<?php  // $Id$
///////////////////////////////////////////////////////////////////////////
//                                                                       //
// WebCT FORMAT                                                          //
//                                                                       //
///////////////////////////////////////////////////////////////////////////
//                                                                       //
// NOTICE OF COPYRIGHT                                                   //
//                                                                       //
// Part of Moodle - Modular Object-Oriented Dynamic Learning Environment //
//                  http://moodle.com                                    //
//                                                                       //
// Copyright (C) 2004 ASP Consulting   http://www.asp-consulting.net     //
//                                                                       //
// 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:                          //
//                                                                       //
//          http://www.gnu.org/copyleft/gpl.html                         //
//                                                                       //
///////////////////////////////////////////////////////////////////////////

// Based on format.php, included by ../../import.php
/**
 * @package questionbank
 * @subpackage importexport
 */

function unhtmlentities($string){
    $search = array ("'<script[?>]*?>.*?</script>'si",  // remove javascript
                 "'<[\/\!]*?[^<?>]*?>'si",  // remove HTML tags
                 "'([\r\n])[\s]+'",  // remove spaces
                 "'&(quot|#34);'i",  // remove HTML entites
                 "'&(amp|#38);'i",
                 "'&(lt|#60);'i",
                 "'&(gt|#62);'i",
                 "'&(nbsp|#160);'i",
                 "'&(iexcl|#161);'i",
                 "'&(cent|#162);'i",
                 "'&(pound|#163);'i",
                 "'&(copy|#169);'i",
                 "'&#(\d+);'e");  // Evaluate like PHP
    $replace = array ("",
                  "",
                  "\\1",
                  "\"",
                  "&",
                  "<",
                  "?>",
                  " ",
                  chr(161),
                  chr(162),
                  chr(163),
                  chr(169),
                  "chr(\\1)");
    return preg_replace ($search, $replace, $string);
}

class qformat_webct_modified_calculated_qtype extends question_calculated_qtype {
// We need to make a modification of this qtype so that
// it will be able to save webct style calculated questions
// The difference between webct and Moodle is that webct
// pass the individual data items as part of the question
// while Moodle core treat them separately

    function save_question_options($question, $options = false) {

        if (false !== $options) {
            // function is called from save_question...
            return parent::save_question_options($question, $options);
        }

        // function is called from format.php...

        $datasetdatas = $question->datasets;

        // Set dataset
        $form->dataset = array();
        foreach ($datasetdatas as $datasetname => $notimportant) {
            // Literal  - question local - name
            $form->dataset[] = "1-0-$datasetname";
        }

        $subtypeoptions->answers = $question->answers;
        $subtypeoptions->units = $question->units;

        unset($question->datasets);
        unset($question->answers);
        unset($question->units);

        $this->save_question($question, $form, 'not used', $subtypeoptions);

        // Save dataset options and items...

        // Get datasetdefinitions
        global $CFG;
        $datasetdefs = get_records_sql(
                "SELECT a.*
                   FROM {$CFG->prefix}question_dataset_definitions a,
                        {$CFG->prefix}question_datasets b
                  WHERE a.id = b.datasetdefinition
                    AND b.question = '$question->id' ");

        foreach ($datasetdefs as $datasetdef) {
            $datasetdata = $datasetdatas[$datasetdef->name];

            // Set items and retrieve ->itemcout
            $item->definition = $datasetdef->id;
            for ($item->itemnumber=1 ; isset($datasetdata->items["$item->itemnumber"]) ; ++$item->itemnumber) {
                $item->value = $datasetdata->items["$item->itemnumber"];
                if (!insert_record('question_dataset_items', $item)) {
                    error("Unable to insert dataset item $item->itemnumber with $item->value for $datasetdef->name");
                }
            }
            $datasetdef->itemcount = $item->itemnumber - 1;

            //  Retrieve ->options
            if (is_numeric($datasetdata->min) && is_numeric($datasetdata->max)
                    && $datasetdata->min <= $datasetdata->max) {
                if (is_numeric($datasetdata->dec)) {
                    $dec = max(0, ceil($datasetdata->dec));
                } else {
                    $dec = 1; // A try
                }

                $datasetdef->options = "uniform:$datasetdata->min:$datasetdata->max:$dec";
            } else {
                $datasetdef->options = '';
            }

            // Save definition
            if ($datasetdef->itemcount || $datasetdef->options) {
                if (!update_record('question_dataset_definitions', $datasetdef)) {
                    error("Unable to update dataset definition $datasetdef->name on question $question->id");
                }
            }
        }

        // Done
        return true;
    }
}
$QTYPES[CALCULATED] = new qformat_webct_modified_calculated_qtype();

function qformat_webct_convert_formula($formula) {

    // Remove empty space, as it would cause problems otherwise:
    $formula = str_replace(' ', '', $formula);

    // Remove paranthesis after e,E and *10**:
    while (ereg('[0-9.](e|E|\\*10\\*\\*)\\([+-]?[0-9]+\\)', $formula, $regs)) {
        $formula = str_replace(
                $regs[0], ereg_replace('[)(]', '', $regs[0]), $formula);
    }

    // Replace *10** with e where possible
    while (ereg(
            '(^[+-]?|[^eE][+-]|[^0-9eE+-])[0-9.]+\\*10\\*\\*[+-]?[0-9]+([^0-9.eE]|$)',
            $formula, $regs)) {
        $formula = str_replace(
                $regs[0], str_replace('*10**', 'e', $regs[0]), $formula);
    }

    // Replace other 10** with 1e where possible
    while (ereg('(^|[^0-9.eE])10\\*\\*[+-]?[0-9]+([^0-9.eE]|$)', $formula, $regs)) {
        $formula = str_replace(
                $regs[0], str_replace('10**', '1e', $regs[0]), $formula);
    }

    // Replace all other base**exp with the PHP equivalent function pow(base,exp)
    // (Pretty tricky to exchange an operator with a function)
    while (2 == count($splits = explode('**', $formula, 2))) {

        // Find $base
        if (ereg('^(.*[^0-9.eE])?(([0-9]+(\\.[0-9]*)?|\\.[0-9]+)([eE][+-]?[0-9]+)?|\\{[^}]*\\})$',
                $splits[0], $regs)) {
            // The simple cases
            $base = $regs[2];
            $splits[0] = $regs[1];

        } else if (ereg('\\)$', $splits[0])) {
            // Find the start of this parenthesis
            $deep = 1;
            for ($i = 1 ; $deep ; ++$i) {
                if (!ereg('^(.*[^[:alnum:]_])?([[:alnum:]_]*([)(])([^)(]*[)(]){'.$i.'})$',
                        $splits[0], $regs)) {
                    error("Parenthesis before ** is not properly started in $splits[0]**");
                }
                if ('(' == $regs[3]) {
                    --$deep;
                } else if (')' == $regs[3]) {
                    ++$deep;
                } else {
                    error("Impossible character $regs[3] detected as parenthesis character");
                }
            }
            $base = $regs[2];
            $splits[0] = $regs[1];

        } else {
            error("Bad base before **: $splits[0]**");
        }

        // Find $exp (similar to above but a little easier)
        if (ereg('^([+-]?(\\{[^}]\\}|([0-9]+(\\.[0-9]*)?|\\.[0-9]+)([eE][+-]?[0-9]+)?))(.*)',
                $splits[1], $regs)) {
            // The simple case
            $exp = $regs[1];
            $splits[1] = $regs[6];

        } else if (ereg('^[+-]?[[:alnum:]_]*\\(', $splits[1])) {
            // Find the end of the parenthesis
            $deep = 1;
            for ($i = 1 ; $deep ; ++$i) {
                if (!ereg('^([+-]?[[:alnum:]_]*([)(][^)(]*){'.$i.'}([)(]))(.*)',
                        $splits[1], $regs)) {
                    error("Parenthesis after ** is not properly closed in **$splits[1]");
                }
                if (')' == $regs[3]) {
                    --$deep;
                } else if ('(' == $regs[3]) {
                    ++$deep;
                } else {
                    error("Impossible character $regs[3] detected as parenthesis character");
                }
            }
            $exp = $regs[1];
            $splits[1] = $regs[4];
        }

        // Replace it!
        $formula = "$splits[0]pow($base,$exp)$splits[1]";
    }

    // Nothing more is known to need to be converted

    return $formula;
}

class qformat_webct extends qformat_default {

    function provide_import() {
      return true;
    }

    function readquestions ($lines) {
        $qtypecalculated = new qformat_webct_modified_calculated_qtype();
        $webctnumberregex =
                '[+-]?([0-9]+(\\.[0-9]*)?|\\.[0-9]+)((e|E|\\*10\\*\\*)([+-]?[0-9]+|\\([+-]?[0-9]+\\)))?';

        $questions = array();
        $errors = array();
        $warnings = array();
        $webct_options = array();

        $ignore_rest_of_question = FALSE;

        $nLineCounter = 0;
        $nQuestionStartLine = 0;
        $bIsHTMLText = FALSE;
        $lines[] = ":EOF:";    // for an easiest processing of the last line
    //    $question = $this->defaultquestion();

        foreach ($lines as $line) {
            $nLineCounter++;
            $line = iconv("Windows-1252","UTF-8",$line);
            // Processing multiples lines strings

            if (isset($questiontext) and is_string($questiontext)) {
                if (ereg("^:",$line)) {
                    $question->questiontext = addslashes(trim($questiontext));
                    unset($questiontext);
                }
                 else {
                    $questiontext .= str_replace('\:', ':', $line);
                    continue;
                }
            }

            if (isset($answertext) and is_string($answertext)) {
                if (ereg("^:",$line)) {
                    $answertext = addslashes(trim($answertext));
                    $question->answer[$currentchoice] = $answertext;
                    $question->subanswers[$currentchoice] = $answertext;
                    unset($answertext);
                }
                 else {
                    $answertext .= str_replace('\:', ':', $line);
                    continue;
                }
            }

            if (isset($responsetext) and is_string($responsetext)) {
                if (ereg("^:",$line)) {
                    $question->subquestions[$currentchoice] = addslashes(trim($responsetext));
                    unset($responsetext);
                }
                 else {
                    $responsetext .= str_replace('\:', ':', $line);
                    continue;
                }
            }

            if (isset($feedbacktext) and is_string($feedbacktext)) {
                if (ereg("^:",$line)) {
                    $question->feedback[$currentchoice] = addslashes(trim($feedbacktext));
                    unset($feedbacktext);
                }
                 else {
                    $feedbacktext .= str_replace('\:', ':', $line);
                    continue;
                }
            }

            $line = trim($line);

            if (eregi("^:(TYPE|EOF):",$line)) {
                // New Question or End of File
                if (isset($question)) {            // if previous question exists, complete, check and save it

                    // Setup default value of missing fields
                    if (!isset($question->name)) {
                        $question->name = $question->questiontext;
                    }
                    if (strlen($question->name) > 255) {
                        $question->name = substr($question->name,0,250)."...";
                        $warnings[] = get_string("questionnametoolong", "quiz", $nQuestionStartLine);
                    }
                    if (!isset($question->defaultgrade)) {
                        $question->defaultgrade = 1;
                    }
                    if (!isset($question->image)) {
                        $question->image = "";
                    }

                    // Perform sanity checks
                    $QuestionOK = TRUE;
                    if (strlen($question->questiontext) == 0) {
                        $warnings[] = get_string("missingquestion", "quiz", $nQuestionStartLine);
                        $QuestionOK = FALSE;
                    }
                    if (sizeof($question->answer) < 1) {  // a question must have at least 1 answer
                       $errors[] = get_string("missinganswer", "quiz", $nQuestionStartLine);
                       $QuestionOK = FALSE;
                    }
                    else {
                        // Create empty feedback array
                        $question->feedback = array();
                        foreach ($question->answer as $key => $dataanswer) {
                            $question->feedback[$key] = '';
                        }
                        $maxfraction = -1;
                        $totalfraction = 0;
                        foreach($question->fraction as $fraction) {
                            if ($fraction > 0) {
                                $totalfraction += $fraction;
                            }
                            if ($fraction > $maxfraction) {
                                $maxfraction = $fraction;
                            }
                        }
                        switch ($question->qtype) {
                            case SHORTANSWER:
                                if ($maxfraction != 1) {
                                    $maxfraction = $maxfraction * 100;
                                    $errors[] = "'$question->name': ".get_string("wronggrade", "quiz", $nLineCounter).' '.get_string("fractionsnomax", "quiz", $maxfraction);
                                    $QuestionOK = FALSE;
                                }
                                break;

                            case MULTICHOICE:
                                if ($question->single) {
                                    if ($maxfraction != 1) {
                                        $maxfraction = $maxfraction * 100;
                                        $errors[] = "'$question->name': ".get_string("wronggrade", "quiz", $nLineCounter).' '.get_string("fractionsnomax", "quiz", $maxfraction);
                                        $QuestionOK = FALSE;
                                    }
                                } else {
                                    $totalfraction = round($totalfraction,2);
                                    if ($totalfraction != 1) {
                                echo "<p>$totalfraction</p>";
                                        $totalfraction = $totalfraction * 100;
                                        $errors[] = "'$question->name': ".get_string("wronggrade", "quiz", $nLineCounter).' '.get_string("fractionsaddwrong", "quiz", $totalfraction);
                                        $QuestionOK = FALSE;
                                    }
                                }
                                break;

                            case CALCULATED:
                                foreach ($question->answers as $answer) {
                                    if ($formulaerror =qtype_calculated_find_formula_errors($answer->answer)) {
                                        $warnings[] = "'$question->name': ". $formulaerror;
                                        $QuestionOK = FALSE;
                                    }
                                }
                                break;

                            default:
                                // No problemo
                        }
                    }

                    if ($QuestionOK) {
                        // $question->feedback = array();
                        $questions[] = $question;    // store it
                        unset($question);            // and prepare a new one
                        $question = $this->defaultquestion();
                    }
                }
                $nQuestionStartLine = $nLineCounter;
            }

            // Processing Question Header

            if (eregi("^:TYPE:MC:1(.*)",$line,$webct_options)) {
                // Multiple Choice Question with only one good answer
                $question = $this->defaultquestion();
                $question->qtype = MULTICHOICE;
                $question->single = 1;        // Only one answer is allowed
                $ignore_rest_of_question = FALSE;
                continue;
            }

            if (eregi("^:TYPE:MC:N(.*)",$line,$webct_options)) {
                // Multiple Choice Question with several good answers
                $question = $this->defaultquestion();
                $question->qtype = MULTICHOICE;
                $question->single = 0;        // Many answers allowed
                $ignore_rest_of_question = FALSE;
                continue;
            }

            if (eregi("^:TYPE:S",$line)) {
                // Short Answer Question
                $question = $this->defaultquestion();
                $question->qtype = SHORTANSWER;
                $question->usecase = 0;       // Ignore case
                $ignore_rest_of_question = FALSE;
                continue;
            }

            if (eregi("^:TYPE:C",$line)) {
                // Calculated Question
                $warnings[] = get_string("calculatedquestion", "quiz", $nLineCounter);
                unset($question);
                $ignore_rest_of_question = TRUE;         // Question Type not handled by Moodle
             /*   $question->qtype = CALCULATED;
                $question->answers = array(); // No problem as they go as :FORMULA: from webct
                $question->units = array();
                $question->datasets = array();

                // To make us pass the end-of-question sanity checks
                $question->answer = array('dummy');
                $question->fraction = array('1.0');

                $currentchoice = -1;
                $ignore_rest_of_question = FALSE;*/
                continue;
            }

            if (eregi("^:TYPE:M",$line)) {
                // Match Question
                $question = $this->defaultquestion();
                $question->qtype = MATCH;
                $ignore_rest_of_question = FALSE;         // match question processing is not debugged
                continue;
            }

            if (eregi("^:TYPE:P",$line)) {
                // Paragraph Question
                $warnings[] = get_string("paragraphquestion", "quiz", $nLineCounter);
                unset($question);
                $ignore_rest_of_question = TRUE;         // Question Type not handled by Moodle
                continue;
            }

            if (eregi("^:TYPE:",$line)) {
                // Unknow Question
                $warnings[] = get_string("unknowntype", "quiz", $nLineCounter);
                unset($question);
                $ignore_rest_of_question = TRUE;         // Question Type not handled by Moodle
                continue;
            }

            if ($ignore_rest_of_question) {
                continue;
            }

            if (eregi("^:TITLE:(.*)",$line,$webct_options)) {
                $name = trim($webct_options[1]);
                if (strlen($name) > 255) {
                    $name = substr($name,0,250)."...";
                    $warnings[] = get_string("questionnametoolong", "quiz", $nLineCounter);
                }
                $question->name = addslashes($name);
                continue;
            }

            if (eregi("^:IMAGE:(.*)",$line,$webct_options)) {
                $filename = trim($webct_options[1]);
                if (eregi("^http://",$filename)) {
                    $question->image = $filename;
                }
                continue;
            }

            // Need to put the parsing of calculated items here to avoid ambitiuosness:
            // if question isn't defined yet there is nothing to do here (avoid notices)
            if (!isset($question)) {
                continue;
            } 
            if (isset($question->qtype ) && CALCULATED == $question->qtype && ereg(
                    "^:([[:lower:]].*|::.*)-(MIN|MAX|DEC|VAL([0-9]+))::?:?($webctnumberregex)", $line, $webct_options)) {
                $datasetname = ereg_replace('^::', '', $webct_options[1]);
                $datasetvalue = qformat_webct_convert_formula($webct_options[4]);
                switch ($webct_options[2]) {
                    case 'MIN':
                        $question->datasets[$datasetname]->min = $datasetvalue;
                        break;
                    case 'MAX':
                        $question->datasets[$datasetname]->max = $datasetvalue;
                        break;
                    case 'DEC':
                        $datasetvalue = floor($datasetvalue); // int only!
                        $question->datasets[$datasetname]->dec = max(0, $datasetvalue);
                        break;
                    default:
                        // The VAL case:
                        $question->datasets[$datasetname]->items[$webct_options[3]] = $datasetvalue;
                        break;
                }
                continue;
            }


            $bIsHTMLText = eregi(":H$",$line);  // True if next lines are coded in HTML
            if (eregi("^:QUESTION",$line)) {
                $questiontext="";               // Start gathering next lines
                continue;
            }

            if (eregi("^:ANSWER([0-9]+):([^:]+):([0-9\.\-]+):(.*)",$line,$webct_options)) {      /// SHORTANSWER
                $currentchoice=$webct_options[1];
                $answertext=$webct_options[2];            // Start gathering next lines
                $question->fraction[$currentchoice]=($webct_options[3]/100);
                continue;
            }

            if (eregi("^:ANSWER([0-9]+):([0-9\.\-]+)",$line,$webct_options)) {
                $answertext="";                 // Start gathering next lines
                $currentchoice=$webct_options[1];
                $question->fraction[$currentchoice]=($webct_options[2]/100);
                continue;
            }

            if (eregi('^:FORMULA:(.*)', $line, $webct_options)) {
                // Answer for a CALCULATED question
                ++$currentchoice;
                $question->answers[$currentchoice]->answer =
                        qformat_webct_convert_formula($webct_options[1]);

                // Default settings:
                $question->answers[$currentchoice]->fraction = 1.0;
                $question->answers[$currentchoice]->tolerance = 0.0;
                $question->answers[$currentchoice]->tolerancetype = 2; // nominal (units in webct)
                $question->answers[$currentchoice]->feedback = '';
                $question->answers[$currentchoice]->correctanswerlength = 4;

                $datasetnames = $qtypecalculated->find_dataset_names($webct_options[1]);
                foreach ($datasetnames as $datasetname) {
                    $question->datasets[$datasetname]->items = array();
                }
                continue;
            }

            if (eregi("^:L([0-9]+)",$line,$webct_options)) {
                $answertext="";                 // Start gathering next lines
                $currentchoice=$webct_options[1];
                $question->fraction[$currentchoice]=1; 
                continue;
            }

            if (eregi("^:R([0-9]+)",$line,$webct_options)) {
                $responsetext="";                // Start gathering next lines
                $currentchoice=$webct_options[1];
                continue;
            }

            if (eregi("^:REASON([0-9]+):?",$line,$webct_options)) {
                $feedbacktext="";               // Start gathering next lines
                $currentchoice=$webct_options[1];
                continue;
            }

            if (isset($question->qtype ) && CALCULATED == $question->qtype && eregi('^:ANS-DEC:([1-9][0-9]*)', $line, $webct_options)) {
                // We can but hope that this always appear before the ANSTYPE property
                $question->answers[$currentchoice]->correctanswerlength = $webct_options[1];
                continue;
            }

            if (isset($question->qtype )&& CALCULATED == $question->qtype && eregi("^:TOL:($webctnumberregex)", $line, $webct_options)) {
                // We can but hope that this always appear before the TOL property
                $question->answers[$currentchoice]->tolerance =
                        qformat_webct_convert_formula($webct_options[1]);
                continue;
            }

            if (isset($question->qtype )&& CALCULATED == $question->qtype && eregi('^:TOLTYPE:percent', $line)) {
                // Percentage case is handled as relative in Moodle:
                $question->answers[$currentchoice]->tolerance /= 100;
                $question->answers[$currentchoice]->tolerancetype = 1; // Relative
                continue;
            }

            if (eregi('^:UNITS:(.+)', $line, $webct_options)
                    and $webctunits = trim($webct_options[1])) {
                // This is a guess - I really do not know how different webct units are separated...
                $webctunits = explode(':', $webctunits);
                $unitrec->multiplier = 1.0; // Webct does not seem to support this
                foreach ($webctunits as $webctunit) {
                    $unitrec->unit = trim($webctunit);
                    $question->units[] = $unitrec;
                }
                continue;
            }

            if (!empty($question->units) && eregi('^:UNITREQ:(.*)', $line, $webct_options)
                    && !$webct_options[1]) {
                // There are units but units are not required so add the no unit alternative
                // We can but hope that the UNITS property always appear before this property
                $unitrec->unit = '';
                $unitrec->multiplier = 1.0;
                $question->units[] = $unitrec;
                continue;
            }

            if (!empty($question->units) && eregi('^:UNITCASE:', $line)) {
                // This could be important but I was not able to figure out how
                // it works so I ignore it for now
                continue;
            }

            if (isset($question->qtype )&& CALCULATED == $question->qtype && eregi('^:ANSTYPE:dec', $line)) {
                // Houston - we have a problem
                // Moodle does not support this - we try something defensively by
                // setting the correct answer length to 5, it shoud be enough for
                // most cases
                $question->answers[$currentchoice]->correctanswerlength = 5;
                continue;
            }
        }

        if (sizeof($errors) > 0) {
            echo "<p>".get_string("errorsdetected", "quiz", sizeof($errors))."</p><ul>";
            foreach($errors as $error) {
                echo "<li>$error</li>";
            }
            echo "</ul>";
            unset($questions);     // no questions imported
        }

        if (sizeof($warnings) > 0) {
            echo "<p>".get_string("warningsdetected", "quiz", sizeof($warnings))."</p><ul>";
            foreach($warnings as $warning) {
                echo "<li>$warning</li>";
            }
            echo "</ul>";
        }
        return $questions;
    }
}

?>
