<?php

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 * Description of numeracy
 *
 * @author gregory
 */
class numeracy2 {
   
    private $user;
    private $subSubject;

    /**
     * Setup new numbers engine
     * 
     * @param bool $test Enable debug mode.
     */
    public function __construct($user,$sub) {
       
        $this->user = $user;
        $this->subSubject = $sub;

    }

    public function getNumeracy() {
        
        //print_a(['user'=>$this->user,'subSubject'=>$this->subSubject]);
        $difficulty = $this->difficulty();
        $question = $this->numeracySwitch($difficulty);
        $questionHtml = $this->htmlify($question);
        
        e107::getDb()->insert('tkLastQuestion', ['user'=>$this->user,'LastQuestionHtml'=>base64_encode($questionHtml)]);
        
        e107::getRender()->tablerender('Numeracy', $questionHtml);
    }
    
    private function numeracySwitch($difficulty) {
        switch ($this->subSubject) {
            
            case 'addition':
                return $this->basic('+',$difficulty);
            case 'subtraction':
                return $this->basic('-',$difficulty);
            case 'multiplication':
                return $this->basic('x',$difficulty);
            case 'rounding':
                return $this->Rounding($difficulty);
            case 'division':
                return $this->Division($difficulty);
        }
    }

    /**
     * Return the difficulty based on previously answered questions.
     *
     * @return int Difficulty as percent.
     */
    private function difficulty() {

        $stats = e107::getDb()->retrieve("SELECT (SUM(correct)/COUNT(correct)*100) as percent,COUNT(correct) as count
            FROM e107.`e107_tkReport` WHERE 
            answereddatestamp >= unix_timestamp((NOW()) - INTERVAL 1 MONTH)
            AND username = '$this->user' AND subject = '$this->subSubject';");
        
        if ($stats["count"]==0) {
            return 1;
        } else {
            return $stats;
        }
        
    }

    private function getNumbers($difficulty,$sign){
//TODO add finer grain control for multiplication here
        if($sign=='x'||$sign=='/')
        {
            $difficulty['count'] = (int)$difficulty['count']/4;
            $difficulty['percent'] = (int)$difficulty['percent']/6;
        }
        
        if($difficulty['count']>=300) {
            $startingNumber = mt_rand(0, (int) pow($difficulty['count'],($difficulty['percent']/100)*2));
            $endingNumber = mt_rand(0, (int) pow($difficulty['count'],($difficulty['percent']/100)*2));
            $returnNumbers = [$startingNumber,$endingNumber];
        }elseif($difficulty['count']>=200){
            $startingNumber = mt_rand(0, (int) $difficulty['count']+($difficulty['percent']/100)*2);
            $endingNumber = mt_rand(0, (int) $difficulty['count']+($difficulty['percent']/100)*2);
            $returnNumbers = $this->flipNumbers($startingNumber,$endingNumber);
        }elseif($difficulty['count']>=100){
            $startingNumber = mt_rand(0, (int) ($difficulty['percent'])*2);
            $endingNumber = mt_rand(0, (int) ($difficulty['percent'])*2);
            $returnNumbers = $this->flipNumbers($startingNumber,$endingNumber);
        }else{
            $startingNumber = mt_rand(0, $difficulty['count']+1);
            $endingNumber = mt_rand(0, $difficulty['count']+1);
            $returnNumbers = $this->flipNumbers($startingNumber,$endingNumber);
        }

        //print_a(['Original'=>['1'=>$startingNumber,'2'=>$endingNumber],'FlipNumbers'=>$returnNumbers,'user'=>$this->user,'diff'=>$difficulty]);
        return $returnNumbers;

    }

    private function flipNumbers($startingNumber,$endingNumber){
        if($startingNumber>$endingNumber){
            return [$startingNumber,$endingNumber];
        }else{
            return [$endingNumber,$startingNumber];
        }
    }
    
    private function basic($sign,$difficulty) {
        
        $numbers = $this->getNumbers($difficulty,$sign);

        $firstNumber = $numbers[0];
        $secondNumber = $numbers[1];
        $TempQuestion = [];
        
        $TempQuestion[] = $firstNumber;
        $TempQuestion[] = $sign;
        $TempQuestion[] = $secondNumber;
        
        $solution['+'] = ($firstNumber + $secondNumber); 
        $solution['-'] = ($firstNumber - $secondNumber); 
        $solution['x'] = ($firstNumber * $secondNumber); 
        
        return [ 'answer1'=>$solution[$sign], 'question'=>$TempQuestion, 'type'=>$this->subSubject];
        
    }

    private function Division($difficulty) {
        
        $numbers = $this->getNumbers($difficulty,'/');

        $firstNumber = $numbers[1];
        $secondNumber = $numbers[2];
        $divNumber = $firstNumber * $secondNumber;
        $TempQuestion = [];
        
        $TempQuestion[] = $divNumber;
        $TempQuestion[] = '/';
        $TempQuestion[] = $secondNumber;
        
        $solution['/'] = ($divNumber / $secondNumber); 
        
        return [ 'answer1'=>$solution['/'], 'question'=>$TempQuestion, 'type'=>$this->subSubject];
        
    }
    
    private function Rounding($difficulty) {
        
        $firstNumber = sprintf("%01.2f", (float) rand(100, (int) ($difficulty) * 100) / 100);
        $TempQuestion = [];
        
        $TempQuestion[] = $firstNumber;
        $TempQuestion[] = 'r';
        
        $solution['r'] = (sprintf("%01.2f", round($firstNumber / 5, 2) * 5)); 
        
        return [ 'answer1'=>$solution['r'], 'question'=>$TempQuestion, 'type'=>$this->subSubject];

    }

    private function htmlify($question) {
        
        $frm = e107::getForm();

        $fString = $frm->open('questionForm', 'post', '', ['autocomplete' => 'off', 'class' => 'formclass']);
        $fString .= $frm->label('<h4>'.ucfirst($this->subSubject).'</h4>') . "</br>\n";
        $fString .= $frm->label('Solve the following equation.') . "\n";
        $fString .= '</br>';
        
        foreach ($question['question'] as $seq) {
            $fString .= $frm->label($seq . " &nbsp; ") . "\n";
        }
        
        $fString .= '</br></br>';
        $fString .= $frm->text('a1', '', 80, ['placeholder' => 'Write answer here!', 'autocomplete' => "off", 'spellcheck' => "false"]) . "\n";
        $fString .= $frm->hidden('checkerData', TkAnswerStore::issue($this->user, $question), ['id' => 'checkerData']);
        $fString .= $frm->hidden('subject', $this->subSubject, ['id' => 'subject']);
        $fString .= '</br>' . "\n";
        $fString .= e107::getForm()->button('Answer', 'Check answer') . "\n";
        $fString .= e107::getForm()->close();
        $fString .= '</br></br>';
        
        return $fString;
        
    }

}