<?php
/*
	+-----------------------------------------------------------------------------+
	| ILIAS open source                                                           |
	+-----------------------------------------------------------------------------+
	| Copyright (c) 1998-2006 ILIAS open source, University of Cologne            |
	|                                                                             |
	| This program is free software; you can redistribute it and/or               |
	| modify it under the terms of the GNU General Public License                 |
	| as published by the Free Software Foundation; either version 2              |
	| of the License, or (at your option) any later version.                      |
	|                                                                             |
	| This program 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 General Public License for more details.                                |
	|                                                                             |
	| You should have received a copy of the GNU General Public License           |
	| along with this program; if not, write to the Free Software                 |
	| Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. |
	+-----------------------------------------------------------------------------+
*/

include_once "./classes/class.ilObjectAccess.php";
include_once "./survey/classes/inc.SurveyConstants.php";

/**
* Class ilObjSurveyAccess
*
*
* @author Alex Killing <alex.killing@gmx.de>
* @author Helmut Schottmüller <helmut.schottmueller@mac.com>
* @version $Id: class.ilObjSurveyAccess.php,v 1.15 2006/07/20 21:23:46 hschottm Exp $
*
* @package Survey
*/
class ilObjSurveyAccess extends ilObjectAccess
{
	/**
	* Checks wether a user may invoke a command or not
	* (this method is called by ilAccessHandler::checkAccess)
	*
	* Please do not check any preconditions handled by
	* ilConditionHandler here.
	*
	* @param	string		$a_cmd		command (not permission!)
	* @param	string		$a_permission	permission
	* @param	int			$a_ref_id	reference id
	* @param	int			$a_obj_id	object id
	* @param	int			$a_user_id	user id (if not provided, current user is taken)
	*
	* @return	boolean		true, if everything is ok
	*/
	function _checkAccess($a_cmd, $a_permission, $a_ref_id, $a_obj_id, $a_user_id = "")
	{
		global $ilUser, $lng, $rbacsystem, $ilAccess;

		if ($a_user_id == "")
		{
			$a_user_id = $ilUser->getId();
		}

		switch ($a_permission)
		{
			case "visible":
				if (!ilObjSurveyAccess::_lookupCreationComplete($a_obj_id) &&
					(!$rbacsystem->checkAccess('write', $a_ref_id)))
				{
					$ilAccess->addInfoItem(IL_NO_OBJECT_ACCESS, $lng->txt("warning_survey_not_complete"));
					return false;
				}
				break;
		}

		switch ($a_cmd)
		{
			case "run":
				if (!ilObjSurveyAccess::_lookupCreationComplete($a_obj_id)
					|| !(ilObjSurveyAccess::_lookupOnline($a_obj_id) == 1))
				{
					$ilAccess->addInfoItem(IL_NO_OBJECT_ACCESS, $lng->txt("warning_survey_not_complete"));
					return false;
				}
				break;

			case "evaluation":
				if (!ilObjSurveyAccess::_lookupCreationComplete($a_obj_id))
				{
					$ilAccess->addInfoItem(IL_NO_OBJECT_ACCESS, $lng->txt("warning_survey_not_complete"));
					return false;
				}
				if ($rbacsystem->checkAccess("write",$a_ref_id) || ilObjSurveyAccess::_hasEvaluationAccess($a_obj_id, $a_user_id))
				{
					return true;
				}
				else
				{
					$ilAccess->addInfoItem(IL_NO_OBJECT_ACCESS, $lng->txt("no_permission"));
					return false;
				}
				break;
		}

		return true;
	}
	
	
	/**
	 * get commands
	 * 
	 * this method returns an array of all possible commands/permission combinations
	 * 
	 * example:	
	 * $commands = array
	 *	(
	 *		array("permission" => "read", "cmd" => "view", "lang_var" => "show"),
	 *		array("permission" => "write", "cmd" => "edit", "lang_var" => "edit"),
	 *	);
	 */
	function _getCommands()
	{
		$commands = array
		(
			array("permission" => "read", "cmd" => "infoScreen", "lang_var" => "svy_run", "default" => true),
			array("permission" => "write", "cmd" => "properties", "lang_var" => "edit"),
			array("permission" => "read", "cmd" => "evaluation", "lang_var" => "svy_evaluation")
		);
		
		return $commands;
	}

	//
	// object specific access related methods
	//

	/**
	* checks wether all necessary parts of the survey are given
	*/
	function _lookupCreationComplete($a_obj_id)
	{
		global $ilDB;

		$q = sprintf("SELECT * FROM survey_survey WHERE obj_fi=%s",
			$ilDB->quote($a_obj_id)
		);
		$result = $ilDB->query($q);

		if ($result->numRows() == 1)
		{
			$row = $result->fetchRow(DB_FETCHMODE_OBJECT);
		}
		if (!$row->complete)
		{
			return false;
		}

		return true;
	}

	/**
	* get evaluation access
	*/
	function _lookupEvaluationAccess($a_obj_id)
	{
		global $ilDB;

		$q = sprintf("SELECT * FROM survey_survey WHERE obj_fi=%s",
			$ilDB->quote($a_obj_id)
		);
		$result = $ilDB->query($q);
		if ($result->numRows() == 1)
		{
			$row = $result->fetchRow(DB_FETCHMODE_OBJECT);
		}

		return $row->evaluation_access;
	}
	
	function _isSurveyParticipant($user_id, $survey_id)
	{
		global $ilDB;

		$q = sprintf("SELECT finished_id FROM survey_finished WHERE user_fi = %s AND survey_fi = %s",
			$ilDB->quote($user_id . ""),
			$ilDB->quote($survey_id . "")
		);
		$result = $ilDB->query($q);
		if ($result->numRows() == 1)
		{
			return true;
		}
		else
		{
			return false;
		}
	}
	
	function _lookupAnonymize($a_obj_id)
	{
		global $ilDB;

		$q = sprintf("SELECT anonymize FROM survey_survey WHERE obj_fi = %s",
			$ilDB->quote($a_obj_id . "")
		);
		$result = $ilDB->query($q);
		if ($result->numRows() == 1)
		{
			$row = $result->fetchRow(DB_FETCHMODE_ASSOC);
			return $row["anonymize"];
		}
		else
		{
			return 0;
		}
	}
	
	function _hasEvaluationAccess($a_obj_id, $user_id)
	{
		$evaluation_access = ilObjSurveyAccess::_lookupEvaluationAccess($a_obj_id);
		switch ($evaluation_access)
		{
			case 0:
				// no evaluation access
				return false;
				break;
			case 1:
				// evaluation access for all users
				return true;
				break;
			case 2:
				// evaluation access for participants
				// check if the user with the given id is a survey participant

				// show the evaluation button for anonymized surveys for all users
				// access is only granted with the survey access code
				if (ilObjSurveyAccess::_lookupAnonymize($a_obj_id) == 1) return true;
				
				global $ilDB;
				$q = sprintf("SELECT survey_id FROM survey_survey WHERE obj_fi = %s",
					$ilDB->quote($a_obj_id . "")
				);
				$result = $ilDB->query($q);
				if ($result->numRows() == 1)
				{
					$row = $result->fetchRow(DB_FETCHMODE_ASSOC);
					if (ilObjSurveyAccess::_isSurveyParticipant($user_id, $row["survey_id"]))
					{
						return true;
					}
				}
				// TODO: add an additional check for anonymous users who could have and survey access code
				//       on the other hand: if someone publishes a survey with anonymous access and evaluation access
				//       he or she should grant evaluation access for all users...
				return false;
				break;
		}
	}

	/**
	* get status
	*/
	function _lookupOnline($a_obj_id)
	{
		global $ilDB;

		$q = sprintf("SELECT * FROM survey_survey WHERE obj_fi=%s",
			$ilDB->quote($a_obj_id)
		);
		$result = $ilDB->query($q);
		if ($result->numRows() == 1) {
			$row = $result->fetchRow(DB_FETCHMODE_OBJECT);
		}

		return $row->status;
	}

	/**
	* get finished status
	*
	* @param	int		$a_obj_id		survey id
	*/
	function _lookupFinished($a_obj_id, $a_user_id = "")
	{
		global $ilDB, $ilUser;

		$finished = "";
		if (!strlen($a_user_id)) $a_user_id = $ilUser->getId();

		$q = sprintf("SELECT * FROM survey_survey WHERE obj_fi = %s",
			$ilDB->quote($a_obj_id)
		);
		$result = $ilDB->query($q);
		if ($result->numRows() == 1)
		{
			$row = $result->fetchRow(DB_FETCHMODE_OBJECT);
			if ($row->anonymize == 1)
			{
				$q = sprintf("SELECT * FROM survey_finished, survey_anonymous WHERE survey_finished.survey_fi = %s AND survey_finished.survey_fi = survey_anonymous.survey_fi AND survey_anonymous.user_key = %s AND survey_anonymous.survey_key = survey_finished.anonymous_id",
					$ilDB->quote($row->survey_id),
					$ilDB->quote(md5($a_user_id) . "")
				);
			}
			else
			{
				$q = sprintf("SELECT * FROM survey_finished WHERE survey_fi = %s AND user_fi = %s",
					$ilDB->quote($row->survey_id),
					$ilDB->quote($a_user_id)
				);
			}
			$result = $ilDB->query($q);
			if ($result->numRows() == 1)
			{
				$row = $result->fetchRow(DB_FETCHMODE_OBJECT);
				$finished = (int)$row->state;
			}
		}

		return $finished;
	}
	
	/**
	* check whether goto script will succeed
	*/
	function _checkGoto($a_target)
	{
		global $ilAccess;
		
		$t_arr = explode("_", $a_target);

		if ($t_arr[0] != "svy" || ((int) $t_arr[1]) <= 0)
		{
			return false;
		}

		if ($ilAccess->checkAccess("read", "", $t_arr[1]))
		{
			return true;
		}
		return false;
	}


}

?>
