3 files changed, 174 insertions, 3 deletions

diff --git a/application/ApplicationUtils.php b/application/ApplicationUtils.php
index b0e94e24..274331e1 100644
--- a/application/ApplicationUtils.php
+++ b/application/ApplicationUtils.php
@@ -4,6 +4,110 @@
  */
 class ApplicationUtils
 {
+    private static $GIT_URL = 'https://raw.githubusercontent.com/shaarli/Shaarli';
+    private static $GIT_BRANCHES = array('master', 'stable');
+    private static $VERSION_FILE = 'shaarli_version.php';
+    private static $VERSION_START_TAG = '<?php /* ';
+    private static $VERSION_END_TAG = ' */ ?>';
+
+    /**
+     * Gets the latest version code from the Git repository
+     *
+     * The code is read from the raw content of the version file on the Git server.
+     *
+     * @return mixed the version code from the repository if available, else 'false'
+     */
+    public static function getLatestGitVersionCode($url, $timeout=2)
+    {
+        list($headers, $data) = get_http_url($url, $timeout);
+
+        if (strpos($headers[0], '200 OK') === false) {
+            error_log('Failed to retrieve ' . $url);
+            return false;
+        }
+
+        return str_replace(
+            array(self::$VERSION_START_TAG, self::$VERSION_END_TAG, PHP_EOL),
+            array('', '', ''),
+            $data
+        );
+    }
+
+    /**
+     * Checks if a new Shaarli version has been published on the Git repository
+     *
+     * Updates checks are run periodically, according to the following criteria:
+     * - the update checks are enabled (install, global config);
+     * - the user is logged in (or this is an open instance);
+     * - the last check is older than a given interval;
+     * - the check is non-blocking if the HTTPS connection to Git fails;
+     * - in case of failure, the update file's modification date is updated,
+     *   to avoid intempestive connection attempts.
+     *
+     * @param string $currentVersion the current version code
+     * @param string $updateFile     the file where to store the latest version code
+     * @param int    $checkInterval  the minimum interval between update checks (in seconds
+     * @param bool   $enableCheck    whether to check for new versions
+     * @param bool   $isLoggedIn     whether the user is logged in
+     *
+     * @throws Exception an invalid branch has been set for update checks
+     *
+     * @return mixed the new version code if available and greater, else 'false'
+     */
+    public static function checkUpdate($currentVersion,
+                                       $updateFile,
+                                       $checkInterval,
+                                       $enableCheck,
+                                       $isLoggedIn,
+                                       $branch='stable')
+    {
+        if (! $isLoggedIn) {
+            // Do not check versions for visitors
+            return false;
+        }
+
+        if (empty($enableCheck)) {
+            // Do not check if the user doesn't want to
+            return false;
+        }
+
+        if (is_file($updateFile) && (filemtime($updateFile) > time() - $checkInterval)) {
+            // Shaarli has checked for updates recently - skip HTTP query
+            $latestKnownVersion = file_get_contents($updateFile);
+
+            if (version_compare($latestKnownVersion, $currentVersion) == 1) {
+                return $latestKnownVersion;
+            }
+            return false;
+        }
+
+        if (! in_array($branch, self::$GIT_BRANCHES)) {
+            throw new Exception(
+                'Invalid branch selected for updates: "' . $branch . '"'
+            );
+        }
+
+        // Late Static Binding allows overriding within tests
+        // See http://php.net/manual/en/language.oop5.late-static-bindings.php
+        $latestVersion = static::getLatestGitVersionCode(
+            self::$GIT_URL . '/' . $branch . '/' . self::$VERSION_FILE
+        );
+
+        if (! $latestVersion) {
+            // Only update the file's modification date
+            file_put_contents($updateFile, $currentVersion);
+            return false;
+        }
+
+        // Update the file's content and modification date
+        file_put_contents($updateFile, $latestVersion);
+
+        if (version_compare($latestVersion, $currentVersion) == 1) {
+            return $latestVersion;
+        }
+
+        return false;
+    }
 
     /**
      * Checks the PHP version to ensure Shaarli can run
diff --git a/application/LinkDB.php b/application/LinkDB.php
index 15fadbc3..f771ac8b 100644
--- a/application/LinkDB.php
+++ b/application/LinkDB.php
@@ -57,18 +57,25 @@ class LinkDB implements Iterator, Countable, ArrayAccess
     // Hide public links
     private $_hidePublicLinks;
 
+    // link redirector set in user settings.
+    private $_redirector;
+
     /**
      * Creates a new LinkDB
      *
      * Checks if the datastore exists; else, attempts to create a dummy one.
      *
-     * @param $isLoggedIn is the user logged in?
+     * @param string  $datastore       datastore file path.
+     * @param boolean $isLoggedIn      is the user logged in?
+     * @param boolean $hidePublicLinks if true all links are private.
+     * @param string  $redirector      link redirector set in user settings.
      */
-    function __construct($datastore, $isLoggedIn, $hidePublicLinks)
+    function __construct($datastore, $isLoggedIn, $hidePublicLinks, $redirector = '')
     {
         $this->_datastore = $datastore;
         $this->_loggedIn = $isLoggedIn;
         $this->_hidePublicLinks = $hidePublicLinks;
+        $this->_redirector = $redirector;
         $this->_checkDB();
         $this->_readDB();
     }
@@ -259,7 +266,14 @@ You use the community supported version of the original Shaarli project, by Seba
 
         // Escape links data
         foreach($this->_links as &$link) { 
-            sanitizeLink($link); 
+            sanitizeLink($link);
+            // Do not use the redirector for internal links (Shaarli note URL starting with a '?').
+            if (!empty($this->_redirector) && !startsWith($link['url'], '?')) {
+                $link['real_url'] = $this->_redirector . urlencode($link['url']);
+            }
+            else {
+                $link['real_url'] = $link['url'];
+            }
         }
     }
 
diff --git a/application/Utils.php b/application/Utils.php
index b8579b48..f84f70e4 100644
--- a/application/Utils.php
+++ b/application/Utils.php
@@ -148,3 +148,56 @@ function is_session_id_valid($sessionId)
 
     return true;
 }
+
+/**
+ * In a string, converts URLs to clickable links.
+ *
+ * @param string $text       input string.
+ * @param string $redirector if a redirector is set, use it to gerenate links.
+ *
+ * @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, $redirector)
+{
+    $regex = '!(((?:https?|ftp|file)://|apt:|magnet:)\S+[[:alnum:]]/?)!si';
+
+    if (empty($redirector)) {
+        return preg_replace($regex, '<a href="$1">$1</a>', $text);
+    }
+    // Redirector is set, urlencode the final URL.
+    return preg_replace_callback(
+        $regex,
+        function ($matches) use ($redirector) {
+            return '<a href="' . $redirector . urlencode($matches[1]) .'">'. $matches[1] .'</a>';
+        },
+        $text
+    );
+}
+
+/**
+ * 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
+ * TODO: Move me to ApplicationUtils when it's ready.
+ *
+ * @param string $description shaare's description.
+ * @param string $redirector  if a redirector is set, use it to gerenate links.
+ *
+ * @return string formatted description.
+ */
+function format_description($description, $redirector) {
+    return nl2br(space2nbsp(text2clickable($description, $redirector)));
+}