//
// Created by selim on 8/22/23.
//

#include "Ppu.h"

namespace nes {

    Ppu::Ppu(): _column{}, _scanline{}, _status{} {
        _frameBuffer = std::make_unique<Pixel[]>(SCREEN_WIDTH*SCREEN_HEIGHT);
    }

    void Ppu::tick() {

        if(_column < SCREEN_WIDTH && _scanline < SCREEN_HEIGHT && _scanline >= 0) {
            Pixel black = {0, 0, 0, 100};
            Pixel white = {255, 255, 255, 100};
            Pixel pixel = std::rand() % 2 == 0 ? black : white;
            setPixel(_scanline, _column, pixel);
        }

        _column++;
        if(_column >= 341) {
            _column = 0;
            _scanline++;

            if(_scanline >= 261) {
                _scanline = -1;
                onNewFrame(_frameBuffer.get());
            }
        }
    }

    void Ppu::write(uint16_t address, uint8_t value) {
        switch (address) {
            default:
                break;
        }
    }

    uint8_t Ppu::read(uint16_t address) {
        switch (address) {
            case Status:
                uint8_t value = _status.value & 0xE0;
                _status.verticalBlank = 0;
                return value;
        }
    }

    void Ppu::setPixel(uint16_t row, uint16_t column, Pixel pixel) {
        size_t index = row*SCREEN_WIDTH + column;
        _frameBuffer[index] = pixel;
    }
}