DVDoug\BoxPacker\ItemList

Complexity

Total Complexity

13

Size/Duplication

Total Lines	110
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

7 Methods

Rating	Name	Duplication	Size	Complexity
A	insert()	0	3	1
A	top()	0	9	2
A	getIterator()	0	8	2
A	compare()	0	12	3
A	count()	0	3	1
A	insertFromArray()	0	4	2
A	extract()	0	8	2

<?php
/**
 * Box packing (3D bin packing, knapsack problem).
 *
 * @author Doug Wright
 */
declare(strict_types=1);

namespace DVDoug\BoxPacker;

use ArrayIterator;
use Countable;
use IteratorAggregate;
use Traversable;

/**
 * List of items to be packed, ordered by volume.
 *
 * @author Doug Wright
 */
class ItemList implements Countable, IteratorAggregate
{
    /**
     * List containing items.
     *
     * @var Item[]
     */
    private $list = [];

    /**
     * Has this list already been sorted?
     *
     * @var bool
     */
    private $isSorted = false;

    /**
     * @param Item $item
     */
    public function insert(Item $item)
    {
        $this->list[] = $item;
    }

    /**
     * Do a bulk insert.
     *
     * @internal
     *
     * @param Item[] $items
     */
    public function insertFromArray(array $items): void
    {
        foreach ($items as $item) {
            $this->insert($item);
        }
    }

    /**
     * @internal
     *
     * @return Item
     */
    public function extract(): Item
    {
        if (!$this->isSorted) {
            usort($this->list, [$this, 'compare']);
            $this->isSorted = true;
        }

        return array_shift($this->list);
    }

    /**
     * @internal
     *
     * @return Item
     */
    public function top(): Item
    {
        if (!$this->isSorted) {
            usort($this->list, [$this, 'compare']);
            $this->isSorted = true;
        }
        $temp = $this->list;

        return reset($temp);
    }

    /**
     * @return Traversable
     */
    public function getIterator(): Traversable
    {
        if (!$this->isSorted) {
            usort($this->list, [$this, 'compare']);
            $this->isSorted = true;
        }

        return new ArrayIterator($this->list);
    }

    /**
     * Number of items in list.
     *
     * @return int
     */
    public function count(): int
    {
        return count($this->list);
    }

    /**
     * @param Item $itemA
     * @param Item $itemB
     *
     * @return int
     */
    private function compare(Item $itemA, Item $itemB): int
    {
        $itemAVolume = $itemA->getWidth() * $itemA->getLength() * $itemA->getDepth();
        $itemBVolume = $itemB->getWidth() * $itemB->getLength() * $itemB->getDepth();
        $volumeDecider = $itemBVolume <=> $itemAVolume;
        $weightDecider = $itemB->getWeight() - $itemA->getWeight();
        if ($volumeDecider !== 0) {
            return $volumeDecider;
        } elseif ($weightDecider !== 0) {
            return $weightDecider;
        } else {
            return $itemA->getDescription() <=> $itemB->getDescription();
        }
    }
}