#include "../stdafx.h"

#include "../window_gui.h"

#include "../string_func.h"

#include "../strings_func.h"

#include "../window_func.h"

#include "../zoom_func.h"

#include "../timer/timer.h"

#include "../timer/timer_window.h"

#include "dropdown_type.h"

#include "dropdown_widget.h"

#include "../safeguards.h"

void DropDownListItem::Draw(const Rect &r, bool sel, Colours bg_colour) const

{

	int c1 = _colour_gradient[bg_colour][3];

	int c2 = _colour_gradient[bg_colour][7];

	int mid = CenterBounds(r.top, r.bottom, 0);

	GfxFillRect(r.left, mid - WidgetDimensions::scaled.bevel.bottom, r.right, mid - 1, c1);

	GfxFillRect(r.left, mid, r.right, mid + WidgetDimensions::scaled.bevel.top - 1, c2);

}

uint DropDownListStringItem::Width() const

{

	return GetStringBoundingBox(this->String()).width + WidgetDimensions::scaled.dropdowntext.Horizontal();

}

void DropDownListStringItem::Draw(const Rect &r, bool sel, Colours bg_colour) const

{

	Rect ir = r.Shrink(WidgetDimensions::scaled.dropdowntext);

	DrawString(ir.left, ir.right, r.top, this->String(), sel ? TC_WHITE : TC_BLACK);

}

/**

 * Natural sorting comparator function for DropDownList::sort().

 * @param first Left side of comparison.

 * @param second Right side of comparison.

 * @return true if \a first precedes \a second.

 * @warning All items in the list need to be derivates of DropDownListStringItem.

 */

/* static */ bool DropDownListStringItem::NatSortFunc(std::unique_ptr<const DropDownListItem> const &first, std::unique_ptr<const DropDownListItem> const &second)

{

	std::string str1 = GetString(static_cast<const DropDownListStringItem*>(first.get())->String());

	std::string str2 = GetString(static_cast<const DropDownListStringItem*>(second.get())->String());

	return StrNaturalCompare(str1, str2) < 0;

}

StringID DropDownListParamStringItem::String() const

{

	for (uint i = 0; i < lengthof(this->decode_params); i++) SetDParam(i, this->decode_params[i]);

	return this->string;

}

StringID DropDownListCharStringItem::String() const

{

	SetDParamStr(0, this->raw_string);

	return this->string;

}

DropDownListIconItem::DropDownListIconItem(SpriteID sprite, PaletteID pal, StringID string, int result, bool masked) : DropDownListParamStringItem(string, result, masked), sprite(sprite), pal(pal)

{

	this->dim = GetSpriteSize(sprite);

	this->sprite_y = dim.height;

}

uint DropDownListIconItem::Height(uint width) const

{

	return std::max(this->dim.height, (uint)FONT_HEIGHT_NORMAL);

}

uint DropDownListIconItem::Width() const

{

	return DropDownListParamStringItem::Width() + this->dim.width + WidgetDimensions::scaled.hsep_wide;

}

void DropDownListIconItem::Draw(const Rect &r, bool sel, Colours bg_colour) const

{

	bool rtl = _current_text_dir == TD_RTL;

	Rect ir = r.Shrink(WidgetDimensions::scaled.dropdowntext);

	Rect tr = ir.Indent(this->dim.width + WidgetDimensions::scaled.hsep_normal, rtl);

	DrawSprite(this->sprite, this->pal, ir.WithWidth(this->dim.width, rtl).left, CenterBounds(r.top, r.bottom, this->sprite_y));

	DrawString(tr.left, tr.right, CenterBounds(r.top, r.bottom, FONT_HEIGHT_NORMAL), this->String(), sel ? TC_WHITE : TC_BLACK);

}

void DropDownListIconItem::SetDimension(Dimension d)

{

	this->dim = d;

}

static const NWidgetPart _nested_dropdown_menu_widgets[] = {

	NWidget(NWID_HORIZONTAL),

		NWidget(WWT_PANEL, COLOUR_END, WID_DM_ITEMS), SetMinimalSize(1, 1), SetScrollbar(WID_DM_SCROLL), EndContainer(),

		NWidget(NWID_SELECTION, INVALID_COLOUR, WID_DM_SHOW_SCROLL),

			NWidget(NWID_VSCROLLBAR, COLOUR_END, WID_DM_SCROLL),

		EndContainer(),

	EndContainer(),

};

static WindowDesc _dropdown_desc(

	WDP_MANUAL, nullptr, 0, 0,

	WC_DROPDOWN_MENU, WC_NONE,

	WDF_NO_FOCUS,

	_nested_dropdown_menu_widgets, lengthof(_nested_dropdown_menu_widgets)

);

/** Drop-down menu window */

struct DropdownWindow : Window {

	int parent_button;            ///< Parent widget number where the window is dropped from.

	const DropDownList list;      ///< List with dropdown menu items.

	int selected_index;           ///< Index of the selected item in the list.

	byte click_delay;             ///< Timer to delay selection.

	bool drag_mode;

	bool instant_close;           ///< Close the window when the mouse button is raised.

	int scrolling;                ///< If non-zero, auto-scroll the item list (one time).

	Point position;               ///< Position of the topleft corner of the window.

	Scrollbar *vscroll;

	/**

	 * Create a dropdown menu.

	 * @param parent        Parent window.

	 * @param list          Dropdown item list.

	 * @param selected      Index of the selected item in the list.

	 * @param button        Widget of the parent window doing the dropdown.

	 * @param instant_close Close the window when the mouse button is raised.

	 * @param position      Topleft position of the dropdown menu window.

	 * @param size          Size of the dropdown menu window.

	 * @param wi_colour     Colour of the parent widget.

	 * @param scroll        Dropdown menu has a scrollbar.

	 */

	DropdownWindow(Window *parent, DropDownList &&list, int selected, int button, bool instant_close, const Point &position, const Dimension &size, Colours wi_colour, bool scroll)

			: Window(&_dropdown_desc), list(std::move(list))

	{

		assert(this->list.size() > 0);

		this->position = position;

		this->CreateNestedTree();

		this->vscroll = this->GetScrollbar(WID_DM_SCROLL);

		uint items_width = size.width - (scroll ? NWidgetScrollbar::GetVerticalDimension().width : 0);

		NWidgetCore *nwi = this->GetWidget<NWidgetCore>(WID_DM_ITEMS);

		nwi->SetMinimalSizeAbsolute(items_width, size.height + WidgetDimensions::scaled.fullbevel.Vertical() * 2);

		nwi->colour = wi_colour;

		nwi = this->GetWidget<NWidgetCore>(WID_DM_SCROLL);

		nwi->colour = wi_colour;

		this->GetWidget<NWidgetStacked>(WID_DM_SHOW_SCROLL)->SetDisplayedPlane(scroll ? 0 : SZSP_NONE);

		this->FinishInitNested(0);

		CLRBITS(this->flags, WF_WHITE_BORDER);

		/* Total length of list */

		int list_height = 0;

		for (const auto &item : this->list) {

			list_height += item->Height(items_width);

		}

		/* Capacity is the average number of items visible */

		this->vscroll->SetCapacity(size.height * this->list.size() / list_height);

		this->vscroll->SetCount(this->list.size());

		this->parent           = parent;

		this->parent_button    = button;

		this->selected_index   = selected;

		this->click_delay      = 0;

		this->drag_mode        = true;

		this->instant_close    = instant_close;

	}

	void Close() override

	{

		/* Finish closing the dropdown, so it doesn't affect new window placement.

		 * Also mark it dirty in case the callback deals with the screen. (e.g. screenshots). */

		this->Window::Close();

		Point pt = _cursor.pos;

		pt.x -= this->parent->left;

		pt.y -= this->parent->top;

		this->parent->OnDropdownClose(pt, this->parent_button, this->selected_index, this->instant_close);

		/* Set flag on parent widget to indicate that we have just closed. */

		NWidgetCore *nwc = this->parent->GetWidget<NWidgetCore>(this->parent_button);

		if (nwc != nullptr) SetBit(nwc->disp_flags, NDB_DROPDOWN_CLOSED);

	}

	void OnFocusLost(bool closing) override

	{

	}

	Point OnInitialPosition(int16 sm_width, int16 sm_height, int window_number) override

	{

		return this->position;

	}

	/**

	 * Find the dropdown item under the cursor.

	 * @param[out] value Selected item, if function returns \c true.

	 * @return Cursor points to a dropdown item.

	 */

	bool GetDropDownItem(int &value)

	{

		if (GetWidgetFromPos(this, _cursor.pos.x - this->left, _cursor.pos.y - this->top) < 0) return false;

		const Rect &r = this->GetWidget<NWidgetBase>(WID_DM_ITEMS)->GetCurrentRect().Shrink(WidgetDimensions::scaled.fullbevel);

		int y     = _cursor.pos.y - this->top - r.top - WidgetDimensions::scaled.fullbevel.top;

		int width = r.Width();

		int pos   = this->vscroll->GetPosition();

		for (const auto &item : this->list) {

			/* Skip items that are scrolled up */

			if (--pos >= 0) continue;

			int item_height = item->Height(width);

			if (y < item_height) {

				if (item->masked || !item->Selectable()) return false;

				value = item->result;

				return true;

			}

			y -= item_height;

		}

		return false;

	}

	void DrawWidget(const Rect &r, int widget) const override

	{

		if (widget != WID_DM_ITEMS) return;

		Colours colour = this->GetWidget<NWidgetCore>(widget)->colour;

		Rect ir = r.Shrink(WidgetDimensions::scaled.fullbevel).Shrink(RectPadding::zero, WidgetDimensions::scaled.fullbevel);

		int y = ir.top;

		int pos = this->vscroll->GetPosition();

		for (const auto &item : this->list) {

			int item_height = item->Height(ir.Width());

			/* Skip items that are scrolled up */

			if (--pos >= 0) continue;

			if (y + item_height - 1 <= ir.bottom) {

				bool selected = (this->selected_index == item->result);

				if (selected) GfxFillRect(ir.left, y, ir.right, y + item_height - 1, PC_BLACK);

				item->Draw({ir.left, y, ir.right, y + item_height - 1}, selected, colour);

				if (item->masked) {

					GfxFillRect(ir.left, y, ir.right, y + item_height - 1, _colour_gradient[colour][5], FILLRECT_CHECKER);

				}

			}

			y += item_height;

		}

	}

	void OnClick(Point pt, int widget, int click_count) override

	{

		if (widget != WID_DM_ITEMS) return;

		int item;

		if (this->GetDropDownItem(item)) {

			this->click_delay = 4;

			this->selected_index = item;

			this->SetDirty();

		}

	}

	/** Rate limit how fast scrolling happens. */

	IntervalTimer<TimerWindow> scroll_interval = {std::chrono::milliseconds(30), [this](auto) {

		if (this->scrolling == 0) return;

		if (this->vscroll->UpdatePosition(this->scrolling)) this->SetDirty();

		this->scrolling = 0;

	}};

	void OnMouseLoop() override

	{

		if (this->click_delay != 0 && --this->click_delay == 0) {

			/* Close the dropdown, so it doesn't affect new window placement.

			 * Also mark it dirty in case the callback deals with the screen. (e.g. screenshots). */

			this->Close();

			this->parent->OnDropdownSelect(this->parent_button, this->selected_index);

			return;

		}

		if (this->drag_mode) {

			int item;

			if (!_left_button_clicked) {

				this->drag_mode = false;

				if (!this->GetDropDownItem(item)) {

					if (this->instant_close) this->Close();

					return;

				}

				this->click_delay = 2;

			} else {

				if (_cursor.pos.y <= this->top + 2) {

					/* Cursor is above the list, set scroll up */

					this->scrolling = -1;

					return;

				} else if (_cursor.pos.y >= this->top + this->height - 2) {

					/* Cursor is below list, set scroll down */

					this->scrolling = 1;

					return;

				}

				if (!this->GetDropDownItem(item)) return;

			}

			if (this->selected_index != item) {

				this->selected_index = item;

				this->SetDirty();

			}

		}

	}

};

/**

 * Show a drop down list.

 * @param w        Parent window for the list.

 * @param list     Prepopulated DropDownList.

 * @param selected The initially selected list item.

 * @param button   The widget which is passed to Window::OnDropdownSelect and OnDropdownClose.

 *                 Unless you override those functions, this should be then widget index of the dropdown button.

 * @param wi_rect  Coord of the parent drop down button, used to position the dropdown menu.

 * @param instant_close Set to true if releasing mouse button should close the

 *                      list regardless of where the cursor is.

 */

void ShowDropDownListAt(Window *w, DropDownList &&list, int selected, int button, Rect wi_rect, Colours wi_colour, bool instant_close)

{

	CloseWindowByClass(WC_DROPDOWN_MENU);

	/* The preferred position is just below the dropdown calling widget */

	int top = w->top + wi_rect.bottom + 1;

	/* The preferred width equals the calling widget */

	uint width = wi_rect.Width();

	/* Longest item in the list */

	uint max_item_width = 0;

	/* Total height of list */

	uint height = 0;

	for (const auto &item : list) {

		height += item->Height(width);

		max_item_width = std::max(max_item_width, item->Width());

	}

	max_item_width += WidgetDimensions::scaled.fullbevel.Horizontal();

	/* Scrollbar needed? */

	bool scroll = false;

	/* Is it better to place the dropdown above the widget? */

	bool above = false;

	/* Available height below (or above, if the dropdown is placed above the widget). */

	uint available_height = std::max(GetMainViewBottom() - top - (int)WidgetDimensions::scaled.fullbevel.Vertical() * 2, 0);

	/* If the dropdown doesn't fully fit below the widget... */

	if (height > available_height) {

		uint available_height_above = std::max(w->top + wi_rect.top - GetMainViewTop() - (int)WidgetDimensions::scaled.fullbevel.Vertical() * 2, 0);

		/* Put the dropdown above if there is more available space. */

		if (available_height_above > available_height) {

			above = true;

			available_height = available_height_above;

		}

		/* If the dropdown doesn't fully fit, we need a dropdown. */

		if (height > available_height) {

			scroll = true;

			uint avg_height = height / (uint)list.size();

			/* Fit the list; create at least one row, even if there is no height available. */

			uint rows = std::max<uint>(available_height / avg_height, 1);

			height = rows * avg_height;