1 files changed, 600 insertions, 0 deletions

diff --git a/application/bookmark/LinkDB.php b/application/bookmark/LinkDB.php
new file mode 100644
index 00000000..c13a1141
--- /dev/null
+++ b/application/bookmark/LinkDB.php
@@ -0,0 +1,600 @@
+<?php
+
+namespace Shaarli\Bookmark;
+
+use ArrayAccess;
+use Countable;
+use DateTime;
+use Iterator;
+use Shaarli\Bookmark\Exception\LinkNotFoundException;
+use Shaarli\Exceptions\IOException;
+use Shaarli\FileUtils;
+
+/**
+ * Data storage for links.
+ *
+ * This object behaves like an associative array.
+ *
+ * Example:
+ *    $myLinks = new LinkDB();
+ *    echo $myLinks[350]['title'];
+ *    foreach ($myLinks as $link)
+ *       echo $link['title'].' at url '.$link['url'].'; description:'.$link['description'];
+ *
+ * Available keys:
+ *  - id:       primary key, incremental integer identifier (persistent)
+ *  - description: description of the entry
+ *  - created:  creation date of this entry, DateTime object.
+ *  - updated:  last modification date of this entry, DateTime object.
+ *  - private:  Is this link private? 0=no, other value=yes
+ *  - tags:     tags attached to this entry (separated by spaces)
+ *  - title     Title of the link
+ *  - url       URL of the link. Used for displayable links (no redirector, relative, etc.).
+ *              Can be absolute or relative.
+ *              Relative URLs are permalinks (e.g.'?m-ukcw')
+ *  - real_url  Absolute processed URL.
+ *  - shorturl  Permalink smallhash
+ *
+ * Implements 3 interfaces:
+ *  - ArrayAccess: behaves like an associative array;
+ *  - Countable:   there is a count() method;
+ *  - Iterator:    usable in foreach () loops.
+ *
+ * ID mechanism:
+ *   ArrayAccess is implemented in a way that will allow to access a link
+ *   with the unique identifier ID directly with $link[ID].
+ *   Note that it's not the real key of the link array attribute.
+ *   This mechanism is in place to have persistent link IDs,
+ *   even though the internal array is reordered by date.
+ *   Example:
+ *     - DB: link #1 (2010-01-01) link #2 (2016-01-01)
+ *     - Order: #2 #1
+ *     - Import links containing: link #3 (2013-01-01)
+ *     - New DB: link #1 (2010-01-01) link #2 (2016-01-01) link #3 (2013-01-01)
+ *     - Real order: #2 #3 #1
+ */
+class LinkDB implements Iterator, Countable, ArrayAccess
+{
+    // Links are stored as a PHP serialized string
+    private $datastore;
+
+    // Link date storage format
+    const LINK_DATE_FORMAT = 'Ymd_His';
+
+    // List of links (associative array)
+    //  - key:   link date (e.g. "20110823_124546"),
+    //  - value: associative array (keys: title, description...)
+    private $links;
+
+    // List of all recorded URLs (key=url, value=link offset)
+    // for fast reserve search (url-->link offset)
+    private $urls;
+
+    /**
+     * @var array List of all links IDS mapped with their array offset.
+     *            Map: id->offset.
+     */
+    protected $ids;
+
+    // List of offset keys (for the Iterator interface implementation)
+    private $keys;
+
+    // Position in the $this->keys array (for the Iterator interface)
+    private $position;
+
+    // Is the user logged in? (used to filter private links)
+    private $loggedIn;
+
+    // Hide public links
+    private $hidePublicLinks;
+
+    // link redirector set in user settings.
+    private $redirector;
+
+    /**
+     * Set this to `true` to urlencode link behind redirector link, `false` to leave it untouched.
+     *
+     * Example:
+     *   anonym.to needs clean URL while dereferer.org needs urlencoded URL.
+     *
+     * @var boolean $redirectorEncode parameter: true or false
+     */
+    private $redirectorEncode;
+
+    /**
+     * Creates a new LinkDB
+     *
+     * Checks if the datastore exists; else, attempts to create a dummy one.
+     *
+     * @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.
+     * @param boolean $redirectorEncode Enable urlencode on redirected urls (default: true).
+     */
+    public function __construct(
+        $datastore,
+        $isLoggedIn,
+        $hidePublicLinks,
+        $redirector = '',
+        $redirectorEncode = true
+    ) {
+    
+        $this->datastore = $datastore;
+        $this->loggedIn = $isLoggedIn;
+        $this->hidePublicLinks = $hidePublicLinks;
+        $this->redirector = $redirector;
+        $this->redirectorEncode = $redirectorEncode === true;
+        $this->check();
+        $this->read();
+    }
+
+    /**
+     * Countable - Counts elements of an object
+     */
+    public function count()
+    {
+        return count($this->links);
+    }
+
+    /**
+     * ArrayAccess - Assigns a value to the specified offset
+     */
+    public function offsetSet($offset, $value)
+    {
+        // TODO: use exceptions instead of "die"
+        if (!$this->loggedIn) {
+            die(t('You are not authorized to add a link.'));
+        }
+        if (!isset($value['id']) || empty($value['url'])) {
+            die(t('Internal Error: A link should always have an id and URL.'));
+        }
+        if (($offset !== null && !is_int($offset)) || !is_int($value['id'])) {
+            die(t('You must specify an integer as a key.'));
+        }
+        if ($offset !== null && $offset !== $value['id']) {
+            die(t('Array offset and link ID must be equal.'));
+        }
+
+        // If the link exists, we reuse the real offset, otherwise new entry
+        $existing = $this->getLinkOffset($offset);
+        if ($existing !== null) {
+            $offset = $existing;
+        } else {
+            $offset = count($this->links);
+        }
+        $this->links[$offset] = $value;
+        $this->urls[$value['url']] = $offset;
+        $this->ids[$value['id']] = $offset;
+    }
+
+    /**
+     * ArrayAccess - Whether or not an offset exists
+     */
+    public function offsetExists($offset)
+    {
+        return array_key_exists($this->getLinkOffset($offset), $this->links);
+    }
+
+    /**
+     * ArrayAccess - Unsets an offset
+     */
+    public function offsetUnset($offset)
+    {
+        if (!$this->loggedIn) {
+            // TODO: raise an exception
+            die('You are not authorized to delete a link.');
+        }
+        $realOffset = $this->getLinkOffset($offset);
+        $url = $this->links[$realOffset]['url'];
+        unset($this->urls[$url]);
+        unset($this->ids[$realOffset]);
+        unset($this->links[$realOffset]);
+    }
+
+    /**
+     * ArrayAccess - Returns the value at specified offset
+     */
+    public function offsetGet($offset)
+    {
+        $realOffset = $this->getLinkOffset($offset);
+        return isset($this->links[$realOffset]) ? $this->links[$realOffset] : null;
+    }
+
+    /**
+     * Iterator - Returns the current element
+     */
+    public function current()
+    {
+        return $this[$this->keys[$this->position]];
+    }
+
+    /**
+     * Iterator - Returns the key of the current element
+     */
+    public function key()
+    {
+        return $this->keys[$this->position];
+    }
+
+    /**
+     * Iterator - Moves forward to next element
+     */
+    public function next()
+    {
+        ++$this->position;
+    }
+
+    /**
+     * Iterator - Rewinds the Iterator to the first element
+     *
+     * Entries are sorted by date (latest first)
+     */
+    public function rewind()
+    {
+        $this->keys = array_keys($this->ids);
+        $this->position = 0;
+    }
+
+    /**
+     * Iterator - Checks if current position is valid
+     */
+    public function valid()
+    {
+        return isset($this->keys[$this->position]);
+    }
+
+    /**
+     * Checks if the DB directory and file exist
+     *
+     * If no DB file is found, creates a dummy DB.
+     */
+    private function check()
+    {
+        if (file_exists($this->datastore)) {
+            return;
+        }
+
+        // Create a dummy database for example
+        $this->links = array();
+        $link = array(
+            'id' => 1,
+            'title' => t('The personal, minimalist, super-fast, database free, bookmarking service'),
+            'url' => 'https://shaarli.readthedocs.io',
+            'description' => t(
+                'Welcome to Shaarli! This is your first public bookmark. '
+                . 'To edit or delete me, you must first login.
+
+To learn how to use Shaarli, consult the link "Documentation" at the bottom of this page.
+
+You use the community supported version of the original Shaarli project, by Sebastien Sauvage.'
+            ),
+            'private' => 0,
+            'created' => new DateTime(),
+            'tags' => 'opensource software'
+        );
+        $link['shorturl'] = link_small_hash($link['created'], $link['id']);
+        $this->links[1] = $link;
+
+        $link = array(
+            'id' => 0,
+            'title' => t('My secret stuff... - Pastebin.com'),
+            'url' => 'http://sebsauvage.net/paste/?8434b27936c09649#bR7XsXhoTiLcqCpQbmOpBi3rq2zzQUC5hBI7ZT1O3x8=',
+            'description' => t('Shhhh! I\'m a private link only YOU can see. You can delete me too.'),
+            'private' => 1,
+            'created' => new DateTime('1 minute ago'),
+            'tags' => 'secretstuff',
+        );
+        $link['shorturl'] = link_small_hash($link['created'], $link['id']);
+        $this->links[0] = $link;
+
+        // Write database to disk
+        $this->write();
+    }
+
+    /**
+     * Reads database from disk to memory
+     */
+    private function read()
+    {
+        // Public links are hidden and user not logged in => nothing to show
+        if ($this->hidePublicLinks && !$this->loggedIn) {
+            $this->links = array();
+            return;
+        }
+
+        $this->urls = [];
+        $this->ids = [];
+        $this->links = FileUtils::readFlatDB($this->datastore, []);
+
+        $toremove = array();
+        foreach ($this->links as $key => &$link) {
+            if (!$this->loggedIn && $link['private'] != 0) {
+                // Transition for not upgraded databases.
+                unset($this->links[$key]);
+                continue;
+            }
+
+            // Sanitize data fields.
+            sanitizeLink($link);
+
+            // Remove private tags if the user is not logged in.
+            if (!$this->loggedIn) {
+                $link['tags'] = preg_replace('/(^|\s+)\.[^($|\s)]+\s*/', ' ', $link['tags']);
+            }
+
+            // Do not use the redirector for internal links (Shaarli note URL starting with a '?').
+            if (!empty($this->redirector) && !startsWith($link['url'], '?')) {
+                $link['real_url'] = $this->redirector;
+                if ($this->redirectorEncode) {
+                    $link['real_url'] .= urlencode(unescape($link['url']));
+                } else {
+                    $link['real_url'] .= $link['url'];
+                }
+            } else {
+                $link['real_url'] = $link['url'];
+            }
+
+            // To be able to load links before running the update, and prepare the update
+            if (!isset($link['created'])) {
+                $link['id'] = $link['linkdate'];
+                $link['created'] = DateTime::createFromFormat(self::LINK_DATE_FORMAT, $link['linkdate']);
+                if (!empty($link['updated'])) {
+                    $link['updated'] = DateTime::createFromFormat(self::LINK_DATE_FORMAT, $link['updated']);
+                }
+                $link['shorturl'] = smallHash($link['linkdate']);
+            }
+
+            $this->urls[$link['url']] = $key;
+            $this->ids[$link['id']] = $key;
+        }
+    }
+
+    /**
+     * Saves the database from memory to disk
+     *
+     * @throws IOException the datastore is not writable
+     */
+    private function write()
+    {
+        $this->reorder();
+        FileUtils::writeFlatDB($this->datastore, $this->links);
+    }
+
+    /**
+     * Saves the database from memory to disk
+     *
+     * @param string $pageCacheDir page cache directory
+     */
+    public function save($pageCacheDir)
+    {
+        if (!$this->loggedIn) {
+            // TODO: raise an Exception instead
+            die('You are not authorized to change the database.');
+        }
+
+        $this->write();
+
+        invalidateCaches($pageCacheDir);
+    }
+
+    /**
+     * Returns the link for a given URL, or False if it does not exist.
+     *
+     * @param string $url URL to search for
+     *
+     * @return mixed the existing link if it exists, else 'false'
+     */
+    public function getLinkFromUrl($url)
+    {
+        if (isset($this->urls[$url])) {
+            return $this->links[$this->urls[$url]];
+        }
+        return false;
+    }
+
+    /**
+     * Returns the shaare corresponding to a smallHash.
+     *
+     * @param string $request QUERY_STRING server parameter.
+     *
+     * @return array $filtered array containing permalink data.
+     *
+     * @throws LinkNotFoundException if the smallhash is malformed or doesn't match any link.
+     */
+    public function filterHash($request)
+    {
+        $request = substr($request, 0, 6);
+        $linkFilter = new LinkFilter($this->links);
+        return $linkFilter->filter(LinkFilter::$FILTER_HASH, $request);
+    }
+
+    /**
+     * Returns the list of articles for a given day.
+     *
+     * @param string $request day to filter. Format: YYYYMMDD.
+     *
+     * @return array list of shaare found.
+     */
+    public function filterDay($request)
+    {
+        $linkFilter = new LinkFilter($this->links);
+        return $linkFilter->filter(LinkFilter::$FILTER_DAY, $request);
+    }
+
+    /**
+     * Filter links according to search parameters.
+     *
+     * @param array  $filterRequest  Search request content. Supported keys:
+     *                                - searchtags: list of tags
+     *                                - searchterm: term search
+     * @param bool   $casesensitive  Optional: Perform case sensitive filter
+     * @param string $visibility     return only all/private/public links
+     * @param bool   $untaggedonly   return only untagged links
+     *
+     * @return array filtered links, all links if no suitable filter was provided.
+     */
+    public function filterSearch(
+        $filterRequest = array(),
+        $casesensitive = false,
+        $visibility = 'all',
+        $untaggedonly = false
+    ) {
+    
+        // Filter link database according to parameters.
+        $searchtags = isset($filterRequest['searchtags']) ? escape($filterRequest['searchtags']) : '';
+        $searchterm = isset($filterRequest['searchterm']) ? escape($filterRequest['searchterm']) : '';
+
+        // Search tags + fullsearch - blank string parameter will return all links.
+        $type = LinkFilter::$FILTER_TAG | LinkFilter::$FILTER_TEXT; // == "vuotext"
+        $request = [$searchtags, $searchterm];
+
+        $linkFilter = new LinkFilter($this);
+        return $linkFilter->filter($type, $request, $casesensitive, $visibility, $untaggedonly);
+    }
+
+    /**
+     * Returns the list tags appearing in the links with the given tags
+     *
+     * @param array  $filteringTags tags selecting the links to consider
+     * @param string $visibility    process only all/private/public links
+     *
+     * @return array tag => linksCount
+     */
+    public function linksCountPerTag($filteringTags = [], $visibility = 'all')
+    {
+        $links = $this->filterSearch(['searchtags' => $filteringTags], false, $visibility);
+        $tags = [];
+        $caseMapping = [];
+        foreach ($links as $link) {
+            foreach (preg_split('/\s+/', $link['tags'], 0, PREG_SPLIT_NO_EMPTY) as $tag) {
+                if (empty($tag)) {
+                    continue;
+                }
+                // The first case found will be displayed.
+                if (!isset($caseMapping[strtolower($tag)])) {
+                    $caseMapping[strtolower($tag)] = $tag;
+                    $tags[$caseMapping[strtolower($tag)]] = 0;
+                }
+                $tags[$caseMapping[strtolower($tag)]]++;
+            }
+        }
+
+        /*
+         * Formerly used arsort(), which doesn't define the sort behaviour for equal values.
+         * Also, this function doesn't produce the same result between PHP 5.6 and 7.
+         *
+         * So we now use array_multisort() to sort tags by DESC occurrences,
+         * then ASC alphabetically for equal values.
+         *
+         * @see https://github.com/shaarli/Shaarli/issues/1142
+         */
+        $keys = array_keys($tags);
+        $tmpTags = array_combine($keys, $keys);
+        array_multisort($tags, SORT_DESC, $tmpTags, SORT_ASC, $tags);
+        return $tags;
+    }
+
+    /**
+     * Rename or delete a tag across all links.
+     *
+     * @param string $from Tag to rename
+     * @param string $to   New tag. If none is provided, the from tag will be deleted
+     *
+     * @return array|bool List of altered links or false on error
+     */
+    public function renameTag($from, $to)
+    {
+        if (empty($from)) {
+            return false;
+        }
+        $delete = empty($to);
+        // True for case-sensitive tag search.
+        $linksToAlter = $this->filterSearch(['searchtags' => $from], true);
+        foreach ($linksToAlter as $key => &$value) {
+            $tags = preg_split('/\s+/', trim($value['tags']));
+            if (($pos = array_search($from, $tags)) !== false) {
+                if ($delete) {
+                    unset($tags[$pos]); // Remove tag.
+                } else {
+                    $tags[$pos] = trim($to);
+                }
+                $value['tags'] = trim(implode(' ', array_unique($tags)));
+                $this[$value['id']] = $value;
+            }
+        }
+
+        return $linksToAlter;
+    }
+
+    /**
+     * Returns the list of days containing articles (oldest first)
+     * Output: An array containing days (in format YYYYMMDD).
+     */
+    public function days()
+    {
+        $linkDays = array();
+        foreach ($this->links as $link) {
+            $linkDays[$link['created']->format('Ymd')] = 0;
+        }
+        $linkDays = array_keys($linkDays);
+        sort($linkDays);
+
+        return $linkDays;
+    }
+
+    /**
+     * Reorder links by creation date (newest first).
+     *
+     * Also update the urls and ids mapping arrays.
+     *
+     * @param string $order ASC|DESC
+     */
+    public function reorder($order = 'DESC')
+    {
+        $order = $order === 'ASC' ? -1 : 1;
+        // Reorder array by dates.
+        usort($this->links, function ($a, $b) use ($order) {
+            if (isset($a['sticky']) && isset($b['sticky']) && $a['sticky'] !== $b['sticky']) {
+                return $a['sticky'] ? -1 : 1;
+            }
+            return $a['created'] < $b['created'] ? 1 * $order : -1 * $order;
+        });
+
+        $this->urls = [];
+        $this->ids = [];
+        foreach ($this->links as $key => $link) {
+            $this->urls[$link['url']] = $key;
+            $this->ids[$link['id']] = $key;
+        }
+    }
+
+    /**
+     * Return the next key for link creation.
+     * E.g. If the last ID is 597, the next will be 598.
+     *
+     * @return int next ID.
+     */
+    public function getNextId()
+    {
+        if (!empty($this->ids)) {
+            return max(array_keys($this->ids)) + 1;
+        }
+        return 0;
+    }
+
+    /**
+     * Returns a link offset in links array from its unique ID.
+     *
+     * @param int $id Persistent ID of a link.
+     *
+     * @return int Real offset in local array, or null if doesn't exist.
+     */
+    protected function getLinkOffset($id)
+    {
+        if (isset($this->ids[$id])) {
+            return $this->ids[$id];
+        }
+        return null;
+    }
+}