import { useCallback } from 'react';

import { useStoreApi } from './useStore';
import type { UseDragEvent } from '../types';

function useGetPointerPosition() {
  const store = useStoreApi();

  // returns the pointer position projected to the RF coordinate system
  const getPointerPosition = useCallback(({ sourceEvent }: UseDragEvent) => {
    const { transform, snapGrid, snapToGrid } = store.getState();
    const x = sourceEvent.touches ? sourceEvent.touches[0].clientX : sourceEvent.clientX;
    const y = sourceEvent.touches ? sourceEvent.touches[0].clientY : sourceEvent.clientY;

    const pointerPos = {
      x: (x - transform[0]) / transform[2],
      y: (y - transform[1]) / transform[2],
    };

    // we need the snapped position in order to be able to skip unnecessary drag events
    return {
      xSnapped: snapToGrid ? snapGrid[0] * Math.round(pointerPos.x / snapGrid[0]) : pointerPos.x,
      ySnapped: snapToGrid ? snapGrid[1] * Math.round(pointerPos.y / snapGrid[1]) : pointerPos.y,
      ...pointerPos,
    };
  }, []);

  return getPointerPosition;
}

export default useGetPointerPosition;