import { Editor, Location, Path, Point, Range } from 'slate';

export interface GetPointFromLocationOptions {
  /**
   * @default editor.selection
   */
  at?: Location | null;
  /**
   * @default 'focus'
   */
  pointTypeOfRange?: 'anchor' | 'focus';
}

/**
 * Get the point from a location.
 *
 * If the location is a range, get the anchor point.
 *
 * If the location is a path, get the point at this path with offset 0.
 */
export function getPointFromLocation(editor: Editor, options: GetPointFromLocationOptions = {}): Point | undefined {
  const { at = editor.selection, pointTypeOfRange = 'focus' } = options;

  if (!at) {
    return;
  }

  if (Range.isRange(at)) {
    return at[pointTypeOfRange];
  }

  if (Point.isPoint(at)) {
    return at;
  }

  if (Path.isPath(at)) {
    return { path: at, offset: 0 };
  }
}