import type { DataXY, NumberArray } from 'cheminfo-types';

/**
 * Order object of array, x has to be monotone. Ensure x is growing
 * @param data - Object of kind {x:[], y:[]}.
 */
export function xyGrowingX<DataType extends NumberArray = NumberArray>(
  data: DataXY<DataType>,
): DataXY<DataType> {
  const { x, y } = data;

  if (x.length !== y.length) {
    throw new TypeError('length of x and y must be identical');
  }

  if (x.length < 2 || x[0] < (x.at(-1) as number)) return data;

  return {
    x: x.toReversed() as DataType,
    y: y.toReversed() as DataType,
  };
}