1 files changed, 449 insertions, 0 deletions

diff --git a/application/bookmark/LinkFilter.php b/application/bookmark/LinkFilter.php
new file mode 100644
index 00000000..9b966307
--- /dev/null
+++ b/application/bookmark/LinkFilter.php
@@ -0,0 +1,449 @@
+<?php
+
+namespace Shaarli\Bookmark;
+
+use Exception;
+use Shaarli\Bookmark\Exception\LinkNotFoundException;
+
+/**
+ * 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 string Allowed characters for hashtags (regex syntax).
+     */
+    public static $HASHTAG_CHARS = '\p{Pc}\p{N}\p{L}\p{Mn}';
+
+    /**
+     * @var LinkDB all available links.
+     */
+    private $links;
+
+    /**
+     * @param LinkDB $links initialization.
+     */
+    public function __construct($links)
+    {
+        $this->links = $links;
+    }
+
+    /**
+     * Filter links according to parameters.
+     *
+     * @param string $type          Type of filter (eg. tags, permalink, etc.).
+     * @param mixed  $request       Filter content.
+     * @param bool   $casesensitive Optional: Perform case sensitive filter if true.
+     * @param string $visibility    Optional: return only all/private/public links
+     * @param string $untaggedonly  Optional: return only untagged links. Applies only if $type includes FILTER_TAG
+     *
+     * @return array filtered link list.
+     */
+    public function filter($type, $request, $casesensitive = false, $visibility = 'all', $untaggedonly = false)
+    {
+        if (!in_array($visibility, ['all', 'public', 'private'])) {
+            $visibility = 'all';
+        }
+
+        switch ($type) {
+            case self::$FILTER_HASH:
+                return $this->filterSmallHash($request);
+            case self::$FILTER_TAG | self::$FILTER_TEXT: // == "vuotext"
+                $noRequest = empty($request) || (empty($request[0]) && empty($request[1]));
+                if ($noRequest) {
+                    if ($untaggedonly) {
+                        return $this->filterUntagged($visibility);
+                    }
+                    return $this->noFilter($visibility);
+                }
+                if ($untaggedonly) {
+                    $filtered = $this->filterUntagged($visibility);
+                } else {
+                    $filtered = $this->links;
+                }
+                if (!empty($request[0])) {
+                    $filtered = (new LinkFilter($filtered))->filterTags($request[0], $casesensitive, $visibility);
+                }
+                if (!empty($request[1])) {
+                    $filtered = (new LinkFilter($filtered))->filterFulltext($request[1], $visibility);
+                }
+                return $filtered;
+            case self::$FILTER_TEXT:
+                return $this->filterFulltext($request, $visibility);
+            case self::$FILTER_TAG:
+                if ($untaggedonly) {
+                    return $this->filterUntagged($visibility);
+                } else {
+                    return $this->filterTags($request, $casesensitive, $visibility);
+                }
+            case self::$FILTER_DAY:
+                return $this->filterDay($request);
+            default:
+                return $this->noFilter($visibility);
+        }
+    }
+
+    /**
+     * Unknown filter, but handle private only.
+     *
+     * @param string $visibility Optional: return only all/private/public links
+     *
+     * @return array filtered links.
+     */
+    private function noFilter($visibility = 'all')
+    {
+        if ($visibility === 'all') {
+            return $this->links;
+        }
+
+        $out = array();
+        foreach ($this->links as $key => $value) {
+            if ($value['private'] && $visibility === 'private') {
+                $out[$key] = $value;
+            } elseif (!$value['private'] && $visibility === 'public') {
+                $out[$key] = $value;
+            }
+        }
+
+        return $out;
+    }
+
+    /**
+     * Returns the shaare corresponding to a smallHash.
+     *
+     * @param string $smallHash permalink hash.
+     *
+     * @return array $filtered array containing permalink data.
+     *
+     * @throws \Shaarli\Bookmark\Exception\LinkNotFoundException if the smallhash doesn't match any link.
+     */
+    private function filterSmallHash($smallHash)
+    {
+        $filtered = array();
+        foreach ($this->links as $key => $l) {
+            if ($smallHash == $l['shorturl']) {
+                // Yes, this is ugly and slow
+                $filtered[$key] = $l;
+                return $filtered;
+            }
+        }
+
+        if (empty($filtered)) {
+            throw new LinkNotFoundException();
+        }
+
+        return $filtered;
+    }
+
+    /**
+     * Returns the list of links corresponding to a full-text search
+     *
+     * Searches:
+     *  - in the URLs, title and description;
+     *  - are case-insensitive;
+     *  - terms surrounded by quotes " are exact terms search.
+     *  - terms starting with a dash - are excluded (except exact terms).
+     *
+     * Example:
+     *    print_r($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 string $visibility  Optional: return only all/private/public links.
+     *
+     * @return array search results.
+     */
+    private function filterFulltext($searchterms, $visibility = 'all')
+    {
+        if (empty($searchterms)) {
+            return $this->noFilter($visibility);
+        }
+
+        $filtered = array();
+        $search = mb_convert_case(html_entity_decode($searchterms), MB_CASE_LOWER, 'UTF-8');
+        $exactRegex = '/"([^"]+)"/';
+        // Retrieve exact search terms.
+        preg_match_all($exactRegex, $search, $exactSearch);
+        $exactSearch = array_values(array_filter($exactSearch[1]));
+
+        // Remove exact search terms to get AND terms search.
+        $explodedSearchAnd = explode(' ', trim(preg_replace($exactRegex, '', $search)));
+        $explodedSearchAnd = array_values(array_filter($explodedSearchAnd));
+
+        // Filter excluding terms and update andSearch.
+        $excludeSearch = array();
+        $andSearch = array();
+        foreach ($explodedSearchAnd as $needle) {
+            if ($needle[0] == '-' && strlen($needle) > 1) {
+                $excludeSearch[] = substr($needle, 1);
+            } else {
+                $andSearch[] = $needle;
+            }
+        }
+
+        $keys = array('title', 'description', 'url', 'tags');
+
+        // Iterate over every stored link.
+        foreach ($this->links as $id => $link) {
+            // ignore non private links when 'privatonly' is on.
+            if ($visibility !== 'all') {
+                if (!$link['private'] && $visibility === 'private') {
+                    continue;
+                } elseif ($link['private'] && $visibility === 'public') {
+                    continue;
+                }
+            }
+
+            // Concatenate link fields to search across fields.
+            // Adds a '\' separator for exact search terms.
+            $content = '';
+            foreach ($keys as $key) {
+                $content .= mb_convert_case($link[$key], MB_CASE_LOWER, 'UTF-8') . '\\';
+            }
+
+            // Be optimistic
+            $found = true;
+
+            // First, we look for exact term search
+            for ($i = 0; $i < count($exactSearch) && $found; $i++) {
+                $found = strpos($content, $exactSearch[$i]) !== false;
+            }
+
+            // Iterate over keywords, if keyword is not found,
+            // no need to check for the others. We want all or nothing.
+            for ($i = 0; $i < count($andSearch) && $found; $i++) {
+                $found = strpos($content, $andSearch[$i]) !== false;
+            }
+
+            // Exclude terms.
+            for ($i = 0; $i < count($excludeSearch) && $found; $i++) {
+                $found = strpos($content, $excludeSearch[$i]) === false;
+            }
+
+            if ($found) {
+                $filtered[$id] = $link;
+            }
+        }
+
+        return $filtered;
+    }
+
+    /**
+     * generate a regex fragment out of a tag
+     *
+     * @param string $tag to to generate regexs from. may start with '-' to negate, contain '*' as wildcard
+     *
+     * @return string generated regex fragment
+     */
+    private static function tag2regex($tag)
+    {
+        $len = strlen($tag);
+        if (!$len || $tag === "-" || $tag === "*") {
+            // nothing to search, return empty regex
+            return '';
+        }
+        if ($tag[0] === "-") {
+            // query is negated
+            $i = 1; // use offset to start after '-' character
+            $regex = '(?!'; // create negative lookahead
+        } else {
+            $i = 0; // start at first character
+            $regex = '(?='; // use positive lookahead
+        }
+        $regex .= '.*(?:^| )'; // before tag may only be a space or the beginning
+        // iterate over string, separating it into placeholder and content
+        for (; $i < $len; $i++) {
+            if ($tag[$i] === '*') {
+                // placeholder found
+                $regex .= '[^ ]*?';
+            } else {
+                // regular characters
+                $offset = strpos($tag, '*', $i);
+                if ($offset === false) {
+                    // no placeholder found, set offset to end of string
+                    $offset = $len;
+                }
+                // subtract one, as we want to get before the placeholder or end of string
+                $offset -= 1;
+                // we got a tag name that we want to search for. escape any regex characters to prevent conflicts.
+                $regex .= preg_quote(substr($tag, $i, $offset - $i + 1), '/');
+                // move $i on
+                $i = $offset;
+            }
+        }
+        $regex .= '(?:$| ))'; // after the tag may only be a space or the end
+        return $regex;
+    }
+
+    /**
+     * Returns the list of links associated with a given list of tags
+     *
+     * You can specify one or more tags, separated by space or a comma, e.g.
+     *  print_r($mydb->filterTags('linux programming'));
+     *
+     * @param string $tags          list of tags separated by commas or blank spaces.
+     * @param bool   $casesensitive ignore case if false.
+     * @param string $visibility    Optional: return only all/private/public links.
+     *
+     * @return array filtered links.
+     */
+    public function filterTags($tags, $casesensitive = false, $visibility = 'all')
+    {
+        // get single tags (we may get passed an array, even though the docs say different)
+        $inputTags = $tags;
+        if (!is_array($tags)) {
+            // we got an input string, split tags
+            $inputTags = preg_split('/(?:\s+)|,/', $inputTags, -1, PREG_SPLIT_NO_EMPTY);
+        }
+
+        if (!count($inputTags)) {
+            // no input tags
+            return $this->noFilter($visibility);
+        }
+
+        // build regex from all tags
+        $re = '/^' . implode(array_map("self::tag2regex", $inputTags)) . '.*$/';
+        if (!$casesensitive) {
+            // make regex case insensitive
+            $re .= 'i';
+        }
+
+        // create resulting array
+        $filtered = array();
+
+        // iterate over each link
+        foreach ($this->links as $key => $link) {
+            // check level of visibility
+            // ignore non private links when 'privateonly' is on.
+            if ($visibility !== 'all') {
+                if (!$link['private'] && $visibility === 'private') {
+                    continue;
+                } elseif ($link['private'] && $visibility === 'public') {
+                    continue;
+                }
+            }
+            $search = $link['tags']; // build search string, start with tags of current link
+            if (strlen(trim($link['description'])) && strpos($link['description'], '#') !== false) {
+                // description given and at least one possible tag found
+                $descTags = array();
+                // find all tags in the form of #tag in the description
+                preg_match_all(
+                    '/(?<![' . self::$HASHTAG_CHARS . '])#([' . self::$HASHTAG_CHARS . ']+?)\b/sm',
+                    $link['description'],
+                    $descTags
+                );
+                if (count($descTags[1])) {
+                    // there were some tags in the description, add them to the search string
+                    $search .= ' ' . implode(' ', $descTags[1]);
+                }
+            };
+            // match regular expression with search string
+            if (!preg_match($re, $search)) {
+                // this entry does _not_ match our regex
+                continue;
+            }
+            $filtered[$key] = $link;
+        }
+        return $filtered;
+    }
+
+    /**
+     * Return only links without any tag.
+     *
+     * @param string $visibility return only all/private/public links.
+     *
+     * @return array filtered links.
+     */
+    public function filterUntagged($visibility)
+    {
+        $filtered = [];
+        foreach ($this->links as $key => $link) {
+            if ($visibility !== 'all') {
+                if (!$link['private'] && $visibility === 'private') {
+                    continue;
+                } elseif ($link['private'] && $visibility === 'public') {
+                    continue;
+                }
+            }
+
+            if (empty(trim($link['tags']))) {
+                $filtered[$key] = $link;
+            }
+        }
+
+        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 $key => $l) {
+            if ($l['created']->format('Ymd') == $day) {
+                $filtered[$key] = $l;
+            }
+        }
+
+        // sort by date ASC
+        return array_reverse($filtered, true);
+    }
+
+    /**
+     * Convert a list of tags (str) to an array. Also
+     * - handle case sensitivity.
+     * - accepts spaces commas as separator.
+     *
+     * @param string $tags          string containing a list of tags.
+     * @param bool   $casesensitive will convert everything to lowercase if false.
+     *
+     * @return array filtered tags string.
+     */
+    public static function tagsStrToArray($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 preg_split('/\s+/', $tagsOut, -1, PREG_SPLIT_NO_EMPTY);
+    }
+}