3 files changed, 398 insertions, 0 deletions

diff --git a/application/feed/Cache.php b/application/feed/Cache.php
new file mode 100644
index 00000000..e5d43e61
--- /dev/null
+++ b/application/feed/Cache.php
@@ -0,0 +1,38 @@
+<?php
+/**
+ * Cache utilities
+ */
+
+/**
+ * Purges all cached pages
+ *
+ * @param string $pageCacheDir page cache directory
+ *
+ * @return mixed an error string if the directory is missing
+ */
+function purgeCachedPages($pageCacheDir)
+{
+    if (! is_dir($pageCacheDir)) {
+        $error = sprintf(t('Cannot purge %s: no directory'), $pageCacheDir);
+        error_log($error);
+        return $error;
+    }
+
+    array_map('unlink', glob($pageCacheDir.'/*.cache'));
+}
+
+/**
+ * Invalidates caches when the database is changed or the user logs out.
+ *
+ * @param string $pageCacheDir page cache directory
+ */
+function invalidateCaches($pageCacheDir)
+{
+    // Purge cache attached to session.
+    if (isset($_SESSION['tags'])) {
+        unset($_SESSION['tags']);
+    }
+
+    // Purge page cache shared by sessions.
+    purgeCachedPages($pageCacheDir);
+}
diff --git a/application/feed/CachedPage.php b/application/feed/CachedPage.php
new file mode 100644
index 00000000..1c51ac73
--- /dev/null
+++ b/application/feed/CachedPage.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace Shaarli\Feed;
+/**
+ * Simple cache system, mainly for the RSS/ATOM feeds
+ */
+class CachedPage
+{
+    // Directory containing page caches
+    private $cacheDir;
+
+    // Should this URL be cached (boolean)?
+    private $shouldBeCached;
+
+    // Name of the cache file for this URL
+    private $filename;
+
+    /**
+     * Creates a new CachedPage
+     *
+     * @param string $cacheDir       page cache directory
+     * @param string $url            page URL
+     * @param bool   $shouldBeCached whether this page needs to be cached
+     */
+    public function __construct($cacheDir, $url, $shouldBeCached)
+    {
+        // TODO: check write access to the cache directory
+        $this->cacheDir = $cacheDir;
+        $this->filename = $this->cacheDir . '/' . sha1($url) . '.cache';
+        $this->shouldBeCached = $shouldBeCached;
+    }
+
+    /**
+     * Returns the cached version of a page, if it exists and should be cached
+     *
+     * @return string a cached version of the page if it exists, null otherwise
+     */
+    public function cachedVersion()
+    {
+        if (!$this->shouldBeCached) {
+            return null;
+        }
+        if (is_file($this->filename)) {
+            return file_get_contents($this->filename);
+        }
+        return null;
+    }
+
+    /**
+     * Puts a page in the cache
+     *
+     * @param string $pageContent XML content to cache
+     */
+    public function cache($pageContent)
+    {
+        if (!$this->shouldBeCached) {
+            return;
+        }
+        file_put_contents($this->filename, $pageContent);
+    }
+}
diff --git a/application/feed/FeedBuilder.php b/application/feed/FeedBuilder.php
new file mode 100644
index 00000000..dcfd2c89
--- /dev/null
+++ b/application/feed/FeedBuilder.php
@@ -0,0 +1,299 @@
+<?php
+namespace Shaarli\Feed;
+
+use DateTime;
+use LinkDB;
+
+/**
+ * FeedBuilder class.
+ *
+ * Used to build ATOM and RSS feeds data.
+ */
+class FeedBuilder
+{
+    /**
+     * @var string Constant: RSS feed type.
+     */
+    public static $FEED_RSS = 'rss';
+
+    /**
+     * @var string Constant: ATOM feed type.
+     */
+    public static $FEED_ATOM = 'atom';
+
+    /**
+     * @var string Default language if the locale isn't set.
+     */
+    public static $DEFAULT_LANGUAGE = 'en-en';
+
+    /**
+     * @var int Number of links to display in a feed by default.
+     */
+    public static $DEFAULT_NB_LINKS = 50;
+
+    /**
+     * @var LinkDB instance.
+     */
+    protected $linkDB;
+
+    /**
+     * @var string RSS or ATOM feed.
+     */
+    protected $feedType;
+
+    /**
+     * @var array $_SERVER
+     */
+    protected $serverInfo;
+
+    /**
+     * @var array $_GET
+     */
+    protected $userInput;
+
+    /**
+     * @var boolean True if the user is currently logged in, false otherwise.
+     */
+    protected $isLoggedIn;
+
+    /**
+     * @var boolean Use permalinks instead of direct links if true.
+     */
+    protected $usePermalinks;
+
+    /**
+     * @var boolean true to hide dates in feeds.
+     */
+    protected $hideDates;
+
+    /**
+     * @var string server locale.
+     */
+    protected $locale;
+
+    /**
+     * @var DateTime Latest item date.
+     */
+    protected $latestDate;
+
+    /**
+     * Feed constructor.
+     *
+     * @param LinkDB  $linkDB     LinkDB instance.
+     * @param string  $feedType   Type of feed.
+     * @param array   $serverInfo $_SERVER.
+     * @param array   $userInput  $_GET.
+     * @param boolean $isLoggedIn True if the user is currently logged in, false otherwise.
+     */
+    public function __construct($linkDB, $feedType, $serverInfo, $userInput, $isLoggedIn)
+    {
+        $this->linkDB = $linkDB;
+        $this->feedType = $feedType;
+        $this->serverInfo = $serverInfo;
+        $this->userInput = $userInput;
+        $this->isLoggedIn = $isLoggedIn;
+    }
+
+    /**
+     * Build data for feed templates.
+     *
+     * @return array Formatted data for feeds templates.
+     */
+    public function buildData()
+    {
+        // Search for untagged links
+        if (isset($this->userInput['searchtags']) && empty($this->userInput['searchtags'])) {
+            $this->userInput['searchtags'] = false;
+        }
+
+        // Optionally filter the results:
+        $linksToDisplay = $this->linkDB->filterSearch($this->userInput);
+
+        $nblinksToDisplay = $this->getNbLinks(count($linksToDisplay));
+
+        // Can't use array_keys() because $link is a LinkDB instance and not a real array.
+        $keys = array();
+        foreach ($linksToDisplay as $key => $value) {
+            $keys[] = $key;
+        }
+
+        $pageaddr = escape(index_url($this->serverInfo));
+        $linkDisplayed = array();
+        for ($i = 0; $i < $nblinksToDisplay && $i < count($keys); $i++) {
+            $linkDisplayed[$keys[$i]] = $this->buildItem($linksToDisplay[$keys[$i]], $pageaddr);
+        }
+
+        $data['language'] = $this->getTypeLanguage();
+        $data['last_update'] = $this->getLatestDateFormatted();
+        $data['show_dates'] = !$this->hideDates || $this->isLoggedIn;
+        // Remove leading slash from REQUEST_URI.
+        $data['self_link'] = escape(server_url($this->serverInfo))
+            . escape($this->serverInfo['REQUEST_URI']);
+        $data['index_url'] = $pageaddr;
+        $data['usepermalinks'] = $this->usePermalinks === true;
+        $data['links'] = $linkDisplayed;
+
+        return $data;
+    }
+
+    /**
+     * Build a feed item (one per shaare).
+     *
+     * @param array  $link     Single link array extracted from LinkDB.
+     * @param string $pageaddr Index URL.
+     *
+     * @return array Link array with feed attributes.
+     */
+    protected function buildItem($link, $pageaddr)
+    {
+        $link['guid'] = $pageaddr . '?' . $link['shorturl'];
+        // Check for both signs of a note: starting with ? and 7 chars long.
+        if ($link['url'][0] === '?' && strlen($link['url']) === 7) {
+            $link['url'] = $pageaddr . $link['url'];
+        }
+        if ($this->usePermalinks === true) {
+            $permalink = '<a href="' . $link['url'] . '" title="' . t('Direct link') . '">' . t('Direct link') . '</a>';
+        } else {
+            $permalink = '<a href="' . $link['guid'] . '" title="' . t('Permalink') . '">' . t('Permalink') . '</a>';
+        }
+        $link['description'] = format_description($link['description'], '', false, $pageaddr);
+        $link['description'] .= PHP_EOL . '<br>&#8212; ' . $permalink;
+
+        $pubDate = $link['created'];
+        $link['pub_iso_date'] = $this->getIsoDate($pubDate);
+
+        // atom:entry elements MUST contain exactly one atom:updated element.
+        if (!empty($link['updated'])) {
+            $upDate = $link['updated'];
+            $link['up_iso_date'] = $this->getIsoDate($upDate, DateTime::ATOM);
+        } else {
+            $link['up_iso_date'] = $this->getIsoDate($pubDate, DateTime::ATOM);
+        }
+
+        // Save the more recent item.
+        if (empty($this->latestDate) || $this->latestDate < $pubDate) {
+            $this->latestDate = $pubDate;
+        }
+        if (!empty($upDate) && $this->latestDate < $upDate) {
+            $this->latestDate = $upDate;
+        }
+
+        $taglist = array_filter(explode(' ', $link['tags']), 'strlen');
+        uasort($taglist, 'strcasecmp');
+        $link['taglist'] = $taglist;
+
+        return $link;
+    }
+
+    /**
+     * Set this to true to use permalinks instead of direct links.
+     *
+     * @param boolean $usePermalinks true to force permalinks.
+     */
+    public function setUsePermalinks($usePermalinks)
+    {
+        $this->usePermalinks = $usePermalinks;
+    }
+
+    /**
+     * Set this to true to hide timestamps in feeds.
+     *
+     * @param boolean $hideDates true to enable.
+     */
+    public function setHideDates($hideDates)
+    {
+        $this->hideDates = $hideDates;
+    }
+
+    /**
+     * Set the locale. Used to show feed language.
+     *
+     * @param string $locale The locale (eg. 'fr_FR.UTF8').
+     */
+    public function setLocale($locale)
+    {
+        $this->locale = strtolower($locale);
+    }
+
+    /**
+     * Get the language according to the feed type, based on the locale:
+     *
+     *   - RSS format: en-us (default: 'en-en').
+     *   - ATOM format: fr (default: 'en').
+     *
+     * @return string The language.
+     */
+    public function getTypeLanguage()
+    {
+        // Use the locale do define the language, if available.
+        if (!empty($this->locale) && preg_match('/^\w{2}[_\-]\w{2}/', $this->locale)) {
+            $length = ($this->feedType === self::$FEED_RSS) ? 5 : 2;
+            return str_replace('_', '-', substr($this->locale, 0, $length));
+        }
+        return ($this->feedType === self::$FEED_RSS) ? 'en-en' : 'en';
+    }
+
+    /**
+     * Format the latest item date found according to the feed type.
+     *
+     * Return an empty string if invalid DateTime is passed.
+     *
+     * @return string Formatted date.
+     */
+    protected function getLatestDateFormatted()
+    {
+        if (empty($this->latestDate) || !$this->latestDate instanceof DateTime) {
+            return '';
+        }
+
+        $type = ($this->feedType == self::$FEED_RSS) ? DateTime::RSS : DateTime::ATOM;
+        return $this->latestDate->format($type);
+    }
+
+    /**
+     * Get ISO date from DateTime according to feed type.
+     *
+     * @param DateTime    $date   Date to format.
+     * @param string|bool $format Force format.
+     *
+     * @return string Formatted date.
+     */
+    protected function getIsoDate(DateTime $date, $format = false)
+    {
+        if ($format !== false) {
+            return $date->format($format);
+        }
+        if ($this->feedType == self::$FEED_RSS) {
+            return $date->format(DateTime::RSS);
+        }
+        return $date->format(DateTime::ATOM);
+    }
+
+    /**
+     * Returns the number of link to display according to 'nb' user input parameter.
+     *
+     * If 'nb' not set or invalid, default value: $DEFAULT_NB_LINKS.
+     * If 'nb' is set to 'all', display all filtered links (max parameter).
+     *
+     * @param int $max maximum number of links to display.
+     *
+     * @return int number of links to display.
+     */
+    public function getNbLinks($max)
+    {
+        if (empty($this->userInput['nb'])) {
+            return self::$DEFAULT_NB_LINKS;
+        }
+
+        if ($this->userInput['nb'] == 'all') {
+            return $max;
+        }
+
+        $intNb = intval($this->userInput['nb']);
+        if (!is_int($intNb) || $intNb == 0) {
+            return self::$DEFAULT_NB_LINKS;
+        }
+
+        return $intNb;
+    }
+}