SWDB/application/helper/APPLICATION.php

<?php
/**
 * App helper file.
 *
 * Provides a helper to perform app related operations.
 *
 * @author Iñigo Valentin <i@inigovalentin.com>
 * @license https://www.gnu.org/licenses/gpl-3.0.en.html GNU General Public License V3
 * @package SWDB
 */

require_once(PATH::HELPER . "HELPER.php");

/**
 * Application helper.
 *
 * Contains app-related utilities.
 *
 * @category Helper.
 */
final class APPLICATION extends Helper{

    /**
     * Checks if a value is a valid one in a constant class.
     *
     * It will intentionally fail when used for a non constant class.
     *
     * @param string $class Name of the class.
     * @param int $value Value to check.
     * @return bool True if the value is defined, false otherwise.
     */
    public static function valid_id($class, $value){
        if (strtoupper($class) != $class){
            return false;
        }
        if (!class_exists($class, false)){
            return false;
        }
        $reflect = new ReflectionClass($class);
        if (in_array($value, $reflect->getConstants())){
            return true;
        }
        else{
            return false;
        }
    }

    /**
     * Forms an image URL.
     *
     * It will intentionally fail when used for a non constant class.
     *
     * @param string $type Image type. valid values are:
     *   ICON,    LOGO,         CURRENCY,    UNIT,
     *   AREA,    SKILL,        ESSENCE,     RUNE,
     *   GRIND,   ELEMENT,      SKILL_GUILD, DECORATION,
     *   SOURCE,  SKILL_LEADER, INVENTORY,   EFFECT,
     *   BUILDING
     * @param string|int $name Filename, with no path or extension. It can also
     * skip the padding. An id can be used.
     * @return string URL if found. If not, the URL to an 'unknown' icon.
     */
    public static function img($type, $name){
        $pad = 1;
        $url = URL::IMG["UNKNOWN"];
        while ($pad < 10){
            if (isset(PATH::IMG[$type]) && file_exists(PATH::IMG[$type] . str_pad($name, $pad, '0', STR_PAD_LEFT) . ".png")){
                $url = URL::IMG[$type] . str_pad($name, $pad, '0', STR_PAD_LEFT) . ".png";
                break;
            }
            $pad ++;
        }
        return $url;
    }

    /**
     * Calculates the effective damage.
     * 
     * @param int $atk Attack stat.
     * @param int $crr Critical rate stat.
     * @param int $crd Critical damage stat.
     * @return int Damage stat.
     */
    public static function calculate_dmg($atk, $crr, $crd){
        if (! is_numeric($atk) || ! is_numeric($crr) || ! is_numeric($crd)){
            return 0;
        }
        if ($crr > 100){
            $crr = 100;
        }
        $edmg = ceil(($atk * (100 - $crr) / 100) + (($atk + ($atk * $crd / 100)) * $crr / 100));
        return $edmg;
    }

    /**
     *  Calculates the effective HP of a unit.
     * @param int $hp HP stat
     * @param int $def Defense stat.
     * @return int Effective HP.
     */
    public static function calculate_ehp($hp, $def){
        $ehp = ceil(((($def * 3.5) + 1140) * $hp) / 1000);
        return $ehp;
    }
}