1 files changed, 296 insertions, 0 deletions

diff --git a/application/bookmark/LinkUtils.php b/application/bookmark/LinkUtils.php
new file mode 100644
index 00000000..77eb2d95
--- /dev/null
+++ b/application/bookmark/LinkUtils.php
@@ -0,0 +1,296 @@
+<?php
+
+use Shaarli\Bookmark\LinkDB;
+
+/**
+ * Get cURL callback function for CURLOPT_WRITEFUNCTION
+ *
+ * @param string $charset     to extract from the downloaded page (reference)
+ * @param string $title       to extract from the downloaded page (reference)
+ * @param string $description to extract from the downloaded page (reference)
+ * @param string $keywords    to extract from the downloaded page (reference)
+ * @param bool   $retrieveDescription Automatically tries to retrieve description and keywords from HTML content
+ * @param string $curlGetInfo Optionally overrides curl_getinfo function
+ *
+ * @return Closure
+ */
+function get_curl_download_callback(
+    &$charset,
+    &$title,
+    &$description,
+    &$keywords,
+    $retrieveDescription,
+    $curlGetInfo = 'curl_getinfo'
+) {
+    $isRedirected = false;
+    $currentChunk = 0;
+    $foundChunk = null;
+
+    /**
+     * cURL callback function for CURLOPT_WRITEFUNCTION (called during the download).
+     *
+     * While downloading the remote page, we check that the HTTP code is 200 and content type is 'html/text'
+     * Then we extract the title and the charset and stop the download when it's done.
+     *
+     * @param resource $ch   cURL resource
+     * @param string   $data chunk of data being downloaded
+     *
+     * @return int|bool length of $data or false if we need to stop the download
+     */
+    return function (&$ch, $data) use (
+        $retrieveDescription,
+        $curlGetInfo,
+        &$charset,
+        &$title,
+        &$description,
+        &$keywords,
+        &$isRedirected,
+        &$currentChunk,
+        &$foundChunk
+    ) {
+        $currentChunk++;
+        $responseCode = $curlGetInfo($ch, CURLINFO_RESPONSE_CODE);
+        if (!empty($responseCode) && in_array($responseCode, [301, 302])) {
+            $isRedirected = true;
+            return strlen($data);
+        }
+        if (!empty($responseCode) && $responseCode !== 200) {
+            return false;
+        }
+        // After a redirection, the content type will keep the previous request value
+        // until it finds the next content-type header.
+        if (! $isRedirected || strpos(strtolower($data), 'content-type') !== false) {
+            $contentType = $curlGetInfo($ch, CURLINFO_CONTENT_TYPE);
+        }
+        if (!empty($contentType) && strpos($contentType, 'text/html') === false) {
+            return false;
+        }
+        if (!empty($contentType) && empty($charset)) {
+            $charset = header_extract_charset($contentType);
+        }
+        if (empty($charset)) {
+            $charset = html_extract_charset($data);
+        }
+        if (empty($title)) {
+            $title = html_extract_title($data);
+            $foundChunk = ! empty($title) ? $currentChunk : $foundChunk;
+        }
+        if ($retrieveDescription && empty($description)) {
+            $description = html_extract_tag('description', $data);
+            $foundChunk = ! empty($description) ? $currentChunk : $foundChunk;
+        }
+        if ($retrieveDescription && empty($keywords)) {
+            $keywords = html_extract_tag('keywords', $data);
+            if (! empty($keywords)) {
+                $foundChunk = $currentChunk;
+                // Keywords use the format tag1, tag2 multiple words, tag
+                // So we format them to match Shaarli's separator and glue multiple words with '-'
+                $keywords = implode(' ', array_map(function($keyword) {
+                    return implode('-', preg_split('/\s+/', trim($keyword)));
+                }, explode(',', $keywords)));
+            }
+        }
+
+        // We got everything we want, stop the download.
+        // If we already found either the title, description or keywords,
+        // it's highly unlikely that we'll found the other metas further than
+        // in the same chunk of data or the next one. So we also stop the download after that.
+        if ((!empty($responseCode) && !empty($contentType) && !empty($charset)) && $foundChunk !== null
+            && (! $retrieveDescription
+                || $foundChunk < $currentChunk
+                || (!empty($title) && !empty($description) && !empty($keywords))
+            )
+        ) {
+            return false;
+        }
+
+        return strlen($data);
+    };
+}
+
+/**
+ * Extract title from an HTML document.
+ *
+ * @param string $html HTML content where to look for a title.
+ *
+ * @return bool|string Extracted title if found, false otherwise.
+ */
+function html_extract_title($html)
+{
+    if (preg_match('!<title.*?>(.*?)</title>!is', $html, $matches)) {
+        return trim(str_replace("\n", '', $matches[1]));
+    }
+    return false;
+}
+
+/**
+ * Extract charset from HTTP header if it's defined.
+ *
+ * @param string $header HTTP header Content-Type line.
+ *
+ * @return bool|string Charset string if found (lowercase), false otherwise.
+ */
+function header_extract_charset($header)
+{
+    preg_match('/charset="?([^; ]+)/i', $header, $match);
+    if (! empty($match[1])) {
+        return strtolower(trim($match[1]));
+    }
+
+    return false;
+}
+
+/**
+ * Extract charset HTML content (tag <meta charset>).
+ *
+ * @param string $html HTML content where to look for charset.
+ *
+ * @return bool|string Charset string if found, false otherwise.
+ */
+function html_extract_charset($html)
+{
+    // Get encoding specified in HTML header.
+    preg_match('#<meta .*charset=["\']?([^";\'>/]+)["\']? */?>#Usi', $html, $enc);
+    if (!empty($enc[1])) {
+        return strtolower($enc[1]);
+    }
+
+    return false;
+}
+
+/**
+ * Extract meta tag from HTML content in either:
+ *   - OpenGraph: <meta property="og:[tag]" ...>
+ *   - Meta tag: <meta name="[tag]" ...>
+ *
+ * @param string $tag  Name of the tag to retrieve.
+ * @param string $html HTML content where to look for charset.
+ *
+ * @return bool|string Charset string if found, false otherwise.
+ */
+function html_extract_tag($tag, $html)
+{
+    $propertiesKey = ['property', 'name', 'itemprop'];
+    $properties = implode('|', $propertiesKey);
+    // Try to retrieve OpenGraph image.
+    $ogRegex = '#<meta[^>]+(?:'. $properties .')=["\']?(?:og:)?'. $tag .'["\'\s][^>]*content=["\']?(.*?)["\'/>]#';
+    // If the attributes are not in the order property => content (e.g. Github)
+    // New regex to keep this readable... more or less.
+    $ogRegexReverse = '#<meta[^>]+content=["\']([^"\']+)[^>]+(?:'. $properties .')=["\']?(?:og)?:'. $tag .'["\'\s/>]#';
+
+    if (preg_match($ogRegex, $html, $matches) > 0
+        || preg_match($ogRegexReverse, $html, $matches) > 0
+    ) {
+        return $matches[1];
+    }
+
+    return false;
+}
+
+/**
+ * Count private links in given linklist.
+ *
+ * @param array|Countable $links Linklist.
+ *
+ * @return int Number of private links.
+ */
+function count_private($links)
+{
+    $cpt = 0;
+    foreach ($links as $link) {
+        if ($link['private']) {
+            $cpt += 1;
+        }
+    }
+
+    return $cpt;
+}
+
+/**
+ * In a string, converts URLs to clickable links.
+ *
+ * @param string $text       input string.
+ *
+ * @return string returns $text with all links converted to HTML links.
+ *
+ * @see Function inspired from http://www.php.net/manual/en/function.preg-replace.php#85722
+ */
+function text2clickable($text)
+{
+    $regex = '!(((?:https?|ftp|file)://|apt:|magnet:)\S+[a-z0-9\(\)]/?)!si';
+    return preg_replace($regex, '<a href="$1">$1</a>', $text);
+}
+
+/**
+ * Auto-link hashtags.
+ *
+ * @param string $description Given description.
+ * @param string $indexUrl    Root URL.
+ *
+ * @return string Description with auto-linked hashtags.
+ */
+function hashtag_autolink($description, $indexUrl = '')
+{
+    /*
+     * To support unicode: http://stackoverflow.com/a/35498078/1484919
+     * \p{Pc} - to match underscore
+     * \p{N} - numeric character in any script
+     * \p{L} - letter from any language
+     * \p{Mn} - any non marking space (accents, umlauts, etc)
+     */
+    $regex = '/(^|\s)#([\p{Pc}\p{N}\p{L}\p{Mn}]+)/mui';
+    $replacement = '$1<a href="'. $indexUrl .'?addtag=$2" title="Hashtag $2">#$2</a>';
+    return preg_replace($regex, $replacement, $description);
+}
+
+/**
+ * This function inserts &nbsp; where relevant so that multiple spaces are properly displayed in HTML
+ * even in the absence of <pre>  (This is used in description to keep text formatting).
+ *
+ * @param string $text input text.
+ *
+ * @return string formatted text.
+ */
+function space2nbsp($text)
+{
+    return preg_replace('/(^| ) /m', '$1&nbsp;', $text);
+}
+
+/**
+ * Format Shaarli's description
+ *
+ * @param string $description shaare's description.
+ * @param string $indexUrl    URL to Shaarli's index.
+
+ * @return string formatted description.
+ */
+function format_description($description, $indexUrl = '')
+{
+    return nl2br(space2nbsp(hashtag_autolink(text2clickable($description), $indexUrl)));
+}
+
+/**
+ * Generate a small hash for a link.
+ *
+ * @param DateTime $date Link creation date.
+ * @param int      $id   Link ID.
+ *
+ * @return string the small hash generated from link data.
+ */
+function link_small_hash($date, $id)
+{
+    return smallHash($date->format(LinkDB::LINK_DATE_FORMAT) . $id);
+}
+
+/**
+ * Returns whether or not the link is an internal note.
+ * Its URL starts by `?` because it's actually a permalink.
+ *
+ * @param string $linkUrl
+ *
+ * @return bool true if internal note, false otherwise.
+ */
+function is_note($linkUrl)
+{
+    return isset($linkUrl[0]) && $linkUrl[0] === '?';
+}