<?php

namespace TablePress\PhpOffice\PhpSpreadsheet\Calculation\MathTrig;

use TablePress\PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Exception;

class Combinations
{
	use ArrayEnabled;

	/**
	 * COMBIN.
	 *
	 * Returns the number of combinations for a given number of items. Use COMBIN to
	 *        determine the total possible number of groups for a given number of items.
	 *
	 * Excel Function:
	 *        COMBIN(numObjs,numInSet)
	 *
	 * @param mixed $numObjs Number of different objects, or can be an array of numbers
	 * @param mixed $numInSet Number of objects in each combination, or can be an array of numbers
	 *
	 * @return array<mixed>|float|string Number of combinations, or a string containing an error
	 *         If an array of numbers is passed as the argument, then the returned result will also be an array
	 *            with the same dimensions
	 */
	public static function withoutRepetition($numObjs, $numInSet)
	{
		if (is_array($numObjs) || is_array($numInSet)) {
			return self::evaluateArrayArguments([self::class, __FUNCTION__], $numObjs, $numInSet);
		}

		try {
			$numObjs = Helpers::validateNumericNullSubstitution($numObjs, null);
			$numInSet = Helpers::validateNumericNullSubstitution($numInSet, null);
			Helpers::validateNotNegative($numInSet);
			Helpers::validateNotNegative($numObjs - $numInSet);
		} catch (Exception $e) {
			return $e->getMessage();
		}

		/** @var float */
		$quotient = Factorial::fact($numObjs);
		/** @var float */
		$divisor1 = Factorial::fact($numObjs - $numInSet);
		/** @var float */
		$divisor2 = Factorial::fact($numInSet);

		return round($quotient / ($divisor1 * $divisor2));
	}

	/**
	 * COMBINA.
	 *
	 * Returns the number of combinations for a given number of items. Use COMBIN to
	 *        determine the total possible number of groups for a given number of items.
	 *
	 * Excel Function:
	 *        COMBINA(numObjs,numInSet)
	 *
	 * @param mixed $numObjs Number of different objects, or can be an array of numbers
	 * @param mixed $numInSet Number of objects in each combination, or can be an array of numbers
	 *
	 * @return array<mixed>|float|int|string Number of combinations, or a string containing an error
	 *         If an array of numbers is passed as the argument, then the returned result will also be an array
	 *            with the same dimensions
	 */
	public static function withRepetition($numObjs, $numInSet)
	{
		if (is_array($numObjs) || is_array($numInSet)) {
			return self::evaluateArrayArguments([self::class, __FUNCTION__], $numObjs, $numInSet);
		}

		try {
			$numObjs = Helpers::validateNumericNullSubstitution($numObjs, null);
			$numInSet = Helpers::validateNumericNullSubstitution($numInSet, null);
			Helpers::validateNotNegative($numInSet);
			Helpers::validateNotNegative($numObjs);
			$numObjs = (int) $numObjs;
			$numInSet = (int) $numInSet;
			// Microsoft documentation says following is true, but Excel
			//  does not enforce this restriction.
			//Helpers::validateNotNegative($numObjs - $numInSet);
			if ($numObjs === 0) {
				Helpers::validateNotNegative(-$numInSet);

				return 1;
			}
		} catch (Exception $e) {
			return $e->getMessage();
		}

		/** @var float */
		$quotient = Factorial::fact($numObjs + $numInSet - 1);
		/** @var float */
		$divisor1 = Factorial::fact($numObjs - 1);
		/** @var float */
		$divisor2 = Factorial::fact($numInSet);

		return round($quotient / ($divisor1 * $divisor2));
	}
}
