<?php

/*
 +-----------------------------------------------------------------------+
 | This file is part of the Roundcube Webmail client                     |
 | Copyright (C) 2008-2012, The Roundcube Dev Team                       |
 |                                                                       |
 | Licensed under the GNU General Public License version 3 or            |
 | any later version with exceptions for skins & plugins.                |
 | See the README file for a full license statement.                     |
 |                                                                       |
 | PURPOSE:                                                              |
 |  Abstract plugins interface/class                                     |
 |  All plugins need to extend this class                                |
 +-----------------------------------------------------------------------+
 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
 +-----------------------------------------------------------------------+
*/

/**
 * Plugin interface class
 *
 * @package    Framework
 * @subpackage PluginAPI
 */
abstract class rcube_plugin
{
    /**
     * Class name of the plugin instance
     *
     * @var string
     */
    public $ID;

    /**
     * Instance of Plugin API
     *
     * @var rcube_plugin_api
     */
    public $api;

    /**
     * Regular expression defining task(s) to bind with 
     *
     * @var string
     */
    public $task;

    /**
     * Disables plugin in AJAX requests
     *
     * @var boolean
     */
    public $noajax = false;

    /**
     * Disables plugin in framed mode
     *
     * @var boolean
     */
    public $noframe = false;

    /**
     * A list of config option names that can be modified
     * by the user via user interface (with save-prefs command)
     *
     * @var array
     */
    public $allowed_prefs;

    protected $home;
    protected $urlbase;
    private $mytask;


    /**
     * Default constructor.
     *
     * @param rcube_plugin_api $api Plugin API
     */
    public function __construct($api)
    {
        $this->ID      = get_class($this);
        $this->api     = $api;
        $this->home    = $api->dir . $this->ID;
        $this->urlbase = $api->url . $this->ID . '/';
    }

    /**
     * Initialization method, needs to be implemented by the plugin itself
     */
    abstract function init();

    /**
     * Attempt to load the given plugin which is required for the current plugin
     *
     * @param string Plugin name
     * @return boolean True on success, false on failure
     */
    public function require_plugin($plugin_name)
    {
        return $this->api->load_plugin($plugin_name);
    }

    /**
     * Load local config file from plugins directory.
     * The loaded values are patched over the global configuration.
     *
     * @param string $fname Config file name relative to the plugin's folder
     *
     * @return boolean True on success, false on failure
     */
    public function load_config($fname = 'config.inc.php')
    {
        $fpath = $this->home.'/'.$fname;
        $rcube = rcube::get_instance();

        if (is_file($fpath) && !$rcube->config->load_from_file($fpath)) {
            rcube::raise_error(array(
                'code' => 527, 'type' => 'php',
                'file' => __FILE__, 'line' => __LINE__,
                'message' => "Failed to load config from $fpath"), true, false);
            return false;
        }

        return true;
    }

    /**
     * Register a callback function for a specific (server-side) hook
     *
     * @param string $hook     Hook name
     * @param mixed  $callback Callback function as string or array
     *                         with object reference and method name
     */
    public function add_hook($hook, $callback)
    {
        $this->api->register_hook($hook, $callback);
    }

    /**
     * Unregister a callback function for a specific (server-side) hook.
     *
     * @param string $hook     Hook name
     * @param mixed  $callback Callback function as string or array
     *                         with object reference and method name
     */
    public function remove_hook($hook, $callback)
    {
        $this->api->unregister_hook($hook, $callback);
    }

    /**
     * Load localized texts from the plugins dir
     *
     * @param string $dir        Directory to search in
     * @param mixed  $add2client Make texts also available on the client
     *                           (array with list or true for all)
     */
    public function add_texts($dir, $add2client = false)
    {
        $domain = $this->ID;
        $lang   = $_SESSION['language'];
        $langs  = array_unique(array('en_US', $lang));
        $locdir = slashify(realpath(slashify($this->home) . $dir));
        $texts  = array();

        // Language aliases used to find localization in similar lang, see below
        $aliases = array(
            'de_CH' => 'de_DE',
            'es_AR' => 'es_ES',
            'fa_AF' => 'fa_IR',
            'nl_BE' => 'nl_NL',
            'pt_BR' => 'pt_PT',
            'zh_CN' => 'zh_TW',
        );

        // use buffering to handle empty lines/spaces after closing PHP tag
        ob_start();

        foreach ($langs as $lng) {
            $fpath = $locdir . $lng . '.inc';
            if (is_file($fpath) && is_readable($fpath)) {
                include $fpath;
                $texts = (array)$labels + (array)$messages + (array)$texts;
            }
            else if ($lng != 'en_US') {
                // Find localization in similar language (#1488401)
                $alias = null;
                if (!empty($aliases[$lng])) {
                    $alias = $aliases[$lng];
                }
                else if ($key = array_search($lng, $aliases)) {
                    $alias = $key;
                }

                if (!empty($alias)) {
                    $fpath = $locdir . $alias . '.inc';
                    if (is_file($fpath) && is_readable($fpath)) {
                        include $fpath;
                        $texts = (array)$labels + (array)$messages + (array)$texts;
                    }
                }
            }
        }

        ob_end_clean();

        // prepend domain to text keys and add to the application texts repository
        if (!empty($texts)) {
            $add = array();
            foreach ($texts as $key => $value) {
                $add[$domain.'.'.$key] = $value;
            }

            $rcube = rcube::get_instance();
            $rcube->load_language($lang, $add);

            // add labels to client
            if ($add2client) {
                if (is_array($add2client)) {
                    $js_labels = array_map(array($this, 'label_map_callback'), $add2client);
                }
                else {
                    $js_labels = array_keys($add);
                }
                $rcube->output->add_label($js_labels);
            }
        }
    }

    /**
     * Wrapper for rcube::gettext() adding the plugin ID as domain
     *
     * @param string $p Message identifier
     *
     * @return string Localized text
     * @see rcube::gettext()
     */
    public function gettext($p)
    {
        return rcube::get_instance()->gettext($p, $this->ID);
    }

    /**
     * Register this plugin to be responsible for a specific task
     *
     * @param string $task Task name (only characters [a-z0-9_.-] are allowed)
     */
    public function register_task($task)
    {
        if ($this->api->register_task($task, $this->ID)) {
            $this->mytask = $task;
        }
    }

    /**
     * Register a handler for a specific client-request action
     *
     * The callback will be executed upon a request like /?_task=mail&_action=plugin.myaction
     *
     * @param string $action  Action name (should be unique)
     * @param mixed $callback Callback function as string
     *                        or array with object reference and method name
     */
    public function register_action($action, $callback)
    {
        $this->api->register_action($action, $this->ID, $callback, $this->mytask);
    }

    /**
     * Register a handler function for a template object
     *
     * When parsing a template for display, tags like <roundcube:object name="plugin.myobject" />
     * will be replaced by the return value if the registered callback function.
     *
     * @param string $name     Object name (should be unique and start with 'plugin.')
     * @param mixed  $callback Callback function as string or array with object reference
     *                         and method name
     */
    public function register_handler($name, $callback)
    {
        $this->api->register_handler($name, $this->ID, $callback);
    }

    /**
     * Make this javascipt file available on the client
     *
     * @param string $fn File path; absolute or relative to the plugin directory
     */
    public function include_script($fn)
    {
        $this->api->include_script($this->resource_url($fn));
    }

    /**
     * Make this stylesheet available on the client
     *
     * @param string $fn File path; absolute or relative to the plugin directory
     */
    public function include_stylesheet($fn)
    {
        $this->api->include_stylesheet($this->resource_url($fn));
    }

    /**
     * Append a button to a certain container
     *
     * @param array $p Hash array with named parameters (as used in skin templates)
     * @param string $container Container name where the buttons should be added to
     *
     * @see rcube_remplate::button()
     */
    public function add_button($p, $container)
    {
        if ($this->api->output->type == 'html') {
            // fix relative paths
            foreach (array('imagepas', 'imageact', 'imagesel') as $key) {
                if ($p[$key]) {
                    $p[$key] = $this->api->url . $this->resource_url($p[$key]);
                }
            }

            $this->api->add_content($this->api->output->button($p), $container);
        }
    }

    /**
     * Generate an absolute URL to the given resource within the current
     * plugin directory
     *
     * @param string $fn The file name
     *
     * @return string Absolute URL to the given resource
     */
    public function url($fn)
    {
        return $this->api->url . $this->resource_url($fn);
    }

    /**
     * Make the given file name link into the plugin directory
     *
     * @param string $fn Filename
     */
    private function resource_url($fn)
    {
        if ($fn[0] != '/' && !preg_match('|^https?://|i', $fn)) {
            return $this->ID . '/' . $fn;
        }
        else {
            return $fn;
        }
    }

    /**
     * Provide path to the currently selected skin folder within the plugin directory
     * with a fallback to the default skin folder.
     *
     * @return string Skin path relative to plugins directory
     */
    public function local_skin_path()
    {
        $rcube = rcube::get_instance();
        foreach (array($rcube->config->get('skin'), 'larry') as $skin) {
            $skin_path = 'skins/' . $skin;
            if (is_dir(realpath(slashify($this->home) . $skin_path))) {
                break;
            }
        }

        return $skin_path;
    }

    /**
     * Callback function for array_map
     *
     * @param string $key Array key.
     * @return string
     */
    private function label_map_callback($key)
    {
        return $this->ID.'.'.$key;
    }
}
