Sort.php

<?php
/*
 * citeproc-php
 *
 * @link        http://github.com/seboettg/citeproc-php for the source repository
 * @copyright   Copyright (c) 2016 Sebastian Böttger.
 * @license     https://opensource.org/licenses/MIT
 */
 
namespace Seboettg\CiteProc\Style\Sort;
 
use Seboettg\CiteProc\CiteProc;
use Seboettg\CiteProc\Data\DataList;
use Seboettg\CiteProc\Exception\CiteProcException;
use Seboettg\CiteProc\Util\DateHelper;
use Seboettg\CiteProc\Util\Variables;
use Seboettg\Collection\ArrayList;
use SimpleXMLElement;
 
class Sort
{
    private $sortingKeys;
 
    public function __construct(SimpleXMLElement $node)
    {
        $this->sortingKeys = new ArrayList();
        foreach ($node->children() as $child) {
            if ("key" === $child->getName()) {
                $this->sortingKeys->append(new Key($child));
            }
        }
    }
 
    public function sort(&$data)
    {
        if (is_array($data)) {
            $data = new DataList($data);
        }
        $dataToSort = $data->toArray();
        try {
            $data->replace($this->performSort(0, $dataToSort));
        } catch (CiteProcException $e) {
            //nothing to do, because $data is passed by referenced
        }
    }
 
    private function performSort($keyNumber, $dataToSort)
    {
        if (count($dataToSort) < 2) {
            return $dataToSort;
        }
 
        $key = $this->sortingKeys->get($keyNumber);
        $variable = $key->getVariable();
        $groupedItems = [];
 
        if ($key->isDateVariable()) {
            if (DateHelper::hasDateRanges($dataToSort, $variable, "all")) {
                $newKey = clone $key;
                $newKey->setRangePart(2);
                $key->setRangePart(1);
                $this->sortingKeys->append($newKey);
            }
        }
 
        //grouping by value
        foreach ($dataToSort as $citationNumber => $dataItem) {
            if ($key->isNameVariable()) {
                $sortKey = Variables::nameHash($dataItem, $variable);
            } elseif ($key->isNumberVariable()) {
                $sortKey = $dataItem->{$variable};
            } elseif ($key->isDateVariable()) {
                $sortKey = DateHelper::getSortKeyDate($dataItem, $key);
            } elseif ($key->isMacro()) {
                $sortKey = mb_strtolower(strip_tags(CiteProc::getContext()->getMacro(
                    $key->getMacro()
                )->render($dataItem, $citationNumber)));
            } elseif ($variable === "citation-number") {
                $sortKey = $citationNumber + 1;
            } else {
                $sortKey = mb_strtolower(strip_tags($dataItem->{$variable}));
            }
            $groupedItems[$sortKey][] = $dataItem;
        }
 
        if ($this->sortingKeys->count() > ++$keyNumber) {
            foreach ($groupedItems as $group => &$array) {
                if (count($array) > 1) {
                    $array = $this->performSort($keyNumber, $array);
                }
            }
        }
 
        //sorting by array keys
        if ($key->getSort() === "ascending") {
            ksort($groupedItems); //ascending
        } else {
            krsort($groupedItems); //reverse
        }
 
        //the flattened array is the result
        $sortedDataGroups = array_values($groupedItems);
        return $this->flatten($sortedDataGroups);
    }
 
    public function flatten($array)
    {
        $returnArray = [];
        array_walk_recursive($array, function ($a) use (&$returnArray) {
            $returnArray[] = $a;
        });
        return $returnArray;
    }
 
    public function getSortingKeys()
    {
        return $this->sortingKeys;
    }
}