#include "JoyMega.hh"

#include "CommandController.hh"

#include "Event.hh"

#include "IntegerSetting.hh"

#include "JoystickManager.hh"

#include "MSXEventDistributor.hh"

#include "StateChange.hh"

#include "StateChangeDistributor.hh"

#include "serialize.hh"

#include "serialize_meta.hh"

#include "join.hh"

#include "ranges.hh"

#include "unreachable.hh"

#include "xrange.hh"

#include <algorithm>

namespace openmsx {

TclObject JoyMega::getDefaultConfig(JoystickId joyId, const JoystickManager& joystickManager)

{

	auto buttons = joystickManager.getNumButtons(joyId);

	if (!buttons) return {};

	std::array<TclObject, 8> lists;

	auto joy = joyId.str();

	for (auto b : xrange(*buttons)) {

		lists[b % 8].addListElement(tmpStrCat(joy, " button", b));

	}

	return TclObject(TclObject::MakeDictTag{},

		"UP",    makeTclList(tmpStrCat(joy, " -axis1"), tmpStrCat(joy, " hat0 up")),

		"DOWN",  makeTclList(tmpStrCat(joy, " +axis1"), tmpStrCat(joy, " hat0 down")),

		"LEFT",  makeTclList(tmpStrCat(joy, " -axis0"), tmpStrCat(joy, " hat0 left")),

		"RIGHT", makeTclList(tmpStrCat(joy, " +axis0"), tmpStrCat(joy, " hat0 right")),

		"A",     lists[0],

		"B",     lists[1],

		"C",     lists[2],

		"X",     lists[3],

		"Y",     lists[4],

		"Z",     lists[5],

		"SELECT",lists[6],

		"START", lists[7]);

}

JoyMega::JoyMega(CommandController& commandController_,

                 MSXEventDistributor& eventDistributor_,

                 StateChangeDistributor& stateChangeDistributor_,

                 JoystickManager& joystickManager_,

                 uint8_t id_)

	: commandController(commandController_)

	, eventDistributor(eventDistributor_)

	, stateChangeDistributor(stateChangeDistributor_)

	, joystickManager(joystickManager_)

	, configSetting(commandController, tmpStrCat("joymega", id_, "_config"),

		"joymega mapping configuration", getDefaultConfig(JoystickId(id_ - 1), joystickManager).getString())

	, description(strCat("JoyMega based Mega Drive controller ", id_, ". Mapping is fully configurable."))

	, id(id_)

{

	configSetting.setChecker([this](const TclObject& newValue) {

		this->checkJoystickConfig(newValue); });

	try {

		// fill in 'bindings'

		checkJoystickConfig(configSetting.getValue());

	} catch (MSXException& /*e*/) {

		configSetting.setValue(getDefaultConfig(JoystickId(id - 1), joystickManager));

	}

}

JoyMega::~JoyMega()

{

	if (isPluggedIn()) {

		JoyMega::unplugHelper(EmuTime::dummy());

	}

}

void JoyMega::checkJoystickConfig(const TclObject& newValue)

{

	std::array<std::vector<BooleanInput>, 12> newBindings;

	auto& interp = commandController.getInterpreter();

	auto n = newValue.getListLength(interp);

	if (n & 1) {

		throw CommandException("Need an even number of elements");

	}

	for (decltype(n) i = 0; i < n; i += 2) {

		static constexpr std::array<std::string_view, 12> keys = {

			// order is important!

			"UP", "DOWN", "LEFT", "RIGHT",

			"A", "B", "C", "START",

			"X", "Y", "Z", "SELECT",

		};

		std::string_view key  = newValue.getListIndex(interp, i + 0).getString();

		auto it = std::ranges::find(keys, key);

		if (it == keys.end()) {

			throw CommandException(

				"Invalid key: must be one of ", join(keys, ", "));

		}

		auto idx = std::distance(keys.begin(), it);

		TclObject value = newValue.getListIndex(interp, i + 1);

		for (auto j : xrange(value.getListLength(interp))) {

			std::string_view val = value.getListIndex(interp, j).getString();

			auto bind = parseBooleanInput(val);

			if (!bind) {

				throw CommandException("Invalid binding: ", val);

			}

			newBindings[idx].push_back(*bind);

		}

	}

	// only change current bindings when parsing was fully successful

	copy_to_range(newBindings, bindings);

}

// Pluggable

zstring_view JoyMega::getName() const

{

	switch (id) {

		case 1: return "joymega1";

		case 2: return "joymega2";

		default: UNREACHABLE;

	}

}

zstring_view JoyMega::getDescription() const

{

	return description;

}

void JoyMega::plugHelper(Connector& /*connector*/, EmuTime /*time*/)

{

	plugHelper2();

	status = 0xfff;

	cycle = 0;

	// when mode button is pressed when joystick is plugged in, then

	// act as a 3-button joypad (otherwise 6-button)

	cycleMask = (status & 0x800) ? 7 : 1;

}

void JoyMega::plugHelper2()

{

	eventDistributor.registerEventListener(*this);

	stateChangeDistributor.registerListener(*this);

}

void JoyMega::unplugHelper(EmuTime /*time*/)

{

	stateChangeDistributor.unregisterListener(*this);

	eventDistributor.unregisterEventListener(*this);

}

// JoystickDevice

uint8_t JoyMega::read(EmuTime time)

{

	// See http://segaretro.org/Control_Pad_(Mega_Drive)

	// and http://frs.badcoffee.info/hardware/joymega-en.html

	// for a detailed description of the MegaDrive joystick.

	checkTime(time);

	switch (cycle) {

	case 0: case 2: case 4:

		// up/down/left/right/b/c

		return (status & 0x00f) | ((status & 0x060) >> 1);

	case 1: case 3:

		// up/down/0/0/a/start

		return (status & 0x013) | ((status & 0x080) >> 2);

	case 5:

		// 0/0/0/0/a/start

		return (status & 0x010) | ((status & 0x080) >> 2);

	case 6:

		// z/y/x/mode/b/c

		return ((status & 0x400) >> 10) | // z

		       ((status & 0xA00) >>  8) | // start+y

		       ((status & 0x100) >>  6) | // x

		       ((status & 0x060) >>  1);  // c+b

	case 7:

		// 1/1/1/1/a/start

		return (status & 0x010) | ((status & 0x080) >> 2) | 0x0f;

	default:

		UNREACHABLE;

	}

}

void JoyMega::write(uint8_t value, EmuTime time)

{

	checkTime(time);

	lastTime = time;

	if (((value >> 2) & 1) != (cycle & 1)) {

		cycle = (cycle + 1) & cycleMask;

	}

	assert(((value >> 2) & 1) == (cycle & 1));

}

void JoyMega::checkTime(EmuTime time)

{

	if ((time - lastTime) > EmuDuration::usec(1500)) {

		// longer than 1.5ms since last write -> reset cycle

		cycle = 0;

	}

}

// MSXEventListener

void JoyMega::signalMSXEvent(const Event& event, EmuTime time) noexcept

{

	unsigned press = 0;

	unsigned release = 0;

	auto getJoyDeadThreshold = [&](JoystickId joyId) {

		return joystickManager.getJoyDeadThreshold(joyId);

	};

	for (int i : xrange(12)) {

		for (const auto& binding : bindings[i]) {

			if (auto onOff = match(binding, event, getJoyDeadThreshold)) {

				(*onOff ? press : release) |= 1 << i;

			}

		}

	}

	if (((status & ~press) | release) != status) {

		stateChangeDistributor.distributeNew<JoyMegaState>(

			time, id, press, release);

	}

}

// StateChangeListener

void JoyMega::signalStateChange(const StateChange& event)

{

	const auto* js = std::get_if<JoyMegaState>(&event);

	if (!js) return;

	if (js->getId() != id) return;

	status = (status & ~js->getPress()) | js->getRelease();

}

void JoyMega::stopReplay(EmuTime time) noexcept

{

	unsigned newStatus = 0xfff;

	if (newStatus != status) {

		auto release = newStatus & ~status;

		stateChangeDistributor.distributeNew<JoyMegaState>(

			time, id, 0, release);

	}

}

template<typename Archive>

void JoyMega::serialize(Archive& ar, unsigned /*version*/)

{

	ar.serialize("lastTime",  lastTime,

	             "status",    status,

	             "cycle",     cycle,

	             "cycleMask", cycleMask);

	if constexpr (Archive::IS_LOADER) {

		if (isPluggedIn()) {

			plugHelper2();

		}

	}

}

INSTANTIATE_SERIALIZE_METHODS(JoyMega);

REGISTER_POLYMORPHIC_INITIALIZER(Pluggable, JoyMega, "JoyMega");

} // namespace openmsx