#include "Cartridge.hpp"
#include <fstream>
#include <iostream>
#include <string>


const unsigned int HEADER_SIZE = 16u;


#pragma pack(push, 1)
struct Header
{
	uint8_t string[4];
	uint8_t prgSize;
	uint8_t chrSize;
	uint8_t flags6;
	uint8_t flags7;
	uint8_t flags8;
	uint8_t flags9;
	uint8_t flags10;
	uint8_t padding[5];
};
#pragma pack(pop)


void Cartridge::Load(char const* filename)
{
	std::ifstream file(filename, std::ios::binary);

	if (file.is_open())
	{
		char buf[HEADER_SIZE];
		file.read(buf, HEADER_SIZE);

		auto header = reinterpret_cast<Header*>(buf);

		// Trainer
		if (header->flags6 & 0x4)
		{
			char trainerBuf[512];
			file.read(trainerBuf, 512);
		}

		uint32_t prgSize = header->prgSize * 16384;
		prgROM.resize(prgSize);
		file.read(reinterpret_cast<char*>(prgROM.data()), prgSize);

		uint32_t chrSize = header->chrSize * 8192;

		if (chrSize > 0)
		{
			chrROM.resize(chrSize);
			file.read(reinterpret_cast<char*>(chrROM.data()), chrSize);
		}

		file.close();
	}
}