Box.php

<?php
/**
 * Box packing (3D bin packing, knapsack problem)
 * @package BoxPacker
 * @author Doug Wright
 */
namespace DVDoug\BoxPacker;

/**
 * A "box" (or envelope?) to pack items into
 * @author Doug Wright
 * @package BoxPacker
 */
interface Box
{

    /**
     * Reference for box type (e.g. SKU or description)
     * @return string
     */
    public function getReference();

    /**
     * Outer width in mm
     * @return int
     */
    public function getOuterWidth();

    /**
     * Outer length in mm
     * @return int
     */
    public function getOuterLength();

    /**
     * Outer depth in mm
     * @return int
     */
    public function getOuterDepth();

    /**
     * Empty weight in g
     * @return int
     */
    public function getEmptyWeight();

    /**
     * Inner width in mm
     * @return int
     */
    public function getInnerWidth();

    /**
     * Inner length in mm
     * @return int
     */
    public function getInnerLength();

    /**
     * Inner depth in mm
     * @return int
     */
    public function getInnerDepth();

    /**
     * Total inner volume of packing in mm^3
     * @return int
     */
    public function getInnerVolume();

    /**
     * Max weight the packaging can hold in g
     * @return int
     */
    public function getMaxWeight();
}