// This class implements the Intel 8254 chip (and 8253)

//

// * Only the 8254 is emulated, no surrounding hardware.

//   Use the class I8254Interface to do that.

#ifndef I8254_HH

#define I8254_HH

#include "ClockPin.hh"

#include "EmuTime.hh"

#include <array>

#include <cstdint>

namespace openmsx {

class Scheduler;

class ClockPinListener;

class Counter {

public:

	Counter(Scheduler& scheduler, ClockPinListener* listener,

		EmuTime time);

	void reset(EmuTime time);

	[[nodiscard]] uint8_t readIO(EmuTime time);

	[[nodiscard]] uint8_t peekIO(EmuTime time) const;

	void writeIO(uint8_t value, EmuTime time);

	void setGateStatus(bool status, EmuTime time);

	void writeControlWord(uint8_t value, EmuTime time);

	void latchStatus(EmuTime time);

	void latchCounter(EmuTime time);

	template<typename Archive>

	void serialize(Archive& ar, unsigned version);

//private:

	enum class ByteOrder : uint8_t {LOW, HIGH};

private:

	static constexpr uint8_t WRT_FRMT = 0x30;

	static constexpr uint8_t WF_LATCH = 0x00;

	static constexpr uint8_t WF_LOW   = 0x10;

	static constexpr uint8_t WF_HIGH  = 0x20;

	static constexpr uint8_t WF_BOTH  = 0x30;

	static constexpr uint8_t CNTR_MODE = 0x0E;

	static constexpr uint8_t CNTR_M0   = 0x00;

	static constexpr uint8_t CNTR_M1   = 0x02;

	static constexpr uint8_t CNTR_M2   = 0x04;

	static constexpr uint8_t CNTR_M3   = 0x06;

	static constexpr uint8_t CNTR_M4   = 0x08;

	static constexpr uint8_t CNTR_M5   = 0x0A;

	static constexpr uint8_t CNTR_M2_  = 0x0C;

	static constexpr uint8_t CNTR_M3_  = 0x0E;

	void writeLoad(uint16_t value, EmuTime time);

	void advance(EmuTime time);

private:

	ClockPin clock;

	ClockPin output;

	EmuTime currentTime;

	int counter = 0;

	uint16_t latchedCounter;

	uint16_t counterLoad = 0;

	uint8_t control, latchedControl;

	bool ltchCtrl, ltchCntr;

	ByteOrder readOrder, writeOrder;

	uint8_t writeLatch;

	bool gate = true;

	bool active, triggered, counting;

	friend class I8254;

};

class I8254

{

public:

	I8254(Scheduler& scheduler, ClockPinListener* output0,

	      ClockPinListener* output1, ClockPinListener* output2,

	      EmuTime time);

	void reset(EmuTime time);

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

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

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

	void setGate(unsigned cntr, bool status, EmuTime time);

	[[nodiscard]] ClockPin& getClockPin(unsigned cntr);

	[[nodiscard]] ClockPin& getOutputPin(unsigned cntr);

	template<typename Archive>

	void serialize(Archive& ar, unsigned version);

private:

	void readBackHelper(uint8_t value, unsigned cntr, EmuTime time);

private:

	std::array<Counter, 3> counter;

};

} // namespace openmsx

#endif