import { WebSocketStatus } from "@hocuspocus/provider";
import type { DictationUnavailableReason } from "@/features/dictation/dictation-status";

/**
 * The collab document is usable only once the provider is Connected AND has
 * synced (both the local IndexedDB replica and the remote room). Until then the
 * in-browser Y.Doc is empty/stale, so edits would either be dropped or clobber
 * the server's authoritative doc when it finally arrives.
 */
export function isCollabSynced(
  status: WebSocketStatus | string,
  isSynced: boolean,
): boolean {
  return status === WebSocketStatus.Connected && isSynced;
}

/**
 * Whether the page BODY editor may accept edits.
 *
 * `showStatic` is true during the pre-sync window (a read-only static editor is
 * shown). Gating editability on `!showStatic` guarantees the body never becomes
 * editable before the collab doc is synced, so early keystrokes on a freshly
 * created page can't land only in local ProseMirror and then be lost when the
 * server's initial empty doc syncs in (#218). Read-only and view modes are
 * still honored via `editable`/`inEditMode`.
 */
export function isBodyEditable(opts: {
  editable: boolean;
  inEditMode: boolean;
  showStatic: boolean;
}): boolean {
  return opts.editable && opts.inEditMode && !opts.showStatic;
}

/**
 * Whether dictation can start and, when it can't, the cause-specific reason the
 * mic button surfaces. Derives editability from `isBodyEditable` (the single,
 * tested gate) so the published `isEditable` can never diverge from the actual
 * body-editable state and make the tooltip lie (#309).
 *
 * `isDisconnected` is the caller's own boolean (collab connection is in the
 * Disconnected state), passed in so this module stays free of the collab enum.
 */
export function computeDictationAvailability(opts: {
  editable: boolean;
  inEditMode: boolean;
  showStatic: boolean;
  isDisconnected: boolean;
}): { isEditable: boolean; reason: DictationUnavailableReason | null } {
  const isEditable = isBodyEditable({
    editable: opts.editable,
    inEditMode: opts.inEditMode,
    showStatic: opts.showStatic,
  });
  if (isEditable) return { isEditable, reason: null };
  // Permitted to edit and in edit mode but not yet synced (showStatic) → pre-sync.
  if (opts.editable && opts.inEditMode && opts.showStatic) {
    return { isEditable, reason: opts.isDisconnected ? "offline" : "connecting" };
  }
  // No edit permission or not in edit mode.
  return { isEditable, reason: "read-only" };
}