DVDoug\BoxPacker\PackedBoxList

Complexity

Total Complexity

17

Size/Duplication

Total Lines	125
Duplicated Lines	0 %

Test Coverage

Coverage

82.05%

Importance

Changes

0

6 Methods

Rating	Name	Duplication	Size	Complexity
A	getWeightVariance()	0	10	2
A	getVolumeUtilisation()	0	16	3
A	reverseCompare()	0	11	3
A	compare()	0	14	4
A	getMeanWeight()	0	11	3
A	insertFromArray()	0	4	2

<?php
/**
 * Box packing (3D bin packing, knapsack problem).
 *
 * @author Doug Wright
 */

namespace DVDoug\BoxPacker;

/**
 * List of possible packed box choices, ordered by utilisation (item count, volume).
 *
 * @author Doug Wright
 */
class PackedBoxList extends \SplMinHeap
{
    /**
     * Average (mean) weight of boxes.
     *
     * @var float
     */
    protected $meanWeight;

    /**
     * Compare elements in order to place them correctly in the heap while sifting up.
     *
     * @see \SplMinHeap::compare()
     *
     * @param PackedBox $boxA
     * @param PackedBox $boxB
     *
     * @return int
     */
    public function compare($boxA, $boxB)
    {
        $choice = $boxA->getItems()->count() - $boxB->getItems()->count();
        if ($choice == 0) {
            $choice = $boxA->getVolumeUtilisation() - $boxB->getVolumeUtilisation();
        }
        if ($choice == 0) {
            $choice = $boxA->getUsedVolume() - $boxB->getUsedVolume();
        }
        if ($choice == 0) {
            $choice = $boxA->getWeight() - $boxB->getWeight();
        }

        return $choice;
    }

    /**
     * Reversed version of compare.
     *
     * @deprecated
     *
     * @param PackedBox $boxA
     * @param PackedBox $boxB
     *
     * @return int
     */
    public function reverseCompare($boxA, $boxB)
    {
        $choice = $boxB->getItems()->count() - $boxA->getItems()->count();
        if ($choice === 0) {
            $choice = $boxA->getBox()->getInnerVolume() - $boxB->getBox()->getInnerVolume();
        }
        if ($choice === 0) {
            $choice = $boxB->getWeight() - $boxA->getWeight();
        }

        return $choice;
    }

    /**
     * Calculate the average (mean) weight of the boxes.
     *
     * @return float
     */
    public function getMeanWeight()
    {
        if (!is_null($this->meanWeight)) {

The condition ! is_null($this->meanWeight) can never be false.

            return $this->meanWeight;
        }

        foreach (clone $this as $box) {
            $this->meanWeight += $box->getWeight();
        }

        return $this->meanWeight /= $this->count();
    }

    /**
     * Calculate the variance in weight between these boxes.
     *
     * @return float
     */
    public function getWeightVariance()
    {
        $mean = $this->getMeanWeight();

        $weightVariance = 0;
        foreach (clone $this as $box) {
            $weightVariance += pow($box->getWeight() - $mean, 2);
        }

        return round($weightVariance / $this->count(), 1);
    }

    /**
     * Get volume utilisation of the set of packed boxes.
     *
     * @return float
     */
    public function getVolumeUtilisation()
    {
        $itemVolume = 0;
        $boxVolume = 0;

        /** @var PackedBox $box */
        foreach (clone $this as $box) {
            $boxVolume += $box->getBox()->getInnerVolume();

            /** @var Item $item */
            foreach (clone $box->getItems() as $item) {
                $itemVolume += $item->getVolume();
            }
        }

        return round($itemVolume / $boxVolume * 100, 1);
    }

    /**
     * Do a bulk insert.
     *
     * @param array $boxes
     */
    public function insertFromArray(array $boxes)
    {
        foreach ($boxes as $box) {
            $this->insert($box);
        }
    }
}