import { last as lastToolkit } from '../../array/last.ts';
import { toArray } from '../_internal/toArray.ts';
import { isArrayLike } from '../predicate/isArrayLike.ts';

/**
 * Returns the last element of an array.
 *
 * This function takes an array and returns the last element of the array.
 * If the array is empty, the function returns `undefined`.
 *
 * Unlike some implementations, this function is optimized for performance
 * by directly accessing the last index of the array.
 *
 * @template T - The type of elements in the array.
 * @param arr - The array from which to get the last element.
 * @returns The last element of the array, or `undefined` if the array is empty.
 *
 * @example
 * const arr = [1, 2, 3];
 * const lastElement = last(arr);
 * // lastElement will be 3
 *
 * const emptyArr: number[] = [];
 * const noElement = last(emptyArr);
 * // noElement will be undefined
 */
export function last<T>(array: ArrayLike<T> | null | undefined): T | undefined {
  if (!isArrayLike(array) || array.length === 0) {
    return undefined;
  }
  return lastToolkit(toArray(array));
}
