/*
Copyright (C) 2014 sapier

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.
*/

#ifndef TOUCHSCREENGUI_HEADER
#define TOUCHSCREENGUI_HEADER

#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_id = 0,
	backward_id,
	left_id,
	right_id,
	jump_id,
	crunch_id,
	after_last_element_id,
	settings_starter_id,
	rare_controls_starter_id,
	fly_id,
	noclip_id,
	fast_id,
	debug_id,
	camera_id,
	range_id,
	chat_id,
	inventory_id,
	drop_id
} touch_gui_button_id;

typedef enum {
	AHBB_Dir_Top_Bottom,
	AHBB_Dir_Bottom_Top,
	AHBB_Dir_Left_Right,
	AHBB_Dir_Right_Left
} autohide_button_bar_dir;

#define MIN_DIG_TIME_MS 500
#define MAX_TOUCH_COUNT 64
#define BUTTON_REPEAT_DELAY 0.2f

#define SETTINGS_BAR_Y_OFFSET 6.5
#define RARE_CONTROLS_BAR_Y_OFFSET 4

extern const char **touchgui_button_imagenames;

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

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

	void init(ISimpleTextureSource *tsrc, const char *starter_img, int button_id,
			v2s32 UpperLeft, v2s32 LowerRight, autohide_button_bar_dir dir,
			float timeout);

	~AutoHideButtonBar();

	/* add button to be shown */
	void addButton(touch_gui_button_id id, const wchar_t *caption,
			const char *btn_image);

	/* detect settings bar button events */
	bool isButton(const SEvent &event);

	/* handle released hud buttons */
	bool isReleaseButton(int eventID);

	/* step handler */
	void step(float dtime);

	/* deactivate button bar */
	void deactivate();

	/* hide the whole buttonbar */
	void hide();

	/* unhide the buttonbar */
	void show();

private:
	ISimpleTextureSource *m_texturesource;
	irr::video::IVideoDriver *m_driver;
	IGUIEnvironment *m_guienv;
	IEventReceiver *m_receiver;
	v2u32 m_screensize;
	button_info m_starter;
	std::vector<button_info *> m_buttons;

	v2s32 m_upper_left;
	v2s32 m_lower_right;

	/* show settings bar */
	bool m_active;

	bool m_visible;

	/* settings bar timeout */
	float m_timeout;
	float m_timeout_value;
	bool m_initialized;
	autohide_button_bar_dir m_dir;
};

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();

private:
	IrrlichtDevice *m_device;
	IGUIEnvironment *m_guienv;
	IEventReceiver *m_receiver;
	ISimpleTextureSource *m_texturesource;
	v2u32 m_screensize;
	std::map<int, rect<s32> > m_hud_rects;
	std::map<int, 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;

	int m_move_id;
	bool m_move_has_really_moved;
	s64 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(int eventID);

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

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

	/* load texture */
	void loadButtonTexture(button_info *btn, const char *path, rect<s32> button_rect);

	struct id_status
	{
		int 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, int eventID, bool action);

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

	/* handle released hud buttons */
	bool isReleaseHUDButton(int eventID);

	/* handle double taps */
	bool doubleTapDetection();

	/* handle release event */
	void handleReleaseEvent(int evt_id);

	/* get size of regular gui control button */
	int getGuiButtonSize();

	/* doubleclick detection variables */
	struct key_event
	{
		unsigned int down_time;
		s32 x;
		s32 y;
	};

	/* array for saving last known position of a pointer */
	v2s32 m_pointerpos[MAX_TOUCH_COUNT];

	/* array for doubletap detection */
	key_event m_key_events[2];

	/* settings bar */
	AutoHideButtonBar m_settingsbar;

	/* rare controls bar */
	AutoHideButtonBar m_rarecontrolsbar;
};
extern TouchScreenGUI *g_touchscreengui;
#endif
