<?php
/*
**	$Id$
**
**	ITools - the Internet Tools Library
**
**	Copyright (C) 1995-2003 by the ITools Authors.
**	This program is free software; you can redistribute it and/or
**	modify it under the terms of either the GNU General Public License
**	or the GNU Lesser General Public License, as published by the Free
**	Software Foundation. See http://www.gnu.org/licenses/ for details.
**
*/

class it_text extends it_db_record
{
	var $defaultlanguage;		/* Preferred language (without cookie) */
	var $actlanguage;		/* Selected language */
	var $actlanguagename;		/* Name of selected language */
	var $languages = array();	/* Active languages */
	var $languages_available = array(); /* Available languages */
	var $language_failsafe;         /* First available language */
	var $debug;			/* Non-empty if debug mode is desired */
	var $cookiename;                /* Name of the language cookie, default is "LANGUAGE" */
	var $unknown_labels = array();  /* array for spooling unknown labels in
                                           debug mode */

/**
 * Constructor
 * @param $defaultlanguage Optional default language to use
 * @param $tablename Optional name of text database table (default: 'it_texts')
 * @param $debug Optional debug mode: display label of unknown texts, set to 'label' to always display labels instead of actual text
 * @param $db Optional database object, defaults to global $it_db
 * @param $cookiename Optional cookie name (default: 'LANGUAGE')
 */
function it_text($defaultlanguage='de', $tablename='it_texts', $debug='', $db=0, $cookiename='LANGUAGE')
{
	$this->debug = $debug;
	$this->cookiename = $cookiename;

	/* Create database objects */
	if (is_object($db))
		$table = new it_db_table($db, $tablename);
	else
		$table = new it_db_table($GLOBALS['it_db'], $tablename);
	$this->it_db_record($table, 'Label');

	/* Get array of supported languages and their names */
	if (!$this->read('_'))
		internal_error("Can't read language names");
	$languages = explode(',', $table->field_names());
	while (list($index, $code) = each($languages))
	{
		if ($code != 'Label')
		{
			/* If a language's "_" field is unset, ignore it */
			if ($languagename = $this->data[$code])
			{
				$this->languages_available[$code] = $languagename;
				/* Only use a language in browser/cookie detection below if it's not diasbled by a leading '-' */
				if (substr($languagename, 0, 1) != '-')
				{
					$this->languages[$code] = $languagename;
					if (!isset($this->language_failsafe))
						$this->language_failsafe = $code;
				}
			}
		}
	}

	/* Set our default language according to browser preference */
	if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE']))
	{
		/* SQL field names can't contain "-" so we change these to "_" */
		$languages = explode(',', strtr($_SERVER['HTTP_ACCEPT_LANGUAGE'], '-', '_'));
		while (list($key, $lang) = each($languages))
		{
			if (isset($this->languages[$lang]))
			{
				$this->defaultlanguage = $lang;
				debug("Got language from browser: {$this->defaultlanguage}", 6);
				break;
			}
			else
			{
				$short = substr($lang, 0, 2);
				if (isset($this->languages[$short]))
				{
					$this->defaultlanguage = $short;
					debug("Got language family from browser: {$this->defaultlanguage}", 6);
					break;
				}
			}
		}
		if (count($this->languages) == 0)
		        debug("No active languages found!", 5);
	}

	/* If no language matched, use the one that was supplied by our caller */
	if (!isset($this->defaultlanguage))
		$this->defaultlanguage = $defaultlanguage;

	/* If language is still invalid, use the first one from our database */
	if (!$this->languages[$this->defaultlanguage])
	{
		debug("Bad language \"{$this->defaultlanguage}\", using first entry \"{$this->languages[$this->language_failsafe]}\"", 5);
		$this->defaultlanguage = $this->language_failsafe;
	}

	/* If a cookie is set, we use its value as our active language */
	if (isset($_COOKIE[$this->cookiename]) && ($cookie = $_COOKIE[$this->cookiename]))
	{
		if ($this->languages[$cookie])	/* Is this language available? */
		{
			$this->actlanguage = $cookie;
			debug("Got language from cookie: {$this->actlanguage}", 6);
		}
	}

	/* If the cookie supplied no valid language, we use our calculated default language */
	if (!isset($this->actlanguage))
		$this->actlanguage = $this->defaultlanguage;

	/* And finally, record the name of our active language. */
	$this->actlanguagename = $this->languages[$this->actlanguage];

	debug("Used language is {$this->actlanguagename}, default language is {$this->defaultlanguage}.", 6);
}


/**
 * Return a text in the selected language.
 * @param $label Label of text to return
 * @param $raw Optional unused obsolete parameter
 * @param $language Optional language to return text in.
 * @return Localized text string
 */
function text($label, $raw=0, $language='')
{
	if ($this->debug === 'label')
		return $label;
	
	if ($this->read($label))
	{
		if ($language == '')
			$language = $this->actlanguage;

		/*
		** If field is NULL, consider it undefined (and return label if in
		** debug mode). That's why we can't call safe_get_field() here.
		*/
		if (isset($this->data[$language]))
			return $this->data[$language];
	}

	if ($this->debug)
	{
	        $this->unknown_labels[] = $label;
		return "<blink>$label</blink>";
	}
	else
	        return $this->label_unknown($label);
}


/**
 * Localized function called when a label is not found
 * overload this if for example you want to have a silent error behaviour
 * @param $label Text label that was not found in database
 */
function label_unknown($label)
{
        internal_error("No text found for label \"$label\"");
}


/**
 * Return a text in the selected language, with correctly encoded umlauts.
 * Replaces variables of the form {obj.var} with value, e.g. {user.name}
 * NOTE: Invalid object names or non-existing variables are simply deleted.
 * @param $label Label of text to return
 * @param $values Associative array containing values to fill in
 * @param $language Optional language to return text in.
 * @return Localized text string with variables replaced by their values
 */
function etext($label, $values=null, $language='')
{
	return it_text_transmogrify($this->text($label, false, $language), is_array($values) ? $values : null);
}


/**
 * Change language
 * @param $language New language to set
 * @param $setcookie Optional flag if a cookie is to be set (default: true)
 */
function set_language($language, $setcookie=true)
{
	/* If set to an invalid language (via forged GET?) we delete the cookie */
        if ($this->languages_available[$language])
        {
	        if (!$this->languages[$language])
		        debug('Selected an existing but currently disabled language!', 6);
	        $this->actlanguage = $language;
		if ($setcookie)
		        SetCookie($this->cookiename, $this->actlanguage, time() + 31536000, '/');	/* 1 Year */
	}
        else
	{
		$this->actlanguage = $this->defaultlanguage;
		if ($setcookie)
		  SetCookie($this->cookiename, '', time() + 31536000, '/');
	}
}


/**
 * Get active language
 * @return currently active language
 */
function get_language()
{
	return $this->actlanguage;
}


/**
 * Get default language
 * @return default language
 */
function get_default_language()
{
	return $this->defaultlanguage;
}


/**
 * Check if a text entry for a specific label exists
 * @param $label Label to check
 */
function text_exists($label)
{
	if ($this->read($label))
		return 1;
	return 0;
}


/**
 * when running it_text in debug mode, you can use this to die (internal_error)
 * in case there were unknown labels with a list of all unknown labels
 */
function checkout_unknown_labels()
{
	if (count($this->unknown_labels) > 0)
	{
		$debug_text = 'No text found for labels:<br>';
		reset ($this->unknown_labels);
		while($a = each($this->unknown_labels))
			$debug_text .= $a[1]."<br>";

		internal_error($debug_text);
	}
	else
		return 0;
}
	

/**
 * Replaces special chars with their TeX equivalent
 * @param $text Text to convert from ISO-8859-1 to TeX encoding
 * @param $convertlinebreaks Whether to convert LFs to TeX linebreaks
 * @return TeX encoded text to be inserted into TeX template
 */
function texify($text, $convertlinebreaks = true)
{
	$translation = array
	(
		'À' => '{\`A}',
		'Á' => "{\'A}",
		'Â' => '{\^A}',
		'Ã' => '{\~A}',
		'Ä' => '{\"A}',
		'Ç' => '{\c C}',
		'È' => '{\`E}',
		'É' => "{\'E}",
		'Ê' => '{\^E}',
		'Ë' => '{\"E}',
		'Ì' => '{\`I}',
		'Í' => "{\'I}",
		'Î' => '{\^I}',
		'Ï' => '{\"I}',
		'Ñ' => '{\~N}',
		'Ò' => '{\`O}',
		'Ó' => "{\'O}",
		'Ô' => '{\^O}',
		'Õ' => '{\~O}',
		'Ö' => '{\"O}',
		'Ù' => '{\`U}',
		'Ú' => "{\'U}",
		'Û' => '{\^U}',
		'Ü' => '{\"U}',
		'ß' => '{\ss}',
		'à' => '{\`a}',
		'á' => "{\'a}",
		'â' => '{\^a}',
		'ã' => '{\~a}',
		'ä' => '{\"a}',
		'ç' => '{\c c}',
		'è' => '{\`e}',
		'é' => "{\'e}",
		'ê' => '{\^e}',
		'ë' => '{\"e}',
		'ì' => '{\`i}',
		'í' => "{\'i}",
		'î' => '{\^i}',
		'ï' => '{\"i}',
		'ñ' => '{\~n}',
		'ò' => '{\`o}',
		'ó' => "{\'o}",
		'ô' => '{\^o}',
		'õ' => '{\~o}',
		'ö' => '{\"o}',
		'ù' => '{\`u}',
		'ú' => "{\'u}",
		'û' => '{\^u}',
		'ü' => '{\"u}',
		'ÿ' => '{\"y}',
		'"' => "''",
		'\\' => '/',
		'%' => '\%',
		'$' => '\$',
		'#' => '\#',
		'&' => '\&',
		'_' => '\_',
		'^' => '',
	);

	if ($convertlinebreaks)
		$translation["\n"] = "\\\\\n";

	return strtr($text, $translation);
}

} /* End class it_text */


/*
 * Globally available functions without need for object
 */

/*
 * Replaces variables of the form {obj.var} with value, e.g. {user.name}
 * NOTE: Invalid object names or non-existing variables are simply deleted.
 */
function it_text_transmogrify($text, $values=array())
{
	while (preg_match('/{([\w.]+)}/', $text, $regs))
	{
		$path =  explode('.', $regs[1]);
		if ($values)
			$value =& $values;
		else
			$value =& $GLOBALS;

		/* Recurse into nested arrays/object members */
		foreach ($path as $key)
		{
			if (is_object($value))
				$value =& $value->$key;
			else
				$value =& $value[$key];
		}

		$text = str_replace($regs[0], $value, $text);
	}

	return $text;
}


/*
 * Shortcut to $it_text->Text()
 */
function T($label, $raw=0, $language='')
{
	return $GLOBALS['it_text']->text($label, $raw, $language);
}


/*
 * Shortcut to $it_text->etext()
 */
function ET($label, $values=null, $language='')
{
	return $GLOBALS['it_text']->etext($label, $values, $language);
}

/**
 * Shortcut to $it_text->get_language()
 */
function T_lang()
{
	return $GLOBALS['it_text']->get_language();
}

/**
 * Shortcut to $it_text->get_language()
 */
function T_set_language($language, $setcookie=true)
{
	return $GLOBALS['it_text']->set_language($language, $setcookie);
}

/**
 * Shortcut to $it_text->text_exists()
 */
function T_exists($label)
{
	return $GLOBALS['it_text']->text_exists($label);
}
?>