/*
Minetest
Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#pragma once

#include "irrlichttypes_extrabloated.h"
#include "joystick_controller.h"
#include "keycode.h"
#include "renderingengine.h"
#include <unordered_set>

#ifdef HAVE_TOUCHSCREENGUI
#include "gui/touchscreengui.h"
#endif

class InputHandler;

/****************************************************************************
 Fast key cache for main game loop
 ****************************************************************************/

/* This is faster than using getKeySetting with the tradeoff that functions
 * using it must make sure that it's initialised before using it and there is
 * no error handling (for example bounds checking). This is really intended for
 * use only in the main running loop of the client (the_game()) where the faster
 * (up to 10x faster) key lookup is an asset. Other parts of the codebase
 * (e.g. formspecs) should continue using getKeySetting().
 */
struct KeyCache
{

	KeyCache()
	{
		handler = NULL;
		populate();
		populate_nonchanging();
	}

	void populate();

	// Keys that are not settings dependent
	void populate_nonchanging();

	KeyPress key[KeyType::INTERNAL_ENUM_COUNT];
	InputHandler *handler;
};

class MyEventReceiver : public IEventReceiver
{
public:
	// This is the one method that we have to implement
	virtual bool OnEvent(const SEvent &event);

	bool IsKeyDown(const KeyPress &keyCode) const { return keyIsDown.count(keyCode); }

	// Checks whether a key was down and resets the state
	bool WasKeyDown(const KeyPress &keyCode)
	{
		bool b = keyWasDown.count(keyCode);
		if (b)
			keyWasDown.erase(keyCode);
		return b;
	}

	// Checks whether a key was just pressed. State will be cleared
	// in the subsequent iteration of Game::processPlayerInteraction
	bool WasKeyPressed(const KeyPress &keycode) const { return keyWasPressed.count(keycode); }

	// Checks whether a key was just released. State will be cleared
	// in the subsequent iteration of Game::processPlayerInteraction
	bool WasKeyReleased(const KeyPress &keycode) const { return keyWasReleased.count(keycode); }

	void listenForKey(const KeyPress &keyCode) { keysListenedFor.insert(keyCode); }
	void dontListenForKeys() { keysListenedFor.clear(); }

	s32 getMouseWheel()
	{
		s32 a = mouse_wheel;
		mouse_wheel = 0;
		return a;
	}

	void clearInput()
	{
		keyIsDown.clear();
		keyWasDown.clear();
		keyWasPressed.clear();
		keyWasReleased.clear();

		mouse_wheel = 0;
	}

	void clearWasKeyPressed()
	{
		keyWasPressed.clear();
	}

	void clearWasKeyReleased()
	{
		keyWasReleased.clear();
	}

	MyEventReceiver()
	{
#ifdef HAVE_TOUCHSCREENGUI
		m_touchscreengui = NULL;
#endif
	}

	s32 mouse_wheel = 0;

	JoystickController *joystick = nullptr;

#ifdef HAVE_TOUCHSCREENGUI
	TouchScreenGUI *m_touchscreengui;
#endif

private:
	//! The current state of keys
	std::unordered_set<KeyPress> keyIsDown;

	//! Whether a key was down
	std::unordered_set<KeyPress> keyWasDown;

	//! Whether a key has just been pressed
	std::unordered_set<KeyPress> keyWasPressed;

	//! Whether a key has just been released
	std::unordered_set<KeyPress> keyWasReleased;

	//! List of keys we listen for
	std::unordered_set<KeyPress> keysListenedFor;
};

class InputHandler
{
public:
	InputHandler()
	{
		keycache.handler = this;
		keycache.populate();
	}

	virtual ~InputHandler() = default;

	virtual bool isRandom() const
	{
		return false;
	}

	virtual bool isKeyDown(GameKeyType k) = 0;
	virtual bool wasKeyDown(GameKeyType k) = 0;
	virtual bool wasKeyPressed(GameKeyType k) = 0;
	virtual bool wasKeyReleased(GameKeyType k) = 0;
	virtual bool cancelPressed() = 0;

	virtual void clearWasKeyPressed() {}
	virtual void clearWasKeyReleased() {}

	virtual void listenForKey(const KeyPress &keyCode) {}
	virtual void dontListenForKeys() {}

	virtual v2s32 getMousePos() = 0;
	virtual void setMousePos(s32 x, s32 y) = 0;

	virtual s32 getMouseWheel() = 0;

	virtual void step(float dtime) {}

	virtual void clear() {}

	JoystickController joystick;
	KeyCache keycache;
};
/*
	Separated input handler
*/

class RealInputHandler : public InputHandler
{
public:
	RealInputHandler(MyEventReceiver *receiver) : m_receiver(receiver)
	{
		m_receiver->joystick = &joystick;
	}
	virtual bool isKeyDown(GameKeyType k)
	{
		return m_receiver->IsKeyDown(keycache.key[k]) || joystick.isKeyDown(k);
	}
	virtual bool wasKeyDown(GameKeyType k)
	{
		return m_receiver->WasKeyDown(keycache.key[k]) || joystick.wasKeyDown(k);
	}
	virtual bool wasKeyPressed(GameKeyType k)
	{
		return m_receiver->WasKeyPressed(keycache.key[k]) || joystick.wasKeyReleased(k);
	}
	virtual bool wasKeyReleased(GameKeyType k)
	{
		return m_receiver->WasKeyReleased(keycache.key[k]) || joystick.wasKeyReleased(k);
	}
	virtual bool cancelPressed()
	{
		return wasKeyDown(KeyType::ESC) || m_receiver->WasKeyDown(CancelKey);
	}
	virtual void clearWasKeyPressed()
	{
		m_receiver->clearWasKeyPressed();
	}
	virtual void clearWasKeyReleased()
	{
		m_receiver->clearWasKeyReleased();
	}
	virtual void listenForKey(const KeyPress &keyCode)
	{
		m_receiver->listenForKey(keyCode);
	}
	virtual void dontListenForKeys() { m_receiver->dontListenForKeys(); }
	virtual v2s32 getMousePos()
	{
		if (RenderingEngine::get_raw_device()->getCursorControl()) {
			return RenderingEngine::get_raw_device()
					->getCursorControl()
					->getPosition();
		}

		return m_mousepos;
	}

	virtual void setMousePos(s32 x, s32 y)
	{
		if (RenderingEngine::get_raw_device()->getCursorControl()) {
			RenderingEngine::get_raw_device()
					->getCursorControl()
					->setPosition(x, y);
		} else {
			m_mousepos = v2s32(x, y);
		}
	}

	virtual s32 getMouseWheel() { return m_receiver->getMouseWheel(); }

	void clear()
	{
		joystick.clear();
		m_receiver->clearInput();
	}

private:
	MyEventReceiver *m_receiver = nullptr;
	v2s32 m_mousepos;
};

class RandomInputHandler : public InputHandler
{
public:
	RandomInputHandler() = default;

	bool isRandom() const
	{
		return true;
	}

	virtual bool isKeyDown(GameKeyType k) { return keydown.count(keycache.key[k]); }
	virtual bool wasKeyDown(GameKeyType k) { return false; }
	virtual bool wasKeyPressed(GameKeyType k) { return false; }
	virtual bool wasKeyReleased(GameKeyType k) { return false; }
	virtual bool cancelPressed() { return false; }
	virtual v2s32 getMousePos() { return mousepos; }
	virtual void setMousePos(s32 x, s32 y) { mousepos = v2s32(x, y); }

	virtual s32 getMouseWheel() { return 0; }

	virtual void step(float dtime);

	s32 Rand(s32 min, s32 max);

private:
	std::unordered_set<KeyPress> keydown;
	v2s32 mousepos;
	v2s32 mousespeed;
};