<?php
/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
# ***** BEGIN LICENSE BLOCK *****
# This file is part of Plume Framework, a simple PHP Application Framework.
# Copyright (C) 2001-2007 Loic d'Anterroches and contributors.
#
# Plume Framework is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Plume Framework is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# ***** END LICENSE BLOCK ***** */

/**
 * The main class of the framework. From where all start.
 *
 * The __autoload function is automatically set.
 */
class Pluf
{
    /**
     * Start the Plume Framework.
     *
     * Load the configuration files. 
     *
     * @param string Configuration file to use
     */
    static function start($config)
    {
        $GLOBALS['_PX_starttime'] = microtime(true);
        $GLOBALS['_PX_uniqid'] = uniqid($GLOBALS['_PX_starttime'], true);
        $GLOBALS['_PX_signal'] = array();
        $GLOBALS['_PX_locale'] = array();
        Pluf::loadConfig($config);
        date_default_timezone_set(Pluf::f('time_zone', 'Europe/Berlin'));
        mb_internal_encoding(Pluf::f('encoding', 'UTF-8'));
        mb_regex_encoding(Pluf::f('encoding', 'UTF-8'));
    }

    /**
     * Load the given configuration file.
     *
     * The configuration is saved in the $GLOBALS['_PX_config'] array.
     * The relations between the models are loaded in $GLOBALS['_PX_models'].
     *
     * @param string Configuration file to load.
     */
    static function loadConfig($config_file)
    {
        if (false !== ($file=Pluf::fileExists($config_file))) {
            $GLOBALS['_PX_config'] = require $file;
        } else {
            throw new Exception('Configuration file does not exist: '.$config_file);
        }
        // Load the relations for each installed application. Each
        // application folder must be in the include path.
        self::loadRelations(!Pluf::f('debug', false));
    }

    /**
     * Get the model relations and signals.
     *
     * If not in debug mode, it will automatically cache the
     * information. This allows one include file when many
     * applications and thus many includes are needed.
     *
     * Signals and relations are cached in the same file as the way to
     * go for signals is to put them in the relations.php file.
     *
     * @param bool Use the cache (true)
     */
    static function loadRelations($usecache=true)
    {
        $GLOBALS['_PX_models'] = array();
        $GLOBALS['_PX_models_init_cache'] = array();
        $apps = Pluf::f('installed_apps', array());
        $cache = Pluf::f('tmp_folder').'/Pluf_relations_cache_'.md5(serialize($apps)).'.phps';
        if ($usecache and file_exists($cache)) {
            list($GLOBALS['_PX_models'],
                 $GLOBALS['_PX_models_related'],
                 $GLOBALS['_PX_signal']) = include $cache;
            return;
        }
        $m = $GLOBALS['_PX_models'];
        foreach ($apps as $app) {
            $m = array_merge_recursive($m, require $app.'/relations.php');
        }
        $GLOBALS['_PX_models'] = $m;

        $_r = array(
                    'relate_to' => array(),
                    'relate_to_many' => array(),
                    );
        foreach ($GLOBALS['_PX_models'] as $model => $relations) {
            foreach ($relations as $type => $related) {
                foreach ($related as $related_model) {
                    if (!isset($_r[$type][$related_model])) {
                        $_r[$type][$related_model] = array();
                    }
                    $_r[$type][$related_model][] = $model;
                }
            }
        }
        $_r['foreignkey'] = $_r['relate_to'];
        $_r['manytomany'] = $_r['relate_to_many'];
        $GLOBALS['_PX_models_related'] = $_r;

        // $GLOBALS['_PX_signal'] is automatically set by the require
        // statement and possibly in the configuration file.
        if ($usecache) {
            $s = var_export(array($GLOBALS['_PX_models'],
                                  $GLOBALS['_PX_models_related'],
                                  $GLOBALS['_PX_signal']), true);
            if (@file_put_contents($cache, '<?php return '.$s.';'."\n",
                                   LOCK_EX)) {
                chmod($cache, 0755);
            }
        }
    }

    /**
     * Access a configuration variable.
     *
     * @param string Configuration variable
     * @param mixed Possible default value if value is not set ('')
     * @return mixed Configuration variable or default value if not defined.
     */
    static function f($cfg, $default='')
    {
        if (isset($GLOBALS['_PX_config'][$cfg])) {
            return $GLOBALS['_PX_config'][$cfg];
        }
        return $default;
    }

    /**
     * Access an array of configuration variables having a given
     * prefix.
     *
     * @param string Prefix.
     * @param bool Strip the prefix from the keys (false).
     * @return array Configuration variables.
     */
    static function pf($pfx, $strip=false)
    {
        $ret = array();
        $pfx_len = strlen($pfx);
        foreach ($GLOBALS['_PX_config'] as $key=>$val) {
            if (0 === strpos($key, $pfx)) {
                if (!$strip) {
                    $ret[$key] = $val;
                } else {
                    $ret[substr($key, $pfx_len)] = $val;
                }
            }
        }
        return $ret;
    }


    /**
     * Returns a given object. 
     *
     * Loads automatically the corresponding class file if needed.
     * If impossible to get the class $model, exception is thrown.
     *
     * @param string Model to load.
     * @param mixed Extra parameters for the constructor of the model.
     */
    public static function factory($model, $params=null)
    {
        if ($params !== null) {
            return new $model($params);
        }
        return new $model();
    }

    /**
     * Load a class depending on its name.
     *
     * Throw an exception if not possible to load the class.
     *
     * @param string Class to load.
     */
    public static function loadClass($class)
    {
        if (class_exists($class, false)) {
            return;
        }
        $file = str_replace('_', DIRECTORY_SEPARATOR, $class) . '.php';
        include $file;
        if (!class_exists($class, false)) {
            $error = 'Impossible to load the class: '.$class."\n".
                'Tried to include: '.$file."\n".
                'Include path: '.get_include_path();
            throw new Exception($error);
        }
    }

    /**
     * Load a function depending on its name.
     *
     * The implementation file of the function
     * MyApp_Youpla_Boum_Stuff() is MyApp/Youpla/Boum.php That way it
     * is possible to group all the related function in one file.
     *
     * Throw an exception if not possible to load the function.
     *
     * @param string Function to load.
     */
    public static function loadFunction($function)
    {
        if (function_exists($function)) {
            return;
        }
        $elts = explode('_', $function);
        array_pop($elts);
        $file = implode(DIRECTORY_SEPARATOR, $elts) . '.php';
        if (false !== ($file=Pluf::fileExists($file))) {
            include $file;
        }
        if (!function_exists($function)) {
            throw new Exception('Impossible to load the function: '.$function);
        }
    }


    /**
     * Hack for [[php file_exists()]] that checks the include_path.
     * 
     * Use this to see if a file exists anywhere in the include_path.
     * 
     * <code type="php">
     * $file = 'path/to/file.php';
     * if (Pluf::fileExists('path/to/file.php')) {
     *     include $file;
     * }
     * </code>
     *
     * @credits Paul M. Jones <pmjones@solarphp.net>
     *  
     * @param string $file Check for this file in the include_path.
     * @return mixed Full path to the file if the file exists and 
     *         is readable in the include_path, false if not.
     */
    public static function fileExists($file)
    {
        $file = trim($file);
        if (!$file) {
            return false;
        }
        // using an absolute path for the file?
        // dual check for Unix '/' and Windows '\',
        // or Windows drive letter and a ':'.
        $abs = ($file[0] == '/' || $file[0] == '\\' || $file[1] == ':');
        if ($abs && file_exists($file)) {
            return $file;
        }
        // using a relative path on the file
        $path = explode(PATH_SEPARATOR, ini_get('include_path'));
        foreach ($path as $dir) {
            // strip Unix '/' and Windows '\'
            $target = rtrim($dir, '\\/').DIRECTORY_SEPARATOR.$file;
            if (file_exists($target)) {
                return $target;
            }
        }
        // never found it
        return false;
    }

    /**
     * Helper to load the default database connection.
     *
     * This method is just dispatching to the function define in the
     * configuration by the 'db_get_connection' key or use the default
     * 'Pluf_DB_getConnection'. If you want to use your own function,
     * take a look at the Pluf_DB_getConnection function to use the
     * same approach for your method.
     *
     * The extra parameters can be used to selectively connect to a
     * given database. When the ORM is getting a connection, it is
     * passing the current model as parameter. That way you could get
     * different databases for different models.
     * 
     * @param mixed Extra parameters. 
     * @return resource DB connection.
     */
    public static function &db($extra=null)
    {
        $func = Pluf::f('db_get_connection', 'Pluf_DB_getConnection');
        Pluf::loadFunction($func);
        $a = $func($extra);
        return $a;
    }
}


/**
 * Translate a string.
 *
 * @param string String to be translated.
 * @return string Translated string.
 */
function __($str)
{
    $locale = (isset($GLOBALS['_PX_current_locale'])) ? $GLOBALS['_PX_current_locale'] : 'en';
    if (!empty($GLOBALS['_PX_locale'][$locale][$str][0])) {
        return $GLOBALS['_PX_locale'][$locale][$str][0];
    }
    return $str;
}

/**
 * Translate the plural form of a string.
 *
 * @param string Singular form of the string.
 * @param string Plural form of the string.
 * @param int Number of elements.
 * @return string Translated string.
 */
function _n($sing, $plur, $n)
{
    $locale = (isset($GLOBALS['_PX_current_locale'])) ? $GLOBALS['_PX_current_locale'] : 'en';
    if (isset($GLOBALS['_PX_current_locale_plural_form'])) {
        $pform = $GLOBALS['_PX_current_locale_plural_form'];
    } else {
        $pform = Pluf_Translation::getPluralForm($locale);
    }
    $index = Pluf_Translation::$pform($n);
    if (!empty($GLOBALS['_PX_locale'][$locale][$sing.'#'.$plur][$index])) {
        return $GLOBALS['_PX_locale'][$locale][$sing.'#'.$plur][$index];
    }
    // We have no translations or default English
    if ($n == 1) {
        return $sing;
    }
    return $plur;
}

/**
 * Autoload function.
 *
 * @param string Class name.
 */
function __autoload($class_name)
{
    try {
        Pluf::loadClass($class_name);
    } catch (Exception $e) {
        if (Pluf::f('debug')) {
            print $e->getMessage();
            die();
        }
        eval("class $class_name { 
          function __construct() { 
            throw new Exception('Class $class_name not found');
          }
          
          static function __callstatic(\$m, \$args) {
            throw new Exception('Class $class_name not found');
          }
        }"); 
    }
}

/**
 * Exception to catch the PHP errors.
 *
 * @credits errd 
 * @see http://www.php.net/manual/en/function.set-error-handler.php
 */
class PlufErrorHandlerException extends Exception 
{
    public function setLine($line) 
    { 
        $this->line = $line;
    }

    public function setFile($file) 
    {
        $this->file = $file;
    }
}

/**
 * The function that is the real error handler.
 */
function PlufErrorHandler($code, $string, $file, $line) 
{ 
    if (0 == error_reporting()) return false;
    if (E_STRICT == $code 
        && 
        (
         0 === strpos($file, Pluf::f('pear_path','/usr/share/php/'))
         or
         false !== strripos($file, 'pear') // if pear in the path, ignore
         )
        ) {
        return;
    }
    $exception = new PlufErrorHandlerException($string, $code);
    $exception->setLine($line);
    $exception->setFile($file);
    throw $exception;
}

// Set the error handler only if not performing the unittests.
if (!defined('IN_UNIT_TESTS')) {
    set_error_handler('PlufErrorHandler', error_reporting());
}


/**
 * Shortcut needed all over the place.
 *
 * Note that in some cases, we need to escape strings not in UTF-8, so
 * this is not possible to safely use a call to htmlspecialchars. This
 * is why str_replace is used.
 *
 * @param string Raw string
 * @return string HTML escaped string
 */
function Pluf_esc($string) 
{
    return str_replace(array('&',     '"',      '<',    '>'),
                       array('&', '"', '<', '>'),
                       (string) $string);
}