6 files changed, 294 insertions, 40 deletions

diff --git a/application/FileUtils.php b/application/FileUtils.php
index 6cac9825..b8ad8970 100644
--- a/application/FileUtils.php
+++ b/application/FileUtils.php
@@ -1,21 +1,76 @@
 <?php
+
+require_once 'exceptions/IOException.php';
+
 /**
- * Exception class thrown when a filesystem access failure happens
+ * Class FileUtils
+ *
+ * Utility class for file manipulation.
  */
-class IOException extends Exception
+class FileUtils
 {
-    private $path;
+    /**
+     * @var string
+     */
+    protected static $phpPrefix = '<?php /* ';
+
+    /**
+     * @var string
+     */
+    protected static $phpSuffix = ' */ ?>';
 
     /**
-     * Construct a new IOException
+     * Write data into a file (Shaarli database format).
+     * The data is stored in a PHP file, as a comment, in compressed base64 format.
+     *
+     * The file will be created if it doesn't exist.
+     *
+     * @param string $file    File path.
+     * @param string $content Content to write.
+     *
+     * @return int|bool Number of bytes written or false if it fails.
      *
-     * @param string $path    path to the resource that cannot be accessed
-     * @param string $message Custom exception message.
+     * @throws IOException The destination file can't be written.
      */
-    public function __construct($path, $message = '')
+    public static function writeFlatDB($file, $content)
     {
-        $this->path = $path;
-        $this->message = empty($message) ? 'Error accessing' : $message;
-        $this->message .= PHP_EOL . $this->path;
+        if (is_file($file) && !is_writeable($file)) {
+            // The datastore exists but is not writeable
+            throw new IOException($file);
+        } else if (!is_file($file) && !is_writeable(dirname($file))) {
+            // The datastore does not exist and its parent directory is not writeable
+            throw new IOException(dirname($file));
+        }
+
+        return file_put_contents(
+            $file,
+            self::$phpPrefix.base64_encode(gzdeflate(serialize($content))).self::$phpSuffix
+        );
+    }
+
+    /**
+     * Read data from a file containing Shaarli database format content.
+     * If the file isn't readable or doesn't exists, default data will be returned.
+     *
+     * @param string $file    File path.
+     * @param mixed  $default The default value to return if the file isn't readable.
+     *
+     * @return mixed The content unserialized, or default if the file isn't readable, or false if it fails.
+     */
+    public static function readFlatDB($file, $default = null)
+    {
+        // Note that gzinflate is faster than gzuncompress.
+        // See: http://www.php.net/manual/en/function.gzdeflate.php#96439
+        if (is_readable($file)) {
+            return unserialize(
+                gzinflate(
+                    base64_decode(
+                        substr(file_get_contents($file), strlen(self::$phpPrefix), -strlen(self::$phpSuffix))
+                    )
+                )
+            );
+        }
+
+        return $default;
     }
 }
diff --git a/application/History.php b/application/History.php
new file mode 100644
index 00000000..f93b0356
--- /dev/null
+++ b/application/History.php
@@ -0,0 +1,200 @@
+<?php
+
+/**
+ * Class History
+ *
+ * Handle the history file tracing events in Shaarli.
+ * The history is stored as JSON in a file set by 'resource.history' setting.
+ *
+ * Available data:
+ *   - event: event key
+ *   - datetime: event date, in ISO8601 format.
+ *   - id: event item identifier (currently only link IDs).
+ *
+ * Available event keys:
+ *   - CREATED: new link
+ *   - UPDATED: link updated
+ *   - DELETED: link deleted
+ *   - SETTINGS: the settings have been updated through the UI.
+ *
+ * Note: new events are put at the beginning of the file and history array.
+ */
+class History
+{
+    /**
+     * @var string Action key: a new link has been created.
+     */
+    const CREATED = 'CREATED';
+
+    /**
+     * @var string Action key: a link has been updated.
+     */
+    const UPDATED = 'UPDATED';
+
+    /**
+     * @var string Action key: a link has been deleted.
+     */
+    const DELETED = 'DELETED';
+
+    /**
+     * @var string Action key: settings have been updated.
+     */
+    const SETTINGS = 'SETTINGS';
+
+    /**
+     * @var string History file path.
+     */
+    protected $historyFilePath;
+
+    /**
+     * @var array History data.
+     */
+    protected $history;
+
+    /**
+     * @var int History retention time in seconds (1 month).
+     */
+    protected $retentionTime = 2678400;
+
+    /**
+     * History constructor.
+     *
+     * @param string $historyFilePath History file path.
+     * @param int    $retentionTime   History content rentention time in seconds.
+     *
+     * @throws Exception if something goes wrong.
+     */
+    public function __construct($historyFilePath, $retentionTime = null)
+    {
+        $this->historyFilePath = $historyFilePath;
+        if ($retentionTime !== null) {
+            $this->retentionTime = $retentionTime;
+        }
+    }
+
+    /**
+     * Initialize: read history file.
+     *
+     * Allow lazy loading (don't read the file if it isn't necessary).
+     */
+    protected function initialize()
+    {
+        $this->check();
+        $this->read();
+    }
+
+    /**
+     * Add Event: new link.
+     *
+     * @param array $link Link data.
+     */
+    public function addLink($link)
+    {
+        $this->addEvent(self::CREATED, $link['id']);
+    }
+
+    /**
+     * Add Event: update existing link.
+     *
+     * @param array $link Link data.
+     */
+    public function updateLink($link)
+    {
+        $this->addEvent(self::UPDATED, $link['id']);
+    }
+
+    /**
+     * Add Event: delete existing link.
+     *
+     * @param array $link Link data.
+     */
+    public function deleteLink($link)
+    {
+        $this->addEvent(self::DELETED, $link['id']);
+    }
+
+    /**
+     * Add Event: settings updated.
+     */
+    public function updateSettings()
+    {
+        $this->addEvent(self::SETTINGS);
+    }
+
+    /**
+     * Save a new event and write it in the history file.
+     *
+     * @param string $status Event key, should be defined as constant.
+     * @param mixed  $id     Event item identifier (e.g. link ID).
+     */
+    protected function addEvent($status, $id = null)
+    {
+        if ($this->history === null) {
+            $this->initialize();
+        }
+
+        $item = [
+            'event' => $status,
+            'datetime' => (new DateTime())->format(DateTime::ATOM),
+            'id' => $id !== null ? $id : '',
+        ];
+        $this->history = array_merge([$item], $this->history);
+        $this->write();
+    }
+
+    /**
+     * Check that the history file is writable.
+     * Create the file if it doesn't exist.
+     *
+     * @throws Exception if it isn't writable.
+     */
+    protected function check()
+    {
+        if (! is_file($this->historyFilePath)) {
+            FileUtils::writeFlatDB($this->historyFilePath, []);
+        }
+
+        if (! is_writable($this->historyFilePath)) {
+            throw new Exception('History file isn\'t readable or writable');
+        }
+    }
+
+    /**
+     * Read JSON history file.
+     */
+    protected function read()
+    {
+        $this->history = FileUtils::readFlatDB($this->historyFilePath, []);
+        if ($this->history === false) {
+            throw new Exception('Could not parse history file');
+        }
+    }
+
+    /**
+     * Write JSON history file and delete old entries.
+     */
+    protected function write()
+    {
+        $comparaison = new DateTime('-'. $this->retentionTime . ' seconds');
+        foreach ($this->history as $key => $value) {
+            if (DateTime::createFromFormat(DateTime::ATOM, $value['datetime']) < $comparaison) {
+                unset($this->history[$key]);
+            }
+        }
+        FileUtils::writeFlatDB($this->historyFilePath, array_values($this->history));
+    }
+
+    /**
+     * Get the History.
+     *
+     * @return array
+     */
+    public function getHistory()
+    {
+        if ($this->history === null) {
+            $this->initialize();
+        }
+
+        return $this->history;
+    }
+}
diff --git a/application/LinkDB.php b/application/LinkDB.php
index 1e4d7ce8..0d3c85bd 100644
--- a/application/LinkDB.php
+++ b/application/LinkDB.php
@@ -50,12 +50,6 @@ class LinkDB implements Iterator, Countable, ArrayAccess
     // Link date storage format
     const LINK_DATE_FORMAT = 'Ymd_His';
 
-    // Datastore PHP prefix
-    protected static $phpPrefix = '<?php /* ';
-
-    // Datastore PHP suffix
-    protected static $phpSuffix = ' */ ?>';
-
     // List of links (associative array)
     //  - key:   link date (e.g. "20110823_124546"),
     //  - value: associative array (keys: title, description...)
@@ -295,16 +289,7 @@ You use the community supported version of the original Shaarli project, by Seba
             return;
         }
 
-        // Read data
-        // Note that gzinflate is faster than gzuncompress.
-        // See: http://www.php.net/manual/en/function.gzdeflate.php#96439
-        $this->links = array();
-
-        if (file_exists($this->datastore)) {
-            $this->links = unserialize(gzinflate(base64_decode(
-                substr(file_get_contents($this->datastore),
-                       strlen(self::$phpPrefix), -strlen(self::$phpSuffix)))));
-        }
+        $this->links = FileUtils::readFlatDB($this->datastore, []);
 
         $toremove = array();
         foreach ($this->links as $key => &$link) {
@@ -361,19 +346,7 @@ You use the community supported version of the original Shaarli project, by Seba
      */
     private function write()
     {
-        if (is_file($this->datastore) && !is_writeable($this->datastore)) {
-            // The datastore exists but is not writeable
-            throw new IOException($this->datastore);
-        } else if (!is_file($this->datastore) && !is_writeable(dirname($this->datastore))) {
-            // The datastore does not exist and its parent directory is not writeable
-            throw new IOException(dirname($this->datastore));
-        }
-
-        file_put_contents(
-            $this->datastore,
-            self::$phpPrefix.base64_encode(gzdeflate(serialize($this->links))).self::$phpSuffix
-        );
-
+        FileUtils::writeFlatDB($this->datastore, $this->links);
     }
 
     /**
diff --git a/application/NetscapeBookmarkUtils.php b/application/NetscapeBookmarkUtils.php
index ab346f81..bbfde138 100644
--- a/application/NetscapeBookmarkUtils.php
+++ b/application/NetscapeBookmarkUtils.php
@@ -95,10 +95,11 @@ class NetscapeBookmarkUtils
      * @param array         $files     Server $_FILES parameters
      * @param LinkDB        $linkDb    Loaded LinkDB instance
      * @param ConfigManager $conf      instance
+     * @param History       $history   History instance
      *
      * @return string Summary of the bookmark import status
      */
-    public static function import($post, $files, $linkDb, $conf)
+    public static function import($post, $files, $linkDb, $conf, $history)
     {
         $filename = $files['filetoupload']['name'];
         $filesize = $files['filetoupload']['size'];
@@ -182,6 +183,7 @@ class NetscapeBookmarkUtils
                 $linkDb[$existingLink['id']] = $newLink;
                 $importCount++;
                 $overwriteCount++;
+                $history->updateLink($newLink);
                 continue;
             }
 
@@ -193,6 +195,7 @@ class NetscapeBookmarkUtils
             $newLink['shorturl'] = link_small_hash($newLink['created'], $newLink['id']);
             $linkDb[$newLink['id']] = $newLink;
             $importCount++;
+            $history->addLink($newLink);
         }
 
         $linkDb->save($conf->get('resource.page_cache'));
diff --git a/application/config/ConfigManager.php b/application/config/ConfigManager.php
index 7bfbfc72..86a917fb 100644
--- a/application/config/ConfigManager.php
+++ b/application/config/ConfigManager.php
@@ -301,6 +301,7 @@ class ConfigManager
         $this->setEmpty('resource.updates', 'data/updates.txt');
         $this->setEmpty('resource.log', 'data/log.txt');
         $this->setEmpty('resource.update_check', 'data/lastupdatecheck.txt');
+        $this->setEmpty('resource.history', 'data/history.php');
         $this->setEmpty('resource.raintpl_tpl', 'tpl/');
         $this->setEmpty('resource.theme', 'default');
         $this->setEmpty('resource.raintpl_tmp', 'tmp/');
diff --git a/application/exceptions/IOException.php b/application/exceptions/IOException.php
new file mode 100644
index 00000000..b563b23d
--- /dev/null
+++ b/application/exceptions/IOException.php
@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * Exception class thrown when a filesystem access failure happens
+ */
+class IOException extends Exception
+{
+    private $path;
+
+    /**
+     * Construct a new IOException
+     *
+     * @param string $path    path to the resource that cannot be accessed
+     * @param string $message Custom exception message.
+     */
+    public function __construct($path, $message = '')
+    {
+        $this->path = $path;
+        $this->message = empty($message) ? 'Error accessing' : $message;
+        $this->message .= ' "' . $this->path .'"';
+    }
+}