/*
Copyright (C) 2014 sapier
Copyright (C) 2014-2020 Maksim Gamarnik [MoNTE48] MoNTE48@mail.ua

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 3.0 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 <IEventReceiver.h>
#include <IGUIButton.h>
#include <IGUIEnvironment.h>

#include <map>
#include <vector>

#include "client/tile.h"
#include "game.h"

using namespace irr;
using namespace irr::core;
using namespace irr::gui;

typedef enum
{
	forward_one,
	forward_two,
	forward_three,
	backward_one,
	backward_two,
	backward_three,
	left_id,
	right_id,
	empty_id,
	inventory_id,
	drop_id,
	jump_id,
	crunch_id,
	escape_id,
	minimap_id,
	range_id,
	camera_id,
	chat_id,
//	noclip_id,
//	fast_id,
	after_last_element_id
} touch_gui_button_id;

#define MIN_DIG_TIME        500
#define BUTTON_REPEAT_DELAY 0.2f
#define SLOW_BUTTON_REPEAT  1.0f

struct button_info
{
	float            repeatcounter;
	float            repeatdelay;
	irr::EKEY_CODE   keycode;
	std::vector<size_t> ids;
	IGUIButton *guibutton = NULL;
	bool             immediate_release;
};

class TouchScreenGUI
{
public:
	TouchScreenGUI(IrrlichtDevice *device, IEventReceiver *receiver);

	~TouchScreenGUI();

	void translateEvent(const SEvent &event);

	void init(ISimpleTextureSource *tsrc);

	double getYawChange()
	{
		double res = m_camera_yaw_change;
		m_camera_yaw_change = 0;
		return res;
	}

	double getPitch() { return m_camera_pitch; }

	/* Returns a line which describes what the player is pointing at.
	 * The starting point and looking direction are significant,
	 * the line should be scaled to match its length to the actual distance
	 * the player can reach.
	 * The line starts at the camera and ends on the camera's far plane.
	 * The coordinates do not contain the camera offset. */
	line3d<f32> getShootline() { return m_shootline; }

	void step(float dtime);

	void resetHud();

	void registerHudItem(int index, const rect<s32> &rect);

	void Toggle(bool visible);

	void hide();

	void show();

	void handleReleaseAll();

private:
	IrrlichtDevice           *m_device;
	IGUIEnvironment          *m_guienv;
	IEventReceiver           *m_receiver;
	ISimpleTextureSource     *m_texturesource;
	v2u32 m_screensize;
	double m_touchscreen_threshold;
	std::map<int, rect<s32> > m_hud_rects;
	std::map<size_t, irr::EKEY_CODE> m_hud_ids;
	bool                      m_visible; // is the gui visible

	// value in degree
	double m_camera_yaw_change;
	double m_camera_pitch;

	/* A line starting at the camera and pointing towards the
	 * selected object.
	 * The line ends on the camera's far plane.
	 * The coordinates do not contain the camera offset. */
	line3d<f32> m_shootline;

	rect<s32> m_control_pad_rect;

	size_t m_move_id;
	bool m_move_has_really_moved;
	u64 m_move_downtime;
	bool m_move_sent_as_mouse_event;
	v2s32 m_move_downlocation;

	button_info m_buttons[after_last_element_id];

	// gui button detection
	touch_gui_button_id getButtonID(s32 x, s32 y);

	// gui button by eventID
	touch_gui_button_id getButtonID(size_t eventID);

	// check if a button has changed
	void handleChangedButton(const SEvent &event);

	// initialize a button
	void initButton(touch_gui_button_id id, const rect<s32> &button_rect,
					const std::wstring &caption, bool immediate_release,
					float repeat_delay = BUTTON_REPEAT_DELAY);

	struct id_status
	{
		size_t id;
		int X;
		int Y;
	};

	// vector to store known ids and their initial touch positions
	std::vector<id_status> m_known_ids;

	// handle a button event
	void handleButtonEvent(touch_gui_button_id bID, size_t eventID, bool action);

	// handle pressed hud buttons
	bool isHUDButton(const SEvent &event);

	// handle quick touch
	bool quickTapDetection();

	// handle release event
	void handleReleaseEvent(size_t evt_id);

	// long-click detection variables
	struct key_event
	{
		u64 down_time;
		s32 x;
		s32 y;
	};

	// array for saving last known position of a pointer
	std::map<size_t, v2s32> m_pointerpos;

	// array for long-click detection
	key_event m_key_events[2];
};

extern TouchScreenGUI *g_touchscreengui;