import { chunk as chunkToolkit } from '../../array/chunk.ts';
import { toArray } from '../_internal/toArray.ts';
import { isArrayLike } from '../predicate/isArrayLike.ts';

/**
 * Splits an array into smaller arrays of a specified length.
 *
 * This function takes an input array and divides it into multiple smaller arrays,
 * each of a specified length. If the input array cannot be evenly divided,
 * the final sub-array will contain the remaining elements.
 *
 * @template T The type of elements in the array.
 * @param arr - The array to be chunked into smaller arrays.
 * @param size - The size of each smaller array. Must be a positive integer.
 * @returns A two-dimensional array where each sub-array has a maximum length of `size`.
 *
 * @example
 * // Splits an array of numbers into sub-arrays of length 2
 * chunk([1, 2, 3, 4, 5], 2);
 * // Returns: [[1, 2], [3, 4], [5]]
 *
 * @example
 * // Splits an array of strings into sub-arrays of length 3
 * chunk(['a', 'b', 'c', 'd', 'e', 'f', 'g'], 3);
 * // Returns: [['a', 'b', 'c'], ['d', 'e', 'f'], ['g']]
 */
export function chunk<T>(arr: ArrayLike<T> | null | undefined, size = 1): T[][] {
  size = Math.max(Math.floor(size), 0);
  if (size === 0 || !isArrayLike(arr) || Number.isNaN(size)) {
    return [];
  }

  const array = toArray(arr);

  if (array.length === 0) {
    return [];
  }

  if (!isFinite(size)) {
    return [array];
  }

  return chunkToolkit(array, size);
}
