<?php

class TestSummary
{
    public int $maxMark; // Maximum mark
    public int $mark; // Collected mark
    private float $percentage; // Ratio of correct answers

    // Calculate percentage.
    private function calculatePercentage(): void
    {
        if ($this->maxMark > 0) {
            $this->percentage = $this->mark / (double)$this->maxMark * 100.0;
        } else { // avoid division by zero
            $this->percentage = 0.0;
        }
    }

    function __construct(int $taskN, int $correctAnswerN)
    {
        $this->maxMark = $taskN;
        $this->mark = $correctAnswerN;
        $this->calculatePercentage();
    }

    // Get max mark.
    function getMaxMark(): int
    {
        return $this->maxMark;
    }

    // Get mark.
    function getMark(): int
    {
        return $this->mark;
    }

    function setMark(int $mark): void
    {
        $this->mark = $mark;
        $this->calculatePercentage();
    }

    // Get ratio of correct results.
    function getPercentage(): float
    {
        return ($this->mark * 100.0) / $this->maxMark;
    }

    // Build from array.
    static function fromArray(array $a): TestSummary
    {
        if (!isset($a["max_mark"]) || !isset($a["mark"])) { // backward compatibility
            return new TestSummary($a["challenge_n"], $a["correct_answer_n"]);
        } else {
            return new TestSummary($a["max_mark"], $a["mark"]);
        }
    }

    // Convert to array.
    function toArray(): array
    {
        return ["challenge_n" => $this->maxMark, "correct_answer_n" => $this->mark, "percentage" => $this->percentage];
    }
}