/**
 * vim: set ts=4 :
 * ===============================================================
 * SourceMod, Copyright (C) 2004-2007 AlliedModders LLC. 
 * All rights reserved.
 * ===============================================================
 *
 *  This file is part of the SourceMod/SourcePawn SDK.  This file may only be 
 * used or modified under the Terms and Conditions of its License Agreement, 
 * which is found in public/licenses/LICENSE.txt.  As of this notice, derivative 
 * works must be licensed under the GNU General Public License (version 2 or 
 * greater).  A copy of the GPL is included under public/licenses/GPL.txt.
 * 
 * To view the latest information, see: http://www.sourcemod.net/license.php
 *
 * Version: $Id$
 */

#ifndef _INCLUDE_SOURCEMOD_MENU_SYSTEM_H_
#define _INCLUDE_SOURCEMOD_MENU_SYSTEM_H_

#include <IShareSys.h>

#define SMINTERFACE_MENUMANAGER_NAME		"IMenuManager"
#define SMINTERFACE_MENUMANAGER_VERSION		1

/**
 * @file IMenuManager.h
 * @brief Abstracts on-screen menus for clients.
 */

namespace SourceMod
{
	/**
	 * @brief Used to determine how an item selection is interpreted.
	 */
	enum ItemSelection
	{
		ItemSel_None,					/**< Invalid selection */
		ItemSel_Back,					/**< Go back one page */
		ItemSel_Next,					/**< Go forward one page */
		ItemSel_Exit,					/**< Menu was exited */
		ItemSel_Item,					/**< Valid item selection */
	};

	/**
	 * @brief Used to determine which order to search for items in.
	 */
	enum ItemOrder
	{
		ItemOrder_Ascending,			/**< Items should be drawn ascendingly */
		ItemOrder_Descending,			/**< Items should be drawn descendingly */
	};

	/**
	 * @brief Pairs an item type with an item menu position.
	 */
	struct menu_slots_t
	{
		ItemSelection type;				/**< Item selection type */
		unsigned int item;				/**< Item position, if applicable */
	};

	class IBaseMenu;
	class IMenuDisplay;
	class IMenuHandler;

	/**
	 * @brief Describes menu display information.
	 */
	struct menu_states_t
	{
		unsigned int apiVers;			/**< Must be filled with the API version */
		IBaseMenu *menu;				/**< Menu pointer, or NULL if there is only a display */
		IMenuHandler *mh;				/**< Menu callbacks handler */
		unsigned int firstItem;			/**< MENU ONLY: First item displayed on the last page */
		unsigned int lastItem;			/**< MENU ONLY: Last item displayed on the last page */
		menu_slots_t slots[11];			/**< MENU ONLY: Item selection table (first index is 1) */
	};

	#define ITEMDRAW_DEFAULT		(0)		/**< Item should be drawn normally */
	#define ITEMDRAW_DISABLED		(1<<0)	/**< Item is drawn but not selectable */
	#define ITEMDRAW_RAWLINE		(1<<1)	/**< Item should be a raw line, without a slot */
	#define ITEMDRAW_NOTEXT			(1<<2)	/**< No text should be drawn */
	#define ITEMDRAW_SPACER			(1<<3)	/**< Item should be drawn as a spacer, if possible */
	#define ITEMDRAW_IGNORE	((1<<1)|(1<<2))	/**< Item should be completely ignored (rawline + notext)

	/**
	 * @brief Information about item drawing.
	 */
	struct ItemDrawInfo
	{
		ItemDrawInfo()
		{
			style = 0;
			display = NULL;
		}
		ItemDrawInfo(const char *DISPLAY, unsigned int STYLE=ITEMDRAW_DEFAULT) 
			: display(DISPLAY), style(STYLE)
		{
		}
		unsigned int style;				/**< ITEMDRAW style flags */
		const char *display;			/**< Display text (NULL for none) */
	};

	/**
	 * @brief Reasons for a menu dying.
	 */
	enum MenuCancelReason
	{
		MenuCancel_Disconnect = -1,	/** Client dropped from the server */
		MenuCancel_Interrupt = -2,	/** Client was interrupted with another menu */
		MenuCancel_Exit = -3,		/** Client selected "exit" on a paginated menu */
		MenuCancel_NoDisplay = -4,	/** Menu could not be displayed to the client */
	};

	#define MENU_NO_PAGINATION			-1		/**< Menu should not be paginated (10 items max) */
	#define MENU_TIME_FOREVER			0		/**< Menu should be displayed as long as possible */

	/**
	 * @brief Extended menu options.
	 */
	enum MenuOption
	{
		MenuOption_IntroMessage,				/**< CONST CHAR *: Valve menus only; defaults to:
													 "You have a menu, hit ESC"
													 */
		MenuOption_IntroColor,					/**< INT[4]: Valve menus only; specifies the intro message colour
													 using R,G,B,A (defaults to 255,0,0,255)
													 */
		MenuOption_Priority,					/**< INT *: Valve menus only; priority (less is higher) */
	};

	/**
	 * @brief Describes the menu a player is viewing.
	 */
	enum MenuSource
	{
		MenuSource_None = 0,					/**< No menu is being displayed */
		MenuSource_External = 1,				/**< External menu, no pointer */
		MenuSource_BaseMenu = 2,				/**< An IBaseMenu pointer. */
		MenuSource_Display = 3,					/**< IMenuDisplay source, no pointer */
	};

	class IMenuStyle;

	/**
	 * @brief Sets how a raw menu should be drawn.
	 */
	class IMenuDisplay
	{
	public:
		/**
		 * @brief Returns the parent IMenuStyle pointer.
		 *
		 * @return				IMenuStyle pointer which created
		 *						this object.
		 */
		virtual IMenuStyle *GetParentStyle() =0;

		/**
		 * @brief Resets/clears the cached display text.
		 */
		virtual void Reset() =0;

		/**
		 * @brief Sets how the title should be drawn.
		 *
		 * @param text			Text string to display for the title.
		 * @param onlyIfEmpty	Only sets the title if one does not already 
		 *						exist.
		 */
		virtual void DrawTitle(const char *text, bool onlyIfEmpty=false) =0;

		/**
		 * @brief Adds an item to the menu and returns the position (1-10).
		 *
		 * Note: Item will fail to draw if there are too many items,
		 * or the item is not drawable (for example, invisible).	
		 * 
		 * @return				Item draw position, or 0 on failure.
		 */
		virtual unsigned int DrawItem(const ItemDrawInfo &item) =0;

		/**
		 * @brief Draws a raw line of text, if supported.  The line does not 
		 * need to be newline terminated.
		 *
		 * @return				True on success, false if not supported.
		 */
		virtual bool DrawRawLine(const char *rawline) =0;

		/**
		 * @brief Sets an extended menu option.
		 *
		 * @param option		Option type.
		 * @param valuePtr		Pointer of the type expected by the option.
		 * @return				True on success, false if option or value is not supported.
		 */
		virtual bool SetExtOption(MenuOption option, const void *valuePtr) =0;

		/**
		 * @brief Returns whether the display is capable of rendering an item
		 * with the given flags.
		 *
		 * @param flags			ITEMDRAW flags.
		 * @return				True if renderable, false otherwise.
		 */
		virtual bool CanDrawItem(unsigned int drawFlags) =0;

		/**
		 * @brief Sends the menu display to a client.
		 *
		 * @param client		Client index to display to.
		 * @param handler		Menu handler to use.
		 * @param time			Time to hold menu for.
		 * @return				True on success, false otherwise.
		 */
		virtual bool SendDisplay(int client, IMenuHandler *handler, unsigned int time) =0;

		/**
		 * @brief Destroys the display object.
		 */
		virtual void DeleteThis() =0;
	};

	/**
	 * @brief Describes a "MenuStyle" system which manages
	 * menu drawing and construction.
	 */
	class IMenuStyle
	{
	public:
		/**
		 * @brief Returns the style API version.
		 *
		 * @return				API version.
		 */
		virtual unsigned int GetStyleAPIVersion()
		{
			return SMINTERFACE_MENUMANAGER_VERSION;
		}

		/**
		 * @brief Returns the name of the menu style.
		 *
		 * @return				String containing the style name.
		 */
		virtual const char *GetStyleName() =0;

		/**
		 * @brief Creates an IMenuDisplay object.
		 *
		 * Note: the object should be freed using ::DeleteThis.
		 *
		 * @return				IMenuDisplay object.
		 */
		virtual IMenuDisplay *CreateDisplay() =0;

		/**
		 * @brief Creates an IBaseMenu object of this style.
		 *
		 * Note: the object should be freed using IBaseMenu::Destroy.
		 *
		 * @return				An IBaseMenu pointer.
		 */
		virtual IBaseMenu *CreateMenu() =0;

		/**
		 * @brief Returns the maximum number of items per page.
		 *
		 * @return				Number of items per page.
		 */
		virtual unsigned int GetMaxPageItems() =0;

		/**
		 * @brief Returns whether or not a client is viewing a menu.
		 *
		 * @param client		Client index.
		 * @param object		Optional pointer to retrieve menu object,
		 *						if any.
		 * @return				MenuSource value.
		 */
		virtual MenuSource GetClientMenu(int client, void **object) =0;

		/**
		 * @brief Cancels a client's menu.
		 *
		 * @param client		Client index.
		 * @param autoIgnore	If true, no menus can be created during 
		 *						the cancellation process.
		 * @return				True if a menu was cancelled, false otherwise.
		 */
		virtual bool CancelClientMenu(int client, bool autoIgnore=false) =0;
	};

	/**
	 * @brief High-level interface for building menus.
	 */
	class IBaseMenu
	{
	public:
		/**
		 * @brief Appends an item to the end of a menu.
		 *
		 * @param info			Item information string.
		 * @param draw			Default drawing information.
		 * @return				True on success, false on item limit reached.
		 */
		virtual bool AppendItem(const char *info, const ItemDrawInfo &draw) =0;

		/**
		 * @brief Inserts an item into the menu before a certain position; 
		 * the new item will be at the given position and all next items 
		 * pushed forward.
		 *
		 * @param position		Position, starting from 0.
		 * @param info			Item information string.
		 * @param draw			Default item draw info.
		 * @return				True on success, false on invalid menu position
		 */
		virtual bool InsertItem(unsigned int position, const char *info, const ItemDrawInfo &draw) =0;

		/**
		 * @brief Removes an item from the menu.
		 *
		 * @param position		Position, starting from 0.
		 * @return				True on success, false on invalid menu position.
		 */
		virtual bool RemoveItem(unsigned int position) =0;

		/**
		 * @brief Removes all items from the menu.
		 */
		virtual void RemoveAllItems() =0;

		/**
		 * @brief Returns an item's info.
		 *
		 * @param position		Position, starting from 0.
		 * @param draw			Optional pointer to store a draw information.
		 * @return				Info string pointer, or NULL if position was invalid.
		 */
		virtual const char *GetItemInfo(unsigned int position, ItemDrawInfo *draw) =0;

		/**
		 * @brief Returns the number of items.
		 *
		 * @return				Number of items in the menu.
		 */
		virtual unsigned int GetItemCount() =0;

		/** 
		 * @brief Sets the menu's pagination,.
		 *
		 * @param itemsPerPage	Number of items per page, or MENU_NO_PAGINATION.
		 * @return				True on success, false if itemsPerPage is too large.
		 */
		virtual bool SetPagination(unsigned int itemsPerPage) =0;

		/**
		 * @brief Returns an item's pagination.
		 *
		 * @return				Pagination setting.
		 */
		virtual unsigned int GetPagination() =0;

		/**
		 * @brief Returns the menu style.
		 * 
		 * @return				Menu style.
		 */
		virtual IMenuStyle *GetDrawStyle() =0;

		/**
		 * @brief Sets the menu's display title/message.
		 *
		 * @param message		Message (format options allowed).
		 */
		virtual void SetDefaultTitle(const char *message) =0;

		/**
		 * @brief Returns the menu's display/title message.
		 *
		 * @return				Message string.
		 */
		virtual const char *GetDefaultTitle() =0;

		/**
		 * @brief Sets an extended menu option.
		 *
		 * @param option		Option type.
		 * @param valuePtr		Pointer of the type expected by the option.
		 * @return				True on success, false if option or value is not supported.
		 */
		virtual bool SetExtOption(MenuOption option, const void *valuePtr) =0;

		/**
		 * @brief Creates a new IMenuDisplay object using extended options specific
		 * to the IMenuStyle parent.  Titles, items, etc, are not copied.
		 *
		 * Note: The object should be freed with IMenuDisplay::DeleteThis.
		 *
		 * @return				IMenuDisplay pointer.
		 */
		virtual IMenuDisplay *CreateDisplay() =0;

		/**
		 * @brief Returns whether or not the menu should have an "Exit" button for
		 * paginated menus.
		 *
		 * @return				True to have an exit button, false otherwise.
		 */
		virtual bool GetExitButton() =0;
		
		/**
		 * @brief Sets whether or not the menu should have an "Exit" button for
		 * paginated menus.
		 *
		 * @param set			True to enable, false to disable the exit button.
		 * @return				True on success, false if the exit button is 
		 *						non-optional.
		 */
		virtual bool SetExitButton(bool set) =0;

		/**
		 * @brief Sends the menu to a client.
		 *
		 * @param client		Client index to display to.
		 * @param handler		Menu handler to use.
		 * @param time			Time to hold menu for.
		 * @return				True on success, false otherwise.
		 */
		virtual bool Display(int client, IMenuHandler *handler, unsigned int time) =0;

		/**
		 * @brief Destroys the menu and frees all associated resources.1
		 */
		virtual void Destroy() =0;

		/**
		 * @brief Cancels the menu on all client's displays.  While the menu is
		 * being cancelled, the menu may not be re-displayed to any clients.
		 *
		 * @return				Number of menus cancelled.
		 */
		virtual void Cancel() =0;
	};

	/** 
	 * @brief Contains callbacks for menu actions.
	 */
	class IMenuHandler
	{
	public:
		/**
		 * @brief Returns the menu api verison.
		 *
		 * @return				Menu API version.
		 */
		virtual unsigned int GetMenuAPIVersion2()
		{
			return SMINTERFACE_MENUMANAGER_VERSION;
		}

		/** 
		 * @brief A display/selection cycle has started.
		 *
		 * @param menu			Menu pointer.
		 */
		virtual void OnMenuStart(IBaseMenu *menu)
		{
		}

		/**
		 * @brief Called before a menu is being displayed.  This is where
		 * you can set an alternate title on the menu.
		 *
		 * @param menu			Menu pointer.
		 * @param client		Client index.
		 * @param display		IMenuDisplay pointer.
		 */
		virtual void OnMenuDisplay(IBaseMenu *menu, int client, IMenuDisplay *display)
		{
		}

		/**
		 * @brief Called when an item is selected.
		 *
		 * @param menu			Menu pointer.
		 * @param client		Client that selected the item.
		 * @param item			Item number.
		 */
		virtual void OnMenuSelect(IBaseMenu *menu, int client, unsigned int item)
		{
		}

		/**
		 * @brief An active menu display was dropped from a client.
		 *
		 * @param menu			Menu pointer.
		 * @param client		Client that had the menu.
		 * @param reason		Menu cancellation reason.
		 */
		virtual void OnMenuCancel(IBaseMenu *menu, int client, MenuCancelReason reason)
		{
		}

		/**
		 * @brief A display/selection cycle has ended.
		 *
		 * @param menu			Menu pointer.
		 */
		virtual void OnMenuEnd(IBaseMenu *menu)
		{
		}

		/**
		 * @brief Called when requesting how to render an item.
		 *
		 * @param menu			Menu pointer.
		 * @param client		Client index receiving the menu.
		 * @param item			Item number in the menu.
		 * @param style			ITEMSTYLE flags, by reference for modification.
		 */
		virtual void OnMenuDrawItem(IBaseMenu *menu, int client, unsigned int item, unsigned int &style)
		{
		}

		/**
		 * @brief Called when requesting how to draw an item's text.
		 *
		 * @param menu			Menu pointer.
		 * @param client		Client index receiving the menu.
		 * @param item			Item number in the menu.
		 * @param display		Pointer to the display text string (changeable).
		 */
		virtual void OnMenuDisplayItem(IBaseMenu *menu, int client, unsigned int item, const char **display)
		{
		}
	};

	/** 
	 * @brief Handles a vote menu.
	 */
	class IMenuVoteHandler : public IMenuHandler
	{
	public:
		/**
		 * @brief Called when a vote ends.
		 *
		 * @param menu			Menu pointer.
		 * @param item			Item position that was chosen by a majority.
		 */
		virtual void OnMenuVoteEnd(IBaseMenu *menu, unsigned int item) =0;
	};

	/**
	 * @brief Manages menu creation and displaying.
	 */
	class IMenuManager : public SMInterface
	{
	public:
		virtual const char *GetInterfaceName()
		{
			return SMINTERFACE_MENUMANAGER_NAME;
		}
		virtual unsigned int GetInterfaceVersion()
		{
			return SMINTERFACE_MENUMANAGER_VERSION;
		}
	public:
		/**
		 * @brief Finds a style by name.
		 *
		 * @param name			Name of the style (case insensitive).
		 * @return				IMenuStyle pointer, or NULL if not found.
		 */
		virtual IMenuStyle *FindStyleByName(const char *name) =0;

		/**
		 * @brief Broadcasts a menu to a number of clients.
		 *
		 * @param menu			Menu pointer.
		 * @param handler		IMenuHandler pointer.
		 * @param clients		Array of client indexes.
		 * @param numClients	Number of clients in the array.
		 * @param time			Time to hold the menu.
		 * @return				Number of clients the menu will be waiting on.
		 */
		virtual unsigned int BroadcastMenu(IBaseMenu *menu, 
									IMenuHandler *handler,
									int clients[], 
									unsigned int numClients,
									unsigned int time) =0;

		/**
		 * @brief Broadcasts a menu to a number of clients as a vote menu.
		 *
		 * @param menu			Menu pointer.
		 * @param handler		IMenuHandler pointer.
		 * @param clients		Array of client indexes.
		 * @param numClients	Number of clients in the array.
		 * @param time			Time to hold the menu.
		 * @return				Number of clients the menu will be waiting on.
		 */
		virtual unsigned int VoteMenu(IBaseMenu *menu, 
									IMenuVoteHandler *handler,
									int clients[], 
									unsigned int numClients,
									unsigned int time) =0;

		/**
		 * @brief Returns the default draw style Core is using.
		 *
		 * @return				Menu style pointer.
		 */
		virtual IMenuStyle *GetDefaultStyle() =0;

		/** 
		 * @brief Sets the default draw style Core uses.
		 *
		 * @param style			Menu style.
		 * @return				True on success, false on failure.
		 */
		virtual bool SetDefaultStyle(IMenuStyle *style) =0;

		/**
		 * @brief Given a set of menu states, converts it to an IDisplay object.
		 *
		 * The state parameter is both INPUT and OUTPUT.
		 * INPUT: menu, mh, firstItem, lastItem
		 * OUTPUT: display, firstItem, lastItem, slots
		 *
		 * @param client		Client index.
		 * @param states		Menu states.
		 * @return				IDisplay pointer, or NULL if no items could be 
		 *						found in the IBaseMenu pointer, or NULL if any
		 *						other error occurred.  Any valid pointer must
		 *						be freed using IMenuDisplay::DeleteThis.
		 */
		virtual IMenuDisplay *RenderMenu(int client, menu_states_t &states, ItemOrder order) =0;
	};
}

#endif //_INCLUDE_SOURCEMOD_MENU_SYSTEM_H_