/*
** input.cpp
**
** This file is part of mkxp.
**
** Copyright (C) 2013 Jonas Kulla <Nyocurio@gmail.com>
**
** mkxp is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 2 of the License, or
** (at your option) any later version.
**
** mkxp is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with mkxp.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "input.h"
#include "sharedstate.h"
#include "eventthread.h"
#include "keybindings.h"
#include "exception.h"
#include "util.h"

#include <SDL3/SDL_scancode.h>
#include <SDL3/SDL_mouse.h>

#include <SDL3/SDL_stdinc.h>
#include <assert.h>

#define BUTTON_CODE_COUNT 24

struct ButtonState{
	bool pressed;
	bool triggered;
	bool repeated;

	ButtonState()
		: pressed(false),
		  triggered(false),
		  repeated(false)
	{}
};

struct KbBindingData{
	SDL_Scancode source;
	Input::ButtonCode target;
};

struct Binding{
	Binding(Input::ButtonCode target = Input::None)
		: target(target)
	{}

	virtual bool sourceActive() const = 0;
	virtual bool sourceRepeatable() const = 0;

	Input::ButtonCode target;
};

/* Keyboard binding */
struct KbBinding : public Binding{
	KbBinding() {}

	KbBinding(const KbBindingData &data)
		: Binding(data.target),
		  source(data.source)
	{}

	bool sourceActive() const{
		/* Special case aliases */
		if (source == SDL_SCANCODE_LSHIFT)
			return EventThread::keyStates[source]
			    || EventThread::keyStates[SDL_SCANCODE_RSHIFT];

		if (source == SDL_SCANCODE_RETURN)
			return EventThread::keyStates[source]
			    || EventThread::keyStates[SDL_SCANCODE_KP_ENTER];

		return EventThread::keyStates[source];
	}

	bool sourceRepeatable() const{
		return (source >= SDL_SCANCODE_A     && source <= SDL_SCANCODE_0)    ||
		       (source >= SDL_SCANCODE_RIGHT && source <= SDL_SCANCODE_UP)   ||
		       (source >= SDL_SCANCODE_F1    && source <= SDL_SCANCODE_F12);
	}

	SDL_Scancode source;
};

/* Controller button binding */
struct GcButtonBinding : public Binding{
	GcButtonBinding() {}

	bool sourceActive() const{
		return EventThread::gcState.buttons[source];
	}

	bool sourceRepeatable() const{
		return true;
	}

	uint8_t source;
};

/* Controller axis binding */
struct GcAxisBinding : public Binding{
	GcAxisBinding() {}

	GcAxisBinding(uint8_t source, AxisDir dir, Input::ButtonCode target)
	    : Binding(target),
	      source(source),
	      dir(dir)
	{}

	bool sourceActive() const{
		int val = EventThread::gcState.axes[source];

		if (dir == Negative)
			return val < -JAXIS_THRESHOLD;
		else /* dir == Positive */
			return val > JAXIS_THRESHOLD;
	}

	bool sourceRepeatable() const{
		return true;
	}

	uint8_t source;
	AxisDir dir;
};

/* Joystick button binding */
struct JsButtonBinding : public Binding{
	JsButtonBinding() {}

	bool sourceActive() const{
		return EventThread::joyState.buttons[source];
	}

	bool sourceRepeatable() const{
		return true;
	}

	uint8_t source;
};

/* Joystick axis binding */
struct JsAxisBinding : public Binding{
	JsAxisBinding() {}

	JsAxisBinding(uint8_t source, AxisDir dir, Input::ButtonCode target)
	    : Binding(target),
	      source(source),
	      dir(dir)
	{}

	bool sourceActive() const{
		int val = EventThread::joyState.axes[source];

		if (dir == Negative)
			return val < -JAXIS_THRESHOLD;
		else /* dir == Positive */
			return val > JAXIS_THRESHOLD;
	}

	bool sourceRepeatable() const{
		return true;
	}

	uint8_t source;
	AxisDir dir;
};

/* Joystick hat binding */
struct JsHatBinding : public Binding{
	JsHatBinding() {}

	JsHatBinding(uint8_t source, uint8_t pos, Input::ButtonCode target)
	    : Binding(target),
	      source(source),
	      pos(pos)
	{}

	bool sourceActive() const{
		/* For a diagonal input accept it as an input for both the axes */
		return (pos & EventThread::joyState.hats[source]) != 0;
	}

	bool sourceRepeatable() const{
		return true;
	}

	uint8_t source;
	uint8_t pos;
};

/* Mouse button binding */
struct MsBinding : public Binding{
	MsBinding() {}

	MsBinding(int buttonIndex, Input::ButtonCode target)
	    : Binding(target),
	      index(buttonIndex)
	{}

	bool sourceActive() const{
		return EventThread::mouseState.buttons[index];
	}

	bool sourceRepeatable() const{
		return false;
	}

	int index;
};

/* Not rebindable */
static const KbBindingData staticKbBindings[] ={
	{ SDL_SCANCODE_F5,     Input::F5    },
	{ SDL_SCANCODE_F6,     Input::F6    },
	{ SDL_SCANCODE_F7,     Input::F7    },
	{ SDL_SCANCODE_F8,     Input::F8    },
	{ SDL_SCANCODE_F9,     Input::F9    }
};

static elementsN(staticKbBindings);

/* Maps ButtonCode enum values to indices
 * in the button state array */
static const int mapToIndex[] = {
	0, 0,
	1, 0, 2, 0, 3, 0, 4, 0,
	0,
	5, 6, 7, 8, 9, 10, 11, 12,
	0, 0,
	13, 14, 15,
	0,
	16, 17, 18, 19, 20,
	0, 0, 0, 0, 0, 0, 0, 0,
	21, 22, 23
};

static elementsN(mapToIndex);

static const Input::ButtonCode dirs[] = { Input::Down, Input::Left, Input::Right, Input::Up };

static const int dirFlags[] = {
	1 << Input::Down,
	1 << Input::Left,
	1 << Input::Right,
	1 << Input::Up
};

/* Dir4 is always zero on these combinations */
static const int deadDirFlags[] = {
	dirFlags[0] | dirFlags[3],
	dirFlags[1] | dirFlags[2]
};

static const Input::ButtonCode otherDirs[4][3] = {
	{ Input::Left, Input::Right, Input::Up    }, /* Down  */
	{ Input::Down, Input::Up,    Input::Right }, /* Left  */
	{ Input::Down, Input::Up,    Input::Left  }, /* Right */
	{ Input::Left, Input::Right, Input::Up    }  /* Up    */
};

// storing wheel as buffer cause yes.
struct MouseFrameState {
	float wheelX, wheelY;
	bool wheelFlipped;
};

struct InputPrivate {
	std::vector<KbBinding> kbStatBindings;
	std::vector<KbBinding> kbBindings;
	std::vector<GcAxisBinding> gcABindings;
	std::vector<GcButtonBinding> gcBBindings;
	std::vector<JsAxisBinding> jsABindings;
	std::vector<JsHatBinding> jsHBindings;
	std::vector<JsButtonBinding> jsBBindings;
	std::vector<MsBinding> msBindings;

	/* Collective binding array */
	std::vector<Binding*> bindings;

	ButtonState stateArray[BUTTON_CODE_COUNT*2];

	ButtonState *states;
	ButtonState *statesOld;

	Input::ButtonCode repeating;
	unsigned int repeatCount;

	bool triedExit;

	struct{
		int active;
		Input::ButtonCode previous;
	} dir4Data;

	struct{
		int active;
	} dir8Data;

	MouseFrameState mouseWheelState;

	InputPrivate(const RGSSThreadData &rtData){
		initStaticKbBindings();
		initMsBindings();

		/* Main thread should have these posted by now */
		checkBindingChange(rtData);

		states    = stateArray;
		statesOld = stateArray + BUTTON_CODE_COUNT;

		/* Clear buffers */
		clearBuffer();
		swapBuffers();
		clearBuffer();

		repeating = Input::None;
		repeatCount = 0;

		dir4Data.active = 0;
		dir4Data.previous = Input::None;

		dir8Data.active = 0;

		triedExit = false;

		mouseWheelState = { 0, 0 };
	}

	inline ButtonState &getStateCheck(int code){
		int index;

		if (code < 0 || (size_t) code > mapToIndexN-1)
			index = 0;
		else
			index = mapToIndex[code];

		return states[index];
	}

	inline ButtonState &getState(Input::ButtonCode code){
		return states[mapToIndex[code]];
	}

	inline ButtonState &getOldState(Input::ButtonCode code){
		return statesOld[mapToIndex[code]];
	}

	void swapBuffers(){
		ButtonState *tmp = states;
		states = statesOld;
		statesOld = tmp;
	}

	void clearBuffer(){
		const size_t size = sizeof(ButtonState) * BUTTON_CODE_COUNT;
		SDL_memset(states, 0, size);
	}

	void checkBindingChange(const RGSSThreadData &rtData){
		BDescVec d;

		if (!rtData.bindingUpdateMsg.poll(d))
			return;

		applyBindingDesc(d);
	}

	template<class B>
	void appendBindings(std::vector<B> &bind){
		for (size_t i = 0; i < bind.size(); ++i)
			bindings.push_back(&bind[i]);
	}

	void setBindingDescs(const std::vector<SourceDesc> &descs, const Input::ButtonCode &target){
		// cleaning
		kbBindings.erase(
		    std::remove_if(
		        kbBindings.begin(),
		        kbBindings.end(),
		        [target](const KbBinding& b)
		        { return b.target == target; }
		    ),
		    kbBindings.end()
		);
		gcABindings.erase(
		    std::remove_if(
		        gcABindings.begin(),
		        gcABindings.end(),
		        [target](const GcAxisBinding& b)
		        { return b.target == target; }
		    ),
		    gcABindings.end()
		);
		gcBBindings.erase(
		    std::remove_if(
		        gcBBindings.begin(),
		        gcBBindings.end(),
		        [target](const GcButtonBinding& b)
		        { return b.target == target; }
		    ),
		    gcBBindings.end()
		);
		jsABindings.erase(
		    std::remove_if(
		        jsABindings.begin(),
		        jsABindings.end(),
		        [target](const JsAxisBinding& b)
		        { return b.target == target; }
		    ),
		    jsABindings.end()
		);
		jsHBindings.erase(
		    std::remove_if(
		        jsHBindings.begin(),
		        jsHBindings.end(),
		        [target](const JsHatBinding& b)
		        { return b.target == target; }
		    ),
		    jsHBindings.end()
		);
		jsBBindings.erase(
		    std::remove_if(
		        jsBBindings.begin(),
		        jsBBindings.end(),
		        [target](const JsButtonBinding& b)
		        { return b.target == target; }
		    ),
		    jsBBindings.end()
		);
		
		
		for (size_t i = 0; i < descs.size(); ++i){
			const SourceDesc &src = descs[i];

			if (target == Input::None)
				continue;

			switch (src.type){
			case Invalid :
				break;
			case Key :
			{
				KbBinding bind;
				bind.source = src.d.scan;
				bind.target = target;
				kbBindings.push_back(bind);

				break;
			}
			case CAxis :
			{
				GcAxisBinding bind;
				bind.source = src.d.ja.axis;
				bind.dir = src.d.ja.dir;
				bind.target = target;
				gcABindings.push_back(bind);

				break;
			}
			case CButton :
			{
				GcButtonBinding bind;
				bind.source = src.d.jb;
				bind.target = target;
				gcBBindings.push_back(bind);

				break;
			}
			case JAxis :
			{
				JsAxisBinding bind;
				bind.source = src.d.ja.axis;
				bind.dir = src.d.ja.dir;
				bind.target = target;
				jsABindings.push_back(bind);

				break;
			}
			case JHat :
			{
				JsHatBinding bind;
				bind.source = src.d.jh.hat;
				bind.pos = src.d.jh.pos;
				bind.target = target;
				jsHBindings.push_back(bind);

				break;
			}
			case JButton :
			{
				JsButtonBinding bind;
				bind.source = src.d.jb;
				bind.target = target;
				jsBBindings.push_back(bind);

				break;
			}
			default :
				assert(!"unreachable");
			}
		}

		bindings.clear();

		appendBindings(kbStatBindings);
		appendBindings(msBindings);

		appendBindings(kbBindings);
		appendBindings(gcABindings);
		appendBindings(gcBBindings);
		appendBindings(jsABindings);
		appendBindings(jsHBindings);
		appendBindings(jsBBindings);
	}

	void applyBindingDesc(const BDescVec &d){
		kbBindings.clear();
		gcABindings.clear();
		gcBBindings.clear();
		jsABindings.clear();
		jsHBindings.clear();
		jsBBindings.clear();

		for (size_t i = 0; i < d.size(); ++i){
			const BindingDesc &desc = d[i];
			const SourceDesc &src = desc.src;

			if (desc.target == Input::None)
				continue;

			switch (desc.src.type){
			case Invalid :
				break;
			case Key :
			{
				KbBinding bind;
				bind.source = src.d.scan;
				bind.target = desc.target;
				kbBindings.push_back(bind);

				break;
			}
			case CAxis :
			{
				GcAxisBinding bind;
				bind.source = src.d.ja.axis;
				bind.dir = src.d.ja.dir;
				bind.target = desc.target;
				gcABindings.push_back(bind);

				break;
			}
			case CButton :
			{
				GcButtonBinding bind;
				bind.source = src.d.jb;
				bind.target = desc.target;
				gcBBindings.push_back(bind);

				break;
			}
			case JAxis :
			{
				JsAxisBinding bind;
				bind.source = src.d.ja.axis;
				bind.dir = src.d.ja.dir;
				bind.target = desc.target;
				jsABindings.push_back(bind);

				break;
			}
			case JHat :
			{
				JsHatBinding bind;
				bind.source = src.d.jh.hat;
				bind.pos = src.d.jh.pos;
				bind.target = desc.target;
				jsHBindings.push_back(bind);

				break;
			}
			case JButton :
			{
				JsButtonBinding bind;
				bind.source = src.d.jb;
				bind.target = desc.target;
				jsBBindings.push_back(bind);

				break;
			}
			default :
				assert(!"unreachable");
			}
		}

		bindings.clear();

		appendBindings(kbStatBindings);
		appendBindings(msBindings);

		appendBindings(kbBindings);
		appendBindings(gcABindings);
		appendBindings(gcBBindings);
		appendBindings(jsABindings);
		appendBindings(jsHBindings);
		appendBindings(jsBBindings);
	}

	void initStaticKbBindings(){
		kbStatBindings.clear();

		for (size_t i = 0; i < staticKbBindingsN; ++i)
			kbStatBindings.push_back(KbBinding(staticKbBindings[i]));
	}

	void initMsBindings(){
		msBindings.resize(3);

		size_t i = 0;
		msBindings[i++] = MsBinding(SDL_BUTTON_LEFT,   Input::MouseLeft);
		msBindings[i++] = MsBinding(SDL_BUTTON_MIDDLE, Input::MouseMiddle);
		msBindings[i++] = MsBinding(SDL_BUTTON_RIGHT,  Input::MouseRight);
	}

	void pollBindings(Input::ButtonCode &repeatCand){
		for (size_t i = 0; i < bindings.size(); ++i)
			pollBindingPriv(*bindings[i], repeatCand);

		updateDir4();
		updateDir8();
	}

	void pollBindingPriv(const Binding &b, Input::ButtonCode &repeatCand){
		if (!b.sourceActive())
			return;

		if (b.target == Input::None)
			return;

		ButtonState &state = getState(b.target);
		ButtonState &oldState = getOldState(b.target);

		state.pressed = true;

		/* Must have been released before to trigger */
		if (!oldState.pressed)
			state.triggered = true;

		/* Unbound keys don't create/break repeat */
		if (repeatCand != Input::None)
			return;

		if (repeating != b.target &&
			!oldState.pressed)
		{
			if (b.sourceRepeatable())
				repeatCand = b.target;
			else
				/* Unrepeatable keys still break current repeat */
				repeating = Input::None;
		}
	}

	void updateDir4(){
		int dirFlag = 0;

		for (size_t i = 0; i < 4; ++i)
			dirFlag |= (getState(dirs[i]).pressed ? dirFlags[i] : 0);

		if (dirFlag == deadDirFlags[0] || dirFlag == deadDirFlags[1]){
			dir4Data.active = Input::None;
			return;
		}

		if (dir4Data.previous != Input::None){
			/* Check if prev still pressed */
			if (getState(dir4Data.previous).pressed){
				for (size_t i = 0; i < 3; ++i){
					Input::ButtonCode other =
							otherDirs[(dir4Data.previous/2)-1][i];

					if (!getState(other).pressed)
						continue;

					dir4Data.active = other;
					return;
				}
			}
		}

		for (size_t i = 0; i < 4; ++i){
			if (!getState(dirs[i]).pressed)
				continue;

			dir4Data.active = dirs[i];
			dir4Data.previous = dirs[i];
			return;
		}

		dir4Data.active   = Input::None;
		dir4Data.previous = Input::None;
	}

	void updateDir8(){
		static const int combos[4][4] = {
			{ 2, 1, 3, 0 },
			{ 1, 4, 0, 7 },
			{ 3, 0, 6, 9 },
			{ 0, 7, 9, 8 }
		};

		dir8Data.active = 0;

		for (size_t i = 0; i < 4; ++i) {
			Input::ButtonCode one = dirs[i];

			if (!getState(one).pressed)
				continue;

			for (int j = 0; j < 3; ++j){
				Input::ButtonCode other = otherDirs[i][j];

				if (!getState(other).pressed)
					continue;

				dir8Data.active = combos[(one/2)-1][(other/2)-1];
				return;
			}

			dir8Data.active = one;
			return;
		}
	}
};


Input::Input(const RGSSThreadData &rtData){
	p = new InputPrivate(rtData);
}

void Input::update(){
	shState->checkShutdown();
	p->checkBindingChange(shState->rtData());

	p->swapBuffers();
	p->clearBuffer();

	// updating mouse wheel state
	{
		p->mouseWheelState.wheelFlipped = EventThread::mouseState.wheelFlipped;
		p->mouseWheelState.wheelX = EventThread::mouseState.wheelX;
		p->mouseWheelState.wheelY = EventThread::mouseState.wheelY;

		EventThread::mouseState.wheelFlipped = false;
		EventThread::mouseState.wheelX = 0;
		EventThread::mouseState.wheelY = 0;
	}

	ButtonCode repeatCand = None;

	/* Poll all bindings */
	p->pollBindings(repeatCand);

	/* Check for new repeating key */
	if (repeatCand != None && repeatCand != p->repeating){
		p->repeating = repeatCand;
		p->repeatCount = 0;
		p->getState(repeatCand).repeated = true;

		return;
	}

	/* Check if repeating key is still pressed */
	if (p->getState(p->repeating).pressed){
		p->repeatCount++;

		bool repeated;
		repeated = p->repeatCount >= 15 && ((p->repeatCount+1) % 4) == 0;

		p->getState(p->repeating).repeated |= repeated;

		return;
	}

	p->repeating = None;

	RGSSThreadData &rtData = shState->rtData();
	p->triedExit = rtData.triedExit;
	rtData.triedExit.clear();
}

bool Input::isPressed(int button){
	return p->getStateCheck(button).pressed;
}

bool Input::isTriggered(int button){
	return p->getStateCheck(button).triggered;
}

bool Input::isRepeated(int button){
	return p->getStateCheck(button).repeated;
}

int Input::dir4Value(){
	return p->dir4Data.active;
}

int Input::dir8Value(){
	return p->dir8Data.active;
}

int Input::mouseX(){
	RGSSThreadData &rtData = shState->rtData();

	return (EventThread::mouseState.x - rtData.screenOffset.x) * rtData.sizeResoRatio.x;
}

int Input::mouseY(){
	RGSSThreadData &rtData = shState->rtData();

	return (EventThread::mouseState.y - rtData.screenOffset.y) * rtData.sizeResoRatio.y;
}

void Input::setBinding(std::vector<SourceDesc> descs, Input::ButtonCode target){
	p->setBindingDescs(descs, target);
}

// wheel support :3
float Input::wheelX() { return p->mouseWheelState.wheelX; }
float Input::wheelY() { return p->mouseWheelState.wheelY; }
bool Input::wheelFlipped() { return p->mouseWheelState.wheelFlipped; }

bool Input::hasQuit(){
	return p->triedExit;
}

Input::~Input(){
	delete p;
}