<?php
/*********************************************************************************************************
  "Ensemble" is the proprietary property of The Regents of the University of California ("The Regents.")

  Copyright (c) 2005-10 The Regents of the University of California, Davis campus. All Rights Reserved.

  Redistribution and use in source and binary forms, with or without modification, are permitted by
  nonprofit, research institutions for research use only, provided the conditions in the included
  license agreement are met.

  Refer to the file "ensemble_license.txt" for the license agreement,
  located in the top level directory of this distribution.

**********************************************************************************************************/
//Author: Stefan Tomic
//Janata Lab
//Center for Mind and Brain
//Developed for the Ensemble Project


//A conditional form handler calls this function to ensure that a set of conditions 
//(a specific set of responses) have passed before going on.
//If any one condition is fails, the $condition_met variable is set to false
//the conditional form handler will determine what to do next based on this value.

//the conditional reference $_SESSION['condref_#'] tracks whether or not a form has been displayed
//for the purposes of checking whether a specific form_id has been previously visited. This is for
//support of conditionals across multiple experiments, since the order of occurrence of the specific 
// form_id is variable.
//set the condref for the current form_id to false. This will be set to true if the form displays (in htmlhead_name_mesg_formhead.php)

require_once('../include/variables.php');
require_once('../include/functions.php');

$_SESSION['condref_'.$form_id] = FALSE;
$condition_met = TRUE;

$condition_code = ($row_form_info['condition'] != "")? $row_form_info['condition'] : $row_form_info['old_condition'];
$condition_matlab = ($row_form_info['condition_matlab'] != "")? $row_form_info['condition_matlab'] : $row_form_info['old_condition_matlab'];

if($condition_code != "") {
	//split up the conditions string into an double array of conditions
	//the rows of the double array reference a particular condition
	//the columns indicate the fields (form order,question_id,form_question_number,question_iteration,subquestion,trial_id,type,response) of the condition
	$condition_array = explode("\n",$condition_code);
	$num_conditions = count($condition_array);	
	
	unset($conditions);
	foreach($condition_array as $key=>$value) 
		$conditions[] = explode(",",$value);

			
	//for each condition, check the response table 
	for($i_condition = 0;$i_condition < $num_conditions; $i_condition++) {
	
		unset($condition_test_response);
	
		//find the form number that we want to query the previous responses from
		//if form number field was negative, go back that many forms, if positive, the form number indicates the form order in the experiment

		//reference to the entire condition string (used for setting flags on this condition)

		$condition_form_occurrence = $conditions[$i_condition][0];
		$condition_form_id = $conditions[$i_condition][1];
		$condition_trial_form = $conditions[$i_condition][2];
		$condition_question_id = $conditions[$i_condition][3];
		$condition_form_question_num = $conditions[$i_condition][4];
		$condition_question_iteration = $conditions[$i_condition][5];
		$condition_subquestion = $conditions[$i_condition][6];
		if($condition_trial_form)
			$condition_trial_order = $_SESSION['trial_order'] - $conditions[$i_condition][7];
		else
			$condition_trial_order = 0;

		$condition_stim = $conditions[$i_condition][8];
		$condition_type = $conditions[$i_condition][9];
		for($i_response = 10;$i_response < count($conditions[$i_condition]);$i_response++)
			$condition_test_response[] = $conditions[$i_condition][$i_response];

		//check the condref for the form that this condition depends on
		//if condref is false, the parent form was not visited the last time around
		$condition_reference = 'condref_'.$condition_form_id;
		if(isset($_SESSION[$condition_reference]) && !($_SESSION[$condition_reference])) {
				$condition_met = FALSE;
				break;
		}
		
		$check_same_stim = ($condition_stim == 'same_stim' && $_SESSION['stimulus_id'] != NULL) ? sprintf("AND stimulus_id = %d ",$_SESSION['stimulus_id']) : "";
		
		//select the last response given by the subject.
		//this may be either a trial response or a regular questionnaire response
		//The session_id and subject_id are selected and either the fields (question_id, etc) associated with the question, or the trial_id
		//The parenthesis before trial_order and at the end indicate that the OR clause should be given priority in the selection logic
		if($_SESSION['encrypted_response_table']) {
			$enc_key = subinfo_encryption_key();
			$select_fields = sprintf("aes_decrypt(response_text,'%s') as response_text, aes_decrypt(response_enum,'%s') as response_enum",$enc_key,$enc_key);
		}
		else {
			$select_fields = "response_text,response_enum";
		}
		$sql_conditional_response = sprintf("SELECT %s from %s left join form_x_trial using (form_id,trial_id) ",$select_fields,$_SESSION['response_table']).
									sprintf("WHERE session_id = %d and subject_id = %s and %s.form_id = %d ",
											GetSQLValueString($_SESSION['session_id'],"int"),
											GetSQLValueString($_SESSION['subject_id'],"text"),
											$_SESSION['response_table'],
											GetSQLValueString($condition_form_id,"int")).
									$check_same_stim.
									sprintf("AND (trial_order = %d ",$condition_trial_order).
									sprintf("OR question_id = %d AND form_question_num = %d ",
											GetSQLValueString($condition_question_id,"int"),
											GetSQLValueString($condition_form_question_num,"int")).
									sprintf("AND question_iteration = %d AND subquestion = %d) order by response_order",
											GetSQLValueString($condition_question_iteration,"int"),
											GetSQLValueString($condition_subquestion,"int"));
		
		mysql_select_db($database_subject,$subject);
		$conditional_response = mysql_query($sql_conditional_response,$subject) or report_error_form(mysql_error());


		if($condition_form_occurrence < 0)
			$num_response = mysql_num_rows($conditional_response) + $condition_form_occurence;
		else
			$num_response = $condition_form_occurence;

		for($i_response = 0; $i_response < $num_response; $i_response++) {
			$row_conditional_response = mysql_fetch_assoc($conditional_response);
		}

		
		//check all responses that apply to this condition
		//if the condition is met by any one response, the condition is considered met
		for($i_response = 0;$i_response < count($condition_test_response);$i_response++) {
			
			switch($condition_type) {		
					case "response_enum":
						$bitmask = pow(2,((int)($condition_test_response[$i_response] - 1)));
						//since the response can contain more than one enum answer (submitted via checkbox)
						//we are performing a bitwise AND with $bitmask, which only corresponds to a single answer
						//this means that we don't need an exact match for the condition to pass
						//As long as the subject matched at least one of their enums to a single enum necessary to pass
						//the condition, then the condition passes.
						if((boolean) ($row_conditional_response[$condition_type] & $bitmask)) 
							$condition_met = TRUE;
						else
							$condition_met = FALSE;
						break;
					case "response_text":
						if($row_conditional_response[$condition_type] != $condition_test_response[$i_response])
							$condition_met = FALSE;
						else 
							$condition_met = TRUE;
						break;
			}
			//break out of inner for loop if we found a match, then $condition_met == TRUE for that response
			if($condition_met) {
				break;
			}
		}
		
		//break out of condition checking if a condition has not been met
		if(!($condition_met)) {
			break;
		}
		
			
	} //for loop
}


if($condition_met && ($condition_matlab != "")) {

	$pass_matlab_command = parse_matlab_arguments($condition_matlab);

	$matrpc_recv = matrpc_message($pass_matlab_command);
	
	if($matrpc_recv == $COND_MATLAB_FALSE_STRING)
		$condition_met = FALSE;
	elseif($matrpc_recv == $COND_MATLAB_TRUE_STRING)
		$condition_met = TRUE;
	else
		report_error_form(sprintf("Matlab conditional function \"%s\" returned \"%s\" when \"%s\" or \"%s\" was expected.",
						  $pass_matlab_command,$matrpc_recv,$COND_MATLAB_TRUE_STRING,$COND_MATLAB_FALSE_STRING),"form_processing/check_conditions.php");
}

//if the handler needs to break out of a loop due to condition(s) not passing, then skip forms
if(!($condition_met) && isset($exit_loop_if_cond_not_met) && $exit_loop_if_cond_not_met) {

	if(isset($_SESSION['loop_end']) && isset($_SESSION['loop_goto'])) {
		$_SESSION['num_skip_forms'] = $_SESSION['loop_end'] - $_SESSION['last_visited'] + 1;

	}
	else {
	
		//loop end hasn't been recorded yet so see if we can find the next end of loop
		//if it is found, skip that many forms, otherwise, just skip one form.
		$sql_find_loop = sprintf("select form_order,goto from experiment_x_form where experiment_id = %d and form_order >= %d and goto is not null order by form_order",$_SESSION['experiment_id'],$_SESSION['last_visited']);
		$loop_end = mysql_select($sql_find_loop);
		if(!is_null($loop_end['goto'])) 
			$_SESSION['num_skip_forms'] = $loop_end['form_order'] - $_SESSION['last_visited'] + 1;
		else
			$_SESSION['num_skip_forms'] = 1;

	}
}


//don't display this form and move on to the next if condition(s) were not met.
if(!($condition_met)) {
		include($questionnaire_dir."form_processing/update_session.php");	
}
?>