#include "RomNational.hh"
#include "CacheLine.hh"
#include "SRAM.hh"
#include "one_of.hh"
#include "serialize.hh"
#include "xrange.hh"
#include <memory>

namespace openmsx {

RomNational::RomNational(const DeviceConfig& config, Rom&& rom_)
	: Rom16kBBlocks(config, std::move(rom_))
{
	sram = std::make_unique<SRAM>(getName() + " SRAM", 0x1000, config);
	reset(EmuTime::dummy());
}

void RomNational::reset(EmuTime::param /*time*/)
{
	control = 0;
	for (auto region : xrange(4)) {
		setRom(region, 0);
		bankSelect[region] = 0;
		invalidateDeviceRCache((region * 0x4000) + (0x3FF0 & CacheLine::HIGH),
		                       CacheLine::SIZE);
	}
	sramAddr = 0; // TODO check this
}

byte RomNational::peekMem(word address, EmuTime::param time) const
{
	if ((control & 0x04) && ((address & 0x7FF9) == 0x7FF0)) {
		// TODO check mirrored
		// 7FF0 7FF2 7FF4 7FF6   bank select read back
		int bank = (address & 6) / 2;
		return bankSelect[bank];
	}
	if ((control & 0x02) && ((address & 0x3FFF) == 0x3FFD)) {
		// SRAM read
		return (*sram)[sramAddr & 0x0FFF];
	}
	return Rom16kBBlocks::peekMem(address, time);
}

byte RomNational::readMem(word address, EmuTime::param time)
{
	byte result = RomNational::peekMem(address, time);
	if ((control & 0x02) && ((address & 0x3FFF) == 0x3FFD)) {
		++sramAddr;
	}
	return result;
}

const byte* RomNational::getReadCacheLine(word address) const
{
	if ((0x3FF0 & CacheLine::HIGH) == (address & 0x3FFF)) {
		return nullptr;
	} else {
		return Rom16kBBlocks::getReadCacheLine(address);
	}
}

void RomNational::writeMem(word address, byte value, EmuTime::param /*time*/)
{
	// TODO bank switch address mirrored?
	if (address == 0x6000) {
		bankSelect[1] = value;
		setRom(1, value); // !!
		invalidateDeviceRCache(0x7FF0 & CacheLine::HIGH, CacheLine::SIZE);
	} else if (address == 0x6400) {
		bankSelect[0] = value;
		setRom(0, value); // !!
		invalidateDeviceRCache(0x3FF0 & CacheLine::HIGH, CacheLine::SIZE);
	} else if (address == 0x7000) {
		bankSelect[2] = value;
		setRom(2, value);
		invalidateDeviceRCache(0xBFF0 & CacheLine::HIGH, CacheLine::SIZE);
	} else if (address == 0x7400) {
		bankSelect[3] = value;
		setRom(3, value);
		invalidateDeviceRCache(0xFFF0 & CacheLine::HIGH, CacheLine::SIZE);
	} else if (address == 0x7FF9) {
		// write control byte
		control = value;
	} else if (control & 0x02) {
		address &= 0x3FFF;
		if (address == 0x3FFA) {
			// SRAM address bits 23-16
			sramAddr = (sramAddr & 0x00FFFF) | value << 16;
		} else if (address == 0x3FFB) {
			// SRAM address bits 15-8
			sramAddr = (sramAddr & 0xFF00FF) | value << 8;
		} else if (address == 0x3FFC) {
			// SRAM address bits 7-0
			sramAddr = (sramAddr & 0xFFFF00) | value;
		} else if (address == 0x3FFD) {
			sram->write((sramAddr++ & 0x0FFF), value);
		}
	}
}

byte* RomNational::getWriteCacheLine(word address)
{
	if (address == one_of(0x6000 & CacheLine::HIGH,
	                      0x6400 & CacheLine::HIGH,
	                      0x7000 & CacheLine::HIGH,
	                      0x7400 & CacheLine::HIGH,
	                      0x7FF9 & CacheLine::HIGH)) {
		return nullptr;
	} else if ((address & 0x3FFF) == (0x3FFA & CacheLine::HIGH)) {
		return nullptr;
	} else {
		return unmappedWrite.data();
	}
}

template<typename Archive>
void RomNational::serialize(Archive& ar, unsigned /*version*/)
{
	ar.template serializeBase<Rom16kBBlocks>(*this);
	ar.serialize("control",    control,
	             "sramAddr",   sramAddr,
	             "bankSelect", bankSelect);
}
INSTANTIATE_SERIALIZE_METHODS(RomNational);
REGISTER_MSXDEVICE(RomNational, "RomNational");

} // namespace openmsx
