<?php
declare(strict_types=1);

/**
 * @copyright Copyright (c) 2018, Michael Weimann (<mail@michael-weimann.eu>)
 *
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

namespace OC;

/**
 * Helper class that covers memory info.
 */
class MemoryInfo {

        const RECOMMENDED_MEMORY_LIMIT = 512 * 1024 * 1024;

        /**
         * Tests if the memory limit is greater or equal the recommended value.
         *
         * @return bool
         */
        public function isMemoryLimitSufficient(): bool {
                $memoryLimit = $this->getMemoryLimit();
                return $memoryLimit === -1 || $memoryLimit >= self::RECOMMENDED_MEMORY_LIMIT;
        }

        /**
         * Returns the php memory limit.
         *
         * @return int The memory limit in bytes.
         */
 public function getMemoryLimit(): int {
                $iniValue = trim(ini_get('memory_limit'));
                if ($iniValue === '-1') {
                        return -1;
                } else if (is_numeric($iniValue) === true) {
                        return (int)$iniValue;
                } else {
                        return $this->memoryLimitToBytes($iniValue);
                }
        }

        /**
         * Converts the ini memory limit to bytes.
         *
         * @param string $memoryLimit The "memory_limit" ini value
         * @return int
         */
        private function memoryLimitToBytes(string $memoryLimit): int {
                $last = strtolower(substr($memoryLimit, -1));
                $memoryLimit = (int)substr($memoryLimit, 0, -1);

                // intended fall trough
                switch($last) {
                        case 'g':
                                $memoryLimit *= 1024;
                        case 'm':
                                $memoryLimit *= 1024;
                        case 'k':
                                $memoryLimit *= 1024;
                }

                return $memoryLimit;
        }
}