<?php

declare(strict_types=1);

namespace SimAVRPHP;

use SimAVRPHP\Exceptions\InvalidAddressException;

class ProgramCounter
{
    private const int RESET_PC_VALUE = 0;

    private int $programCounter = self::RESET_PC_VALUE;

    public function get(): int
    {
        return $this->programCounter;
    }

    public function jump(int $address): void
    {
        if (($address % 2) != 0) {
            throw new InvalidAddressException("Invalid address", $address);
        }

        $this->programCounter = $address;
    }

    public function relativeJump(int $address): void
    {
        $this->jump($this->programCounter + $address);
    }

    public function stepWords(int $word): int
    {
        $this->programCounter += ($word << 1);
        return $this->programCounter;
    }

    public function reset(): void
    {
        $this->programCounter = self::RESET_PC_VALUE;
    }
}