<?php
/**
* Class LinkFilter.
*
* Perform search and filter operation on link data list.
*/
class LinkFilter
{
/**
* @var string permalinks.
*/
public static $FILTER_HASH = 'permalink';
/**
* @var string text search.
*/
public static $FILTER_TEXT = 'fulltext';
/**
* @var string tag filter.
*/
public static $FILTER_TAG = 'tags';
/**
* @var string filter by day.
*/
public static $FILTER_DAY = 'FILTER_DAY';
/**
* @var array all available links.
*/
private $links;
/**
* @param array $links initialization.
*/
public function __construct($links)
{
$this->links = $links;
}
/**
* Filter links according to parameters.
*
* @param string $type Type of filter (eg. tags, permalink, etc.).
* @param string $request Filter content.
* @param bool $casesensitive Optional: Perform case sensitive filter if true.
* @param bool $privateonly Optional: Only returns private links if true.
*
* @return array filtered link list.
*/
public function filter($type, $request, $casesensitive = false, $privateonly = false)
{
switch($type) {
case self::$FILTER_HASH:
return $this->filterSmallHash($request);
break;
case self::$FILTER_TEXT:
return $this->filterFulltext($request, $privateonly);
break;
case self::$FILTER_TAG:
return $this->filterTags($request, $casesensitive, $privateonly);
break;
case self::$FILTER_DAY:
return $this->filterDay($request);
break;
default:
return $this->noFilter($privateonly);
}
}
/**
* Unknown filter, but handle private only.
*
* @param bool $privateonly returns private link only if true.
*
* @return array filtered links.
*/
private function noFilter($privateonly = false)
{
if (! $privateonly) {
krsort($this->links);
return $this->links;
}
$out = array();
foreach ($this->links as $value) {
if ($value['private']) {
$out[$value['linkdate']] = $value;
}
}
krsort($out);
return $out;
}
/**
* Returns the shaare corresponding to a smallHash.
*
* @param string $smallHash permalink hash.
*
* @return array $filtered array containing permalink data.
*/
private function filterSmallHash($smallHash)
{
$filtered = array();
foreach ($this->links as $l) {
if ($smallHash == smallHash($l['linkdate'])) {
// Yes, this is ugly and slow
$filtered[$l['linkdate']] = $l;
return $filtered;
}
}
return $filtered;
}
/**
* Returns the list of links corresponding to a full-text search
*
* Searches:
* - in the URLs, title and description;
* - are case-insensitive.
*
* Example:
* print_r($mydb->filterFulltext('hollandais'));
*
* mb_convert_case($val, MB_CASE_LOWER, 'UTF-8')
* - allows to perform searches on Unicode text
* - see https://github.com/shaarli/Shaarli/issues/75 for examples
*
* @param string $searchterms search query.
* @param bool $privateonly return only private links if true.
*
* @return array search results.
*/
private function filterFulltext($searchterms, $privateonly = false)
{
// FIXME: explode(' ',$searchterms) and perform a AND search.
// FIXME: accept double-quotes to search for a string "as is"?
$filtered = array();
$search = mb_convert_case($searchterms, MB_CASE_LOWER, 'UTF-8');
$explodedSearch = explode(' ', trim($search));
$keys = array('title', 'description', 'url', 'tags');
// Iterate over every stored link.
foreach ($this->links as $link) {
$found = false;
// ignore non private links when 'privatonly' is on.
if (! $link['private'] && $privateonly === true) {
continue;
}
// Iterate over searchable link fields.
foreach ($keys as $key) {
// Search full expression.
if (strpos(
mb_convert_case($link[$key], MB_CASE_LOWER, 'UTF-8'),
$search
) !== false) {
$found = true;
}
if ($found) {
break;
}
}
if ($found) {
$filtered[$link['linkdate']] = $link;
}
}
krsort($filtered);
return $filtered;
}
/**
* Returns the list of links associated with a given list of tags
*
* You can specify one or more tags, separated by space or a comma, e.g.
* print_r($mydb->filterTags('linux programming'));
*
* @param string $tags list of tags separated by commas or blank spaces.
* @param bool $casesensitive ignore case if false.
* @param bool $privateonly returns private links only.
*
* @return array filtered links.
*/
public function filterTags($tags, $casesensitive = false, $privateonly = false)
{
$searchtags = $this->tagsStrToArray($tags, $casesensitive);
$filtered = array();
foreach ($this->links as $l) {
// ignore non private links when 'privatonly' is on.
if (! $l['private'] && $privateonly === true) {
continue;
}
$linktags = $this->tagsStrToArray($l['tags'], $casesensitive);
if (count(array_intersect($linktags, $searchtags)) == count($searchtags)) {
$filtered[$l['linkdate']] = $l;
}
}
krsort($filtered);
return $filtered;
}
/**
* Returns the list of articles for a given day, chronologically sorted
*
* Day must be in the form 'YYYYMMDD' (e.g. '20120125'), e.g.
* print_r($mydb->filterDay('20120125'));
*
* @param string $day day to filter.
*
* @return array all link matching given day.
*
* @throws Exception if date format is invalid.
*/
public function filterDay($day)
{
if (! checkDateFormat('Ymd', $day)) {
throw new Exception('Invalid date format');
}
$filtered = array();
foreach ($this->links as $l) {
if (startsWith($l['linkdate'], $day)) {
$filtered[$l['linkdate']] = $l;
}
}
ksort($filtered);
return $filtered;
}
/**
* Convert a list of tags (str) to an array. Also
* - handle case sensitivity.
* - accepts spaces commas as separator.
* - remove private tags for loggedout users.
*
* @param string $tags string containing a list of tags.
* @param bool $casesensitive will convert everything to lowercase if false.
*
* @return array filtered tags string.
*/
public function tagsStrToArray($tags, $casesensitive)
{
// We use UTF-8 conversion to handle various graphemes (i.e. cyrillic, or greek)
$tagsOut = $casesensitive ? $tags : mb_convert_case($tags, MB_CASE_LOWER, 'UTF-8');
$tagsOut = str_replace(',', ' ', $tagsOut);
return explode(' ', trim($tagsOut));
}
}
