<?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 numeracy {
   
    public $state = "error";
    private $debug = false;
    private $sql;
    private $user;
    private $difficultyValue;
    private $returnData;

    /**
     * Setup new numbers engine
     * 
     * @param bool $test Enable debug mode.
     */
    public function __construct($test = false) {
       
        if ($test) {
            $this->debug = true;
        }
        $this->sql = e107::getDB();
        $this->user = e107::getUser()->getLoginName();
        $this->state = "ready";
    }

    public function getNumeracy() {

        $this->difficultyValue = $this->difficulty();
        $switchValue = rand(0,(int)$this->difficultyValue/16.6);
        
        if($this->debug) {
            $this->returnData['difficulty'] = $this->difficultyValue;            
            $this->returnData['switchValue'] = $switchValue;
        }
        
        $this->numeracySwitch($switchValue);
        
        return $this->returnData;
    }
    
    private function numeracySwitch($switchValue) {
        switch ($switchValue) {
            
            case 0:
                $this->returnData['question'] = $this->basic('+');
                break;
            case 1:
                $this->returnData['question'] = $this->basic('-');
                break;
            case 2:
                $this->returnData['question'] = $this->basic('x');
                break;
            case 3:
                $this->returnData['question'] = $this->Rounding();
                break;
            case 4:
            case 5:
                $this->returnData['question'] = $this->Division();
                break;
            default:
                break;
        }
    }

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

        $query = "SELECT (SUM(correct)/COUNT(correct)*100) as percent
            FROM e107.`e107_tkReport` WHERE 
            answereddatestamp >= unix_timestamp((NOW()) - INTERVAL 1 MONTH)
            AND username = '$this->user' AND subject = '".__CLASS__."';";

        if($this->debug) {
            $this->returnData['difficultySQL'] = $query;
        }
        
        $this->sql->gen($query);
        while ($row = $this->sql->fetch()) {
            if (is_numeric($row["percent"])) {
                return (int)$row["percent"];
            } else {
                return 1;
            }
        }
     
    }
    
    private function basic($sign) {
        
        $firstNumber = rand(1, (int) ($this->difficultyValue * ($this->difficultyValue/5)));
        $secondNumber = rand(1, (int) ($this->difficultyValue * ($this->difficultyValue/5)));
        $TempQuestion = [];
        
        $TempQuestion[] = $firstNumber;
        $TempQuestion[] = $sign;
        $TempQuestion[] = $secondNumber;
        
        $solution['+'] = ($firstNumber + $secondNumber); 
        $solution['-'] = ($firstNumber - $secondNumber); 
        $solution['x'] = ($firstNumber * $secondNumber); 
        
        return [ 'answer1'=>$solution[$sign], 'question'=>$TempQuestion, 'type'=>__CLASS__];
        
    }

    private function Division() {
        
        $firstNumber = rand(1, (int) ($this->difficultyValue * ($this->difficultyValue/13)));
        $secondNumber = rand(1, (int) ($this->difficultyValue * ($this->difficultyValue/13)));
        $divNumber = $firstNumber * $secondNumber;
        $TempQuestion = [];
        
        $TempQuestion[] = $divNumber;
        $TempQuestion[] = '/';
        $TempQuestion[] = $secondNumber;
        
        $solution['/'] = ($divNumber / $secondNumber); 
        
        return [ 'answer1'=>$solution['/'], 'question'=>$TempQuestion, 'type'=>__CLASS__];
        
    }
    
    private function Rounding() {
        
        $firstNumber = sprintf("%01.2f", (float) rand(100, (int) ($this->difficultyValue) * 100) / 100);
        $TempQuestion = [];
        
        $TempQuestion[] = $firstNumber;
        $TempQuestion[] = 'r';
        
        $solution['r'] = (sprintf("%01.2f", round($firstNumber / 5, 2) * 5)); 
        
        return [ 'answer1'=>$solution['r'], 'question'=>$TempQuestion, 'type'=>__CLASS__];

    }

}