#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