<?php
  /**
   * Copyright (c) 2014 Arthur Schiwon <blizzz@owncloud.com>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   *
   */
  namespace OC\Share;
  
  class SearchResultSorter {
  	private $search;
  	private $encoding;
  	private $key;
  	private $log;
  
  	/**
  	 * @param $search the search term as was given by the user
  	 * @param $key the array key containing the value that should be compared
  	 * against
  	 * @param $encoding optional, encoding to use, defaults to UTF-8
  	 * @param $log optional, an \OC\Log instance
  	 */
  	public function __construct($search, $key, \OC\Log $log = null, $encoding = 'UTF-8') {
  		$this->encoding = $encoding;
  		$this->key = $key;
  		$this->log = $log;
  		$this->search = mb_strtolower($search, $this->encoding);
  	}
  
  	/**
  	 * User and Group names matching the search term at the beginning shall appear
  	 * on top of the share dialog. Following entries in alphabetical order.
  	 * Callback function for usort. http://php.net/usort
  	 */
  	public function sort($a, $b) {
  		if(!isset($a[$this->key]) || !isset($b[$this->key])) {
  			if(!is_null($this->log)) {
  				$this->log->error('Sharing dialogue: cannot sort due to ' .
  								  'missing array key', array('app' => 'core'));
  			}
  			return 0;
  		}
  		$nameA = mb_strtolower($a[$this->key], $this->encoding);
  		$nameB = mb_strtolower($b[$this->key], $this->encoding);
  		$i = mb_strpos($nameA, $this->search, 0, $this->encoding);
  		$j = mb_strpos($nameB, $this->search, 0, $this->encoding);
  
  		if($i === $j || $i > 0 && $j > 0) {
  			return strcmp(mb_strtolower($nameA, $this->encoding),
  						  mb_strtolower($nameB, $this->encoding));
  		} elseif ($i === 0) {
  			return -1;
  		} else {
  			return 1;
  		}
  	}
  }