/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD 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 OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

/** @file newgrf_gui.cpp GUI to change NewGRF settings. */

#include "stdafx.h"
#include "error.h"
#include "settings_gui.h"
#include "newgrf.h"
#include "strings_func.h"
#include "window_func.h"
#include "gamelog.h"
#include "settings_type.h"
#include "settings_func.h"
#include "dropdown_type.h"
#include "dropdown_func.h"
#include "network/network.h"
#include "network/network_content.h"
#include "sortlist_type.h"
#include "stringfilter_type.h"
#include "querystring_gui.h"
#include "core/geometry_func.hpp"
#include "newgrf_text.h"
#include "textfile_gui.h"
#include "tilehighlight_func.h"
#include "fios.h"
#include "timer/timer.h"
#include "timer/timer_window.h"
#include "zoom_func.h"
#include "core/string_consumer.hpp"

#include "widgets/newgrf_widget.h"
#include "widgets/misc_widget.h"

#include "table/sprites.h"
#include "table/strings.h"

#include "safeguards.h"

/**
 * Show the first NewGRF error we can find.
 */
void ShowNewGRFError()
{
	/* Do not show errors when entering the main screen */
	if (_game_mode == GameMode::Menu) return;

	for (const auto &c : _grfconfig) {
		/* Only show Fatal and Error level messages */
		if (c->errors.empty()) continue;

		const GRFError &error = c->errors.back();
		if (error.severity != STR_NEWGRF_ERROR_MSG_FATAL && error.severity != STR_NEWGRF_ERROR_MSG_ERROR) continue;

		std::vector<StringParameter> params;
		params.emplace_back(c->GetName());
		params.emplace_back(error.message != STR_NULL ? error.message : STR_JUST_RAW_STRING);
		params.emplace_back(error.custom_message);
		params.emplace_back(c->filename);
		params.emplace_back(error.data);
		for (const uint32_t &value : error.param_value) params.emplace_back(value);

		if (error.severity == STR_NEWGRF_ERROR_MSG_FATAL) {
			ShowErrorMessage(GetEncodedStringWithArgs(STR_NEWGRF_ERROR_FATAL_POPUP, params), {}, WarningLevel::Critical);
		} else {
			ShowErrorMessage(GetEncodedStringWithArgs(STR_NEWGRF_ERROR_POPUP, params), {}, WarningLevel::Error);
		}
		break;
	}
}

static StringID GetGRFPaletteString(uint8_t palette)
{
	if (palette & GRFP_BLT_32BPP) {
		return (palette & GRFP_USE_WINDOWS) ? STR_NEWGRF_SETTINGS_PALETTE_LEGACY_32BPP : STR_NEWGRF_SETTINGS_PALETTE_DEFAULT_32BPP;
	}
	return (palette & GRFP_USE_WINDOWS) ? STR_NEWGRF_SETTINGS_PALETTE_LEGACY : STR_NEWGRF_SETTINGS_PALETTE_DEFAULT;
}

static void ShowNewGRFInfo(const GRFConfig &c, const Rect &r, bool show_params)
{
	Rect tr = r.Shrink(WidgetDimensions::scaled.frametext);
	for (const GRFError &error : c.errors) {
		std::array<StringParameter, 3 + std::tuple_size_v<decltype(error.param_value)>> params{};
		auto it = params.begin();
		*it++ = error.custom_message; // is skipped by built-in messages
		*it++ = c.filename;
		*it++ = error.data;
		for (const uint32_t &value : error.param_value) *it++ = value;

		tr.top = DrawStringMultiLine(tr, GetString(error.severity, GetStringWithArgs(error.message != STR_NULL ? error.message : STR_JUST_RAW_STRING, {params.begin(), it})));
	}

	/* Draw filename or not if it is not known (GRF sent over internet) */
	if (!c.filename.empty()) {
		tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_FILENAME, c.filename));
	}

	/* Prepare and draw GRF ID */
	tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_GRF_ID, fmt::format("{:08X}", std::byteswap(c.ident.grfid))));

	if ((_settings_client.gui.newgrf_developer_tools || _settings_client.gui.newgrf_show_old_versions) && c.version != 0) {
		tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_VERSION, c.version));
	}
	if ((_settings_client.gui.newgrf_developer_tools || _settings_client.gui.newgrf_show_old_versions) && c.min_loadable_version != 0) {
		tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_MIN_VERSION, c.min_loadable_version));
	}

	/* Prepare and draw MD5 sum */
	tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_MD5SUM, FormatArrayAsHex(c.ident.md5sum)));

	/* Show GRF parameter list */
	if (show_params) {
		if (!c.param.empty()) {
			tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_PARAMETER, STR_JUST_RAW_STRING, GRFBuildParamList(c)));
		} else {
			tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_PARAMETER, STR_NEWGRF_SETTINGS_PARAMETER_NONE, std::monostate{}));
		}

		/* Draw the palette of the NewGRF */
		tr.top = DrawStringMultiLine(tr, GetString(STR_NEWGRF_SETTINGS_PALETTE, GetGRFPaletteString(c.palette)));
	}

	/* Show flags */
	if (c.status == GRFStatus::NotFound)       tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_NOT_FOUND);
	if (c.status == GRFStatus::Disabled)        tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_DISABLED);
	if (c.flags.Test(GRFConfigFlag::Invalid))    tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_INCOMPATIBLE);
	if (c.flags.Test(GRFConfigFlag::Compatible)) tr.top = DrawStringMultiLine(tr, STR_NEWGRF_COMPATIBLE_LOADED);

	/* Draw GRF info if it exists */
	if (auto desc = c.GetDescription(); desc.has_value() && !desc->empty()) {
		tr.top = DrawStringMultiLine(tr, GetString(STR_JUST_RAW_STRING, std::move(*desc)), TextColour::Black);
	} else {
		tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_NO_INFO);
	}
}

/**
 * Window for setting the parameters of a NewGRF.
 */
struct NewGRFParametersWindow : public Window {
	static GRFParameterInfo dummy_parameter_info; ///< Dummy info in case a newgrf didn't provide info about some parameter.
	GRFConfig &grf_config; ///< Set the parameters of this GRFConfig.
	int32_t clicked_button = INT32_MAX; ///< The row in which a button was clicked or INT32_MAX when none is selected.
	bool clicked_increase = false; ///< True if the increase button was clicked, false for the decrease button.
	bool clicked_dropdown = false; ///< Whether the dropdown is open.
	bool closing_dropdown = false; ///< True, if the dropdown list is currently closing.
	int32_t clicked_row = INT32_MAX; ///< The selected parameter, or INT32_MAX when none is selected.
	int line_height = 0; ///< Height of a row in the matrix widget.
	Scrollbar *vscroll = nullptr;
	bool action14present = false; ///< True if action14 information is present.
	bool editable = false; ///< Allow editing parameters.

	NewGRFParametersWindow(WindowDesc &desc, bool is_baseset, GRFConfig &c, bool editable) : Window(desc),
		grf_config(c),
		editable(editable)
	{
		this->action14present = (this->grf_config.num_valid_params != GRFConfig::MAX_NUM_PARAMS || !this->grf_config.param_info.empty());

		this->CreateNestedTree();
		this->GetWidget<NWidgetCore>(WID_NP_CAPTION)->SetStringTip(is_baseset ? STR_BASEGRF_PARAMETERS_CAPTION : STR_NEWGRF_PARAMETERS_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS);
		this->vscroll = this->GetScrollbar(WID_NP_SCROLLBAR);
		this->GetWidget<NWidgetStacked>(WID_NP_SHOW_NUMPAR)->SetDisplayedPlane(this->action14present ? SZSP_HORIZONTAL : 0);
		this->GetWidget<NWidgetStacked>(WID_NP_SHOW_DESCRIPTION)->SetDisplayedPlane(this->action14present ? 0 : SZSP_HORIZONTAL);
		this->FinishInitNested();  // Initializes 'this->line_height' as side effect.

		this->SetWidgetDisabledState(WID_NP_RESET, !this->editable);

		this->InvalidateData();
	}

	/**
	 * Get a dummy parameter-info object with default information.
	 * @param nr The param number that should be changed.
	 * @return GRFParameterInfo with dummy information about the given parameter.
	 */
	static GRFParameterInfo &GetDummyParameterInfo(uint nr)
	{
		dummy_parameter_info.param_nr = nr;
		return dummy_parameter_info;
	}

	/**
	 * Test if GRF Parameter Info exists for a given parameter index.
	 * @param nr The param number that should be tested.
	 * @return True iff the parameter info exists.
	 */
	bool HasParameterInfo(uint nr) const
	{
		return nr < this->grf_config.param_info.size() && this->grf_config.param_info[nr].has_value();
	}

	/**
	 * Get GRF Parameter Info exists for a given parameter index.
	 * If the parameter info does not exist, a dummy parameter-info is returned instead.
	 * @param nr The param number that should be got.
	 * @return Reference to the GRFParameterInfo.
	 */
	GRFParameterInfo &GetParameterInfo(uint nr) const
	{
		return this->HasParameterInfo(nr) ? this->grf_config.param_info[nr].value() : GetDummyParameterInfo(nr);
	}

	void UpdateWidgetSize(WidgetID widget, Dimension &size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension &fill, [[maybe_unused]] Dimension &resize) override
	{
		switch (widget) {
			case WID_NP_NUMPAR_DEC:
			case WID_NP_NUMPAR_INC: {
				size.width  = std::max(SETTING_BUTTON_WIDTH / 2, GetCharacterHeight(FontSize::Normal));
				size.height = std::max(SETTING_BUTTON_HEIGHT, GetCharacterHeight(FontSize::Normal));
				break;
			}

			case WID_NP_NUMPAR: {
				Dimension d = GetStringBoundingBox(GetString(this->GetWidget<NWidgetCore>(widget)->GetString(), GetParamMaxValue(GRFConfig::MAX_NUM_PARAMS)));
				d.width += padding.width;
				d.height += padding.height;
				size = maxdim(size, d);
				break;
			}

			case WID_NP_BACKGROUND:
				this->line_height = std::max(SETTING_BUTTON_HEIGHT, GetCharacterHeight(FontSize::Normal)) + padding.height;

				resize.width = 1;
				fill.height = resize.height = this->line_height;
				size.height = 5 * this->line_height;
				break;

			case WID_NP_DESCRIPTION:
				/* Minimum size of 4 lines. The 500 is the default size of the window. */
				Dimension suggestion = {500U - WidgetDimensions::scaled.frametext.Horizontal(), (uint)GetCharacterHeight(FontSize::Normal) * 4 + WidgetDimensions::scaled.frametext.Vertical()};
				for (const auto &par_info : this->grf_config.param_info) {
					if (!par_info.has_value()) continue;
					auto desc = GetGRFStringFromGRFText(par_info->desc);
					if (!desc.has_value()) continue;
					Dimension d = GetStringMultiLineBoundingBox(*desc, suggestion);
					d.height += WidgetDimensions::scaled.frametext.Vertical();
					suggestion = maxdim(d, suggestion);
				}
				size.height = suggestion.height;
				break;
		}
	}

	std::string GetWidgetString(WidgetID widget, StringID stringid) const override
	{
		switch (widget) {
			case WID_NP_NUMPAR:
				return GetString(STR_NEWGRF_PARAMETERS_NUM_PARAM, this->vscroll->GetCount());

			default:
				return this->Window::GetWidgetString(widget, stringid);
		}
	}

	std::pair<StringParameter, StringParameter> GetValueParams(const GRFParameterInfo &par_info, uint32_t value) const
	{
		if (par_info.type == GRFParameterType::Bool) return {value != 0 ? STR_CONFIG_SETTING_ON : STR_CONFIG_SETTING_OFF, {}};

		auto it = std::ranges::lower_bound(par_info.value_names, value, std::less{}, &GRFParameterInfo::ValueName::first);
		if (it != std::end(par_info.value_names) && it->first == value) {
			if (auto label = GetGRFStringFromGRFText(it->second); label.has_value()) return {STR_JUST_RAW_STRING, *label};
		}

		return {STR_JUST_INT, value};
	}

	std::string GetSettingString(const GRFParameterInfo &par_info, int i, uint32_t value) const
	{
		auto [param1, param2] = this->GetValueParams(par_info, value);
		auto name = GetGRFStringFromGRFText(par_info.name);
		return name.has_value()
			? GetString(STR_NEWGRF_PARAMETERS_SETTING, STR_JUST_RAW_STRING, std::string(*name), param1, param2)
			: GetString(STR_NEWGRF_PARAMETERS_SETTING, STR_NEWGRF_PARAMETERS_DEFAULT_NAME, i + 1, param1, param2);
	}

	void DrawWidget(const Rect &r, WidgetID widget) const override
	{
		if (widget == WID_NP_DESCRIPTION) {
			if (!this->HasParameterInfo(this->clicked_row)) return;
			const GRFParameterInfo &par_info = this->GetParameterInfo(this->clicked_row);
			auto desc = GetGRFStringFromGRFText(par_info.desc);
			if (!desc.has_value()) return;
			DrawStringMultiLine(r.Shrink(WidgetDimensions::scaled.framerect), *desc, TextColour::Black);
			return;
		} else if (widget != WID_NP_BACKGROUND) {
			return;
		}

		Rect ir = r.Shrink(WidgetDimensions::scaled.frametext, RectPadding::zero);
		bool rtl = _current_text_dir == TD_RTL;
		uint buttons_left = rtl ? ir.right - SETTING_BUTTON_WIDTH : ir.left;
		Rect tr = ir.Indent(SETTING_BUTTON_WIDTH + WidgetDimensions::scaled.hsep_wide, rtl);

		int button_y_offset = (this->line_height - SETTING_BUTTON_HEIGHT) / 2;
		int text_y_offset = (this->line_height - GetCharacterHeight(FontSize::Normal)) / 2;
		for (int32_t i = this->vscroll->GetPosition(); this->vscroll->IsVisible(i) && i < this->vscroll->GetCount(); i++) {
			GRFParameterInfo &par_info = this->GetParameterInfo(i);
			uint32_t current_value = this->grf_config.GetValue(par_info);
			bool selected = (i == this->clicked_row);

			if (par_info.type == GRFParameterType::Bool) {
				DrawBoolButton(buttons_left, ir.top + button_y_offset, Colours::Yellow, Colours::Mauve, current_value != 0, this->editable);
			} else if (par_info.type == GRFParameterType::UintEnum) {
				if (par_info.complete_labels) {
					DrawDropDownButton(buttons_left, ir.top + button_y_offset, Colours::Yellow, this->clicked_row == i && this->clicked_dropdown, this->editable);
				} else {
					DrawArrowButtons(buttons_left, ir.top + button_y_offset, Colours::Yellow, (this->clicked_button == i) ? 1 + (this->clicked_increase != rtl) : 0, this->editable && current_value > par_info.min_value, this->editable && current_value < par_info.max_value);
				}
			}

			DrawString(tr.left, tr.right, ir.top + text_y_offset, this->GetSettingString(par_info, i, current_value), selected ? TextColour::White : TextColour::LightBlue);
			ir.top += this->line_height;
		}
	}

	void OnPaint() override
	{
		if (this->closing_dropdown) {
			this->closing_dropdown = false;
			this->clicked_dropdown = false;
		}
		this->DrawWidgets();
	}

	void OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count) override
	{
		switch (widget) {
			case WID_NP_NUMPAR_DEC:
				if (this->editable && !this->action14present && !this->grf_config.param.empty()) {
					this->grf_config.param.pop_back();
					this->InvalidateData();
					SetWindowDirty(WindowClass::GameOptions, GameOptionsWindowNumber::NewGRFState);
				}
				break;

			case WID_NP_NUMPAR_INC:
				if (this->editable && !this->action14present && this->grf_config.param.size() < this->grf_config.num_valid_params) {
					this->grf_config.param.emplace_back(0);
					this->InvalidateData();
					SetWindowDirty(WindowClass::GameOptions, GameOptionsWindowNumber::NewGRFState);
				}
				break;

			case WID_NP_BACKGROUND: {
				if (!this->editable) break;
				int32_t num = this->vscroll->GetScrolledRowFromWidget(pt.y, this, WID_NP_BACKGROUND);
				if (num >= this->vscroll->GetCount()) break;

				if (this->clicked_row != num) {
					this->CloseChildWindows(WindowClass::QueryString);
					this->CloseChildWindows(WindowClass::DropdownMenu);
					this->clicked_row = num;
					this->clicked_dropdown = false;
				}

				Rect r = this->GetWidget<NWidgetBase>(widget)->GetCurrentRect().Shrink(WidgetDimensions::scaled.frametext, RectPadding::zero);
				int x = pt.x - r.left;
				if (_current_text_dir == TD_RTL) x = r.Width() - 1 - x;

				GRFParameterInfo &par_info = this->GetParameterInfo(num);

				/* One of the arrows is clicked */
				uint32_t old_val = this->grf_config.GetValue(par_info);
				if (par_info.type != GRFParameterType::Bool && IsInsideMM(x, 0, SETTING_BUTTON_WIDTH) && par_info.complete_labels) {
					if (this->clicked_dropdown) {
						/* unclick the dropdown */
						this->CloseChildWindows(WindowClass::DropdownMenu);
						this->clicked_dropdown = false;
						this->closing_dropdown = false;
					} else {
						int rel_y = (pt.y - r.top) % this->line_height;

						Rect wi_rect;
						wi_rect.left = pt.x - (_current_text_dir == TD_RTL ? SETTING_BUTTON_WIDTH - 1 - x : x);;
						wi_rect.right = wi_rect.left + SETTING_BUTTON_WIDTH - 1;
						wi_rect.top = pt.y - rel_y + (this->line_height - SETTING_BUTTON_HEIGHT) / 2;
						wi_rect.bottom = wi_rect.top + SETTING_BUTTON_HEIGHT - 1;

						/* For dropdowns we also have to check the y position thoroughly, the mouse may not above the just opening dropdown */
						if (pt.y >= wi_rect.top && pt.y <= wi_rect.bottom) {
							this->clicked_dropdown = true;
							this->closing_dropdown = false;

							DropDownList list;
							for (const auto &[value, name] : par_info.value_names) {
								auto text = GetGRFStringFromGRFText(name);
								assert(text.has_value()); // ensured by "complete_labels"
								list.push_back(MakeDropDownListStringItem(GetString(STR_JUST_RAW_STRING, std::string(*text)), value));
							}

							ShowDropDownListAt(this, std::move(list), old_val, WID_NP_SETTING_DROPDOWN, wi_rect, Colours::Orange);
						}
					}
				} else if (IsInsideMM(x, 0, SETTING_BUTTON_WIDTH)) {
					uint32_t val = old_val;
					if (par_info.type == GRFParameterType::Bool) {
						val = !val;
					} else {
						if (x >= SETTING_BUTTON_WIDTH / 2) {
							/* Increase button clicked */
							if (val < par_info.max_value) val++;
							this->clicked_increase = true;
						} else {
							/* Decrease button clicked */
							if (val > par_info.min_value) val--;
							this->clicked_increase = false;
						}
					}
					if (val != old_val) {
						this->grf_config.SetValue(par_info, val);

						this->clicked_button = num;
						this->unclick_timeout.Reset();
					}
				} else if (par_info.type == GRFParameterType::UintEnum && !par_info.complete_labels && click_count >= 2) {
					/* Display a query box so users can enter a custom value. */
					ShowQueryString(GetString(STR_JUST_INT, old_val), STR_CONFIG_SETTING_QUERY_CAPTION, 10, this, CS_NUMERAL, {});
				}
				this->SetDirty();
				break;
			}

			case WID_NP_RESET:
				if (!this->editable) break;
				this->grf_config.SetParameterDefaults();
				this->InvalidateData();
				SetWindowDirty(WindowClass::GameOptions, GameOptionsWindowNumber::NewGRFState);
				break;
		}
	}

	void OnQueryTextFinished(std::optional<std::string> str) override
	{
		if (!str.has_value() || str->empty()) return;
		auto value = ParseInteger<int32_t>(*str, 10, true);
		if (!value.has_value()) return;
		GRFParameterInfo &par_info = this->GetParameterInfo(this->clicked_row);
		this->grf_config.SetValue(par_info, *value);
		this->SetDirty();
	}

	void OnDropdownSelect(WidgetID widget, int index, int) override
	{
		if (widget != WID_NP_SETTING_DROPDOWN) return;
		assert(this->clicked_dropdown);
		GRFParameterInfo &par_info = this->GetParameterInfo(this->clicked_row);
		this->grf_config.SetValue(par_info, index);
		this->SetDirty();
	}

	void OnDropdownClose(Point, WidgetID widget, int, int, bool) override
	{
		if (widget != WID_NP_SETTING_DROPDOWN) return;
		/* We cannot raise the dropdown button just yet. OnClick needs some hint, whether
		 * the same dropdown button was clicked again, and then not open the dropdown again.
		 * So, we only remember that it was closed, and process it on the next OnPaint, which is
		 * after OnClick. */
		assert(this->clicked_dropdown);
		this->closing_dropdown = true;
		this->SetDirty();
	}

	void OnResize() override
	{
		this->vscroll->SetCapacityFromWidget(this, WID_NP_BACKGROUND);
	}

	/**
	 * Some data on this window has become invalid.
	 * @param data Information about the changed data.
	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
	 */
	void OnInvalidateData([[maybe_unused]] int data = 0, [[maybe_unused]] bool gui_scope = true) override
	{
		if (!gui_scope) return;
		if (!this->action14present) {
			this->SetWidgetDisabledState(WID_NP_NUMPAR_DEC, !this->editable || this->grf_config.param.empty());
			this->SetWidgetDisabledState(WID_NP_NUMPAR_INC, !this->editable || std::size(this->grf_config.param) >= this->grf_config.num_valid_params);
		}

		this->vscroll->SetCount(this->action14present ? this->grf_config.num_valid_params : this->grf_config.param.size());
		if (this->clicked_row != INT32_MAX && this->clicked_row >= this->vscroll->GetCount()) {
			this->clicked_row = INT32_MAX;
			this->CloseChildWindows(WindowClass::QueryString);
		}
	}

	/** When reset, unclick the button after a small timeout. */
	TimeoutTimer<TimerWindow> unclick_timeout = {std::chrono::milliseconds(150), [this]() {
		this->clicked_button = INT32_MAX;
		this->SetDirty();
	}};
};
GRFParameterInfo NewGRFParametersWindow::dummy_parameter_info(0);


static constexpr std::initializer_list<NWidgetPart> _nested_newgrf_parameter_widgets = {
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_CLOSEBOX, Colours::Mauve),
		NWidget(WWT_CAPTION, Colours::Mauve, WID_NP_CAPTION),
		NWidget(WWT_DEFSIZEBOX, Colours::Mauve),
	EndContainer(),
	NWidget(NWID_SELECTION, Colours::Invalid, WID_NP_SHOW_NUMPAR),
		NWidget(WWT_PANEL, Colours::Mauve), SetResize(1, 0), SetFill(1, 0), SetPIP(4, 0, 4),
			NWidget(NWID_HORIZONTAL), SetPIP(4, 0, 4),
				NWidget(WWT_PUSHARROWBTN, Colours::Yellow, WID_NP_NUMPAR_DEC), SetMinimalSize(12, 12), SetArrowWidgetTypeTip(ArrowWidgetType::Decrease),
				NWidget(WWT_PUSHARROWBTN, Colours::Yellow, WID_NP_NUMPAR_INC), SetMinimalSize(12, 12), SetArrowWidgetTypeTip(ArrowWidgetType::Increase),
				NWidget(WWT_TEXT, Colours::Invalid, WID_NP_NUMPAR), SetResize(1, 0), SetFill(1, 0), SetPadding(0, 0, 0, 4),
			EndContainer(),
		EndContainer(),
	EndContainer(),
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_MATRIX, Colours::Mauve, WID_NP_BACKGROUND), SetMinimalSize(188, 182), SetResize(1, 1), SetFill(1, 0), SetMatrixDataTip(1, 0), SetScrollbar(WID_NP_SCROLLBAR),
		NWidget(NWID_VSCROLLBAR, Colours::Mauve, WID_NP_SCROLLBAR),
	EndContainer(),
	NWidget(NWID_SELECTION, Colours::Invalid, WID_NP_SHOW_DESCRIPTION),
		NWidget(WWT_PANEL, Colours::Mauve, WID_NP_DESCRIPTION), SetResize(1, 0), SetFill(1, 0),
		EndContainer(),
	EndContainer(),
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_PUSHTXTBTN, Colours::Mauve, WID_NP_RESET), SetStringTip(STR_NEWGRF_PARAMETERS_RESET, STR_NEWGRF_PARAMETERS_RESET_TOOLTIP),
		NWidget(WWT_PANEL, Colours::Mauve), SetResize(1, 0), SetFill(1, 0),
		EndContainer(),
		NWidget(WWT_RESIZEBOX, Colours::Mauve),
	EndContainer(),
};

/** Window definition for the change grf parameters window */
static WindowDesc _newgrf_parameters_desc(
	WindowPosition::Center, "settings_newgrf_config", 500, 208,
	WindowClass::NewGRFParameters, WindowClass::None,
	{},
	_nested_newgrf_parameter_widgets
);

void OpenGRFParameterWindow(bool is_baseset, GRFConfig &c, bool editable)
{
	CloseWindowByClass(WindowClass::NewGRFParameters);
	new NewGRFParametersWindow(_newgrf_parameters_desc, is_baseset, c, editable);
}

/** Window for displaying the textfile of a NewGRF. */
struct NewGRFTextfileWindow : public TextfileWindow {
	const GRFConfig *grf_config = nullptr; ///< View the textfile of this GRFConfig.

	NewGRFTextfileWindow(Window *parent, TextfileType file_type, const GRFConfig *c) : TextfileWindow(parent, file_type), grf_config(c)
	{
		this->ConstructWindow();

		auto textfile = this->grf_config->GetTextfile(file_type);
		this->LoadTextfile(textfile.value(), Subdirectory::NewGrf);
	}

	std::string GetWidgetString(WidgetID widget, StringID stringid) const override
	{
		if (widget == WID_TF_CAPTION) {
			return GetString(stringid, STR_CONTENT_TYPE_NEWGRF, this->grf_config->GetName());
		}

		return this->Window::GetWidgetString(widget, stringid);
	}
};

void ShowNewGRFTextfileWindow(Window *parent, TextfileType file_type, const GRFConfig *c)
{
	parent->CloseChildWindowById(WindowClass::Textfile, file_type);
	new NewGRFTextfileWindow(parent, file_type, c);
}

typedef std::map<uint32_t, const GRFConfig *> GrfIdMap; ///< Map of grfid to the grf config.

/**
 * Add all grf configs from \a c into the map.
 * @param lst Grf list to add.
 * @param grfid_map Map to add them to.
 */
static void FillGrfidMap(const GRFConfigList &lst, GrfIdMap &grfid_map)
{
	for (const auto &c : lst) {
		grfid_map.emplace(c->ident.grfid, c.get());
	}
}

static void NewGRFConfirmationCallback(Window *w, bool confirmed);
static void ShowSavePresetWindow(std::string_view initial_text);

/**
 * Window for showing NewGRF files
 */
struct NewGRFWindow : public Window, NewGRFScanCallback {
	typedef GUIList<const GRFConfig *, std::nullptr_t, StringFilter &> GUIGRFConfigList;

	static const uint EDITBOX_MAX_SIZE   =  50;

	static Listing   last_sorting;   ///< Default sorting of #GUIGRFConfigList.
	static Filtering last_filtering; ///< Default filtering of #GUIGRFConfigList.
	static const std::initializer_list<GUIGRFConfigList::SortFunction   * const> sorter_funcs; ///< Sort functions of the #GUIGRFConfigList.
	static const std::initializer_list<GUIGRFConfigList::FilterFunction * const> filter_funcs; ///< Filter functions of the #GUIGRFConfigList.

	GUIGRFConfigList avails{}; ///< Available (non-active) grfs.
	const GRFConfig *avail_sel = nullptr; ///< Currently selected available grf. \c nullptr is none is selected.
	int avail_pos = -1; ///< Index of #avail_sel if existing, else \c -1.
	StringFilter string_filter{}; ///< Filter for available grf.
	QueryString filter_editbox; ///< Filter editbox;

	StringList grf_presets{}; ///< List of known NewGRF presets.

	GRFConfigList actives{}; ///< Temporary active grf list to which changes are made.
	GRFConfig *active_sel = nullptr; ///< Selected active grf item.

	GRFConfigList &orig_list; ///< List active grfs in the game. Used as initial value, may be updated by the window.
	bool editable = false; ///< Is the window editable?
	bool show_params = false; ///< Are the grf-parameters shown in the info-panel?
	bool execute = false; ///< On pressing 'apply changes' are grf changes applied immediately, or only list is updated.
	int preset = -1; ///< Selected preset or \c -1 if none selected.
	int active_over = -1; ///< Active GRF item over which another one is dragged, \c -1 if none.
	bool modified = false; ///< The list of active NewGRFs has been modified since the last time they got saved.

	Scrollbar *vscroll = nullptr;
	Scrollbar *vscroll2 = nullptr;

	NewGRFWindow(WindowDesc &desc, bool editable, bool show_params, bool execute, GRFConfigList &orig_list) : Window(desc), filter_editbox(EDITBOX_MAX_SIZE), orig_list(orig_list)
	{
		this->editable    = editable;
		this->execute     = execute;
		this->show_params = show_params;

		CopyGRFConfigList(this->actives, orig_list, false);
		this->grf_presets = GetGRFPresetList();

		this->CreateNestedTree();
		this->vscroll = this->GetScrollbar(WID_NS_SCROLLBAR);
		this->vscroll2 = this->GetScrollbar(WID_NS_SCROLL2BAR);

		this->GetWidget<NWidgetStacked>(WID_NS_SHOW_REMOVE)->SetDisplayedPlane(this->editable ? 0 : 1);
		this->GetWidget<NWidgetStacked>(WID_NS_SHOW_EDIT)->SetDisplayedPlane(this->editable ? 0 : (this->show_params ? 1 : SZSP_HORIZONTAL));
		this->GetWidget<NWidgetStacked>(WID_NS_SHOW_APPLY)->SetDisplayedPlane(this->editable && this->execute ? 0 : SZSP_VERTICAL);
		this->FinishInitNested(GameOptionsWindowNumber::NewGRFState);

		this->querystrings[WID_NS_FILTER] = &this->filter_editbox;
		this->filter_editbox.cancel_button = QueryString::ACTION_CLEAR;
		if (editable) {
			this->SetFocusedWidget(WID_NS_FILTER);
		} else {
			this->DisableWidget(WID_NS_FILTER);
		}

		this->avails.SetListing(this->last_sorting);
		this->avails.SetFiltering(this->last_filtering);
		this->avails.SetSortFuncs(this->sorter_funcs);
		this->avails.SetFilterFuncs(this->filter_funcs);
		this->avails.ForceRebuild();

		this->OnInvalidateData(GOID_NEWGRF_CURRENT_LOADED);
	}

	void Close([[maybe_unused]] int data = 0) override
	{
		CloseWindowByClass(WindowClass::NewGRFParameters);
		CloseWindowByClass(WindowClass::SavePreset);

		if (this->editable && this->modified && !this->execute && !_exit_game) {
			CopyGRFConfigList(this->orig_list, this->actives, true);
			ResetGRFConfig(false);
			ReloadNewGRFData();
		}

		this->Window::Close();
	}

	int GetCurrentActivePosition() const
	{
		if (this->active_sel != nullptr) {
			auto it = std::ranges::find_if(this->actives, [this](const auto &c) { return c.get() == this->active_sel; });
			if (it != std::end(this->actives)) return static_cast<int>(std::distance(std::begin(this->actives), it));
		}
		return -1;
	}

	/**
	 * Test whether the currently active set of NewGRFs can be upgraded with the available NewGRFs.
	 * @return Whether an upgrade is possible.
	 */
	bool CanUpgradeCurrent()
	{
		GrfIdMap grfid_map;
		FillGrfidMap(this->actives, grfid_map);

		for (const auto &a : _all_grfs) {
			GrfIdMap::const_iterator iter = grfid_map.find(a->ident.grfid);
			if (iter != grfid_map.end() && a->version > iter->second->version) return true;
		}
		return false;
	}

	/** Upgrade the currently active set of NewGRFs. */
	void UpgradeCurrent()
	{
		GrfIdMap grfid_map;
		FillGrfidMap(this->actives, grfid_map);

		for (const auto &a : _all_grfs) {
			GrfIdMap::iterator iter = grfid_map.find(a->ident.grfid);
			if (iter == grfid_map.end() || iter->second->version >= a->version) continue;

			auto c = std::ranges::find_if(this->actives, [&iter](const auto &grfconfig) { return grfconfig.get() == iter->second; });
			assert(c != std::end(this->actives));
			auto d = std::make_unique<GRFConfig>(*a);
			if (d->IsCompatible((*c)->version)) {
				d->CopyParams(**c);
			} else {
				d->SetParameterDefaults();
			}
			if (this->active_sel == c->get()) {
				CloseWindowByClass(WindowClass::NewGRFParameters);
				this->CloseChildWindows(WindowClass::Textfile);
				this->active_sel = nullptr;
			}
			*c = std::move(d);
			iter->second = c->get();
		}
	}

	void UpdateWidgetSize(WidgetID widget, Dimension &size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension &fill, [[maybe_unused]] Dimension &resize) override
	{
		switch (widget) {
			case WID_NS_FILE_LIST:
			{
				Dimension d = maxdim(GetScaledSpriteSize(SPR_SQUARE), GetScaledSpriteSize(SPR_WARNING_SIGN));
				fill.height = resize.height = std::max<uint>(d.height + 2U, GetCharacterHeight(FontSize::Normal));
				size.height = std::max(size.height, padding.height + 6 * resize.height);
				break;
			}

			case WID_NS_AVAIL_LIST:
			{
				Dimension d = maxdim(GetScaledSpriteSize(SPR_SQUARE), GetScaledSpriteSize(SPR_WARNING_SIGN));
				fill.height = resize.height = std::max<uint>(d.height + 2U, GetCharacterHeight(FontSize::Normal));
				size.height = std::max(size.height, padding.height + 8 * resize.height);
				break;
			}

			case WID_NS_NEWGRF_INFO_TITLE: {
				Dimension dim = GetStringBoundingBox(STR_NEWGRF_SETTINGS_INFO_TITLE);
				size.height = std::max(size.height, dim.height + WidgetDimensions::scaled.frametext.Vertical());
				size.width  = std::max(size.width,  dim.width  + WidgetDimensions::scaled.frametext.Horizontal());
				break;
			}

			case WID_NS_NEWGRF_INFO:
				size.height = std::max<uint>(size.height, WidgetDimensions::scaled.framerect.Vertical() + 10 * GetCharacterHeight(FontSize::Normal));
				break;

			case WID_NS_PRESET_LIST: {
				Dimension d = GetStringBoundingBox(STR_NUM_CUSTOM);
				for (const auto &i : this->grf_presets) {
					d = maxdim(d, GetStringBoundingBox(GetString(STR_JUST_RAW_STRING, i)));
				}
				d.width += padding.width;
				size = maxdim(d, size);
				break;
			}

			case WID_NS_CONTENT_DOWNLOAD:
			case WID_NS_CONTENT_DOWNLOAD2: {
				Dimension d = GetStringBoundingBox(STR_NEWGRF_SETTINGS_FIND_MISSING_CONTENT_BUTTON);
				size = maxdim(d, GetStringBoundingBox(STR_INTRO_ONLINE_CONTENT));
				size.width  += padding.width;
				size.height += padding.height;
				break;
			}
		}
	}

	void OnResize() override
	{
		this->vscroll->SetCapacityFromWidget(this, WID_NS_FILE_LIST, WidgetDimensions::scaled.framerect.Vertical());
		this->vscroll2->SetCapacityFromWidget(this, WID_NS_AVAIL_LIST, WidgetDimensions::scaled.framerect.Vertical());
	}

	std::string GetWidgetString(WidgetID widget, StringID stringid) const override
	{
		switch (widget) {
			case WID_NS_PRESET_LIST:
				if (this->preset == -1) return GetString(STR_NUM_CUSTOM);

				return this->grf_presets[this->preset];

			default:
				return this->Window::GetWidgetString(widget, stringid);
		}
	}

	/**
	 * Pick the palette for the sprite of the grf to display.
	 * @param c grf to display.
	 * @return Palette for the sprite.
	 */
	inline PaletteID GetPalette(const GRFConfig &c) const
	{
		PaletteID pal;

		/* Pick a colour */
		switch (c.status) {
			case GRFStatus::NotFound:
			case GRFStatus::Disabled:
				pal = PALETTE_TO_RED;
				break;
			case GRFStatus::Activated:
				pal = PALETTE_TO_GREEN;
				break;
			default:
				pal = PALETTE_TO_BLUE;
				break;
		}

		/* Do not show a "not-failure" colour when it actually failed to load */
		if (pal != PALETTE_TO_RED) {
			if (c.flags.Test(GRFConfigFlag::Static)) {
				pal = PALETTE_TO_GREY;
			} else if (c.flags.Test(GRFConfigFlag::Compatible)) {
				pal = PALETTE_TO_ORANGE;
			}
		}

		return pal;
	}

	void DrawWidget(const Rect &r, WidgetID widget) const override
	{
		switch (widget) {
			case WID_NS_FILE_LIST: {
				const Rect br = r.Shrink(WidgetDimensions::scaled.bevel);
				GfxFillRect(br, PC_BLACK);

				Rect tr = r.Shrink(WidgetDimensions::scaled.framerect);
				uint step_height = this->GetWidget<NWidgetBase>(WID_NS_FILE_LIST)->resize_y;
				Dimension square = GetSpriteSize(SPR_SQUARE);
				Dimension warning = GetSpriteSize(SPR_WARNING_SIGN);
				int square_offset_y = (step_height - square.height) / 2;
				int warning_offset_y = (step_height - warning.height) / 2;
				int offset_y = (step_height - GetCharacterHeight(FontSize::Normal)) / 2;

				bool rtl = _current_text_dir == TD_RTL;
				uint text_left    = rtl ? tr.left : tr.left + square.width + 13;
				uint text_right   = rtl ? tr.right - square.width - 13 : tr.right;
				uint square_left  = rtl ? tr.right - square.width - 3 : tr.left + 3;
				uint warning_left = rtl ? tr.right - square.width - warning.width - 8 : tr.left + square.width + 8;

				int i = 0;
				for (const auto &c : this->actives) {
					if (this->vscroll->IsVisible(i)) {
						std::string text = c->GetName();
						bool h = (this->active_sel == c.get());
						PaletteID pal = this->GetPalette(*c);

						if (h) {
							GfxFillRect(br.left, tr.top, br.right, tr.top + step_height - 1, PC_DARK_BLUE);
						} else if (i == this->active_over) {
							/* Get index of current selection. */
							int active_sel_pos = this->GetCurrentActivePosition();
							if (active_sel_pos != this->active_over) {
								uint top = (active_sel_pos < 0 || this->active_over < active_sel_pos) ? tr.top + 1 : tr.top + step_height - 2;
								GfxFillRect(tr.left, top - 1, tr.right, top + 1, PC_GREY);
							}
						}
						DrawSprite(SPR_SQUARE, pal, square_left, tr.top + square_offset_y);
						if (!c->errors.empty()) DrawSprite(SPR_WARNING_SIGN, 0, warning_left, tr.top + warning_offset_y);
						uint txtoffset = c->errors.empty() ? 0 : warning.width;
						DrawString(text_left + (rtl ? 0 : txtoffset), text_right - (rtl ? txtoffset : 0), tr.top + offset_y, std::move(text), h ? TextColour::White : TextColour::Orange);
						tr.top += step_height;
					}
					i++;
				}
				if (i == this->active_over && this->vscroll->IsVisible(i)) { // Highlight is after the last GRF entry.
					GfxFillRect(tr.left, tr.top, tr.right, tr.top + 2, PC_GREY);
				}
				break;
			}

			case WID_NS_AVAIL_LIST: {
				const Rect br = r.Shrink(WidgetDimensions::scaled.bevel);
				GfxFillRect(br, this->active_over == -2 ? PC_DARK_GREY : PC_BLACK);

				Rect tr = r.Shrink(WidgetDimensions::scaled.framerect);
				uint step_height = this->GetWidget<NWidgetBase>(WID_NS_AVAIL_LIST)->resize_y;
				int offset_y = (step_height - GetCharacterHeight(FontSize::Normal)) / 2;

				auto [first, last] = this->vscroll2->GetVisibleRangeIterators(this->avails);
				for (auto it = first; it != last; ++it) {
					const GRFConfig *c = *it;
					bool h = (c == this->avail_sel);
					std::string text = c->GetName();

					if (h) GfxFillRect(br.left, tr.top, br.right, tr.top + step_height - 1, PC_DARK_BLUE);
					DrawString(tr.left, tr.right, tr.top + offset_y, std::move(text), h ? TextColour::White : TextColour::Silver);
					tr.top += step_height;
				}
				break;
			}

			case WID_NS_NEWGRF_INFO_TITLE: {
				/* Create the nice darker rectangle at the details top. */
				GfxFillRect(r.Shrink(WidgetDimensions::scaled.bevel), GetColourGradient(Colours::Mauve, Shade::Normal));
				DrawString(r.left, r.right, CentreBounds(r.top, r.bottom, GetCharacterHeight(FontSize::Normal)), STR_NEWGRF_SETTINGS_INFO_TITLE, TextColour::FromString, SA_HOR_CENTER);
				break;
			}

			case WID_NS_NEWGRF_INFO: {
				const GRFConfig *selected = this->active_sel;
				if (selected == nullptr) selected = this->avail_sel;
				if (selected != nullptr) {
					ShowNewGRFInfo(*selected, r, this->show_params);
				}
				break;
			}
		}
	}

	void OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count) override
	{
		if (widget >= WID_NS_NEWGRF_TEXTFILE && widget < WID_NS_NEWGRF_TEXTFILE + TFT_CONTENT_END) {
			if (this->active_sel == nullptr && this->avail_sel == nullptr) return;

			ShowNewGRFTextfileWindow(this, (TextfileType)(widget - WID_NS_NEWGRF_TEXTFILE), this->active_sel != nullptr ? this->active_sel : this->avail_sel);
			return;
		}

		switch (widget) {
			case WID_NS_PRESET_LIST: {
				DropDownList list;

				/* Add 'None' option for clearing list */
				list.push_back(MakeDropDownListStringItem(STR_NONE, -1));

				for (uint i = 0; i < this->grf_presets.size(); i++) {
					list.push_back(MakeDropDownListStringItem(std::string{this->grf_presets[i]}, i));
				}

				this->CloseChildWindows(WindowClass::QueryString); // Remove the parameter query window
				ShowDropDownList(this, std::move(list), this->preset, WID_NS_PRESET_LIST, 0, DropDownOption::Filterable);
				break;
			}

			case WID_NS_OPEN_URL: {
				const GRFConfig *c = (this->avail_sel == nullptr) ? this->active_sel : this->avail_sel;
				auto url = c->GetURL();
				if (url.has_value()) OpenBrowser(std::move(*url));
				break;
			}

			case WID_NS_PRESET_SAVE:
				ShowSavePresetWindow((this->preset == -1) ? std::string_view{} : this->grf_presets[this->preset]);
				break;

			case WID_NS_PRESET_DELETE:
				if (this->preset == -1) return;

				DeleteGRFPresetFromConfig(this->grf_presets[this->preset]);
				this->grf_presets = GetGRFPresetList();
				this->preset = -1;
				this->InvalidateData();
				this->CloseChildWindows(WindowClass::QueryString); // Remove the parameter query window
				break;

			case WID_NS_MOVE_UP: { // Move GRF up
				if (this->active_sel == nullptr || !this->editable) break;

				int pos = this->GetCurrentActivePosition();
				if (pos <= 0) break;

				std::swap(this->actives[pos - 1], this->actives[pos]);

				this->vscroll->ScrollTowards(pos - 1);
				this->preset = -1;
				this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
				break;
			}

			case WID_NS_MOVE_DOWN: { // Move GRF down
				if (this->active_sel == nullptr || !this->editable) break;

				int pos = this->GetCurrentActivePosition();
				if (pos == -1 || static_cast<size_t>(pos) >= this->actives.size() - 1) break;

				std::swap(this->actives[pos], this->actives[pos + 1]);

				this->vscroll->ScrollTowards(pos + 1);
				this->preset = -1;
				this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
				break;
			}

			case WID_NS_FILE_LIST: { // Select an active GRF.
				ResetObjectToPlace();

				const GRFConfig *old_sel = this->active_sel;
				uint i = this->vscroll->GetScrolledRowFromWidget(pt.y, this, WID_NS_FILE_LIST, WidgetDimensions::scaled.framerect.top);
				if (i < this->actives.size()) {
					this->active_sel = this->actives[i].get();
				} else {
					this->active_sel = nullptr;
				}
				if (this->active_sel != old_sel) {
					CloseWindowByClass(WindowClass::NewGRFParameters);
					this->CloseChildWindows(WindowClass::Textfile);
				}
				this->avail_sel = nullptr;
				this->avail_pos = -1;

				this->InvalidateData();
				if (click_count == 1) {
					if (this->editable && this->active_sel != nullptr) SetObjectToPlaceWnd(SPR_CURSOR_MOUSE, PAL_NONE, HT_DRAG, this);
					break;
				}
				/* With double click, continue */
				[[fallthrough]];
			}

			case WID_NS_REMOVE: { // Remove GRF
				if (this->active_sel == nullptr || !this->editable) break;
				CloseWindowByClass(WindowClass::NewGRFParameters);
				this->CloseChildWindows(WindowClass::Textfile);

				/* Choose the next GRF file to be the selected file. */
				int pos = this->GetCurrentActivePosition();
				if (pos < 0) break;

				auto it = std::next(std::begin(this->actives), pos);
				it = this->actives.erase(it);
				if (this->actives.empty()) {
					this->active_sel = nullptr;
				} else if (it == std::end(this->actives)) {
					this->active_sel = this->actives.back().get();
				} else {
					this->active_sel = it->get();
				}
				this->preset = -1;
				this->avail_pos = -1;
				this->avail_sel = nullptr;
				this->avails.ForceRebuild();
				this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
				break;
			}

			case WID_NS_UPGRADE: { // Upgrade GRF.
				if (!this->editable || this->actives.empty()) break;
				UpgradeCurrent();
				this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
				break;
			}

			case WID_NS_AVAIL_LIST: { // Select a non-active GRF.
				ResetObjectToPlace();

				auto it = this->vscroll2->GetScrolledItemFromWidget(this->avails, pt.y, this, WID_NS_AVAIL_LIST, WidgetDimensions::scaled.framerect.top);
				this->active_sel = nullptr;
				CloseWindowByClass(WindowClass::NewGRFParameters);
				if (it != std::end(this->avails)) {
					if (this->avail_sel != *it) this->CloseChildWindows(WindowClass::Textfile);
					this->avail_sel = *it;
					this->avail_pos = static_cast<int>(std::distance(std::begin(this->avails), it));
				}
				this->InvalidateData();
				if (click_count == 1) {
					if (this->editable && this->avail_sel != nullptr && !this->avail_sel->flags.Test(GRFConfigFlag::Invalid)) SetObjectToPlaceWnd(SPR_CURSOR_MOUSE, PAL_NONE, HT_DRAG, this);
					break;
				}
				/* With double click, continue */
				[[fallthrough]];
			}

			case WID_NS_ADD:
				if (this->avail_sel == nullptr || !this->editable || this->avail_sel->flags.Test(GRFConfigFlag::Invalid)) break;

				this->AddGRFToActive();
				break;

			case WID_NS_APPLY_CHANGES: // Apply changes made to GRF list
				if (!this->editable) break;

				ShowQuery(
					GetEncodedString(STR_NEWGRF_POPUP_CAUTION_CAPTION),
					GetEncodedString(STR_NEWGRF_CONFIRMATION_TEXT),
					this,
					NewGRFConfirmationCallback
				);

				this->CloseChildWindows(WindowClass::QueryString); // Remove the parameter query window
				break;

			case WID_NS_VIEW_PARAMETERS:
			case WID_NS_SET_PARAMETERS: { // Edit parameters
				if (this->active_sel == nullptr || !this->show_params || this->active_sel->num_valid_params == 0) break;

				OpenGRFParameterWindow(false, *this->active_sel, this->editable);
				this->InvalidateData(GOID_NEWGRF_CHANGES_MADE);
				break;
			}

			case WID_NS_TOGGLE_PALETTE:
				if (this->active_sel != nullptr && this->editable) {
					this->active_sel->palette ^= GRFP_USE_MASK;
					this->SetDirty();
					this->InvalidateData(GOID_NEWGRF_CHANGES_MADE);
				}
				break;

			case WID_NS_CONTENT_DOWNLOAD:
			case WID_NS_CONTENT_DOWNLOAD2:
				if (!_network_available) {
					ShowErrorMessage(GetEncodedString(STR_NETWORK_ERROR_NOTAVAILABLE), {}, WarningLevel::Error);
				} else {
					this->CloseChildWindows(WindowClass::QueryString); // Remove the parameter query window

					ShowMissingContentWindow(this->actives);
				}
				break;

			case WID_NS_RESCAN_FILES:
			case WID_NS_RESCAN_FILES2:
				RequestNewGRFScan(this);
				break;
		}
	}

	void OnNewGRFsScanned() override
	{
		if (this->active_sel == nullptr) this->CloseChildWindows(WindowClass::Textfile);
		this->avail_sel = nullptr;
		this->avail_pos = -1;
		this->avails.ForceRebuild();
		this->CloseChildWindows(WindowClass::QueryString); // Remove the parameter query window
	}

	void OnDropdownSelect(WidgetID widget, int index, int) override
	{
		if (widget != WID_NS_PRESET_LIST) return;
		if (!this->editable) return;

		ClearGRFConfigList(this->actives);
		this->preset = index;

		if (index != -1) {
			this->actives = LoadGRFPresetFromConfig(this->grf_presets[index]);
		}
		this->avails.ForceRebuild();

		ResetObjectToPlace();
		CloseWindowByClass(WindowClass::NewGRFParameters);
		this->CloseChildWindows(WindowClass::Textfile);
		this->active_sel = nullptr;
		this->InvalidateData(GOID_NEWGRF_CHANGES_MADE);
	}

	void OnQueryTextFinished(std::optional<std::string> str) override
	{
		if (!str.has_value()) return;

		SaveGRFPresetToConfig(*str, this->actives);
		this->grf_presets = GetGRFPresetList();

		/* Switch to this preset */
		for (uint i = 0; i < this->grf_presets.size(); i++) {
			if (this->grf_presets[i] == str) {
				this->preset = i;
				break;
			}
		}

		this->InvalidateData();
	}

	/**
	 * Updates the scroll bars for the active and inactive NewGRF lists.
	 */
	void UpdateScrollBars()
	{
		/* Update scrollbars */
		this->vscroll->SetCount(this->actives.size() + 1); // Reserve empty space for drag and drop handling.

		if (this->avail_pos >= 0) this->vscroll2->ScrollTowards(this->avail_pos);
	}

	/**
	 * Some data on this window has become invalid.
	 * @param data Information about the changed data. @see GameOptionsInvalidationData
	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
	 */
	void OnInvalidateData([[maybe_unused]] int data = 0, [[maybe_unused]] bool gui_scope = true) override
	{
		if (!gui_scope) return;
		switch (data) {
			default:
				/* Nothing important to do */
				break;

			case GOID_NEWGRF_RESCANNED:
				/* Search the list for items that are now found and mark them as such. */
				for (auto &c : this->actives) {
					bool compatible = c->flags.Test(GRFConfigFlag::Compatible);
					if (c->status != GRFStatus::NotFound && !compatible) continue;

					const GRFConfig *f = FindGRFConfig(c->ident.grfid, FindGRFConfigMode::Exact, compatible ? &c->original_md5sum : &c->ident.md5sum);
					if (f == nullptr || f->flags.Test(GRFConfigFlag::Invalid)) continue;

					c = std::make_unique<GRFConfig>(*f);
				}

				this->avails.ForceRebuild();
				[[fallthrough]];

			case GOID_NEWGRF_CURRENT_LOADED:
				this->modified = false;
				UpdateScrollBars();
				break;

			case GOID_NEWGRF_LIST_EDITED:
				this->preset = -1;
				[[fallthrough]];

			case GOID_NEWGRF_CHANGES_MADE:
				UpdateScrollBars();

				/* Changes have been made to the list of active NewGRFs */
				this->modified = true;

				break;
		}

		this->BuildAvailables();

		this->SetWidgetDisabledState(WID_NS_APPLY_CHANGES, !((this->editable && this->modified) || _settings_client.gui.newgrf_developer_tools));
		this->SetWidgetsDisabledState(!this->editable,
			WID_NS_PRESET_LIST,
			WID_NS_TOGGLE_PALETTE
		);
		this->SetWidgetDisabledState(WID_NS_ADD, !this->editable || this->avail_sel == nullptr || this->avail_sel->flags.Test(GRFConfigFlag::Invalid));
		this->SetWidgetDisabledState(WID_NS_UPGRADE, !this->editable || this->actives.empty() || !this->CanUpgradeCurrent());

		bool disable_all = this->active_sel == nullptr || !this->editable;
		this->SetWidgetsDisabledState(disable_all,
			WID_NS_REMOVE,
			WID_NS_MOVE_UP,
			WID_NS_MOVE_DOWN
		);

		const GRFConfig *selected_config = (this->avail_sel == nullptr) ? this->active_sel : this->avail_sel;
		for (TextfileType tft : EnumRange(TFT_CONTENT_BEGIN, TFT_CONTENT_END)) {
			this->SetWidgetDisabledState(WID_NS_NEWGRF_TEXTFILE + tft, selected_config == nullptr || !selected_config->GetTextfile(tft).has_value());
		}
		this->SetWidgetDisabledState(WID_NS_OPEN_URL, selected_config == nullptr || !selected_config->GetURL().has_value());

		this->SetWidgetDisabledState(WID_NS_SET_PARAMETERS, !this->show_params || this->active_sel == nullptr || this->active_sel->num_valid_params == 0);
		this->SetWidgetDisabledState(WID_NS_VIEW_PARAMETERS, !this->show_params || this->active_sel == nullptr || this->active_sel->num_valid_params == 0);
		this->SetWidgetDisabledState(WID_NS_TOGGLE_PALETTE, disable_all ||
				(!(_settings_client.gui.newgrf_developer_tools || _settings_client.gui.scenario_developer) && ((selected_config->palette & GRFP_GRF_MASK) != GRFP_GRF_UNSET)));

		if (!disable_all) {
			/* All widgets are now enabled, so disable widgets we can't use */
			if (this->active_sel == this->actives.front().get()) this->DisableWidget(WID_NS_MOVE_UP);
			if (this->active_sel == this->actives.back().get()) this->DisableWidget(WID_NS_MOVE_DOWN);
		}

		this->SetWidgetDisabledState(WID_NS_PRESET_DELETE, this->preset == -1);

		bool has_missing = false;
		bool has_compatible = false;
		for (const auto &c : this->actives) {
			has_missing    |= c->status == GRFStatus::NotFound;
			has_compatible |= c->flags.Test(GRFConfigFlag::Compatible);
		}
		StringID text;
		StringID tool_tip;
		if (has_missing || has_compatible) {
			text = STR_NEWGRF_SETTINGS_FIND_MISSING_CONTENT_BUTTON;
			tool_tip = STR_NEWGRF_SETTINGS_FIND_MISSING_CONTENT_TOOLTIP;
		} else {
			text = STR_INTRO_ONLINE_CONTENT;
			tool_tip = STR_INTRO_TOOLTIP_ONLINE_CONTENT;
		}
		this->GetWidget<NWidgetCore>(WID_NS_CONTENT_DOWNLOAD)->SetStringTip(text, tool_tip);
		this->GetWidget<NWidgetCore>(WID_NS_CONTENT_DOWNLOAD2)->SetStringTip(text, tool_tip);

		this->SetWidgetDisabledState(WID_NS_PRESET_SAVE, has_missing);
	}

	EventState OnKeyPress([[maybe_unused]] char32_t key, uint16_t keycode) override
	{
		if (!this->editable) return EventState::NotHandled;

		if (this->vscroll2->UpdateListPositionOnKeyPress(this->avail_pos, keycode) == EventState::NotHandled) return EventState::NotHandled;

		if (this->avail_pos >= 0) {
			this->active_sel = nullptr;
			CloseWindowByClass(WindowClass::NewGRFParameters);
			if (this->avail_sel != this->avails[this->avail_pos]) this->CloseChildWindows(WindowClass::Textfile);
			this->avail_sel = this->avails[this->avail_pos];
			this->vscroll2->ScrollTowards(this->avail_pos);
			this->InvalidateData(0);
		}

		return EventState::Handled;
	}

	void OnEditboxChanged(WidgetID widget) override
	{
		if (!this->editable) return;

		if (widget == WID_NS_FILTER) {
			string_filter.SetFilterTerm(this->filter_editbox.text.GetText());
			this->avails.SetFilterState(!string_filter.IsEmpty());
			this->avails.ForceRebuild();
			this->InvalidateData(0);
		}
	}

	void OnDragDrop(Point pt, WidgetID widget) override
	{
		if (!this->editable) return;

		if (widget == WID_NS_FILE_LIST) {
			if (this->active_sel != nullptr) {
				int from_pos = this->GetCurrentActivePosition();

				/* Gets the drag-and-drop destination offset. Ignore the last dummy line. */
				int to_pos = std::min(this->vscroll->GetScrolledRowFromWidget(pt.y, this, WID_NS_FILE_LIST, WidgetDimensions::scaled.framerect.top), this->vscroll->GetCount() - 2);
				if (to_pos != from_pos) { // Don't move NewGRF file over itself.
					if (to_pos > from_pos) ++to_pos;

					auto from = std::next(std::begin(this->actives), from_pos);
					auto to = std::next(std::begin(this->actives), to_pos);
					Slide(from, std::next(from), to);

					this->vscroll->ScrollTowards(to_pos);
					this->preset = -1;
					this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
				}
			} else if (this->avail_sel != nullptr) {
				int to_pos = std::min(this->vscroll->GetScrolledRowFromWidget(pt.y, this, WID_NS_FILE_LIST, WidgetDimensions::scaled.framerect.top), this->vscroll->GetCount() - 1);
				this->AddGRFToActive(to_pos);
				this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
			}
		} else if (widget == WID_NS_AVAIL_LIST && this->active_sel != nullptr) {
			/* Remove active NewGRF file by dragging it over available list. */
			Point dummy = {-1, -1};
			this->OnClick(dummy, WID_NS_REMOVE, 1);
			this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
		}

		ResetObjectToPlace();

		if (this->active_over != -1) {
			/* End of drag-and-drop, hide dragged destination highlight. */
			this->SetWidgetDirty(this->active_over == -2 ? WID_NS_AVAIL_LIST : WID_NS_FILE_LIST);
			this->active_over = -1;
		}
	}

	void OnMouseDrag(Point pt, WidgetID widget) override
	{
		if (!this->editable) return;

		if (widget == WID_NS_FILE_LIST && (this->active_sel != nullptr || this->avail_sel != nullptr)) {
			/* An NewGRF file is dragged over the active list. */
			int to_pos = this->vscroll->GetScrolledRowFromWidget(pt.y, this, WID_NS_FILE_LIST, WidgetDimensions::scaled.framerect.top);
			/* Skip the last dummy line if the source is from the active list. */
			to_pos = std::min(to_pos, this->vscroll->GetCount() - (this->active_sel != nullptr ? 2 : 1));

			if (to_pos != this->active_over) {
				this->active_over = to_pos;
				this->SetWidgetDirty(WID_NS_FILE_LIST);
			}
		} else if (widget == WID_NS_AVAIL_LIST && this->active_sel != nullptr) {
			this->active_over = -2;
			this->SetWidgetDirty(WID_NS_AVAIL_LIST);
		} else if (this->active_over != -1) {
			this->SetWidgetDirty(this->active_over == -2 ? WID_NS_AVAIL_LIST : WID_NS_FILE_LIST);
			this->active_over = -1;
		}
	}

private:
	/** Sort grfs by name. @copydoc GUIList::Sorter */
	static bool NameSorter(const GRFConfig * const &a, const GRFConfig * const &b)
	{
		std::string name_a = StrMakeValid(a->GetName(), {}); // Make a copy without control codes.
		std::string name_b = StrMakeValid(b->GetName(), {}); // Make a copy without control codes.
		int i = StrNaturalCompare(name_a, name_b, true); // Sort by name (natural sorting).
		if (i != 0) return i < 0;

		i = a->version - b->version;
		if (i != 0) return i < 0;

		return a->ident.md5sum < b->ident.md5sum;
	}

	/** Filter grfs by tags/name. @copydoc GUIList::FilterFunction */
	static bool TagNameFilter(const GRFConfig * const *item, StringFilter &filter)
	{
		filter.ResetState();
		filter.AddLine((*item)->GetName());
		filter.AddLine((*item)->filename);
		if (auto desc = (*item)->GetDescription(); desc.has_value()) filter.AddLine(*desc);
		return filter.GetState();;
	}

	void BuildAvailables()
	{
		if (!this->avails.NeedRebuild()) return;

		this->avails.clear();

		for (const auto &c : _all_grfs) {
			if (std::ranges::any_of(this->actives, [&c](const auto &gc) { return gc->ident.HasGrfIdentifier(c->ident.grfid, &c->ident.md5sum); })) continue;

			if (_settings_client.gui.newgrf_show_old_versions) {
				this->avails.push_back(c.get());
			} else {
				const GRFConfig *best = FindGRFConfig(c->ident.grfid, c->flags.Test(GRFConfigFlag::Invalid) ? FindGRFConfigMode::Newest : FindGRFConfigMode::NewestValid);
				/* Never triggers; FindGRFConfig returns either c, or a newer version of c. */
				assert(best != nullptr);

				/*
				 * If the best version is 0, then all NewGRF with this GRF ID
				 * have version 0, so for backward compatibility reasons we
				 * want to show them all.
				 * If we are the best version, then we definitely want to
				 * show that NewGRF!.
				 */
				if (best->version == 0 || best->ident.HasGrfIdentifier(c->ident.grfid, &c->ident.md5sum)) {
					this->avails.push_back(c.get());
				}
			}
		}

		this->avails.Filter(this->string_filter);
		this->avails.RebuildDone();
		this->avails.Sort();

		if (this->avail_sel != nullptr) {
			this->avail_pos = find_index(this->avails, this->avail_sel);
			if (this->avail_pos == -1) {
				this->avail_sel = nullptr;
			}
		}

		this->vscroll2->SetCount(this->avails.size()); // Update the scrollbar
	}

	/**
	 * Insert a GRF into the active list.
	 * @param ins_pos Insert GRF at this position.
	 * @return True if the GRF was successfully added.
	 */
	bool AddGRFToActive(int ins_pos = -1)
	{
		if (this->avail_sel == nullptr || !this->editable || this->avail_sel->flags.Test(GRFConfigFlag::Invalid)) return false;

		this->CloseChildWindows(WindowClass::Textfile);

		/* Get number of non-static NewGRFs. */
		size_t count = std::ranges::count_if(this->actives, [](const auto &gc) { return !gc->flags.Test(GRFConfigFlag::Static); });
		if (count >= NETWORK_MAX_GRF_COUNT) {
			ShowErrorMessage(GetEncodedString(STR_NEWGRF_TOO_MANY_NEWGRFS), {}, WarningLevel::Info);
			return false;
		}

		/* Check for duplicate GRF ID. */
		if (std::ranges::any_of(this->actives, [&grfid = this->avail_sel->ident.grfid](const auto &gc)  { return gc->ident.grfid == grfid; })) {
			ShowErrorMessage(GetEncodedString(STR_NEWGRF_DUPLICATE_GRFID), {}, WarningLevel::Info);
			return false;
		}

		auto entry = (ins_pos >= 0 && static_cast<size_t>(ins_pos) < std::size(this->actives))
			? std::next(std::begin(this->actives), ins_pos)
			: std::end(this->actives);

		/* Copy GRF details from scanned list. */
		entry = this->actives.insert(entry, std::make_unique<GRFConfig>(*this->avail_sel));
		(*entry)->SetParameterDefaults();

		/* Select next (or previous, if last one) item in the list. */
		int new_pos = this->avail_pos + 1;
		if (new_pos >= (int)this->avails.size()) new_pos = this->avail_pos - 1;
		this->avail_pos = new_pos;
		if (new_pos >= 0) this->avail_sel = this->avails[new_pos];

		this->avails.ForceRebuild();
		this->InvalidateData(GOID_NEWGRF_LIST_EDITED);
		return true;
	}
};

/**
 * Show the content list window with all missing grfs from the given list.
 * @param list The list of grfs to check for missing / not exactly matching ones.
 */
void ShowMissingContentWindow(const GRFConfigList &list)
{
	/* Only show the things in the current list, or everything when nothing's selected */
	ContentVector cv;
	for (const auto &c : list) {
		if (c->status != GRFStatus::NotFound && !c->flags.Test(GRFConfigFlag::Compatible)) continue;

		auto ci = std::make_unique<ContentInfo>();
		ci->type = ContentType::NewGRF;
		ci->state = ContentInfo::State::DoesNotExist;
		ci->name = c->GetName();
		ci->unique_id = std::byteswap(c->ident.grfid);
		ci->md5sum = c->flags.Test(GRFConfigFlag::Compatible) ? c->original_md5sum : c->ident.md5sum;
		cv.push_back(std::move(ci));
	}
	ShowNetworkContentListWindow(cv.empty() ? nullptr : &cv, ContentType::NewGRF);
}

Listing NewGRFWindow::last_sorting     = {false, 0};
Filtering NewGRFWindow::last_filtering = {false, 0};

const std::initializer_list<NewGRFWindow::GUIGRFConfigList::SortFunction * const> NewGRFWindow::sorter_funcs = {
	&NameSorter,
};

const std::initializer_list<NewGRFWindow::GUIGRFConfigList::FilterFunction * const> NewGRFWindow::filter_funcs = {
	&TagNameFilter,
};

/**
 * Custom nested widget container for the NewGRF gui.
 * Depending on the space in the gui, it uses either
 * - two column mode, put the #acs and the #avs underneath each other and the #inf next to it, or
 * - three column mode, put the #avs, #acs, and #inf each in its own column.
 */
class NWidgetNewGRFDisplay : public NWidgetBase {
public:
	static const uint MAX_EXTRA_INFO_WIDTH;    ///< Maximal additional width given to the panel.
	static const uint MIN_EXTRA_FOR_3_COLUMNS; ///< Minimal additional width needed before switching to 3 columns.

	std::unique_ptr<NWidgetBase> avs{}; ///< Widget with the available grfs list and buttons.
	std::unique_ptr<NWidgetBase> acs{}; ///< Widget with the active grfs list and buttons.
	std::unique_ptr<NWidgetBase> inf{}; ///< Info panel.
	bool editable = true; ///< Editable status of the parent NewGRF window (if \c false, drop all widgets that make the window editable).

	NWidgetNewGRFDisplay(std::unique_ptr<NWidgetBase> &&avs, std::unique_ptr<NWidgetBase> &&acs, std::unique_ptr<NWidgetBase> &&inf) : NWidgetBase(NWID_CUSTOM)
		, avs(std::move(avs))
		, acs(std::move(acs))
		, inf(std::move(inf))
	{
	}

	void SetupSmallestSize(Window *w) override
	{
		/* Copy state flag from the window. */
		assert(dynamic_cast<NewGRFWindow *>(w) != nullptr);
		NewGRFWindow *ngw = (NewGRFWindow *)w;
		this->editable = ngw->editable;

		this->avs->SetupSmallestSize(w);
		this->acs->SetupSmallestSize(w);
		this->inf->SetupSmallestSize(w);

		uint min_avs_width = this->avs->smallest_x + this->avs->padding.Horizontal();
		uint min_acs_width = this->acs->smallest_x + this->acs->padding.Horizontal();
		uint min_inf_width = this->inf->smallest_x + this->inf->padding.Horizontal();

		uint min_avs_height = this->avs->smallest_y + this->avs->padding.Vertical();
		uint min_acs_height = this->acs->smallest_y + this->acs->padding.Vertical();
		uint min_inf_height = this->inf->smallest_y + this->inf->padding.Vertical();

		/* Smallest window is in two column mode. */
		this->smallest_x = std::max(min_avs_width, min_acs_width) + WidgetDimensions::scaled.hsep_wide + min_inf_width;
		this->smallest_y = std::max(min_inf_height, min_acs_height + WidgetDimensions::scaled.vsep_wide + min_avs_height);

		/* Filling. */
		this->fill_x = std::lcm(this->avs->fill_x, this->acs->fill_x);
		if (this->inf->fill_x > 0 && (this->fill_x == 0 || this->fill_x > this->inf->fill_x)) this->fill_x = this->inf->fill_x;

		this->fill_y = this->avs->fill_y;
		if (this->acs->fill_y > 0 && (this->fill_y == 0 || this->fill_y > this->acs->fill_y)) this->fill_y = this->acs->fill_y;
		this->fill_y = std::lcm(this->fill_y, this->inf->fill_y);

		/* Resizing. */
		this->resize_x = std::lcm(this->avs->resize_x, this->acs->resize_x);
		if (this->inf->resize_x > 0 && (this->resize_x == 0 || this->resize_x > this->inf->resize_x)) this->resize_x = this->inf->resize_x;

		this->resize_y = this->avs->resize_y;
		if (this->acs->resize_y > 0 && (this->resize_y == 0 || this->resize_y > this->acs->resize_y)) this->resize_y = this->acs->resize_y;
		this->resize_y = std::lcm(this->resize_y, this->inf->resize_y);

		/* Make sure the height suits the 3 column (resp. not-editable) format; the 2 column format can easily fill space between the lists */
		this->smallest_y = ComputeMaxSize(min_acs_height, this->smallest_y + this->resize_y - 1, this->resize_y);
	}

	void AssignSizePosition(SizingType sizing, int x, int y, uint given_width, uint given_height, bool rtl) override
	{
		this->StoreSizePosition(sizing, x, y, given_width, given_height);

		uint min_avs_width = this->avs->smallest_x + this->avs->padding.Horizontal();
		uint min_acs_width = this->acs->smallest_x + this->acs->padding.Horizontal();
		uint min_inf_width = this->inf->smallest_x + this->inf->padding.Horizontal();

		uint min_list_width = std::max(min_avs_width, min_acs_width); // Smallest width of the lists such that they have equal width (incl padding).
		uint avs_extra_width = min_list_width - min_avs_width;   // Additional width needed for avs to reach min_list_width.
		uint acs_extra_width = min_list_width - min_acs_width;   // Additional width needed for acs to reach min_list_width.

		/* Use 2 or 3 columns? */
		uint min_three_columns = min_avs_width + min_acs_width + min_inf_width + 2 * WidgetDimensions::scaled.hsep_wide;
		uint min_two_columns   = min_list_width + min_inf_width + WidgetDimensions::scaled.hsep_wide;
		bool use_three_columns = this->editable && (min_three_columns + ScaleGUITrad(MIN_EXTRA_FOR_3_COLUMNS) <= given_width);

		/* Info panel is a separate column in both modes. Compute its width first. */
		uint extra_width, inf_width;
		if (use_three_columns) {
			extra_width = given_width - min_three_columns;
			inf_width = std::min<uint>(ScaleGUITrad(MAX_EXTRA_INFO_WIDTH), extra_width / 2);
		} else {
			extra_width = given_width - min_two_columns;
			inf_width = std::min<uint>(ScaleGUITrad(MAX_EXTRA_INFO_WIDTH), extra_width / 2);
		}
		inf_width = ComputeMaxSize(this->inf->smallest_x, this->inf->smallest_x + inf_width, this->inf->GetHorizontalStepSize(sizing));
		extra_width -= inf_width - this->inf->smallest_x;

		uint inf_height = ComputeMaxSize(this->inf->smallest_y, given_height, this->inf->GetVerticalStepSize(sizing));

		if (use_three_columns) {
			/* Three column display, first make both lists equally wide, then divide whatever is left between both lists.
			 * Only keep track of what avs gets, all other space goes to acs. */
			uint avs_width = std::min(avs_extra_width, extra_width);
			extra_width -= avs_width;
			extra_width -= std::min(acs_extra_width, extra_width);
			avs_width += extra_width / 2;

			avs_width = ComputeMaxSize(this->avs->smallest_x, this->avs->smallest_x + avs_width, this->avs->GetHorizontalStepSize(sizing));

			uint acs_width = given_width - // Remaining space, including horizontal padding.
					inf_width - this->inf->padding.Horizontal() -
					avs_width - this->avs->padding.Horizontal() - 2 * WidgetDimensions::scaled.hsep_wide;
			acs_width = ComputeMaxSize(min_acs_width, acs_width, this->acs->GetHorizontalStepSize(sizing)) -
					this->acs->padding.Horizontal();

			/* Never use fill_y on these; the minimal size is chosen, so that the 3 column view looks nice */
			uint avs_height = ComputeMaxSize(this->avs->smallest_y, given_height, this->avs->resize_y);
			uint acs_height = ComputeMaxSize(this->acs->smallest_y, given_height, this->acs->resize_y);

			/* Assign size and position to the children. */
			if (rtl) {
				x += this->inf->padding.left;
				this->inf->AssignSizePosition(sizing, x, y + this->inf->padding.top, inf_width, inf_height, rtl);
				x += inf_width + this->inf->padding.right + WidgetDimensions::scaled.hsep_wide;
			} else {
				x += this->avs->padding.left;
				this->avs->AssignSizePosition(sizing, x, y + this->avs->padding.top, avs_width, avs_height, rtl);
				x += avs_width + this->avs->padding.right + WidgetDimensions::scaled.hsep_wide;
			}

			x += this->acs->padding.left;
			this->acs->AssignSizePosition(sizing, x, y + this->acs->padding.top, acs_width, acs_height, rtl);
			x += acs_width + this->acs->padding.right + WidgetDimensions::scaled.hsep_wide;

			if (rtl) {
				x += this->avs->padding.left;
				this->avs->AssignSizePosition(sizing, x, y + this->avs->padding.top, avs_width, avs_height, rtl);
			} else {
				x += this->inf->padding.left;
				this->inf->AssignSizePosition(sizing, x, y + this->inf->padding.top, inf_width, inf_height, rtl);
			}
		} else {
			/* Two columns, all space in extra_width goes to both lists. Since the lists are underneath each other,
			 * the column is min_list_width wide at least. */
			uint avs_width = ComputeMaxSize(this->avs->smallest_x, this->avs->smallest_x + avs_extra_width + extra_width,
					this->avs->GetHorizontalStepSize(sizing));
			uint acs_width = ComputeMaxSize(this->acs->smallest_x, this->acs->smallest_x + acs_extra_width + extra_width,
					this->acs->GetHorizontalStepSize(sizing));

			uint min_avs_height = (!this->editable) ? 0 : this->avs->smallest_y + this->avs->padding.Vertical() + WidgetDimensions::scaled.vsep_wide;
			uint min_acs_height = this->acs->smallest_y + this->acs->padding.Vertical();
			uint extra_height = given_height - min_acs_height - min_avs_height;

			/* Never use fill_y on these; instead use WidgetDimensions::scaled.vsep_wide as filler */
			uint avs_height = ComputeMaxSize(this->avs->smallest_y, this->avs->smallest_y + extra_height / 2, this->avs->resize_y);
			if (this->editable) extra_height -= avs_height - this->avs->smallest_y;
			uint acs_height = ComputeMaxSize(this->acs->smallest_y, this->acs->smallest_y + extra_height, this->acs->resize_y);

			/* Assign size and position to the children. */
			if (rtl) {
				x += this->inf->padding.left;
				this->inf->AssignSizePosition(sizing, x, y + this->inf->padding.top, inf_width, inf_height, rtl);
				x += inf_width + this->inf->padding.right + WidgetDimensions::scaled.hsep_wide;

				this->acs->AssignSizePosition(sizing, x + this->acs->padding.left, y + this->acs->padding.top, acs_width, acs_height, rtl);
				if (this->editable) {
					this->avs->AssignSizePosition(sizing, x + this->avs->padding.left, y + given_height - avs_height - this->avs->padding.bottom, avs_width, avs_height, rtl);
				} else {
					this->avs->AssignSizePosition(sizing, 0, 0, this->avs->smallest_x, this->avs->smallest_y, rtl);
				}
			} else {
				this->acs->AssignSizePosition(sizing, x + this->acs->padding.left, y + this->acs->padding.top, acs_width, acs_height, rtl);
				if (this->editable) {
					this->avs->AssignSizePosition(sizing, x + this->avs->padding.left, y + given_height - avs_height - this->avs->padding.bottom, avs_width, avs_height, rtl);
				} else {
					this->avs->AssignSizePosition(sizing, 0, 0, this->avs->smallest_x, this->avs->smallest_y, rtl);
				}
				uint dx = this->acs->current_x + this->acs->padding.Horizontal();
				if (this->editable) {
					dx = std::max(dx, this->avs->current_x + this->avs->padding.Horizontal());
				}
				x += dx + WidgetDimensions::scaled.hsep_wide + this->inf->padding.left;
				this->inf->AssignSizePosition(sizing, x, y + this->inf->padding.top, inf_width, inf_height, rtl);
			}
		}
	}

	void FillWidgetLookup(WidgetLookup &widget_lookup) override
	{
		this->NWidgetBase::FillWidgetLookup(widget_lookup);
		this->avs->FillWidgetLookup(widget_lookup);
		this->acs->FillWidgetLookup(widget_lookup);
		this->inf->FillWidgetLookup(widget_lookup);
	}

	NWidgetCore *GetWidgetFromPos(int x, int y) override
	{
		if (!IsInsideBS(x, this->pos_x, this->current_x) || !IsInsideBS(y, this->pos_y, this->current_y)) return nullptr;

		NWidgetCore *nw = (this->editable) ? this->avs->GetWidgetFromPos(x, y) : nullptr;
		if (nw == nullptr) nw = this->acs->GetWidgetFromPos(x, y);
		if (nw == nullptr) nw = this->inf->GetWidgetFromPos(x, y);
		return nw;
	}

	void Draw(const Window *w) override
	{
		if (this->editable) this->avs->Draw(w);
		this->acs->Draw(w);
		this->inf->Draw(w);
	}
};

const uint NWidgetNewGRFDisplay::MAX_EXTRA_INFO_WIDTH    = 150;
const uint NWidgetNewGRFDisplay::MIN_EXTRA_FOR_3_COLUMNS = 50;

static constexpr std::initializer_list<NWidgetPart> _nested_newgrf_actives_widgets = {
	NWidget(NWID_VERTICAL), SetPIP(0, WidgetDimensions::unscaled.vsep_wide, 0),
		/* Left side, presets. */
		NWidget(NWID_VERTICAL),
			NWidget(NWID_HORIZONTAL),
				NWidget(WWT_TEXT, Colours::Invalid), SetStringTip(STR_NEWGRF_SETTINGS_SELECT_PRESET),
						SetPadding(0, WidgetDimensions::unscaled.hsep_wide, 0, 0),
				NWidget(WWT_DROPDOWN, Colours::Yellow, WID_NS_PRESET_LIST), SetFill(1, 0), SetResize(1, 0),
						SetToolTip(STR_NEWGRF_SETTINGS_PRESET_LIST_TOOLTIP),
			EndContainer(),
			NWidget(NWID_HORIZONTAL, NWidContainerFlag::EqualSize),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_PRESET_SAVE), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_NEWGRF_SETTINGS_PRESET_SAVE, STR_NEWGRF_SETTINGS_PRESET_SAVE_TOOLTIP),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_PRESET_DELETE), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_NEWGRF_SETTINGS_PRESET_DELETE, STR_NEWGRF_SETTINGS_PRESET_DELETE_TOOLTIP),
			EndContainer(),
		EndContainer(),

		NWidget(WWT_FRAME, Colours::Mauve), SetStringTip(STR_NEWGRF_SETTINGS_ACTIVE_LIST), SetPIP(0, WidgetDimensions::unscaled.vsep_wide, 0),
			/* Left side, active grfs. */
			NWidget(NWID_HORIZONTAL),
				NWidget(WWT_PANEL, Colours::Mauve),
					NWidget(WWT_INSET, Colours::Mauve, WID_NS_FILE_LIST), SetMinimalSize(100, 1), SetPadding(2),
							SetFill(1, 1), SetResize(1, 1), SetScrollbar(WID_NS_SCROLLBAR), SetToolTip(STR_NEWGRF_SETTINGS_FILE_TOOLTIP),
					EndContainer(),
				EndContainer(),
				NWidget(NWID_VSCROLLBAR, Colours::Mauve, WID_NS_SCROLLBAR),
			EndContainer(),

			/* Buttons. */
			NWidget(NWID_SELECTION, Colours::Invalid, WID_NS_SHOW_REMOVE),
				NWidget(NWID_HORIZONTAL, NWidContainerFlag::EqualSize), SetPIP(0, WidgetDimensions::unscaled.hsep_wide, 0),
					NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_REMOVE), SetFill(1, 0), SetResize(1, 0),
							SetStringTip(STR_NEWGRF_SETTINGS_REMOVE, STR_NEWGRF_SETTINGS_REMOVE_TOOLTIP),
					NWidget(NWID_VERTICAL),
						NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_MOVE_UP), SetFill(1, 0), SetResize(1, 0),
								SetStringTip(STR_NEWGRF_SETTINGS_MOVEUP, STR_NEWGRF_SETTINGS_MOVEUP_TOOLTIP),
						NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_MOVE_DOWN), SetFill(1, 0), SetResize(1, 0),
								SetStringTip(STR_NEWGRF_SETTINGS_MOVEDOWN, STR_NEWGRF_SETTINGS_MOVEDOWN_TOOLTIP),
					EndContainer(),
					NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_UPGRADE), SetFill(1, 0), SetResize(1, 0),
							SetStringTip(STR_NEWGRF_SETTINGS_UPGRADE, STR_NEWGRF_SETTINGS_UPGRADE_TOOLTIP),
				EndContainer(),

				NWidget(NWID_VERTICAL, NWidContainerFlag::EqualSize),
					NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_RESCAN_FILES2), SetFill(1, 0), SetResize(1, 0),
							SetStringTip(STR_NEWGRF_SETTINGS_RESCAN_FILES, STR_NEWGRF_SETTINGS_RESCAN_FILES_TOOLTIP),
					NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_CONTENT_DOWNLOAD2), SetFill(1, 0), SetResize(1, 0),
							SetStringTip(STR_INTRO_ONLINE_CONTENT, STR_INTRO_TOOLTIP_ONLINE_CONTENT),
				EndContainer(),
			EndContainer(),
		EndContainer(),
	EndContainer(),
};

static constexpr std::initializer_list<NWidgetPart> _nested_newgrf_availables_widgets = {
	NWidget(WWT_FRAME, Colours::Mauve), SetStringTip(STR_NEWGRF_SETTINGS_INACTIVE_LIST), SetPIP(0, WidgetDimensions::unscaled.vsep_wide, 0),
		/* Left side, available grfs, filter edit box. */
		NWidget(NWID_HORIZONTAL), SetPIP(0, WidgetDimensions::unscaled.hsep_wide, 0),
			NWidget(WWT_TEXT, Colours::Invalid), SetFill(0, 1), SetStringTip(STR_NEWGRF_FILTER_TITLE),
			NWidget(WWT_EDITBOX, Colours::Mauve, WID_NS_FILTER), SetFill(1, 0), SetResize(1, 0),
					SetStringTip(STR_LIST_FILTER_OSKTITLE, STR_LIST_FILTER_TOOLTIP),
		EndContainer(),

		/* Left side, available grfs. */
		NWidget(NWID_HORIZONTAL),
			NWidget(WWT_PANEL, Colours::Mauve),
				NWidget(WWT_INSET, Colours::Mauve, WID_NS_AVAIL_LIST), SetMinimalSize(100, 1), SetPadding(2),
						SetFill(1, 1), SetResize(1, 1), SetScrollbar(WID_NS_SCROLL2BAR),
				EndContainer(),
			EndContainer(),
			NWidget(NWID_VSCROLLBAR, Colours::Mauve, WID_NS_SCROLL2BAR),
		EndContainer(),

		/* Left side, available grfs, buttons. */
		NWidget(NWID_HORIZONTAL, NWidContainerFlag::EqualSize), SetPIP(0, WidgetDimensions::unscaled.hsep_wide, 0),
			NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_ADD), SetFill(1, 0), SetResize(1, 0),
					SetStringTip(STR_NEWGRF_SETTINGS_ADD, STR_NEWGRF_SETTINGS_ADD_FILE_TOOLTIP),
			NWidget(NWID_VERTICAL),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_RESCAN_FILES), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_NEWGRF_SETTINGS_RESCAN_FILES, STR_NEWGRF_SETTINGS_RESCAN_FILES_TOOLTIP),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_CONTENT_DOWNLOAD), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_INTRO_ONLINE_CONTENT, STR_INTRO_TOOLTIP_ONLINE_CONTENT),
			EndContainer(),
		EndContainer(),
	EndContainer(),
};

static constexpr std::initializer_list<NWidgetPart> _nested_newgrf_infopanel_widgets = {
	NWidget(NWID_VERTICAL), SetPIP(0, WidgetDimensions::unscaled.vsep_wide, 0),
		/* Right side, info panel. */
		NWidget(WWT_PANEL, Colours::Mauve),
			NWidget(WWT_EMPTY, Colours::Invalid, WID_NS_NEWGRF_INFO_TITLE), SetFill(1, 0), SetResize(1, 0),
			NWidget(WWT_EMPTY, Colours::Invalid, WID_NS_NEWGRF_INFO), SetFill(1, 1), SetResize(1, 1), SetMinimalSize(150, 100),
		EndContainer(),

		/* Right side, info buttons. */
		NWidget(NWID_VERTICAL),
			NWidget(NWID_HORIZONTAL, NWidContainerFlag::EqualSize),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_OPEN_URL), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_CONTENT_OPEN_URL, STR_CONTENT_OPEN_URL_TOOLTIP),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_NEWGRF_TEXTFILE + TFT_README), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_TEXTFILE_VIEW_README, STR_TEXTFILE_VIEW_README_TOOLTIP),
			EndContainer(),
			NWidget(NWID_HORIZONTAL, NWidContainerFlag::EqualSize),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_NEWGRF_TEXTFILE + TFT_CHANGELOG), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_TEXTFILE_VIEW_CHANGELOG, STR_TEXTFILE_VIEW_CHANGELOG_TOOLTIP),
				NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_NEWGRF_TEXTFILE + TFT_LICENSE), SetFill(1, 0), SetResize(1, 0),
						SetStringTip(STR_TEXTFILE_VIEW_LICENCE, STR_TEXTFILE_VIEW_LICENCE_TOOLTIP),
			EndContainer(),
		EndContainer(),

		/* Right side, config buttons. */
		NWidget(NWID_SELECTION, Colours::Invalid, WID_NS_SHOW_EDIT),
			NWidget(NWID_HORIZONTAL, NWidContainerFlag::EqualSize), SetPIP(0, WidgetDimensions::unscaled.hsep_wide, 0),
				NWidget(NWID_VERTICAL),
					NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_SET_PARAMETERS), SetFill(1, 0), SetResize(1, 0),
							SetStringTip(STR_NEWGRF_SETTINGS_SET_PARAMETERS),
					NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_TOGGLE_PALETTE), SetFill(1, 0), SetResize(1, 0),
							SetStringTip(STR_NEWGRF_SETTINGS_TOGGLE_PALETTE, STR_NEWGRF_SETTINGS_TOGGLE_PALETTE_TOOLTIP),
				EndContainer(),
				NWidget(NWID_SELECTION, Colours::Invalid, WID_NS_SHOW_APPLY),
					NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_APPLY_CHANGES), SetFill(1, 0), SetResize(1, 0),
							SetStringTip(STR_NEWGRF_SETTINGS_APPLY_CHANGES),
				EndContainer(),
			EndContainer(),
			NWidget(WWT_PUSHTXTBTN, Colours::Yellow, WID_NS_VIEW_PARAMETERS), SetFill(1, 0), SetResize(1, 0),
					SetStringTip(STR_NEWGRF_SETTINGS_SHOW_PARAMETERS),
		EndContainer(),
	EndContainer(),
};

/** Construct nested container widget for managing the lists and the info panel of the NewGRF GUI. @copydoc NWidgetFunctionType */
std::unique_ptr<NWidgetBase> NewGRFDisplay()
{
	std::unique_ptr<NWidgetBase> avs = MakeNWidgets(_nested_newgrf_availables_widgets, nullptr);
	std::unique_ptr<NWidgetBase> acs = MakeNWidgets(_nested_newgrf_actives_widgets, nullptr);
	std::unique_ptr<NWidgetBase> inf = MakeNWidgets(_nested_newgrf_infopanel_widgets, nullptr);

	return std::make_unique<NWidgetNewGRFDisplay>(std::move(avs), std::move(acs), std::move(inf));
}

/** Widget definition of the manage newgrfs window. */
static constexpr std::initializer_list<NWidgetPart> _nested_newgrf_widgets = {
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_CLOSEBOX, Colours::Mauve),
		NWidget(WWT_CAPTION, Colours::Mauve), SetStringTip(STR_NEWGRF_SETTINGS_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
		NWidget(WWT_DEFSIZEBOX, Colours::Mauve),
	EndContainer(),
	NWidget(WWT_PANEL, Colours::Mauve),
		NWidgetFunction(NewGRFDisplay), SetPadding(WidgetDimensions::unscaled.sparse_resize),
		/* Resize button. */
		NWidget(NWID_HORIZONTAL),
			NWidget(NWID_SPACER), SetFill(1, 0), SetResize(1, 0),
			NWidget(WWT_RESIZEBOX, Colours::Mauve), SetResizeWidgetTypeTip(ResizeWidgetType::HideBevel, STR_TOOLTIP_RESIZE),
		EndContainer(),
	EndContainer(),
};

/** Window definition of the manage newgrfs window. */
static WindowDesc _newgrf_desc(
	WindowPosition::Center, "settings_newgrf", 300, 263,
	WindowClass::GameOptions, WindowClass::None,
	{},
	_nested_newgrf_widgets
);

/**
 * Callback function for the newgrf 'apply changes' confirmation window
 * @param w Window which is calling this callback
 * @param confirmed boolean value, true when yes was clicked, false otherwise
 */
static void NewGRFConfirmationCallback(Window *w, bool confirmed)
{
	if (confirmed) {
		CloseWindowByClass(WindowClass::NewGRFParameters);
		w->CloseChildWindows(WindowClass::Textfile);
		NewGRFWindow *nw = dynamic_cast<NewGRFWindow*>(w);
		assert(nw != nullptr);

		_gamelog.StartAction(GamelogActionType::GRF);
		_gamelog.GRFUpdate(_grfconfig, nw->actives); // log GRF changes
		CopyGRFConfigList(nw->orig_list, nw->actives, false);
		ReloadNewGRFData();
		_gamelog.StopAction();

		/* Show new, updated list */
		int pos = nw->GetCurrentActivePosition();

		CopyGRFConfigList(nw->actives, nw->orig_list, false);

		if (nw->active_sel != nullptr) {
			/* Set current selection from position */
			if (static_cast<size_t>(pos) >= nw->actives.size()) {
				nw->active_sel = nw->actives.back().get();
			} else {
				auto it = std::next(std::begin(nw->actives), pos);
				nw->active_sel = it->get();
			}
		}
		nw->avails.ForceRebuild();
		nw->modified = false;

		w->InvalidateData();

		ReInitAllWindows(false);
		CloseWindowByClass(WindowClass::BuildObject);
	}
}



/**
 * Setup the NewGRF gui
 * @param editable allow the user to make changes to the grfconfig in the window
 * @param show_params show information about what parameters are set for the grf files
 * @param exec_changes if changes are made to the list (editable is true), apply these
 *        changes immediately or only update the list
 * @param config The GRFConfigList that will be shown.
 */
void ShowNewGRFSettings(bool editable, bool show_params, bool exec_changes, GRFConfigList &config)
{
	CloseWindowByClass(WindowClass::GameOptions);
	new NewGRFWindow(_newgrf_desc, editable, show_params, exec_changes, config);
}

/** Widget parts of the save preset window. */
static constexpr std::initializer_list<NWidgetPart> _nested_save_preset_widgets = {
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_CLOSEBOX, Colours::Grey),
		NWidget(WWT_CAPTION, Colours::Grey), SetStringTip(STR_SAVE_PRESET_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
		NWidget(WWT_DEFSIZEBOX, Colours::Grey),
	EndContainer(),
	NWidget(WWT_PANEL, Colours::Grey),
		NWidget(NWID_HORIZONTAL),
			NWidget(WWT_INSET, Colours::Grey, WID_SVP_PRESET_LIST), SetPadding(2, 1, 2, 2),
					SetToolTip(STR_SAVE_PRESET_LIST_TOOLTIP), SetResize(1, 10), SetScrollbar(WID_SVP_SCROLLBAR), EndContainer(),
			NWidget(NWID_VSCROLLBAR, Colours::Grey, WID_SVP_SCROLLBAR),
		EndContainer(),
	EndContainer(),
	NWidget(WWT_PANEL, Colours::Grey),
		NWidget(WWT_EDITBOX, Colours::Grey, WID_SVP_EDITBOX), SetPadding(2, 2, 2, 2), SetFill(1, 0), SetResize(1, 0),
				SetStringTip(STR_SAVE_PRESET_TITLE, STR_SAVE_PRESET_EDITBOX_TOOLTIP),
	EndContainer(),
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_PUSHTXTBTN, Colours::Grey, WID_SVP_SAVE), SetStringTip(STR_SAVE_PRESET_SAVE, STR_SAVE_PRESET_SAVE_TOOLTIP), SetFill(1, 0), SetResize(1, 0),
		NWidget(WWT_RESIZEBOX, Colours::Grey),
	EndContainer(),
};

/** Window description of the preset save window. */
static WindowDesc _save_preset_desc(
	WindowPosition::Center, "save_preset", 140, 110,
	WindowClass::SavePreset, WindowClass::GameOptions,
	WindowDefaultFlag::Modal,
	_nested_save_preset_widgets
);

/** Class for the save preset window. */
struct SavePresetWindow : public Window {
	QueryString presetname_editbox; ///< Edit box of the save preset.
	StringList presets{}; ///< Available presets.
	Scrollbar *vscroll = nullptr; ///< Pointer to the scrollbar widget.
	int selected = -1; ///< Selected entry in the preset list, or \c -1 if none selected.

	/**
	 * Constructor of the save preset window.
	 * @param initial_text Initial text to display in the edit box.
	 */
	SavePresetWindow(std::string_view initial_text) : Window(_save_preset_desc), presetname_editbox(32)
	{
		this->presets = GetGRFPresetList();
		if (!initial_text.empty()) {
			for (uint i = 0; i < this->presets.size(); i++) {
				if (this->presets[i] == initial_text) {
					this->selected = i;
					break;
				}
			}
		}

		this->querystrings[WID_SVP_EDITBOX] = &this->presetname_editbox;
		this->presetname_editbox.ok_button = WID_SVP_SAVE;

		this->CreateNestedTree();
		this->vscroll = this->GetScrollbar(WID_SVP_SCROLLBAR);
		this->FinishInitNested(0);

		this->vscroll->SetCount(this->presets.size());
		this->SetFocusedWidget(WID_SVP_EDITBOX);
		this->presetname_editbox.text.Assign(initial_text);
	}

	~SavePresetWindow() override
	{
	}

	void UpdateWidgetSize(WidgetID widget, Dimension &size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension &fill, [[maybe_unused]] Dimension &resize) override
	{
		switch (widget) {
			case WID_SVP_PRESET_LIST: {
				fill.height = resize.height = GetCharacterHeight(FontSize::Normal);
				size.height = 0;
				for (uint i = 0; i < this->presets.size(); i++) {
					Dimension d = GetStringBoundingBox(this->presets[i]);
					size.width = std::max(size.width, d.width + padding.width);
				}
				size.height = ClampU((uint)this->presets.size(), 5, 20) * resize.height + padding.height;
				break;
			}
		}
	}

	void DrawWidget(const Rect &r, WidgetID widget) const override
	{
		switch (widget) {
			case WID_SVP_PRESET_LIST: {
				const Rect br = r.Shrink(WidgetDimensions::scaled.bevel);
				GfxFillRect(br, PC_BLACK);

				uint step_height = this->GetWidget<NWidgetBase>(WID_SVP_PRESET_LIST)->resize_y;
				int offset_y = (step_height - GetCharacterHeight(FontSize::Normal)) / 2;
				Rect tr = r.Shrink(WidgetDimensions::scaled.framerect);

				auto [first, last] = this->vscroll->GetVisibleRangeIterators(this->presets);
				for (auto it = first; it != last; ++it) {
					int row = static_cast<int>(std::distance(std::begin(this->presets), it));
					if (row == this->selected) GfxFillRect(br.left, tr.top, br.right, tr.top + step_height - 1, PC_DARK_BLUE);

					DrawString(tr.left, tr.right, tr.top + offset_y, *it, (row == this->selected) ? TextColour::White : TextColour::Silver);
					tr.top += step_height;
				}
				break;
			}
		}
	}

	void OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count) override
	{
		switch (widget) {
			case WID_SVP_PRESET_LIST: {
				auto it = this->vscroll->GetScrolledItemFromWidget(this->presets, pt.y, this, WID_SVP_PRESET_LIST);
				if (it != this->presets.end()) {
					this->selected = it - this->presets.begin();
					this->presetname_editbox.text.Assign(*it);
					this->SetWidgetDirty(WID_SVP_PRESET_LIST);
					this->SetWidgetDirty(WID_SVP_EDITBOX);
				}
				break;
			}

			case WID_SVP_SAVE: {
				Window *w = FindWindowById(WindowClass::GameOptions, GameOptionsWindowNumber::NewGRFState);
				if (w != nullptr) {
					auto text = this->presetname_editbox.text.GetText();
					if (!text.empty()) w->OnQueryTextFinished(std::string{text});
				}
				this->Close();
				break;
			}
		}
	}

	void OnResize() override
	{
		this->vscroll->SetCapacityFromWidget(this, WID_SVP_PRESET_LIST, WidgetDimensions::scaled.framerect.Vertical());
	}
};

/**
 * Open the window for saving a preset.
 * @param initial_text Initial text to display in the edit box, or \c nullptr.
 */
static void ShowSavePresetWindow(std::string_view initial_text)
{
	CloseWindowByClass(WindowClass::SavePreset);
	new SavePresetWindow(initial_text);
}

/** Widgets for the progress window. */
static constexpr std::initializer_list<NWidgetPart> _nested_scan_progress_widgets = {
	NWidget(WWT_CAPTION, Colours::Grey), SetStringTip(STR_NEWGRF_SCAN_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
	NWidget(WWT_PANEL, Colours::Grey),
		NWidget(NWID_VERTICAL), SetPIP(0, WidgetDimensions::unscaled.vsep_wide, 0), SetPadding(WidgetDimensions::unscaled.modalpopup),
			NWidget(WWT_LABEL, Colours::Invalid), SetStringTip(STR_NEWGRF_SCAN_MESSAGE), SetFill(1, 0),
			NWidget(WWT_EMPTY, Colours::Invalid, WID_SP_PROGRESS_BAR), SetFill(1, 0),
			NWidget(WWT_EMPTY, Colours::Invalid, WID_SP_PROGRESS_TEXT), SetFill(1, 0), SetMinimalSize(400, 0),
		EndContainer(),
	EndContainer(),
};

/** Description of the widgets and other settings of the window. */
static WindowDesc _scan_progress_desc(
	WindowPosition::Center, {}, 0, 0,
	WindowClass::ModalProgress, WindowClass::None,
	{},
	_nested_scan_progress_widgets
);

/** Window for showing the progress of NewGRF scanning. */
struct ScanProgressWindow : public Window {
	std::string last_name{}; ///< The name of the last 'seen' NewGRF.
	int scanned = 0; ///< The number of NewGRFs that we have seen.

	/** Create the window. */
	ScanProgressWindow() : Window(_scan_progress_desc)
	{
		this->InitNested(1);
	}

	void UpdateWidgetSize(WidgetID widget, Dimension &size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension &fill, [[maybe_unused]] Dimension &resize) override
	{
		switch (widget) {
			case WID_SP_PROGRESS_BAR:
				size = GetStringBoundingBox(GetString(STR_GENERATION_PROGRESS, GetParamMaxValue(100)));
				/* We need some spacing for the 'border' */
				size.height += WidgetDimensions::scaled.frametext.Horizontal();
				size.width  += WidgetDimensions::scaled.frametext.Vertical();
				break;

			case WID_SP_PROGRESS_TEXT: {
				uint64_t max_digits = GetParamMaxDigits(4);
				/* We really don't know the width. We could determine it by scanning the NewGRFs,
				 * but this is the status window for scanning them... */
				size.width = std::max<uint>(size.width, GetStringBoundingBox(GetString(STR_NEWGRF_SCAN_STATUS, max_digits, max_digits)).width + padding.width);
				size.height = GetCharacterHeight(FontSize::Normal) * 2 + WidgetDimensions::scaled.vsep_normal;
				break;
			}
		}
	}

	void DrawWidget(const Rect &r, WidgetID widget) const override
	{
		switch (widget) {
			case WID_SP_PROGRESS_BAR: {
				/* Draw the % complete with a bar and a text */
				DrawFrameRect(r, Colours::Grey, {FrameFlag::BorderOnly, FrameFlag::Lowered});
				Rect ir = r.Shrink(WidgetDimensions::scaled.bevel);
				uint percent = scanned * 100 / std::max(1U, _settings_client.gui.last_newgrf_count);
				DrawFrameRect(ir.WithWidth(ir.Width() * percent / 100, _current_text_dir == TD_RTL), Colours::Mauve, {});
				DrawString(ir.left, ir.right, CentreBounds(ir.top, ir.bottom, GetCharacterHeight(FontSize::Normal)), GetString(STR_GENERATION_PROGRESS, percent), TextColour::FromString, SA_HOR_CENTER);
				break;
			}

			case WID_SP_PROGRESS_TEXT:
				DrawString(r.left, r.right, r.top, GetString(STR_NEWGRF_SCAN_STATUS, this->scanned, _settings_client.gui.last_newgrf_count), TextColour::FromString, SA_HOR_CENTER);

				DrawString(r.left, r.right, r.top + GetCharacterHeight(FontSize::Normal) + WidgetDimensions::scaled.vsep_normal, this->last_name, TextColour::Black, SA_HOR_CENTER);
				break;
		}
	}

	/**
	 * Update the NewGRF scan status.
	 * @param num  The number of NewGRFs scanned so far.
	 * @param name The name of the last scanned NewGRF.
	 */
	void UpdateNewGRFScanStatus(uint num, std::string &&name)
	{
		this->last_name = std::move(name);
		this->scanned = num;
		if (num > _settings_client.gui.last_newgrf_count) _settings_client.gui.last_newgrf_count = num;

		this->SetDirty();
	}
};

/**
 * Update the NewGRF scan status.
 * @param num  The number of NewGRFs scanned so far.
 * @param name The name of the last scanned NewGRF.
 */
void UpdateNewGRFScanStatus(uint num, std::string &&name)
{
	ScanProgressWindow *w = dynamic_cast<ScanProgressWindow *>(FindWindowByClass(WindowClass::ModalProgress));
	if (w == nullptr) w = new ScanProgressWindow();
	w->UpdateNewGRFScanStatus(num, std::move(name));
}
