<?php

/**
 *
 * Function code for the matrix direct sum operation
 *
 * @copyright  Copyright (c) 2018 Mark Baker (https://github.com/MarkBaker/PHPMatrix)
 * @license    https://opensource.org/licenses/MIT    MIT
 */

namespace Matrix;

use Matrix\Operators\DirectSum;

/**
 * Adds two or more matrices
 *
 * @param array<int, mixed> $matrixValues The matrices to add
 * @return Matrix
 * @throws Exception
 */
if (!function_exists(__NAMESPACE__ . '\\directsum')) {
    function directsum(...$matrixValues): Matrix
    {
        if (count($matrixValues) < 2) {
            throw new Exception('DirectSum operation requires at least 2 arguments');
        }

        $matrix = array_shift($matrixValues);

        if (is_array($matrix)) {
            $matrix = new Matrix($matrix);
        }
        if (!$matrix instanceof Matrix) {
            throw new Exception('DirectSum arguments must be Matrix or array');
        }

        $result = new DirectSum($matrix);

        foreach ($matrixValues as $matrix) {
            $result->execute($matrix);
        }

        return $result->result();
    }
}
