/**
 * ObsiGate — Inline editor host (ROADMAP #93)
 *
 * The edition surface (`#editor-container`, containing the CodeMirror editor or
 * the Forge iframe) used to live inside the full-screen `#editor-modal` overlay,
 * which covered both the document read view and the AI assistant sidebar.
 *
 * This module moves that container **into the content area of the document
 * being read** so editing replaces the read view instead of overlaying it:
 *
 *   `#content-area` (or the active pane `.pane-content` in split view)
 *     └── .editor-container.editor-inline   ← the editor, replacing the document
 *
 * Keeping the same DOM nodes (same ids: `#editor-body`, `#editor-save`, …) means
 * CodeMirror, autosave, Yjs collaboration, the AI toolbar and the Forge iframe
 * keep working untouched — only their host moves.
 *
 * Classes:
 *   `.editor-inline`       — set on the container while it hosts an inline session
 *   `.editor-inline-host`  — set on the content area it replaces
 *   `#editor-modal.editor-inline-mode` — the overlay is neutralised (transparent,
 *                          zero-size, no scroll) but keeps `active`, so the mobile
 *                          ribbon anchored to it (`.me-ribbon`) still works.
 */

export const INLINE_CONTAINER_CLASS = 'editor-inline';
export const INLINE_HOST_CLASS = 'editor-inline-host';
export const INLINE_MODAL_CLASS = 'editor-inline-mode';

/** The editor overlay element (`#editor-modal` when present). */
export function getEditorModal() {
  return document.getElementById('editor-modal');
}

/**
 * The editor container, wherever it currently lives (modal or content area).
 * Falls back to a class lookup so the helper also works on a DOM where the id
 * was not set (tests, older markup).
 */
export function getEditorContainer() {
  return (
    document.getElementById('editor-container') ||
    document.querySelector('.editor-container.' + INLINE_CONTAINER_CLASS)
  );
}

/**
 * Content area that should host the inline editor: the pane currently being
 * read. Mirrors viewer.js `getContentArea()` (multi-pane aware).
 */
export function getInlineHostArea() {
  if (typeof window !== 'undefined') {
    if (window._activePaneContentArea) return window._activePaneContentArea;
    if (
      window.PaneManager &&
      typeof window.PaneManager.isSplit === 'function' &&
      window.PaneManager.isSplit() &&
      typeof window.getActiveContentArea === 'function'
    ) {
      return window.getActiveContentArea();
    }
  }
  return document.getElementById('content-area');
}

/** True when an inline edition session currently owns a content area. */
export function isInlineEditorActive() {
  const container = getEditorContainer();
  return !!(container && container.classList.contains(INLINE_CONTAINER_CLASS));
}

/**
 * Query an element inside the editor container, wherever it currently lives
 * (modal or content area). Use it instead of `modal.querySelector(...)` for the
 * header/footer/brand, which move with the container in inline mode (#93).
 */
export function queryEditor(selector) {
  const container = getEditorContainer();
  const scope = container || getEditorModal();
  return scope ? scope.querySelector(selector) : null;
}

/**
 * Move the editor container into `area`, replacing the rendered document.
 * @returns {boolean} true when the container was mounted inline.
 */
export function mountEditorInline(area) {
  const container = getEditorContainer();
  const modal = getEditorModal();
  if (!container || !modal || !area) return false;
  // Already hosted by this very area — nothing to move.
  if (container.parentElement === area) {
    container.classList.add(INLINE_CONTAINER_CLASS);
    area.classList.add(INLINE_HOST_CLASS);
    modal.classList.add(INLINE_MODAL_CLASS);
    return true;
  }
  area.classList.add(INLINE_HOST_CLASS);
  area.replaceChildren(container);
  container.classList.add(INLINE_CONTAINER_CLASS);
  modal.classList.add(INLINE_MODAL_CLASS);
  return true;
}

/**
 * Move the editor container back into the modal and clear the inline classes.
 * The host area is emptied (its read view is gone) and returned so the caller
 * can re-render the document.
 * @returns {HTMLElement|null} the content area that must be re-rendered.
 */
export function unmountEditorInline() {
  const container = getEditorContainer();
  const modal = getEditorModal();
  if (!container || !modal) return null;
  const parent = container.parentElement;
  const host = parent && parent !== modal ? parent : null;
  container.classList.remove(INLINE_CONTAINER_CLASS);
  if (host) {
    host.classList.remove(INLINE_HOST_CLASS);
    if (typeof host.replaceChildren === 'function') host.replaceChildren();
    else host.innerHTML = '';
  }
  modal.classList.remove(INLINE_MODAL_CLASS);
  modal.appendChild(container);
  return host;
}