#include "RomColecoMegaCart.hh"

#include "CacheLine.hh"

#include "MSXException.hh"

#include "serialize.hh"

#include "one_of.hh"

// information source:

// https://github.com/openMSX/openMSX/files/2118720/MegaCart.FAQ.V1-2.pdf

namespace openmsx {

RomColecoMegaCart::RomColecoMegaCart(const DeviceConfig& config, Rom&& rom_)

	: Rom16kBBlocks(config, std::move(rom_))

{

	if (auto size = rom.size() / 1024;

	    size != one_of(128u, 256u, 512u, 1024u)) {

		throw MSXException(

			"MegaCart only supports ROMs of 128kB, 256kB, 512kB and 1024kB "

			"size and not of ", size, "kB.");

	}

	reset(EmuTime::dummy());

}

void RomColecoMegaCart::reset(EmuTime /*time*/)

{

	setUnmapped(0);

	setUnmapped(1);

	// The first 16K of the cartridge (CV 8000h-BFFFh) is fixed and will

	// always contain the highest/last 16K segment of the EPROM.

	setRom(2, unsigned(-1)); // select last block

	setRom(3, 0);

	invalidateDeviceRCache(0xFFC0 & CacheLine::HIGH, CacheLine::SIZE);

}

byte RomColecoMegaCart::readMem(uint16_t address, EmuTime time)

{

	// The last 64 locations will switch banks (FFC0-FFFF). If you have

	// fewer than 64 banks, then the strobe addresses simply repeat where

	// they end. If you have 16 banks, then bank 0 can be strobed at FFC0,

	// FFD0, FFE0, or FFF0.

	if (address >= 0xFFC0) {

		setRom(3, address); // mirroring is handled in superclass

		invalidateDeviceRCache(0xFFC0 & CacheLine::HIGH, CacheLine::SIZE);

	}

	return Rom16kBBlocks::readMem(address, time);

}

const byte* RomColecoMegaCart::getReadCacheLine(uint16_t start) const

{

	if (start >= (0xFFC0 & CacheLine::HIGH)) {

		return nullptr;

	} else {

		return Rom16kBBlocks::getReadCacheLine(start);

	}

}

REGISTER_MSXDEVICE(RomColecoMegaCart, "RomColecoMegaCart");

} // namespace openmsx