const PANEL_COPY = {
  search: {
    title: "Search",
    description: "Search games, apps, and settings across NebulaOS.",
    placeholder: "Search NebulaOS…",
  },
  notifications: {
    title: "Notifications",
    description: "System alerts and download updates will appear here.",
  },
  downloads: {
    title: "Downloads",
    description: "Active and completed downloads will be listed here.",
  },
  controller: {
    title: "Controller Settings",
    description: "Map buttons, adjust dead zones, and test input.",
  },
};

export const createGuidePanelOverlay = ({ mountRoot }) => {
  let openState = false;
  let activePanel = null;
  let onClose = null;
  let overlay = null;

  const renderMarkup = () => {
    mountRoot.insertAdjacentHTML(
      "beforeend",
      `
      <section class="guide-panel-overlay" data-guide-panel-overlay hidden aria-label="Guide panel">
        <div class="guide-panel-sheet panel" role="dialog" aria-modal="true">
          <header class="guide-panel-sheet-head">
            <h2 class="guide-panel-sheet-title" data-panel-title>Panel</h2>
            <p class="muted guide-panel-sheet-desc" data-panel-desc></p>
          </header>
          <div class="guide-panel-sheet-body" data-panel-body></div>
          <button
            type="button"
            class="focusable guide-panel-close"
            data-focusable="true"
            data-row="0"
            data-col="0"
            data-action="close"
            data-focus-key="guide-panel-close"
          >Close</button>
        </div>
      </section>
    `,
    );
    overlay = mountRoot.querySelector("[data-guide-panel-overlay]");
  };

  const getBodyHtml = (panelId) => {
    const copy = PANEL_COPY[panelId];
    if (!copy) {
      return `<p class="muted">This panel is not available yet.</p>`;
    }

    if (panelId === "search") {
      return `
        <label class="guide-panel-search-label">
          <span class="sr-only">Search query</span>
          <input
            type="search"
            class="guide-panel-search-input"
            placeholder="${copy.placeholder}"
            data-panel-search
            autocomplete="off"
          />
        </label>
        <p class="muted guide-panel-hint">Results will appear here. (Placeholder)</p>
      `;
    }

    return `
      <div class="guide-panel-placeholder-card">
        <p class="guide-panel-placeholder-title">${copy.title}</p>
        <p class="muted">${copy.description}</p>
        <p class="guide-panel-placeholder-note">Connected to guide quick actions · stub UI</p>
      </div>
    `;
  };

  const close = () => {
    openState = false;
    activePanel = null;
    if (overlay) {
      overlay.hidden = true;
    }
    onClose?.();
    onClose = null;
  };

  const bindOverlayEvents = () => {
    overlay?.addEventListener("click", (event) => {
      if (event.target === overlay) {
        close();
      }
    });
    overlay?.querySelector(".guide-panel-close")?.addEventListener("click", () => close());
  };

  const open = (panelId, options = {}) => {
    if (!overlay) {
      renderMarkup();
      bindOverlayEvents();
    }

    const copy = PANEL_COPY[panelId] ?? { title: "Panel", description: "" };
    overlay.querySelector("[data-panel-title]").textContent = copy.title;
    overlay.querySelector("[data-panel-desc]").textContent = copy.description ?? "";
    overlay.querySelector("[data-panel-body]").innerHTML = getBodyHtml(panelId);

    openState = true;
    activePanel = panelId;
    onClose = options.onClose ?? null;
    overlay.hidden = false;

    const closeBtn = overlay.querySelector("[data-guide-panel-close], .guide-panel-close");
    closeBtn?.focus({ preventScroll: true });
    closeBtn?.classList.add("is-focused");

    console.log(`[GuidePanel] Opened: ${panelId}`);
  };

  const handleAction = (action) => {
    if (!openState) {
      return false;
    }

    if (action === "accept") {
      close();
      return true;
    }

    if (action === "back" || action === "menu") {
      close();
      return true;
    }

    return true;
  };

  return {
    open,
    close,
    isOpen: () => openState,
    getActivePanel: () => activePanel,
    handleAction,
  };
};