<?php

declare(strict_types=1);

class ArrayUtil
{

	/**
	 * Take an array of arrays, take given key from each sub-array and return
	 * new array with just those corresponding values.
	 */
	public static function flattenByKey(array $list, string $key): array
	{
		return array_column($list, $key);
	}

	/**
	 * Pass an array of arrays you want to merge. The keys of the outer array will become
	 * the inner keys of the resulting array, and vice versa.
	 */
	public static function mergeByKey(array $arrays): array
	{
		$empty = array_combine(array_keys($arrays), array_fill(0, count($arrays), false));
		$out = [];
		foreach ($arrays as $subkey => $array) {
			foreach ($array as $key => $item) {
				if (!isset($out[$key])) {
					$out[$key] = $empty;
				}
				$out[$key][$subkey] = $item;
			}
		}
		return $out;
	}

	/**
	 * Sort array by given column.
	 */
	public static function sortByColumn(array &$array, string $column, int $sortOrder = SORT_ASC, int $sortFlags = SORT_REGULAR): void
	{
		$sorter = array_column($array, $column);
		array_multisort($sorter, $sortOrder, $sortFlags, $array);
	}

	/**
	 * Check whether $array contains all keys given in $keyList
	 *
	 * @param array $array An array
	 * @param array $keyList A list of strings which must all be valid keys in $array
	 */
	public static function hasAllKeys(array $array, array $keyList): bool
	{
		foreach ($keyList as $key) {
			if (!isset($array[$key]))
				return false;
		}
		return true;
	}

	/**
	 * Check if all elements in given array are primitive types,
	 * i.e. not object, array or resource.
	 */
	public static function isOnlyPrimitiveTypes(array $array): bool
	{
		foreach ($array as $item) {
			if (is_array($item) || is_object($item) || is_resource($item))
				return false;
		}
		return true;
	}

	/**
	 * Force each element of given array to be of type $type.
	 */
	public static function forceType(array &$array, string $type): void
	{
		foreach ($array as &$elem) {
			settype($elem, $type);
		}
	}

}