Link filter refactoring

  * introduce class LinkFilter to handle link filter operation (and lighten LinkDB).
  * handle 'private only' in filtering.
  * update template to prefill search fields with current search terms.
  * coding style.
  * unit test (mostly move from LinkDB to LinkFilter).

PS: preparation for #358 #315 and 'AND' search.

3 files changed, 281 insertions, 110 deletions

diff --git a/application/LinkDB.php b/application/LinkDB.php
index 51fa926d..be7d9016 100644
--- a/application/LinkDB.php
+++ b/application/LinkDB.php
@@ -63,6 +63,11 @@ class LinkDB implements Iterator, Countable, ArrayAccess
     private $_redirector;
 
     /**
+     * @var LinkFilter instance.
+     */
+    private $linkFilter;
+
+    /**
      * Creates a new LinkDB
      *
      * Checks if the datastore exists; else, attempts to create a dummy one.
@@ -80,6 +85,7 @@ class LinkDB implements Iterator, Countable, ArrayAccess
         $this->_redirector = $redirector;
         $this->_checkDB();
         $this->_readDB();
+        $this->linkFilter = new LinkFilter($this->_links);
     }
 
     /**
@@ -334,114 +340,18 @@ You use the community supported version of the original Shaarli project, by Seba
     }
 
     /**
-     * Returns the list of links corresponding to a full-text search
+     * Filter links.
      *
-     * 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
-     */
-    public function filterFulltext($searchterms)
-    {
-        // FIXME: explode(' ',$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');
-        $keys = array('title', 'description', 'url', 'tags');
-
-        foreach ($this->_links as $link) {
-            $found = false;
-
-            foreach ($keys as $key) {
-                if (strpos(mb_convert_case($link[$key], MB_CASE_LOWER, 'UTF-8'),
-                           $search) !== false) {
-                    $found = true;
-                }
-            }
-
-            if ($found) {
-                $filtered[$link['linkdate']] = $link;
-            }
-        }
-        krsort($filtered);
-        return $filtered;
-    }
-
-    /**
-     * Returns the list of links associated with a given list of tags
+     * @param string $type          Type of filter.
+     * @param mixed  $request       Search request, string or array.
+     * @param bool   $casesensitive Optional: Perform case sensitive filter
+     * @param bool   $privateonly   Optional: Returns private links only if true.
      *
-     * You can specify one or more tags, separated by space or a comma, e.g.
-     *  print_r($mydb->filterTags('linux programming'));
+     * @return array filtered links
      */
-    public function filterTags($tags, $casesensitive=false)
-    {
-        // Same as above, we use UTF-8 conversion to handle various graphemes (i.e. cyrillic, or greek)
-        // FIXME: is $casesensitive ever true?
-        $t = str_replace(
-            ',', ' ',
-            ($casesensitive ? $tags : mb_convert_case($tags, MB_CASE_LOWER, 'UTF-8'))
-        );
-
-        $searchtags = explode(' ', $t);
-        $filtered = array();
-
-        foreach ($this->_links as $l) {
-            $linktags = explode(
-                ' ',
-                ($casesensitive ? $l['tags']:mb_convert_case($l['tags'], MB_CASE_LOWER, 'UTF-8'))
-            );
-
-            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'));
-     */
-    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 $filtered;
-    }
-
-    /**
-     * Returns the article corresponding to a smallHash
-     */
-    public function filterSmallHash($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 $filtered;
+    public function filter($type, $request, $casesensitive = false, $privateonly = false) {
+        $requestFilter = is_array($request) ? implode(' ', $request) : $request;
+        return $this->linkFilter->filter($type, $requestFilter, $casesensitive, $privateonly);
     }
 
     /**
diff --git a/application/LinkFilter.php b/application/LinkFilter.php
new file mode 100644
index 00000000..cf647371
--- /dev/null
+++ b/application/LinkFilter.php
@@ -0,0 +1,259 @@
+<?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));
+    }
+}
diff --git a/application/Utils.php b/application/Utils.php
index f84f70e4..aeaef9ff 100644
--- a/application/Utils.php
+++ b/application/Utils.php
@@ -72,12 +72,14 @@ function sanitizeLink(&$link)
 
 /**
  * Checks if a string represents a valid date
+
+ * @param string $format The expected DateTime format of the string
+ * @param string $string A string-formatted date
+ *
+ * @return bool whether the string is a valid date
  *
- * @param string        a string-formatted date
- * @param format        the expected DateTime format of the string
- * @return              whether the string is a valid date
- * @see                 http://php.net/manual/en/class.datetime.php
- * @see                 http://php.net/manual/en/datetime.createfromformat.php
+ * @see http://php.net/manual/en/class.datetime.php
+ * @see http://php.net/manual/en/datetime.createfromformat.php
  */
 function checkDateFormat($format, $string)
 {