<?php 

function sanitize_post_path($post_path) {
    $post_path = chop($post_path, '/');

    if($post_path == "") {
        return "";
    }

    if(!preg_match('/^(?:\/[\w-]+)+(?:\.[\w-]+)*$/', $post_path)) {
        echo "Post path match against " . $post_path . " failed!";
        die();
    }

    return $post_path;
}

function escape_tag($tag) {
    return preg_replace_callback('/[\WZ]/', function($match) {
        return "Z" . ord($match[0]);
    }, strtolower($tag));
}

function escape_search_tag($tag) {
    preg_match("/^([\+\-]?)(.*?)(\*?)$/", $tag, $matches);

    if(!isset($matches[1])) {
        echo "Problem with tag!";
        var_dump($tag);
    }

    return $matches[1] . $this->escape_tag($matches[2]) . $matches[3];
}

interface PostdataInterface {
    /* Postdata format:
     *
     * The Postdata array is a simple intermediate data format
     * for the Post content and metadata.
     * It is slightly abstracted from the SQL format itself but will
     * only reformat keys, *not* do any alteration of the data itself.
     * 
     * Any supported fields will be integrated into the database.
     * Other fields will be saved in a JSON structure, and will
     * be restored afterward.
     * 
     * The following fields are mandatory for *writing*
     * - path: String, must be sanitized to consist of just alphanumeric
     *     characters, `_-./`
     *     used to identify the post itself
     * 
     * The following fields may be returned by the database:
     * - id
     * - created_at
     * - updated_at
     * - view_count
     * 
     * The following fields may be supported by the database:
     * - markdown: String, markdown of the post. May be
     *     stored separately and won't be returned by default!
     * - type:  String, defining the type of the post
     * - title: String, self-explanatory
     * - tags:  Array of strings
     * - settings: Hash, recursively merged settings (calculated by DB!)
     * 
     * The following fields are *recommended*, but nothing more:
     * - icon: String, optionally defining
     */

    public function stub_postdata($path);
    public function stub_postdata_tree($path);

    public function set_postdata($data);
    public function set_post_markdown($id, $markdown);

    public function get_postdata($path);
    // Returns a key-value pair of child paths => child data
    public function get_post_children($path,
        $limit = 50, $depth_start = 1, $depth_end = 1,
        $order_by = 'path');
    
    public function get_post_markdown($id);


    // Returns an array of PostData information
    // based on the tag search list
    //
    // Tag searchlist is comprised of space-separated
    // tags. Each tag can have a weighting prefix,
    // and some special tags exist (such as limit:N,
    // order:S).
    public function search_posts($taglist);
}

?>