markerPattern.lastIndex
      });
    }

    if (markers.length < 2) return null;

    var intro = source.slice(0, markers[0].markerStart).trim();
    var items = markers.map(function (marker, index) {
      var nextMarker = markers[index + 1];
      return {
        number: marker.number,
        text: source.slice(marker.contentStart, nextMarker ? nextMarker.markerStart : source.length).trim()
      };
    }).filter(function (item) { return item.text; });

    return items.length >= 2 ? { intro: intro, items: items } : null;
  }

  function appendAssistantContent(bubble, text) {
    var parsed = parseNumberedRecommendations(text);
    if (!parsed) {
      bubble.textContent = text;
      return;
    }

    bubble.classList.add('ebc-rich');
    if (parsed.intro) {
      bubble.appendChild(el('p', { class: 'ebc-intro' }, [parsed.intro]));
    }

    var list = el('div', { class: 'ebc-card-list' });
    parsed.items.forEach(function (item) {
      var card = el('div', { class: 'ebc-card' });
      card.appendChild(el('div', { class: 'ebc-card-number' }, [item.number]));
      card.appendChild(el('div', { class: 'ebc-card-text' }, [item.text]));
      list.appendChild(card);
    });
    bubble.appendChild(list);
  }

  function formatRating(place) {
    if (place.rating === null || place.rating === undefined || place.rating === '') return 'Rating not available';
    var label = String(place.rating);
    if (place.userRatingsTotal !== null && place.userRatingsTotal !== undefined) {
      label += ' (' + String(place.userRatingsTotal) + ' reviews)';
    }
    return label;
  }

  function mapsUrl(place) {
    if (place.location && isFinite(Number(place.location.lat)) && isFinite(Number(place.location.lng))) {
      return 'https://www.google.com/maps/search/?api=1&query=' +
        encodeURIComponent(String(place.location.lat) + ',' + String(place.location.lng)) +
        '&query_place_id=' + encodeURIComponent(place.placeId || place.foodId || place.hotelId || '');
    }
    return 'https://www.google.com/maps/search/?api=1&query=' + encodeURIComponent((place.name || '') + ' ' + (place.address || ''));
  }

  // Only allow http/https links to reach the DOM; anything else is neutralized.
  function safeUrl(url) {
    var s = String(url || '').trim();
    return /^https?:\/\//i.test(s) ? s : '';
  }

  function formatDateTime(value) {
    if (!value) return '';
    var d = new Date(value);
    if (isNaN(d.getTime())) return '';
    try {
      return d.toLocaleString([], { weekday: 'short', hour: '2-digit', minute: '2-digit', month: 'short', day: 'numeric' });
    } catch (e) {
      return d.toISOString();
    }
  }

  function priceLevelLabel(level) {
    var n = Number(level);
    if (!isFinite(n) || n <= 0) return '';
    return new Array(Math.min(4, n) + 1).join('₹');
  }

  function buildPlaceCard(place, opts) {
    opts = opts || {};
    var card = el('article', { class: 'ebc-place-card' });
    var head = el('div', { class: 'ebc-place-head' });
    head.appendChild(el('div', { class: opts.iconClass || 'ebc-place-pin', 'aria-hidden': 'true' }, [opts.icon || '⌖']));
    var titleWrap = el('div', { class: 'ebc-place-title-wrap' });
    titleWrap.appendChild(el('h3', { class: 'ebc-place-name' }, [place.name || opts.fallbackName || 'Unnamed place']));
    titleWrap.appendChild(el('div', { class: 'ebc-place-rating' }, [formatRating(place)]));
    head.appendChild(titleWrap);
    card.appendChild(head);

    if (place.address) card.appendChild(el('p', { class: 'ebc-place-address' }, [place.address]));

    var priceLabel = priceLevelLabel(place.priceLevel);
    if (priceLabel) card.appendChild(el('div', { class: 'ebc-place-price' }, [priceLabel]));

    var tags = Array.isArray(opts.tags) ? opts.tags : (Array.isArray(place.tags) ? place.tags : []);
    if (tags.length) {
      var tagWrap = el('div', { class: 'ebc-place-tags' });
      tags.slice(0, 3).forEach(function (tag) {
        tagWrap.appendChild(el('span', { class: opts.tagClass || 'ebc-place-tag' }, [String(tag).replace(/_/g, ' ')]));
      });
      card.appendChild(tagWrap);
    }

    var links = el('div', { class: 'ebc-place-links' });
    links.appendChild(el('a', { class: 'ebc-place-map', href: mapsUrl(place), target: '_blank', rel: 'noopener noreferrer' }, ['Open map']));
    var site = safeUrl(place.website);
    if (site) links.appendChild(el('a', { class: 'ebc-place-map', href: site, target: '_blank', rel: 'noopener noreferrer' }, ['Website']));
    card.appendChild(links);
    return card;
  }

  function buildFoodCard(food) {
    return buildPlaceCard(food, {
      icon: '🍽', iconClass: 'ebc-food-icon',
      fallbackName: 'Unnamed restaurant',
      tags: Array.isArray(food.cuisines) ? food.cuisines : [],
      tagClass: 'ebc-food-tag',
    });
  }

  function buildAccommodationCard(hotel) {
    return buildPlaceCard(hotel, { icon: '🏨', iconClass: 'ebc-hotel-icon', fallbackName: 'Unnamed stay' });
  }

  function buildTicketCard(t) {
    var card = el('article', { class: 'ebc-ticket-card' });
    var head = el('div', { class: 'ebc-ticket-head' });
    head.appendChild(el('h3', { class: 'ebc-place-name' }, [t.name || 'Ticket']));
    if (t.price) head.appendChild(el('span', { class: 'ebc-ticket-price' }, [String(t.price)]));
    card.appendChild(head);
    if (t.description) card.appendChild(el('p', { class: 'ebc-place-address' }, [t.description]));
    if (Array.isArray(t.keyPoints) && t.keyPoints.length) {
      var ul = el('ul', { class: 'ebc-ticket-points' });
      t.keyPoints.slice(0, 5).forEach(function (kp) {
        ul.appendChild(el('li', {}, [String(kp)]));
      });
      card.appendChild(ul);
    }
    return card;
  }

  function buildActionCard(opts) {
    var card = el('article', { class: 'ebc-action-card' });
    if (opts.title) card.appendChild(el('div', { class: 'ebc-action-title' }, [opts.title]));
    if (opts.note) card.appendChild(el('div', { class: 'ebc-meta' }, [opts.note]));
    var url = safeUrl(opts.url);
    if (url) {
      card.appendChild(el('a', { class: 'ebc-action-btn', href: url, target: '_blank', rel: 'noopener noreferrer' }, [opts.label || 'Open']));
    } else if (opts.label) {
      card.appendChild(el('span', { class: 'ebc-action-btn ebc-action-disabled' }, [opts.label]));
    }
    return card;
  }

  function buildSessionJoinCard(s) {
    var card = el('article', { class: 'ebc-session-card' });
    card.appendChild(el('h3', { class: 'ebc-place-name' }, [s.title || 'Session']));
    var when = formatDateTime(s.startTime);
    if (when) card.appendChild(el('div', { class: 'ebc-meta' }, [when]));
    var url = safeUrl(s.url);
    if (url) card.appendChild(el('a', { class: 'ebc-action-btn', href: url, target: '_blank', rel: 'noopener noreferrer' }, ['Join session']));
    return card;
  }

  // Dispatch a single {type, data} card to its renderer. Unknown types render
  // as a minimal titled note so new backend card types degrade gracefully.
  function renderCard(card) {
    var type = card && card.type;
    var data = (card && card.data) || {};
    switch (type) {
      case 'food': return buildFoodCard(data);
      case 'place': return buildPlaceCard(data);
      case 'accommodation': return buildAccommodationCard(data);
      case 'ticket': return buildTicketCard(data);
      case 'registration': return buildActionCard({
        title: data.open === false ? 'Registration closed' : 'Registration',
        note: data.deadline ? ('Deadline: ' + formatDateTime(data.deadline)) : '',
        url: data.open === false ? '' : data.url,
        label: data.label || (data.open === false ? 'Registration closed' : 'Register'),
      });
      case 'checkin': return buildActionCard({
        title: data.method === 'web' ? 'Online check-in' : 'Check-in',
        url: data.url,
        label: data.label || 'Check in',
      });
      case 'join': return buildActionCard({
        title: 'Join online',
        url: data.url,
        label: data.label || 'Join online',
      });
      case 'session_join': return buildSessionJoinCard(data);
      default:
        if (data && (data.name || data.title || data.label)) {
          return buildActionCard({ title: data.name || data.title || '', url: data.url, label: data.label });
        }
        return null;
    }
  }

  function appendCards(bubble, text, cards) {
    bubble.classList.add('ebc-rich', 'ebc-cards');
    if (text) bubble.appendChild(el('p', { class: 'ebc-intro' }, [text]));
    var list = el('div', { class: 'ebc-cards-list' });
    cards.forEach(function (card) {
      var node = renderCard(card);
      if (node) list.appendChild(node);
    });
    if (list.childNodes.length) bubble.appendChild(list);
  }

  function appendPlaceCards(bubble, text, places) {
    bubble.classList.add('ebc-rich', 'ebc-places');
    if (text) bubble.appendChild(el('p', { class: 'ebc-intro' }, [text]));
    var list = el('div', { class: 'ebc-place-list' });
    places.forEach(function (place) { list.appendChild(buildPlaceCard(place)); });
    bubble.appendChild(list);
  }

  function appendFoodCards(bubble, text, foods) {
    bubble.classList.add('ebc-rich', 'ebc-foods');
    if (text) bubble.appendChild(el('p', { class: 'ebc-intro' }, [text]));
    var list = el('div', { class: 'ebc-food-list' });
    foods.forEach(function (food) { list.appendChild(buildFoodCard(food)); });
    bubble.appendChild(list);
  }

  function scrollAnchorToTop(anchorEl) {
    if (!anchorEl || !messages.contains(anchorEl)) {
      messages.scrollTop = messages.scrollHeight;
      return;
    }
    // Align the user's last message to the top of the visible transcript so the
    // reply can be read from the start without scrolling up.
    var delta = anchorEl.getBoundingClientRect().top - messages.getBoundingClientRect().top;
    messages.scrollTop += delta;
  }

  function addMessage(role, text, opts) {
    opts = opts || {};
    var cards = Array.isArray(opts.cards) ? opts.cards : [];
    var places = Array.isArray(opts.places) ? opts.places : [];
    var foods = Array.isArray(opts.foods) ? opts.foods : [];
    var bubble = el('div', { class: 'ebc-msg' + (role === 'user' ? ' ebc-user' : '') });
    if (role === 'assistant' && cards.length) appendCards(bubble, text, cards);
    else if (role === 'assistant' && foods.length) appendFoodCards(bubble, text, foods);
    else if (role === 'assistant' && places.length) appendPlaceCards(bubble, text, places);
    else if (role === 'assistant') appendAssistantContent(bubble, text);
    else bubble.textContent = text;
    messages.appendChild(bubble);

    if (opts.anchorToTop) {
      // Wait a frame so layout (cards / pre-wrap height) is settled.
      requestAnimationFrame(function () {
        scrollAnchorToTop(opts.anchorToTop);
      });
    } else if (opts.scroll !== false) {
      messages.scrollTop = messages.scrollHeight;
    }
    return bubble;
  }

  function openPanel() {
    ensureOnTop();
    panel.classList.add('ebc-open');
    input.focus();
  }
  function closePanel() {
    panel.classList.remove('ebc-open');
  }

  launcher.addEventListener('click', function () {
    ensureOnTop();
    if (panel.classList.contains('ebc-open')) closePanel();
    else openPanel();
  });
  closeBtn.addEventListener('click', closePanel);
  endBtn.addEventListener('click', function () {
    var endingSessionId = sessionId;
    sessionId = null;
    try { localStorage.removeItem(storageKey); } catch {}
    messages.textContent = '';
    addMessage('assistant', 'This chat has ended. Ask a question to start a new session.');
    if (endingSessionId) {
      http('/public/concierge/' + encodeURIComponent(botId) + '/session/end', {
        sessionId: endingSessionId
      }).catch(function () {});
    }
  });

  function http(path, body) {
    return fetch(apiBase + path, {
      method: body ? 'POST' : 'GET',
      headers: { 'Content-Type': 'application/json' },
      body: body ? JSON.stringify(body) : undefined,
      credentials: 'omit'
    }).then(function (r) {
      return r.json().then(function (j) { return { status: r.status, json: j }; });
    });
  }

  // Load config (and optionally resume a prior WebChatSession from ?session=)
  http('/public/concierge/' + encodeURIComponent(botId) + '/config').then(function (res) {
    if (res.json && res.json.success && res.json.data) {
      title.textContent = res.json.data.eventName ? ('Concierge · ' + res.json.data.eventName) : 'Event Concierge';
      if (res.json.data.maxMessageLength) input.setAttribute('maxlength', String(res.json.data.maxMessageLength));

      var greet = res.json.data.greeting;
      if (!resumeSessionRef) {
        if (greet) addMessage('assistant', greet);
        return;
      }

      return http(
        '/public/concierge/' + encodeURIComponent(botId) + '/session/' + encodeURIComponent(resumeSessionRef)
      ).then(function (sessionRes) {
        if (!sessionRes.json || !sessionRes.json.success || !sessionRes.json.data) {
          setError((sessionRes.json && sessionRes.json.error && sessionRes.json.error.message)
            ? sessionRes.json.error.message
            : 'Could not load that chat session');
          if (greet) addMessage('assistant', greet);
          return;
        }
        var data = sessionRes.json.data;
        sessionId = data.sessionId || null;
        var history = Array.isArray(data.history) ? data.history : [];
        if (!history.length) {
          if (greet) addMessage('assistant', greet);
        } else {
          history.forEach(function (m) {
            if (!m || !m.text) return;
            addMessage(m.role === 'user' ? 'user' : 'assistant', m.text, { scroll: false });
          });
          messages.scrollTop = messages.scrollHeight;
          openPanel();
        }
      }).catch(function () {
        setError('Could not load that chat session');
        if (greet) addMessage('assistant', greet);
      });
    }
  });

  function send() {
    var text = String(input.value || '').trim();
    if (!text) return;
    setError(null);
    input.value = '';
    var userBubble = addMessage('user', text, { scroll: false });
    sendBtn.disabled = true;

    http('/public/concierge/' + encodeURIComponent(botId) + '/chat', {
      sessionId: sessionId || undefined,
      message: text
    }).then(function (res) {
      sendBtn.disabled = false;
      if (!res.json || !res.json.success) {
        setError((res.json && res.json.error && res.json.error.message) ? res.json.error.message : 'Request failed');
        return;
      }
      if (res.json.data && res.json.data.sessionId) {
        sessionId = res.json.data.sessionId;
      }
      var data = res.json.data || {};
      addMessage(
        'assistant',
        data.reply ? data.reply : '…',
        {
          cards: Array.isArray(data.cards) ? data.cards : [],
          places: Array.isArray(data.places) ? data.places : [],
          foods: Array.isArray(data.foods) ? data.foods : [],
          anchorToTop: userBubble,
        }
      );
      // Log detected intent to browser console when backend returns it
      if (res.json.data && res.json.data.intent) {
        // eslint-disable-next-line no-console
        console.info('[EventBuzz Concierge] detected intent:', res.json.data.intent);
      }
    }).catch(function (e) {
      sendBtn.disabled = false;
      setError(e && e.message ? e.message : 'Network error');
    });
  }

  sendBtn.addEventListener('click', send);
  input.addEventListener('keydown', function (e) {
    if (e.key === 'Enter') send();
  });
})();