/*
Copyright (C) 2014 sapier
Copyright (C) 2018 srifqi, Muhammad Rifqi Priyo Susanto
		<muhammadrifqipriyosusanto@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.
*/

#include "touchscreengui.h"
#include "irrlichttypes.h"
#include "irr_v2d.h"
#include "log.h"
#include "client/keycode.h"
#include "settings.h"
#include "gettime.h"
#include "util/numeric.h"
#include "porting.h"
#include "client/guiscalingfilter.h"

#include <iostream>
#include <algorithm>

#include <ISceneCollisionManager.h>

using namespace irr::core;

const char **button_imagenames = (const char *[]) {
	"jump_btn.png",
	"down.png",
	"zoom.png",
	"aux_btn.png"
};

const char **joystick_imagenames = (const char *[]) {
	"joystick_off.png",
	"joystick_bg.png",
	"joystick_center.png"
};

static irr::EKEY_CODE id2keycode(touch_gui_button_id id)
{
	std::string key = "";
	switch (id) {
		case forward_id:
			key = "forward";
			break;
		case left_id:
			key = "left";
			break;
		case right_id:
			key = "right";
			break;
		case backward_id:
			key = "backward";
			break;
		case inventory_id:
			key = "inventory";
			break;
		case drop_id:
			key = "drop";
			break;
		case jump_id:
			key = "jump";
			break;
		case crunch_id:
			key = "sneak";
			break;
		case zoom_id:
			key = "zoom";
			break;
		case special1_id:
			key = "special1";
			break;
		case fly_id:
			key = "freemove";
			break;
		case noclip_id:
			key = "noclip";
			break;
		case fast_id:
			key = "fastmove";
			break;
		case debug_id:
			key = "toggle_debug";
			break;
		case toggle_chat_id:
			key = "toggle_chat";
			break;
		case minimap_id:
			key = "minimap";
			break;
		case chat_id:
			key = "chat";
			break;
		case camera_id:
			key = "camera_mode";
			break;
		case range_id:
			key = "rangeselect";
			break;
		default:
			break;
	}
	assert(!key.empty());
	return keyname_to_keycode(g_settings->get("keymap_" + key).c_str());
}

TouchScreenGUI *g_touchscreengui;

static void load_button_texture(button_info *btn, const char *path,
		const rect<s32> &button_rect, ISimpleTextureSource *tsrc, video::IVideoDriver *driver)
{
	unsigned int tid;
	video::ITexture *texture = guiScalingImageButton(driver,
			tsrc->getTexture(path, &tid), button_rect.getWidth(),
			button_rect.getHeight());
	if (texture) {
		btn->guibutton->setUseAlphaChannel(true);
		if (g_settings->getBool("gui_scaling_filter")) {
			rect<s32> txr_rect = rect<s32>(0, 0, button_rect.getWidth(), button_rect.getHeight());
			btn->guibutton->setImage(texture, txr_rect);
			btn->guibutton->setPressedImage(texture, txr_rect);
			btn->guibutton->setScaleImage(false);
		} else {
			btn->guibutton->setImage(texture);
			btn->guibutton->setPressedImage(texture);
			btn->guibutton->setScaleImage(true);
		}
		btn->guibutton->setDrawBorder(false);
		btn->guibutton->setText(L"");
	}
}

AutoHideButtonBar::AutoHideButtonBar(IrrlichtDevice *device,
		IEventReceiver *receiver) :
			m_driver(device->getVideoDriver()),
			m_guienv(device->getGUIEnvironment()),
			m_receiver(receiver)
{
}

void AutoHideButtonBar::init(ISimpleTextureSource *tsrc,
		const char *starter_img, int button_id, const v2s32 &UpperLeft,
		const v2s32 &LowerRight, autohide_button_bar_dir dir, float timeout)
{
	m_texturesource = tsrc;

	m_upper_left = UpperLeft;
	m_lower_right = LowerRight;

	// init settings bar

	irr::core::rect<int> current_button = rect<s32>(UpperLeft.X, UpperLeft.Y,
			LowerRight.X, LowerRight.Y);

	m_starter.guibutton         = m_guienv->addButton(current_button, nullptr, button_id, L"", nullptr);
	m_starter.guibutton->grab();
	m_starter.repeatcounter     = -1;
	m_starter.keycode           = KEY_OEM_8; // use invalid keycode as it's not relevant
	m_starter.immediate_release = true;
	m_starter.ids.clear();

	load_button_texture(&m_starter, starter_img, current_button,
			m_texturesource, m_driver);

	m_dir = dir;
	m_timeout_value = timeout;

	m_initialized = true;
}

AutoHideButtonBar::~AutoHideButtonBar()
{
	if (m_starter.guibutton) {
		m_starter.guibutton->setVisible(false);
		m_starter.guibutton->drop();
	}
}

void AutoHideButtonBar::addButton(touch_gui_button_id button_id,
		const wchar_t *caption, const char *btn_image)
{

	if (!m_initialized) {
		errorstream << "AutoHideButtonBar::addButton not yet initialized!"
				<< std::endl;
		return;
	}
	int button_size = 0;

	if ((m_dir == AHBB_Dir_Top_Bottom) || (m_dir == AHBB_Dir_Bottom_Top))
		button_size = m_lower_right.X - m_upper_left.X;
	else
		button_size = m_lower_right.Y - m_upper_left.Y;

	irr::core::rect<int> current_button;

	if ((m_dir == AHBB_Dir_Right_Left) || (m_dir == AHBB_Dir_Left_Right)) {
		int x_start = 0;
		int x_end = 0;

		if (m_dir == AHBB_Dir_Left_Right) {
			x_start = m_lower_right.X + (button_size * 1.25 * m_buttons.size())
					+ (button_size * 0.25);
			x_end = x_start + button_size;
		} else {
			x_end = m_upper_left.X - (button_size * 1.25 * m_buttons.size())
					- (button_size * 0.25);
			x_start = x_end - button_size;
		}

		current_button = rect<s32>(x_start, m_upper_left.Y, x_end,
				m_lower_right.Y);
	} else {
		double y_start = 0;
		double y_end = 0;

		if (m_dir == AHBB_Dir_Top_Bottom) {
			y_start = m_lower_right.X + (button_size * 1.25 * m_buttons.size())
					+ (button_size * 0.25);
			y_end = y_start + button_size;
		} else {
			y_end = m_upper_left.X - (button_size * 1.25 * m_buttons.size())
					- (button_size * 0.25);
			y_start = y_end - button_size;
		}

		current_button = rect<s32>(m_upper_left.X, y_start,
				m_lower_right.Y, y_end);
	}

	auto *btn              = new button_info();
	btn->guibutton         = m_guienv->addButton(current_button,
					nullptr, button_id, caption, nullptr);
	btn->guibutton->grab();
	btn->guibutton->setVisible(false);
	btn->guibutton->setEnabled(false);
	btn->repeatcounter     = -1;
	btn->keycode           = id2keycode(button_id);
	btn->immediate_release = true;
	btn->ids.clear();

	load_button_texture(btn, btn_image, current_button, m_texturesource,
			m_driver);

	m_buttons.push_back(btn);
}

void AutoHideButtonBar::addToggleButton(touch_gui_button_id button_id,
		const wchar_t *caption, const char *btn_image_1,
		const char *btn_image_2)
{
	addButton(button_id, caption, btn_image_1);
	button_info *btn = m_buttons.back();
	btn->togglable = 1;
	btn->textures.push_back(btn_image_1);
	btn->textures.push_back(btn_image_2);
}

bool AutoHideButtonBar::isButton(const SEvent &event)
{
	IGUIElement *rootguielement = m_guienv->getRootGUIElement();

	if (rootguielement == nullptr)
		return false;

	gui::IGUIElement *element = rootguielement->getElementFromPoint(
			core::position2d<s32>(event.TouchInput.X, event.TouchInput.Y));

	if (element == nullptr)
		return false;

	if (m_active) {
		// check for all buttons in vector
		auto iter = m_buttons.begin();

		while (iter != m_buttons.end()) {
			if ((*iter)->guibutton == element) {

				auto *translated = new SEvent();
				memset(translated, 0, sizeof(SEvent));
				translated->EventType            = irr::EET_KEY_INPUT_EVENT;
				translated->KeyInput.Key         = (*iter)->keycode;
				translated->KeyInput.Control     = false;
				translated->KeyInput.Shift       = false;
				translated->KeyInput.Char        = 0;

				// add this event
				translated->KeyInput.PressedDown = true;
				m_receiver->OnEvent(*translated);

				// remove this event
				translated->KeyInput.PressedDown = false;
				m_receiver->OnEvent(*translated);

				delete translated;

				(*iter)->ids.push_back(event.TouchInput.ID);

				m_timeout = 0;

				if ((*iter)->togglable == 1) {
					(*iter)->togglable = 2;
					load_button_texture(*iter, (*iter)->textures[1],
							(*iter)->guibutton->getRelativePosition(),
							m_texturesource, m_driver);
				} else if ((*iter)->togglable == 2) {
					(*iter)->togglable = 1;
					load_button_texture(*iter, (*iter)->textures[0],
							(*iter)->guibutton->getRelativePosition(),
							m_texturesource, m_driver);
				}

				return true;
			}
			++iter;
		}
	} else {
		// check for starter button only
		if (element == m_starter.guibutton) {
			m_starter.ids.push_back(event.TouchInput.ID);
			m_starter.guibutton->setVisible(false);
			m_starter.guibutton->setEnabled(false);
			m_active = true;
			m_timeout = 0;

			auto iter = m_buttons.begin();

			while (iter != m_buttons.end()) {
				(*iter)->guibutton->setVisible(true);
				(*iter)->guibutton->setEnabled(true);
				++iter;
			}

			return true;
		}
	}
	return false;
}

void AutoHideButtonBar::step(float dtime)
{
	if (m_active) {
		m_timeout += dtime;

		if (m_timeout > m_timeout_value)
			deactivate();
	}
}

void AutoHideButtonBar::deactivate()
{
	if (m_visible) {
		m_starter.guibutton->setVisible(true);
		m_starter.guibutton->setEnabled(true);
	}
	m_active = false;

	auto iter = m_buttons.begin();

	while (iter != m_buttons.end()) {
		(*iter)->guibutton->setVisible(false);
		(*iter)->guibutton->setEnabled(false);
		++iter;
	}
}

void AutoHideButtonBar::hide()
{
	m_visible = false;
	m_starter.guibutton->setVisible(false);
	m_starter.guibutton->setEnabled(false);

	auto iter = m_buttons.begin();

	while (iter != m_buttons.end()) {
		(*iter)->guibutton->setVisible(false);
		(*iter)->guibutton->setEnabled(false);
		++iter;
	}
}

void AutoHideButtonBar::show()
{
	m_visible = true;

	if (m_active) {
		auto iter = m_buttons.begin();

		while (iter != m_buttons.end()) {
			(*iter)->guibutton->setVisible(true);
			(*iter)->guibutton->setEnabled(true);
			++iter;
		}
	} else {
		m_starter.guibutton->setVisible(true);
		m_starter.guibutton->setEnabled(true);
	}
}

TouchScreenGUI::TouchScreenGUI(IrrlichtDevice *device, IEventReceiver *receiver):
	m_device(device),
	m_guienv(device->getGUIEnvironment()),
	m_receiver(receiver),
	m_settingsbar(device, receiver),
	m_rarecontrolsbar(device, receiver)
{
	for (auto &button : m_buttons) {
		button.guibutton     = nullptr;
		button.repeatcounter = -1;
		button.repeatdelay   = BUTTON_REPEAT_DELAY;
	}

	m_touchscreen_threshold = g_settings->getU16("touchscreen_threshold");
	m_fixed_joystick = g_settings->getBool("fixed_virtual_joystick");
	m_joystick_triggers_special1 = g_settings->getBool("virtual_joystick_triggers_aux");
	m_screensize = m_device->getVideoDriver()->getScreenSize();
	button_size = MYMIN(m_screensize.Y / 4.5f,
			porting::getDisplayDensity() *
			g_settings->getFloat("hud_scaling") * 65.0f);
}

void TouchScreenGUI::initButton(touch_gui_button_id id, const rect<s32> &button_rect,
		const std::wstring &caption, bool immediate_release, float repeat_delay)
{
	button_info *btn       = &m_buttons[id];
	btn->guibutton         = m_guienv->addButton(button_rect, nullptr, id, caption.c_str());
	btn->guibutton->grab();
	btn->repeatcounter     = -1;
	btn->repeatdelay       = repeat_delay;
	btn->keycode           = id2keycode(id);
	btn->immediate_release = immediate_release;
	btn->ids.clear();

	load_button_texture(btn, button_imagenames[id], button_rect,
			m_texturesource, m_device->getVideoDriver());
}

button_info *TouchScreenGUI::initJoystickButton(touch_gui_button_id id,
		const rect<s32> &button_rect, int texture_id, bool visible)
{
	auto *btn = new button_info();
	btn->guibutton = m_guienv->addButton(button_rect, nullptr, id, L"O");
	btn->guibutton->setVisible(visible);
	btn->guibutton->grab();
	btn->ids.clear();

	load_button_texture(btn, joystick_imagenames[texture_id],
			button_rect, m_texturesource, m_device->getVideoDriver());

	return btn;
}

void TouchScreenGUI::init(ISimpleTextureSource *tsrc)
{
	assert(tsrc);

	m_visible       = true;
	m_texturesource = tsrc;

	/* Init joystick display "button"
	 * Joystick is placed on bottom left of screen.
	 */
	if (m_fixed_joystick) {
		m_joystick_btn_off = initJoystickButton(joystick_off_id,
				rect<s32>(button_size,
						m_screensize.Y - button_size * 4,
						button_size * 4,
						m_screensize.Y - button_size), 0);
	} else {
		m_joystick_btn_off = initJoystickButton(joystick_off_id,
				rect<s32>(button_size,
						m_screensize.Y - button_size * 3,
						button_size * 3,
						m_screensize.Y - button_size), 0);
	}

	m_joystick_btn_bg = initJoystickButton(joystick_bg_id,
			rect<s32>(button_size,
					m_screensize.Y - button_size * 4,
					button_size * 4,
					m_screensize.Y - button_size),
			1, false);

	m_joystick_btn_center = initJoystickButton(joystick_center_id,
			rect<s32>(0, 0, button_size, button_size), 2, false);

	// init jump button
	initButton(jump_id,
			rect<s32>(m_screensize.X - (1.75 * button_size),
					m_screensize.Y - button_size,
					m_screensize.X - (0.25 * button_size),
					m_screensize.Y),
			L"x", false);

	// init crunch button
	initButton(crunch_id,
			rect<s32>(m_screensize.X - (3.25 * button_size),
					m_screensize.Y - button_size,
					m_screensize.X - (1.75 * button_size),
					m_screensize.Y),
			L"H", false);

	// init zoom button
	initButton(zoom_id,
			rect<s32>(m_screensize.X - (1.25 * button_size),
					m_screensize.Y - (4 * button_size),
					m_screensize.X - (0.25 * button_size),
					m_screensize.Y - (3 * button_size)),
			L"z", false);

	// init special1/aux button
	if (!m_joystick_triggers_special1)
		initButton(special1_id,
				rect<s32>(m_screensize.X - (1.25 * button_size),
						m_screensize.Y - (2.5 * button_size),
						m_screensize.X - (0.25 * button_size),
						m_screensize.Y - (1.5 * button_size)),
				L"spc1", false);

	m_settingsbar.init(m_texturesource, "gear_icon.png", settings_starter_id,
		v2s32(m_screensize.X - (1.25 * button_size),
			m_screensize.Y - ((SETTINGS_BAR_Y_OFFSET + 1.0) * button_size)
				+ (0.5 * button_size)),
		v2s32(m_screensize.X - (0.25 * button_size),
			m_screensize.Y - (SETTINGS_BAR_Y_OFFSET * button_size)
				+ (0.5 * button_size)),
		AHBB_Dir_Right_Left, 3.0);

	m_settingsbar.addButton(fly_id,     L"fly",       "fly_btn.png");
	m_settingsbar.addButton(noclip_id,  L"noclip",    "noclip_btn.png");
	m_settingsbar.addButton(fast_id,    L"fast",      "fast_btn.png");
	m_settingsbar.addButton(debug_id,   L"debug",     "debug_btn.png");
	m_settingsbar.addButton(camera_id,  L"camera",    "camera_btn.png");
	m_settingsbar.addButton(range_id,   L"rangeview", "rangeview_btn.png");
	m_settingsbar.addButton(minimap_id, L"minimap",   "minimap_btn.png");

	// Chat is shown by default, so chat_hide_btn.png is shown first.
	m_settingsbar.addToggleButton(toggle_chat_id, L"togglechat",
			"chat_hide_btn.png", "chat_show_btn.png");

	m_rarecontrolsbar.init(m_texturesource, "rare_controls.png",
		rare_controls_starter_id,
		v2s32(0.25 * button_size,
			m_screensize.Y - ((RARE_CONTROLS_BAR_Y_OFFSET + 1.0) * button_size)
				+ (0.5 * button_size)),
		v2s32(0.75 * button_size,
			m_screensize.Y - (RARE_CONTROLS_BAR_Y_OFFSET * button_size)
				+ (0.5 * button_size)),
		AHBB_Dir_Left_Right, 2.0);

	m_rarecontrolsbar.addButton(chat_id,      L"Chat", "chat_btn.png");
	m_rarecontrolsbar.addButton(inventory_id, L"inv",  "inventory_btn.png");
	m_rarecontrolsbar.addButton(drop_id,      L"drop", "drop_btn.png");
}

touch_gui_button_id TouchScreenGUI::getButtonID(s32 x, s32 y)
{
	IGUIElement *rootguielement = m_guienv->getRootGUIElement();

	if (rootguielement != nullptr) {
		gui::IGUIElement *element =
				rootguielement->getElementFromPoint(core::position2d<s32>(x, y));

		if (element)
			for (unsigned int i = 0; i < after_last_element_id; i++)
				if (element == m_buttons[i].guibutton)
					return (touch_gui_button_id) i;
	}

	return after_last_element_id;
}

touch_gui_button_id TouchScreenGUI::getButtonID(size_t eventID)
{
	for (unsigned int i = 0; i < after_last_element_id; i++) {
		button_info *btn = &m_buttons[i];

		auto id = std::find(btn->ids.begin(), btn->ids.end(), eventID);

		if (id != btn->ids.end())
			return (touch_gui_button_id) i;
	}

	return after_last_element_id;
}

bool TouchScreenGUI::isHUDButton(const SEvent &event)
{
	// check if hud item is pressed
	for (auto &hud_rect : m_hud_rects) {
		if (hud_rect.second.isPointInside(v2s32(event.TouchInput.X,
				event.TouchInput.Y))) {
			auto *translated = new SEvent();
			memset(translated, 0, sizeof(SEvent));
			translated->EventType = irr::EET_KEY_INPUT_EVENT;
			translated->KeyInput.Key         = (irr::EKEY_CODE) (KEY_KEY_1 + hud_rect.first);
			translated->KeyInput.Control     <span class="hl slc">--trackplacer.lua</span>
<span class="hl slc">--holds code for the track-placing system. the default &apos;track&apos; item will be a craftitem that places rails as needed. this will neither place or change switches nor place vertical rails.</span>

<span class="hl slc">--all new trackplacer code</span>
<span class="hl kwa">local</span> tp<span class="hl opt">={</span>
	tracks<span class="hl opt">={}</span>
<span class="hl opt">}</span>

<span class="hl kwa">function</span> tp<span class="hl opt">.</span><span class="hl kwd">register_tracktype</span><span class="hl opt">(</span>nnprefix<span class="hl opt">,</span> n_suffix<span class="hl opt">)</span>
	<span class="hl kwa">if</span> tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">]</span> <span class="hl kwa">then return end</span><span class="hl slc">--due to the separate registration of slopes and flats for the same nnpref, definition would be overridden here. just don&apos;t.</span>
	tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">]={</span>
		default<span class="hl opt">=</span>n_suffix<span class="hl opt">,</span>
		single_conn<span class="hl opt">={},</span>
		single_conn_1<span class="hl opt">={},</span>
		single_conn_2<span class="hl opt">={},</span>
		double_conn<span class="hl opt">={},</span>
		double_conn_1<span class="hl opt">={},</span>
		double_conn_2<span class="hl opt">={},</span>
		<span class="hl slc">--keys:conn1_conn2 (example:1_4)</span>
		<span class="hl slc">--values:{name=x, param2=x}</span>
		twcycle<span class="hl opt">={},</span>
		twrotate<span class="hl opt">={},</span><span class="hl slc">--indexed by suffix, list, tells order of rotations</span>
		modify<span class="hl opt">={},</span>
	<span class="hl opt">}</span>
<span class="hl kwa">end</span>
<span class="hl kwa">function</span> tp<span class="hl opt">.</span><span class="hl kwd">add_double_conn</span><span class="hl opt">(</span>nnprefix<span class="hl opt">,</span> suffix<span class="hl opt">,</span> rotation<span class="hl opt">,</span> conns<span class="hl opt">)</span>
	<span class="hl kwa">local</span> nodename<span class="hl opt">=</span>nnprefix<span class="hl opt">..</span><span class="hl str">&quot;_&quot;</span><span class="hl opt">..</span>suffix<span class="hl opt">..</span>rotation
	<span class="hl kwa">for</span> i<span class="hl opt">=</span><span class="hl num">0</span><span class="hl opt">,</span><span class="hl num">3</span> <span class="hl kwa">do</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>double_conn<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn1<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)..</span><span class="hl str">&quot;_&quot;</span><span class="hl opt">..((</span>conns<span class="hl opt">.</span>conn2<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>double_conn<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn2<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)..</span><span class="hl str">&quot;_&quot;</span><span class="hl opt">..((</span>conns<span class="hl opt">.</span>conn1<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>double_conn_1<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn1<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)..</span><span class="hl str">&quot;_&quot;</span><span class="hl opt">..((</span>conns<span class="hl opt">.</span>conn2<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>double_conn_2<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn2<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)..</span><span class="hl str">&quot;_&quot;</span><span class="hl opt">..((</span>conns<span class="hl opt">.</span>conn1<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
	<span class="hl kwa">end</span>
	tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>modify<span class="hl opt">[</span>nodename<span class="hl opt">]=</span><span class="hl kwa">true</span>
<span class="hl kwa">end</span>
<span class="hl kwa">function</span> tp<span class="hl opt">.</span><span class="hl kwd">add_single_conn</span><span class="hl opt">(</span>nnprefix<span class="hl opt">,</span> suffix<span class="hl opt">,</span> rotation<span class="hl opt">,</span> conns<span class="hl opt">)</span>
	<span class="hl kwa">local</span> nodename<span class="hl opt">=</span>nnprefix<span class="hl opt">..</span><span class="hl str">&quot;_&quot;</span><span class="hl opt">..</span>suffix<span class="hl opt">..</span>rotation
	<span class="hl kwa">for</span> i<span class="hl opt">=</span><span class="hl num">0</span><span class="hl opt">,</span><span class="hl num">3</span> <span class="hl kwa">do</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>single_conn<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn1<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>single_conn<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn2<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>single_conn_1<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn1<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
		tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>single_conn_2<span class="hl opt">[((</span>conns<span class="hl opt">.</span>conn2<span class="hl opt">+</span><span class="hl num">4</span><span class="hl opt">*</span>i<span class="hl opt">)%</span><span class="hl num">16</span><span class="hl opt">)]={</span>name<span class="hl opt">=</span>nodename<span class="hl opt">,</span> param2<span class="hl opt">=</span>i<span class="hl opt">}</span>
	<span class="hl kwa">end</span>
	tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>modify<span class="hl opt">[</span>nodename<span class="hl opt">]=</span><span class="hl kwa">true</span>
<span class="hl kwa">end</span>


<span class="hl kwa">function</span> tp<span class="hl opt">.</span><span class="hl kwd">add_worked</span><span class="hl opt">(</span>nnprefix<span class="hl opt">,</span> suffix<span class="hl opt">,</span> rotation<span class="hl opt">,</span> cycle_follows<span class="hl opt">)</span>
	tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>twcycle<span class="hl opt">[</span>suffix<span class="hl opt">]=</span>cycle_follows
	<span class="hl kwa">if not</span> tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>twrotate<span class="hl opt">[</span>suffix<span class="hl opt">]</span> <span class="hl kwa">then</span> tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>twrotate<span class="hl opt">[</span>suffix<span class="hl opt">]={}</span> <span class="hl kwa">end</span>
	<span class="hl kwb">table</span><span class="hl opt">.</span><span class="hl kwd">insert</span><span class="hl opt">(</span>tp<span class="hl opt">.</span>tracks<span class="hl opt">[</span>nnprefix<span class="hl opt">].</span>twrotate<span class="hl opt">[</span>suffix<span class="hl opt">],</span> rotation<span class="hl opt">)</span>
<span class="hl kwa">end</span>


<span class="hl com">--[[</span>
<span class="hl com">	rewrite algorithm.</span>
<span class="hl com">	selection criteria: these will never be changed or even selected:</span>
<span class="hl com">	- tracks being already connected on both sides</span>
<span class="hl com">	- tracks that are already connected on one side but are not bendable to the desired position</span>
<span class="hl com">	the following situations can occur:</span>
<span class="hl com">	1. there are two more than two rails around</span>
<span class="hl com">		1.1 there is one or more subset(s) that can be directly connected</span>
<span class="hl com">			-&gt; choose the first possibility</span>
<span class="hl com">		2.2 not</span>
<span class="hl com">			-&gt; choose the first one and orient straight</span>
<span class="hl com">	2. there&apos;s exactly 1 rail around</span>
<span class="hl com">		-&gt; choose and orient straight</span>
<span class="hl com">	3. there&apos;s no rail around</span>
<span class="hl com">		-&gt; set straight</span>
<span class="hl com">]]</span>

<span class="hl kwa">local function</span> <span class="hl kwd">istrackandbc</span><span class="hl opt">(</span>pos_p<span class="hl opt">,</span> conn<span class="hl opt">)</span>
	<span class="hl kwa">local</span> tpos <span class="hl opt">=</span> pos_p
	<span class="hl kwa">local</span> cnode<span class="hl opt">=</span>minetest<span class="hl opt">.</span><span class="hl kwd">get_node</span><span class="hl opt">(</span>advtrains<span class="hl opt">.</span><span class="hl kwd">dirCoordSet</span><span class="hl opt">(</span>tpos<span class="hl opt">,</span> conn<span class="hl opt">.</span>c<span class="hl opt">))</span>
	<span class="hl kwa">if</span> advtrains<span class="hl opt">.</span><span class="hl kwd">is_track_and_drives_on</span><span class="hl opt">(</span>cnode<span class="hl opt">.</span>name<span class="hl opt">,</span> advtrains<span class="hl opt">.</span>all_tracktypes<span class="hl opt">)</span> <span class="hl kwa">then</span>
		<span class="hl kwa">local</span> cconns<span class="hl opt">=</span>advtrains<span class="hl opt">.</span><span class="hl kwd">get_track_connections</span><span class="hl opt">(</span>cnode<span class="hl opt">.</span>name<span class="hl opt">,</span> cnode<span class="hl opt">.</span>param2<span class="hl opt">)</span>
		<span class="hl kwa">return</span> advtrains<span class="hl opt">.</span><span class="hl kwd">conn_matches_to</span><span class="hl opt">(</span>conn<span class="hl opt">,</span> cconns<span class="hl opt">)</span>
	<span class="hl kwa">end</span>
	<span class="hl slc">--try the same 1 node below</span>
	tpos <span class="hl opt">= {</span>x<span class="hl opt">=</span>tpos<span class="hl opt">.</span>x<span class="hl opt">,</span> y<span class="hl opt">=</span>tpos<span class="hl opt">.</span>y<span class="hl opt">-</span><span class="hl num">1</span><span class="hl opt">,</span> z<span class="hl opt">=</span>tpos<span class="hl opt">.</span>z<span class="hl opt">}</span>
	cnode<span class="hl opt">=</span>minetest<span class="hl opt">.</span><span class="hl kwd">get_node</span><span class="hl opt">(</span>advtrains<span class="hl opt">.</span><span class="hl kwd">dirCoordSet</span><span class="hl opt">(</span>tpos<span class="hl opt">,</span> conn<span class="hl opt">.</span>c<span class="hl opt">))</span>
	<span class="hl kwa">if</span> advtrains<span class="hl opt">.</span><span class="hl kwd">is_track_and_drives_on</span><span class="hl opt">(</span>cnode<span class="hl opt">.</span>name<span class="hl opt">,</span> advtrains<span class="hl opt">.</span>all_tracktypes<span class="hl opt">)</span> <span class="hl kwa">then</span>
		<span class="hl kwa">local</span> cconns<span class="hl opt">=</span>advtrains<span class="hl opt">.</span><span class="hl kwd">get_track_connections</span><span class="hl opt">(</span>cnode<span class="hl opt">.</span>name<span class="hl opt">,</span> cnode<span class="hl opt">.</span>param2<span class="hl opt">)</span>
		<span class="hl kwa">return</span> advtrains<span class="hl opt">.</span><span class="hl kwd">conn_matches_to</span><span class="hl opt">(</span>conn<span class="hl opt">,</span> cconns<span class="hl opt">)</span>
	<span class="hl kwa">end</span>
	<span class="hl kwa">return false</span>
<span class="hl kwa">end</span>

<span class="hl kwa">function</span> tp<span class="hl opt">.</span><span class="hl kwd">find_already_connected</span><span class="hl opt">(</span>pos<span class="hl opt">)</span>
	<span class="hl kwa">local</span> dnode<span class="hl opt">=</span>minetest<span class="hl opt">.</span><span class="hl kwd">get_node</span><span class="hl opt">(</span>pos<span class="hl opt">)</span>
	<span class="hl kwa">local</span> dconns<span class="hl opt">=</span>advtrains<span class="hl opt">.</span><span class="hl kwd">get_track_connections</span><span class="hl opt">(</span>dnode<span class="hl opt">.</span>name<span class="hl opt">,</span> dnode<span class="hl opt">.</span>param2<span class="hl opt">)</span>
	<span class="hl kwa">local</span> found_conn
	<span class="hl kwa">for</span> connid<span class="hl opt">,</span> conn <span class="hl kwa">in</span> <span class="hl kwd">ipairs</span><span class="hl opt">(</span>dconns<span class="hl opt">)</span> <span class="hl kwa">do</span>
		<span class="hl kwa">if</span> <span class="hl kwd">istrackandbc</span><span class="hl opt">(</span>pos<span class="hl opt">,</span> conn<span class="hl opt">)</span> <span class="hl kwa">then</span>
			<span class="hl kwa">if</span> found_conn <span class="hl kwa">then</span> <span class="hl slc">--we found one in previous iteration</span>
				<span class="hl kwa">return true</span><span class="hl opt">,</span> <span class="hl kwa">true</span> <span class="hl slc">--signal that it&apos;s connected</span>
			<span class="hl kwa">else</span>
				found_conn <span class="hl opt">=</span> conn<span class="hl opt">.</span>c
			<span class="hl kwa">end</span>
		<span class="hl kwa">end</span>
	<span class="hl kwa">end</span>
	<span class="hl kwa">return</span> found_conn
<span class="hl kwa">end</span>
<span class="hl kwa">function</span> tp<span class="hl opt">.</span><span class="hl kwd">rail_and_can_be_bent</span><span class="hl opt">(</span>originpos<span class="hl opt">,</span> conn<span class="hl opt">)</span>
	<span class="hl kwa">local</span> pos<span class="hl opt">=</span>advtrains<span class="hl opt">.</span><span class="hl kwd">dirCoordSet</span><span class="hl opt">(</span>originpos<span class="hl opt">,</span> conn<span class="hl opt">)</span>
	<span class="hl kwa">local</span> newdir<span class="hl opt">=(</span>conn<span class="hl opt">+</span><span class="hl num">8</span><span class="hl opt">)%</span><span class="hl num">16</span>
	<span class="hl kwa">local</span> node<span class="hl opt">=</span>minetest<span class="hl opt">.</span><span class="hl kwd">get_node</span><span class="hl opt">(</span>pos<span class="hl opt">)</span>
	<span class="hl kwa">if not</span> advtrains<span class="hl opt">.</span><span class="hl kwd">is_track_and_drives_on</span><span class="hl opt">(</span>node<span class="hl opt">.</span>name<span class="hl opt">,</span> advtrains<span class="h