//
// Created by selim on 9/23/23.
//

#include "Dma.h"
#include "Ppu.h"
#include "System.h"

namespace nes {

    Dma::Dma(System *system, Ppu *ppu): _system{system}, _ppu{ppu} {

    }

    bool Dma::active() const {
        return _active;
    }

    void Dma::tick(uint64_t cycles) {
        if(_dummy) {
            if(cycles % 2 == 1) {
                _dummy = false;
            }
        } else {
            if(cycles % 2 == 0) {
                _data = _system->read((_page << 8) | _address);
            } else {
                _ppu->writeOam(_address, _data);
                _address++;

                if(_address == 0) {
                    _active = false;
                    _dummy = true;
                }
            }
        }
    }

    void Dma::start(uint8_t page) {
        _page = page;
        _active = true;
    }

}