// This class implements the PPI (8255)

//

//   PPI    MSX-I/O  Direction  MSX-Function

//  PortA    0xA8      Out     Memory primary slot register

//  PortB    0xA9      In      Keyboard column inputs

//  PortC    0xAA      Out     Keyboard row select / CAPS / CASo / CASm / SND

//  Control  0xAB     In/Out   Mode select for PPI

//

//  Direction indicates the direction normally used on MSX.

//  Reading from an output port returns the last written byte.

//  Writing to an input port has no immediate effect.

//

//  PortA combined with upper half of PortC form groupA

//  PortB               lower                    groupB

//  GroupA can be in programmed in 3 modes

//   - basic input/output

//   - strobed input/output

//   - bidirectional

//  GroupB can only use the first two modes.

//  Only the first mode is used on MSX, only this mode is implemented yet.

//

//  for more detail see

//    http://w3.qahwah.net/joost/openMSX/8255.pdf

#ifndef MSXPPI_HH

#define MSXPPI_HH

#include "I8255.hh"

#include "I8255Interface.hh"

#include "KeyClick.hh"

#include "Keyboard.hh"

#include "MSXDevice.hh"

namespace openmsx {

class CassettePortInterface;

class RenShaTurbo;

class MSXPPI final : public MSXDevice, public I8255Interface

{

public:

	explicit MSXPPI(const DeviceConfig& config);

	~MSXPPI() override;

	void reset(EmuTime time) override;

	void powerDown(EmuTime time) override;

	[[nodiscard]] uint8_t readIO(uint16_t port, EmuTime time) override;

	[[nodiscard]] uint8_t peekIO(uint16_t port, EmuTime time) const override;

	void writeIO(uint16_t port, uint8_t value, EmuTime time) override;

	template<typename Archive>

	void serialize(Archive& ar, unsigned version);

private:

	// I8255Interface

	[[nodiscard]] uint8_t readA (EmuTime time) override;

	[[nodiscard]] uint8_t readB (EmuTime time) override;

	[[nodiscard]] uint4_t readC0(EmuTime time) override;

	[[nodiscard]] uint4_t readC1(EmuTime time) override;

	[[nodiscard]] uint8_t peekA (EmuTime time) const override;

	[[nodiscard]] uint8_t peekB (EmuTime time) const override;

	[[nodiscard]] uint4_t peekC0(EmuTime time) const override;

	[[nodiscard]] uint4_t peekC1(EmuTime time) const override;

	void writeA (uint8_t value, EmuTime time) override;

	void writeB (uint8_t value, EmuTime time) override;

	void writeC0(uint4_t value, EmuTime time) override;

	void writeC1(uint4_t value, EmuTime time) override;

private:

	CassettePortInterface& cassettePort;

	RenShaTurbo& renshaTurbo;

	I8255 i8255;

	KeyClick click;

	Keyboard keyboard;

	uint4_t prevBits = 15;

	uint4_t selectedRow = 0;

};

} // namespace openmsx

#endif