<?php

/* $Id$ */

/* vim: set tabstop=4 shiftwidth=4 expandtab: */

// Written by James Flemer
// <jflemer@alum.rpi.edu>

/* {{{ proto void survey_purge(array survey_ids)
   Purges all traces of survey(s) from the database.
   Returns void. */
function survey_purge($sids) {
	if(is_int($sids)) {
		$sidstr = '='.$sids;
	} else if (is_string($sids)) {
		$sids = split(" ",$sids);
	}
	if(is_array($sids)) {
		$sidstr = array_to_insql($sids);
	}

	// make a list of question IDs
	$sql = "SELECT id FROM ".$GLOBALS['ESPCONFIG']['question_table']." WHERE survey_id ${sidstr}";
	$result = execute_sql($sql);
	$qids = array();
	while(list($qid) = fetch_row($result)) {
        $result->MoveNext();
		array_push($qids, $qid);
	}
	db_close($result);
	$qidstr = array_to_insql($qids);
	
	// work from the bottom up...
	// start with the survey results
	$tables = array('response_bool','response_date','response_multiple','response_other','response_rank','response_single','response_text');
	foreach($tables as $table) {
		$sql = "DELETE FROM ".$GLOBALS['ESPCONFIG'][$table.'_table']." WHERE question_id ${qidstr}";
		$result = execute_sql($sql);
	}
	// then responses
	$sql = "DELETE FROM ".$GLOBALS['ESPCONFIG']['response_table']." WHERE survey_id ${sidstr}";
	execute_sql($sql);

	// then question choices
	$sql = "DELETE FROM ".$GLOBALS['ESPCONFIG']['question_choice_table']." WHERE question_id ${qidstr}";
	execute_sql($sql);

	// then questions
	$sql = "DELETE FROM ".$GLOBALS['ESPCONFIG']['question_table']." WHERE survey_id ${sidstr}";
	execute_sql($sql);

	// then conditions
	$sql = "DELETE FROM ".$GLOBALS['ESPCONFIG']['condition_table']." WHERE survey_id ${sidstr}";
	execute_sql($sql);

	// and finally the survey(s)
	$sql = "DELETE FROM ".$GLOBALS['ESPCONFIG']['survey_table']." WHERE id ${sidstr}";
	execute_sql($sql);

	// erase the access credentials
	$sql = "DELETE FROM ".$GLOBALS['ESPCONFIG']['access_table']." WHERE survey_id ${sidstr}";
	execute_sql($sql);

    // now, erase the accumulated statistics
    // NOTE: we are purging *all* traces of the survey
	if (is_int($sids)) {
		$sids = array ($sids);
	} else if (is_string($sids)) {
		$sids = explode(' ', $sids);
	}

    if (is_array($sids)) {
        esp_require_once('/lib/espsurveystat');
        foreach ($sids as $sid) {
            survey_stat_purge($sid);
        }
	}

	return;
}
/* }}} */

?>