<?php

/**
 * Pico
 *
 * @author Gilbert Pellegrom
 * @link http://picocms.org
 * @license http://opensource.org/licenses/MIT
 * @version 0.8
 */
class Pico
{

    private $config;
    private $plugins;

    /**
     * The constructor carries out all the processing in Pico.
     * Does URL routing, Markdown processing and Twig processing.
     */
    public function __construct()
    {
        // Load plugins
        $this->load_plugins();
        $this->run_hooks('plugins_loaded');

        // Load the settings
        $settings = $this->get_config();
        $this->run_hooks('config_loaded', array(&$settings));

        // Get request url and script url
        $url = '';
        $request_url = (isset($_SERVER['REQUEST_URI'])) ? $_SERVER['REQUEST_URI'] : '';
        $script_url = (isset($_SERVER['PHP_SELF'])) ? $_SERVER['PHP_SELF'] : '';

        // Get our url path and trim the / of the left and the right
        if ($request_url != $script_url) {
            $url = trim(preg_replace('/' . str_replace('/', '\/', str_replace('index.php', '', $script_url)) . '/', '',
                $request_url, 1), '/');
        }
        $url = preg_replace('/\?.*/', '', $url); // Strip query string
        $this->run_hooks('request_url', array(&$url));

        // Get the file path
        if ($url) {
            $file = $settings['content_dir'] . $url;
        } else {
            $file = $settings['content_dir'] . 'index';
        }

        // Load the file
        if (is_dir($file)) {
            $file = $settings['content_dir'] . $url . '/index' . CONTENT_EXT;
        } else {
            $file .= CONTENT_EXT;
        }

        $this->run_hooks('before_load_content', array(&$file));
        if (file_exists($file)) {
            $content = file_get_contents($file);
        } else {
            $this->run_hooks('before_404_load_content', array(&$file));
            $content = file_get_contents($settings['content_dir'] . '404' . CONTENT_EXT);
            header($_SERVER['SERVER_PROTOCOL'] . ' 404 Not Found');
            $this->run_hooks('after_404_load_content', array(&$file, &$content));
        }
        $this->run_hooks('after_load_content', array(&$file, &$content));

        $meta = $this->read_file_meta($content);
        $this->run_hooks('file_meta', array(&$meta));

        $this->run_hooks('before_parse_content', array(&$content));
        $content = $this->parse_content($content);
        $this->run_hooks('after_parse_content', array(&$content));
        $this->run_hooks('content_parsed', array(&$content)); // Depreciated @ v0.8

        // Get all the pages
        $pages = $this->get_pages($settings['base_url'], $settings['pages_order_by'], $settings['pages_order'],
            $settings['excerpt_length']);
        $prev_page = array();
        $current_page = array();
        $next_page = array();
        while ($current_page = current($pages)) {
            if ((isset($meta['title'])) && ($meta['title'] == $current_page['title'])) {
                break;
            }
            next($pages);
        }
        $prev_page = next($pages);
        prev($pages);
        $next_page = prev($pages);
        $this->run_hooks('get_pages', array(&$pages, &$current_page, &$prev_page, &$next_page));

        // Load the theme
        $this->run_hooks('before_twig_register');
        Twig_Autoloader::register();
        $loader = new Twig_Loader_Filesystem(THEMES_DIR . $settings['theme']);
        $twig = new Twig_Environment($loader, $settings['twig_config']);
        $twig->addExtension(new Twig_Extension_Debug());
        $twig_vars = array(
            'config' => $settings,
            'base_dir' => rtrim(ROOT_DIR, '/'),
            'base_url' => $settings['base_url'],
            'theme_dir' => THEMES_DIR . $settings['theme'],
            'theme_url' => $settings['base_url'] . '/' . basename(THEMES_DIR) . '/' . $settings['theme'],
            'site_title' => $settings['site_title'],
            'meta' => $meta,
            'content' => $content,
            'pages' => $pages,
            'prev_page' => $prev_page,
            'current_page' => $current_page,
            'next_page' => $next_page,
            'is_front_page' => $url ? false : true,
        );

        $template = (isset($meta['template']) && $meta['template']) ? $meta['template'] : 'index';
        $this->run_hooks('before_render', array(&$twig_vars, &$twig, &$template));
        $output = $twig->render($template . '.html', $twig_vars);
        $this->run_hooks('after_render', array(&$output));
        echo $output;
    }

    /**
     * Load any plugins
     */
    protected function load_plugins()
    {
        $this->plugins = array();
        $plugins = $this->get_files(PLUGINS_DIR, '.php');
        if (!empty($plugins)) {
            foreach ($plugins as $plugin) {
                include_once($plugin);
                $plugin_name = preg_replace("/\\.[^.\\s]{3}$/", '', basename($plugin));
                if (class_exists($plugin_name)) {
                    $obj = new $plugin_name;
                    $this->plugins[] = $obj;
                }
            }
        }
    }

    /**
     * Parses the content using Parsedown-extra
     *
     * @param string $content the raw txt content
     * @return string $content the Markdown formatted content
     */
    protected function parse_content($content)
    {
        $content = preg_replace('#/\*.+?\*/#s', '', $content, 1); // Remove first comment (with meta)
        $content = str_replace('%base_url%', $this->base_url(), $content);
        $Parsedown = new ParsedownExtra();
		$content= $Parsedown->text($content);

        return $content;
    }

    /**
     * Parses the file meta from the txt file header
     *
     * @param string $content the raw txt content
     * @return array $headers an array of meta values
     */
    protected function read_file_meta($content)
    {
        $config = $this->config;

        $headers = array(
            'title' => 'Title',
            'description' => 'Description',
            'author' => 'Author',
            'date' => 'Date',
            'robots' => 'Robots',
            'template' => 'Template'
        );

        // Add support for custom headers by hooking into the headers array
        $this->run_hooks('before_read_file_meta', array(&$headers));

        foreach ($headers as $field => $regex) {
            if (preg_match('/^[ \t\/*#@]*' . preg_quote($regex, '/') . ':(.*)$/mi', $content, $match) && $match[1]) {
                $headers[$field] = trim(preg_replace("/\s*(?:\*\/|\?>).*/", '', $match[1]));
            } else {
                $headers[$field] = '';
            }
        }

        if (isset($headers['date'])) {
            $headers['date_formatted'] = utf8_encode(strftime($config['date_format'], strtotime($headers['date'])));
        }

        return $headers;
    }

    /**
     * Loads the config
     *
     * @return array $config an array of config values
     */
    protected function get_config()
    {
        if (file_exists(CONFIG_DIR . 'config.php')) {
            $this->config = require(CONFIG_DIR . 'config.php');
        } else if (file_exists(ROOT_DIR . 'config.php')) {
            // deprecated
            $this->config = require(ROOT_DIR . 'config.php');
        }

        $defaults = array(
            'site_title' => 'Pico',
            'base_url' => $this->base_url(),
            'theme' => 'default',
            'date_format' => '%D %T',
            'twig_config' => array('cache' => false, 'autoescape' => false, 'debug' => false),
            'pages_order_by' => 'alpha',
            'pages_order' => 'asc',
            'excerpt_length' => 50,
            'content_dir' => 'content-sample/',
        );

        if (is_array($this->config)) {
            $this->config = array_merge($defaults, $this->config);
        } else {
            $this->config = $defaults;
        }

        return $this->config;
    }

    /**
     * Get a list of pages
     *
     * @param string $base_url the base URL of the site
     * @param string $order_by order by "alpha" or "date"
     * @param string $order order "asc" or "desc"
     * @return array $sorted_pages an array of pages
     */
    protected function get_pages($base_url, $order_by = 'alpha', $order = 'asc', $excerpt_length = 50)
    {
        $config = $this->config;

        $pages = $this->get_files($config['content_dir'], CONTENT_EXT);
        $sorted_pages = array();
        $date_id = 0;
        foreach ($pages as $key => $page) {
            // Skip 404
            if (basename($page) == '404' . CONTENT_EXT) {
                unset($pages[$key]);
                continue;
            }

            // Ignore Emacs (and Nano) temp files
            if (in_array(substr($page, -1), array('~', '#'))) {
                unset($pages[$key]);
                continue;
            }
            // Get title and format $page
            $page_content = file_get_contents($page);
            $page_meta = $this->read_file_meta($page_content);
            $page_content = $this->parse_content($page_content);
            $url = str_replace($config['content_dir'], $base_url . '/', $page);
            $url = str_replace('index' . CONTENT_EXT, '', $url);
            $url = str_replace(CONTENT_EXT, '', $url);
            $data = array(
                'title' => isset($page_meta['title']) ? $page_meta['title'] : '',
                'url' => $url,
                'author' => isset($page_meta['author']) ? $page_meta['author'] : '',
                'date' => isset($page_meta['date']) ? $page_meta['date'] : '',
                'date_formatted' => isset($page_meta['date']) ? utf8_encode(strftime($config['date_format'],
                    strtotime($page_meta['date']))) : '',
                'content' => $page_content,
                'excerpt' => $this->limit_words(strip_tags($page_content), $excerpt_length),
                //this addition allows the 'description' meta to be picked up in content areas... specifically to replace 'excerpt'
                'description' => isset($page_meta['description']) ? $page_meta['description'] : '',

            );

            // Extend the data provided with each page by hooking into the data array
            $this->run_hooks('get_page_data', array(&$data, $page_meta));

            if ($order_by == 'date' && isset($page_meta['date'])) {
                $sorted_pages[$page_meta['date'] . $date_id] = $data;
                $date_id++;
            } else {
                $sorted_pages[$page] = $data;
            }
        }

        if ($order == 'desc') {
            krsort($sorted_pages);
        } else {
            ksort($sorted_pages);
        }

        return $sorted_pages;
    }

    /**
     * Processes any hooks and runs them
     *
     * @param string $hook_id the ID of the hook
     * @param array $args optional arguments
     */
    protected function run_hooks($hook_id, $args = array())
    {
        if (!empty($this->plugins)) {
            foreach ($this->plugins as $plugin) {
                if (is_callable(array($plugin, $hook_id))) {
                    call_user_func_array(array($plugin, $hook_id), $args);
                }
            }
        }
    }

    /**
     * Helper function to work out the base URL
     *
     * @return string the base url
     */
    protected function base_url()
    {
        $config = $this->config;

        if (isset($config['base_url']) && $config['base_url']) {
            return $config['base_url'];
        }

        $url = '';
        $request_url = (isset($_SERVER['REQUEST_URI'])) ? $_SERVER['REQUEST_URI'] : '';
        $script_url = (isset($_SERVER['PHP_SELF'])) ? $_SERVER['PHP_SELF'] : '';
        if ($request_url != $script_url) {
            $url = trim(preg_replace('/' . str_replace('/', '\/', str_replace('index.php', '', $script_url)) . '/', '',
                $request_url, 1), '/');
        }

        $protocol = $this->get_protocol();

        return rtrim(str_replace($url, '', $protocol . "://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']), '/');
    }

    /**
     * Tries to guess the server protocol. Used in base_url()
     *
     * @return string the current protocol
     */
    protected function get_protocol()
    {
        $protocol = 'http';
        if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off' && $_SERVER['HTTPS'] != '') {
            $protocol = 'https';
        }

        return $protocol;
    }

    /**
     * Helper function to recusively get all files in a directory
     *
     * @param string $directory start directory
     * @param string $ext optional limit to file extensions
     * @return array the matched files
     */
    protected function get_files($directory, $ext = '')
    {
        $array_items = array();
        if ($handle = opendir($directory)) {
            while (false !== ($file = readdir($handle))) {
                if (in_array(substr($file, -1), array('~', '#'))) {
                    continue;
                }
                if (preg_match("/^(^\.)/", $file) === 0) {
                    if (is_dir($directory . "/" . $file)) {
                        $array_items = array_merge($array_items, $this->get_files($directory . "/" . $file, $ext));
                    } else {
                        $file = $directory . "/" . $file;
                        if (!$ext || strstr($file, $ext)) {
                            $array_items[] = preg_replace("/\/\//si", "/", $file);
                        }
                    }
                }
            }
            closedir($handle);
        }

        return $array_items;
    }

    /**
     * Helper function to limit the words in a string
     *
     * @param string $string the given string
     * @param int $word_limit the number of words to limit to
     * @return string the limited string
     */
    protected function limit_words($string, $word_limit)
    {
        $words = explode(' ', $string);
        $excerpt = trim(implode(' ', array_splice($words, 0, $word_limit)));
        if (count($words) > $word_limit) {
            $excerpt .= '&hellip;';
        }

        return $excerpt;
    }

}