(function () {
  const boot = window.MaalFlows || {};
  const apiBase = (boot.apiBase || "").replace(/\/$/, "") || new URL(document.currentScript.src).origin;
  const siteKey = boot.siteKey || "9b-plus";
  const lang = (boot.lang || document.documentElement.lang || navigator.language || "cs").slice(0, 2).toLowerCase();
  const storageKey = `maalflows:${siteKey}`;
  const session = loadSession();

  fetch(`${apiBase}/api/widget/config?siteKey=${encodeURIComponent(siteKey)}`)
    .then((res) => res.json())
    .then((config) => mount(config))
    .catch(() => {});

  function mount(config) {
    const site = config.site;
    const settings = site.settings;
    const copy = localized(settings, lang);
    const host = document.createElement("div");
    host.id = "maalflows-widget";
    document.body.append(host);
    const root = host.attachShadow({ mode: "open" });

    root.innerHTML = `
      <style>${styles(settings)}</style>
      <button class="mf-launcher" type="button" aria-label="${copy.title}">
        <span></span>
      </button>
      <section class="mf-panel" aria-live="polite">
        <header>
          <strong>${escapeHtml(copy.title)}</strong>
          <small>${escapeHtml(site.isOnline ? copy.intro : copy.offlineIntro)}</small>
          <button class="mf-close" type="button" aria-label="Close">×</button>
        </header>
        <div class="mf-messages"></div>
        <div class="mf-typing" hidden>Operator pise...</div>
        <form class="mf-form">
          <textarea name="message" required rows="3" placeholder="${escapeHtml(copy.placeholder)}"></textarea>
          <div class="mf-actions">
            <input name="attachments" type="file" accept="image/*" multiple>
            <button type="submit">${escapeHtml(copy.sendLabel)}</button>
          </div>
          <p class="mf-note">Odeslanim zpravy nam predavate udaje potrebne pro odpoved.</p>
        </form>
      </section>
    `;

    const panel = root.querySelector(".mf-panel");
    const launcher = root.querySelector(".mf-launcher");
    const close = root.querySelector(".mf-close");
    const form = root.querySelector(".mf-form");
    const messages = root.querySelector(".mf-messages");
    const typing = root.querySelector(".mf-typing");

    launcher.addEventListener("click", () => panel.classList.toggle("open"));
    close.addEventListener("click", () => panel.classList.remove("open"));

    form.message.addEventListener("input", debounce(() => {
      if (!session.conversationId) return;
      fetch(`${apiBase}/api/widget/conversations/${session.conversationId}/typing`, { method: "POST" }).catch(() => {});
    }, 700));

    form.addEventListener("submit", async (event) => {
      event.preventDefault();
      const body = await payloadFromForm(form);
      if (!body.message.trim()) return;
      addMessage(messages, "visitor", body.message, []);
      form.message.value = "";
      form.attachments.value = "";

      const url = session.conversationId
        ? `${apiBase}/api/widget/conversations/${session.conversationId}/messages`
        : `${apiBase}/api/widget/conversations`;
      const data = await postJson(url, {
        ...body,
        siteKey,
        visitorToken: session.visitorToken,
        currentUrl: location.href,
        referrer: document.referrer,
        browsingHistory: rememberPage(),
        language: navigator.language,
        timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
        device: {
          userAgent: navigator.userAgent,
          platform: navigator.platform,
          viewport: `${innerWidth}x${innerHeight}`
        }
      });

      session.conversationId = data.conversation.conversation.id;
      session.visitorToken = data.visitorToken || session.visitorToken;
      saveSession();
      renderConversation(messages, data.conversation);
      connectEvents(messages, typing);
    });

    rememberPage();
    if (session.conversationId) connectEvents(messages, typing);
  }

  async function payloadFromForm(form) {
    const fd = new FormData(form);
    const files = [...form.attachments.files].slice(0, 3);
    return {
      message: fd.get("message") || "",
      attachments: await Promise.all(files.map(fileToPayload))
    };
  }

  function connectEvents(messages, typing) {
    if (session.events || !session.conversationId) return;
    session.events = new EventSource(`${apiBase}/api/widget/conversations/${session.conversationId}/events`);
    session.events.addEventListener("message", (event) => {
      const data = JSON.parse(event.data);
      if (data.type === "typing" && data.actor === "admin") {
        typing.hidden = false;
        clearTimeout(connectEvents.typingTimer);
        connectEvents.typingTimer = setTimeout(() => { typing.hidden = true; }, 1800);
      }
      if (data.type === "message:new") renderConversation(messages, data.payload);
    });
  }

  function renderConversation(messages, data) {
    messages.innerHTML = "";
    for (const message of data.messages) {
      addMessage(messages, message.senderType, message.body, message.attachments || []);
    }
    messages.scrollTop = messages.scrollHeight;
  }

  function addMessage(messages, sender, body, attachments) {
    const item = document.createElement("article");
    item.className = `mf-message ${sender}`;
    item.innerHTML = `<p>${escapeHtml(body)}</p>${attachments.map((a) => `<a href="${apiBase}${a.url}" target="_blank" rel="noreferrer">${escapeHtml(a.name)}</a>`).join("")}`;
    messages.append(item);
    messages.scrollTop = messages.scrollHeight;
  }

  function localized(settings, language) {
    const pick = (obj) => obj?.[language] || obj?.en || obj?.cs || "";
    return {
      title: pick(settings.title),
      intro: pick(settings.intro),
      offlineIntro: pick(settings.offlineIntro),
      placeholder: pick(settings.placeholder),
      sendLabel: pick(settings.sendLabel)
    };
  }

  function styles(settings) {
    const c = settings.colors;
    const desktop = settings.desktop;
    const mobile = settings.mobile;
    return `
      :host { all: initial; font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: ${c.text}; }
      * { box-sizing: border-box; }
      button, input, textarea { font: inherit; }
      .mf-launcher {
        position: fixed; z-index: 2147483000; ${desktop.side}: ${desktop.sideOffsetPx}px; bottom: ${desktop.bottomPx}px;
        width: 58px; height: 58px; border: 0; border-radius: 50%; background: ${c.brand}; color: ${c.brandText};
        box-shadow: 0 12px 30px rgb(0 0 0 / 22%); cursor: pointer;
      }
      .mf-launcher span, .mf-launcher span:before, .mf-launcher span:after { display: block; background: ${c.brandText}; height: 3px; border-radius: 4px; content: ""; }
      .mf-launcher span { width: 26px; margin: 0 auto; }
      .mf-launcher span:before { transform: translateY(-8px); }
      .mf-launcher span:after { transform: translateY(5px); width: 18px; }
      .mf-panel {
        position: fixed; z-index: 2147483001; ${desktop.side}: ${desktop.sideOffsetPx}px; bottom: ${desktop.bottomPx + 72}px;
        width: min(${desktop.widthPx}px, calc(100vw - 24px)); max-height: min(680px, calc(100vh - 110px)); display: none;
        background: ${c.surface}; border: 1px solid #dfe6e2; border-radius: 8px; overflow: hidden; box-shadow: 0 18px 50px rgb(0 0 0 / 18%);
      }
      .mf-panel.open { display: grid; grid-template-rows: auto minmax(130px, 1fr) auto auto; }
      header { position: relative; display: grid; gap: 3px; background: ${c.brand}; color: ${c.brandText}; padding: 15px 46px 15px 16px; }
      header strong { font-size: 16px; }
      header small { opacity: .92; font-size: 13px; line-height: 1.35; }
      .mf-close { position: absolute; top: 9px; right: 9px; width: 30px; height: 30px; border: 0; border-radius: 6px; background: rgb(255 255 255 / 16%); color: ${c.brandText}; cursor: pointer; }
      .mf-messages { padding: 14px; overflow: auto; display: flex; flex-direction: column; gap: 10px; }
      .mf-message { max-width: 86%; padding: 9px 11px; border-radius: 8px; background: #f1f5f2; color: ${c.text}; }
      .mf-message.admin { align-self: flex-start; background: #eef7f4; }
      .mf-message.visitor { align-self: flex-end; background: ${c.brand}; color: ${c.brandText}; }
      .mf-message p { margin: 0; white-space: pre-wrap; }
      .mf-message a { color: inherit; display: inline-block; margin-top: 6px; }
      .mf-typing { padding: 0 14px 8px; color: ${c.muted}; font-size: 13px; }
      .mf-form { border-top: 1px solid #dfe6e2; padding: 12px; display: grid; gap: 9px; }
      input, textarea { width: 100%; border: 1px solid #dfe6e2; border-radius: 6px; padding: 9px 10px; color: ${c.text}; background: white; }
      textarea { resize: vertical; min-height: 72px; }
      .mf-actions { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 9px; align-items: center; }
      .mf-actions button { border: 0; border-radius: 6px; background: ${c.brand}; color: ${c.brandText}; padding: 10px 13px; cursor: pointer; }
      input[type=file] { font-size: 12px; padding: 7px; }
      .mf-note { margin: 0; color: ${c.muted}; font-size: 11px; line-height: 1.3; }
      @media (max-width: 640px) {
        .mf-launcher { ${mobile.side}: ${mobile.sideOffsetPx}px; bottom: ${mobile.bottomPx}px; }
        .mf-panel { ${mobile.side}: ${mobile.sideOffsetPx}px; bottom: ${mobile.bottomPx + 68}px; width: min(${mobile.widthPx}px, calc(100vw - 24px)); max-height: calc(100vh - 96px); }
      }
    `;
  }

  function rememberPage() {
    const entry = { url: location.href, title: document.title, at: new Date().toISOString() };
    session.history = (session.history || []).filter((item) => item.url !== entry.url).concat(entry).slice(-20);
    saveSession();
    return session.history;
  }

  function loadSession() {
    try {
      const existing = JSON.parse(localStorage.getItem(storageKey) || "{}");
      return { visitorToken: existing.visitorToken || randomId(), conversationId: existing.conversationId || null, history: existing.history || [] };
    } catch {
      return { visitorToken: randomId(), conversationId: null, history: [] };
    }
  }

  function saveSession() {
    localStorage.setItem(storageKey, JSON.stringify({
      visitorToken: session.visitorToken,
      conversationId: session.conversationId,
      history: session.history || []
    }));
  }

  function postJson(url, payload) {
    return fetch(url, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(payload)
    }).then((res) => {
      if (!res.ok) throw new Error(`HTTP ${res.status}`);
      return res.json();
    });
  }

  function fileToPayload(file) {
    return new Promise((resolve) => {
      const reader = new FileReader();
      reader.onload = () => resolve({ name: file.name, type: file.type, size: file.size, dataBase64: reader.result });
      reader.readAsDataURL(file);
    });
  }

  function debounce(fn, delay) {
    let timer;
    return (...args) => {
      clearTimeout(timer);
      timer = setTimeout(() => fn(...args), delay);
    };
  }

  function escapeHtml(value) {
    return String(value ?? "").replace(/[&<>"']/g, (char) => ({
      "&": "&amp;",
      "<": "&lt;",
      ">": "&gt;",
      '"': "&quot;",
      "'": "&#039;"
    })[char]);
  }

  function randomId() {
    return `vis_${Math.random().toString(16).slice(2)}${Date.now().toString(16)}`;
  }
})();