/**
 * Window that let you choose an available AI.
 */
struct AIListWindow : public Window {
	const ScriptInfoList *info_list;    ///< The list of Scripts.
	int selected;                       ///< The currently selected Script.
	CompanyID slot;                     ///< The company we're selecting a new Script for.
	int line_height;                    ///< Height of a row in the matrix widget.
	Scrollbar *vscroll;                 ///< Cache of the vertical scrollbar.

	/**
	 * Constructor for the window.
	 * @param desc The description of the window.
	 * @param slot The company we're changing the AI for.
	 */
	AIListWindow(WindowDesc *desc, CompanyID slot) : Window(desc),
		slot(slot)
	{
		if (slot == OWNER_DEITY) {
			this->info_list = Game::GetUniqueInfoList();
		} else {
			this->info_list = AI::GetUniqueInfoList();
		}

		this->CreateNestedTree();
		this->vscroll = this->GetScrollbar(WID_AIL_SCROLLBAR);
		this->FinishInitNested(); // Initializes 'this->line_height' as side effect.

		this->vscroll->SetCount((int)this->info_list->size() + 1);

		/* Try if we can find the currently selected AI */
		this->selected = -1;
		if (GetConfig(slot)->HasScript()) {
			ScriptInfo *info = GetConfig(slot)->GetInfo();
			int i = 0;
			for (ScriptInfoList::const_iterator it = this->info_list->begin(); it != this->info_list->end(); it++, i++) {
				if ((*it).second == info) {
					this->selected = i;
					break;
				}
			}
		}
	}

	virtual void SetStringParameters(int widget) const
	{
		switch (widget) {
			case WID_AIL_CAPTION:
				SetDParam(0, (this->slot == OWNER_DEITY) ? STR_AI_LIST_CAPTION_GAMESCRIPT : STR_AI_LIST_CAPTION_AI);
				break;
		}
	}

	virtual void UpdateWidgetSize(int widget, Dimension *size, const Dimension &padding, Dimension *fill, Dimension *resize)
	{
		if (widget == WID_AIL_LIST) {
			this->line_height = max((uint)FONT_HEIGHT_NORMAL, GetSpriteSize(SPR_AICONFIG_RANDOM).height) + WD_MATRIX_TOP + WD_MATRIX_BOTTOM;

			resize->width = 1;
			resize->height = this->line_height;
			size->height = 5 * this->line_height;
		}
	}

	virtual void DrawWidget(const Rect &r, int widget) const
	{
		switch (widget) {
			case WID_AIL_LIST: {
				/* Draw a list of all available AIs. */
				int y = this->GetWidget<NWidgetBase>(WID_AIL_LIST)->pos_y;
				Dimension rai = GetSpriteSize(SPR_AICONFIG_RANDOM);
				uint rai_y_offset = (line_height - rai.height) / 2;
				/* First AI in the list is hardcoded to random */
				if (this->vscroll->IsVisible(0)) {
					StringID text = STR_AI_CONFIG_RANDOM_AI;
					if (this->slot == OWNER_DEITY) text = STR_AI_CONFIG_NONE;
					if (text == STR_AI_CONFIG_RANDOM_AI) DrawSprite(SPR_AICONFIG_RANDOM, PAL_NONE, r.left + WD_MATRIX_LEFT, r.left + WD_MATRIX_LEFT + GetSpriteSize(SPR_AICONFIG_RANDOM).width, y + rai_y_offset);
					DrawString(r.left + WD_MATRIX_LEFT + GetSpriteSize(SPR_AICONFIG_RANDOM).width + 10, r.right - WD_MATRIX_LEFT, y + WD_MATRIX_TOP, text, this->selected == -1 ? TC_WHITE : TC_ORANGE);
					y += this->line_height;
				}
				ScriptInfoList::const_iterator it = this->info_list->begin();
				for (int i = 1; it != this->info_list->end(); i++, it++) {
					if (this->vscroll->IsVisible(i)) {
						DrawString(r.left + WD_MATRIX_LEFT, r.right - WD_MATRIX_RIGHT, y + WD_MATRIX_TOP, (*it).second->GetName(), (this->selected == i - 1) ? TC_WHITE : TC_ORANGE);
						y += this->line_height;
					}
				}
				break;
			}
			case WID_AIL_INFO_BG: {
				AIInfo *selected_info = NULL;
				ScriptInfoList::const_iterator it = this->info_list->begin();
				for (int i = 1; selected_info == NULL && it != this->info_list->end(); i++, it++) {
					if (this->selected == i - 1) selected_info = static_cast<AIInfo *>((*it).second);
				}
				/* Some info about the currently selected AI. */
				if (selected_info != NULL) {
					int y = r.top + WD_FRAMERECT_TOP;
					SetDParamStr(0, selected_info->GetAuthor());
					DrawString(r.left + WD_FRAMETEXT_LEFT, r.right - WD_FRAMETEXT_RIGHT, y, STR_AI_LIST_AUTHOR);
					y += FONT_HEIGHT_NORMAL + WD_PAR_VSEP_NORMAL;
					SetDParam(0, selected_info->GetVersion());
					DrawString(r.left + WD_FRAMETEXT_LEFT, r.right - WD_FRAMETEXT_RIGHT, y, STR_AI_LIST_VERSION);
					y += FONT_HEIGHT_NORMAL + WD_PAR_VSEP_NORMAL;
					if (selected_info->GetURL() != NULL) {
						SetDParamStr(0, selected_info->GetURL());
						DrawString(r.left + WD_FRAMETEXT_LEFT, r.right - WD_FRAMETEXT_RIGHT, y, STR_AI_LIST_URL);
						y += FONT_HEIGHT_NORMAL + WD_PAR_VSEP_NORMAL;
					}
					SetDParamStr(0, selected_info->GetDescription());
					DrawStringMultiLine(r.left + WD_FRAMETEXT_LEFT, r.right - WD_FRAMETEXT_RIGHT, y, r.bottom - WD_FRAMERECT_BOTTOM, STR_JUST_RAW_STRING, TC_WHITE);
				}
				break;
			}
		}
	}

	/**
	 * Changes the AI of the current slot.
	 */
	void ChangeAI()
	{
		if (this->selected == -1) {
			GetConfig(slot)->Change(NULL);
		} else {
			ScriptInfoList::const_iterator it = this->info_list->begin();
			for (int i = 0; i < this->selected; i++) it++;
			GetConfig(slot)->Change((*it).second->GetName(), (*it).second->GetVersion());
		}
		InvalidateWindowData(WC_GAME_OPTIONS, WN_GAME_OPTIONS_AI);
		DeleteWindowByClass(WC_AI_SETTINGS);
		DeleteWindowByClass(WC_TEXTFILE);
		DeleteWindowByClass(WC_QUERY_STRING);
	}

	virtual void OnClick(Point pt, int widget, int click_count)
	{
		switch (widget) {
			case WID_AIL_LIST: { // Select one of the AIs
				int sel = this->vscroll->GetScrolledRowFromWidget(pt.y, this, WID_AIL_LIST, 0, this->line_height) - 1;
				if (sel < (int)this->info_list->size()) {
					this->selected = sel;
					this->SetDirty();
					if (click_count > 1) {
						this->ChangeAI();
						delete this;
					}
				}
				break;
			}

			case WID_AIL_ACCEPT: {
				this->ChangeAI();
				delete this;
				break;
			}

			case WID_AIL_CANCEL:
				delete this;
				break;
		}
	}

	virtual void OnResize()
	{
		this->vscroll->SetCapacityFromWidget(this, WID_AIL_LIST);
	}

	/**
	 * 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.
	 */
	virtual void OnInvalidateData(int data = 0, bool gui_scope = true)
	{
		if (_game_mode == GM_NORMAL && Company::IsValidID(this->slot)) {
			delete this;
			return;
		}

		if (!gui_scope) return;

		this->vscroll->SetCount((int)this->info_list->size() + 1);

		/* selected goes from -1 .. length of ai list - 1. */
		this->selected = min(this->selected, this->vscroll->GetCount() - 2);
	}
};