<?php
/*
	PEAR::OAI
	
	A PHP Implementation of the Open Archives Initiative Protocol 
	for Metadata Harvesting (http://www.openarchives.org)
	
    Copyright (C) 2003 ZZ/OSS GbR, http://www.zzoss.com

    This library 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.

    This library 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 library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
	
	Author: Sandro Zic <hide@address.com>
	
	Based on work by Heinrich Stamerjohanns <hide@address.com>
	
	$Id: Error.php,v 1.2 2003/04/22 08:59:33 ordnas Exp $
*/

require_once 'OAI/Base.php';

/**
* OAI_ServerError
* Error handling of OAI server as specified for OAI and HTTP protocol.
*
* @access   public
* @version  $Id: Error.php,v 1.2 2003/04/22 08:59:33 ordnas Exp $
* @package  OAI
* @author   Sandro Zic <hide@address.com> Rewrite for PEAR
* @author   Heinrich Stamerjohanns <hide@address.com> Original Author
*/
class OAI_ServerError
{
    
	/**
    * Error messages returned to requesting party
	*
    * @var  string
	* @see	addMessage(), getMessage()
    */  
	var $error_code = '';

	/**
    * Error messages returned to requesting party
	*
    * @var  string
	* @see	addMessage(), getMessage()
    */  
	var $error_description = '';

    /**
     * message
     *
     * returns a SOAP_Message class that can be sent as a server response
     *
     * @return SOAP_Message 
     * @access public
     */
    function addMessage($code, $argument='', $value='')
    {
		switch ($code) {
			case 'badArgument' :
				$text = 
						"The request includes illegal arguments, is missing required arguments, ".
						"includes a repeated argument, or values for arguments have an illegal syntax.";
				break;
	
			/*
			case 'badGranularity' :
				$text = "The value '$value' of the argument '$argument' is not valid.";
				$code = 'badArgument';
				break;
			*/
			case 'badResumptionToken' :
				$text = "The value of the resumptionToken argument is invalid or expired.";
				break;
			/*
			case 'badRequestMethod' :
				$text = "The request method '$argument' is unknown.";
				$code = 'badVerb';
				break;
			*/
			case 'badVerb' :
				$text = "Value of the verb argument is not a legal OAI-PMH verb, the verb argument ".
						"is missing, or the verb argument is repeated.";
				break;
	
			case 'cannotDisseminateFormat' :
				$text = "The metadata format '".$argument."' identified by the value given for the metadataPrefix ".
						"argument is not supported by the item or by the repository.";
				break;
			
			// not OAI standard
			case 'exclusiveArgument' :
				$text = 'The usage of resumptionToken as an argument allows no other arguments.';
				$code = 'badArgument';
	
			case 'idDoesNotExist' :
				$text = "The value of the identifier argument is unknown or illegal in this repository.";
				break;
			
			// not OAI standard
			case 'missingArgument' :
				$text = "The required argument '$argument' is missing in the request.";
				$code = 'badArgument';
				break;
			
			// not OAI standard
			case 'noRecordsMatch' :
				$text = 'The combination of the given values results in an empty list.';
				break;
	
			case 'noMetadataFormats' :
				$text = 'There are no metadata formats available for the specified item.';
				break;
	
			// not OAI standard
			case 'noVerb' :
				$text = 'The request does not provide any verb.';
				$code = 'badVerb';
				break;
	
			case 'noSetHierarchy' :
				$text = 'The repository does not support sets.';
				break;
	
			default:
				$text = "Unknown error: code: '$code', argument: '$argument', value: '$value'";
				$code = 'badArgument';
		}
	
		$this->error_code = OAI_Base::xmlEncode($code);
		$this->error_description = OAI_Base::xmlEncode($text);
    }
    
    /**
     * Check if errors occured
     *
     * @return boolean 
     * @access public
     */
    function isError()
    {
		if(!strlen($this->error_code)){
			return false;
		} else {
			return true;
		}
    }

    /**
     * getCode
     *
     * returns a string with the error code
     *
     * @return string 
     * @access public
     */
    function getCode()
    {
		return $this->error_code;
    }

    /**
     * Get error description
     *
     * returns a string with the error description
     *
     * @return string 
     * @access public
     */
    function getDescription()
    {
		return $this->error_description;
    }
	
    /**
     * Internal Server Error
     *
     * Returns a HTTP 500 error code and exits application.
     *
	 * @param string $msg	The error message for the administrator.
     * @access public
     */
	function internalServerError($msg)
	{
        // issue HTTP "Internal Server Error" header
        include_once 'HTTP/Header.php';
        HTTP_Header::sendStatusCode(500);
		PEAR::raiseError($msg);
        exit;
	}
}
?>