#ifndef _INCLUDE_SOURCEMOD_MODULE_INTERFACE_H_

 #define _INCLUDE_SOURCEMOD_MODULE_INTERFACE_H_

 #include <IShareSys.h>

 #include <ILibrarySys.h>

 namespace SourceMod

 {

 	class IExtensionInterface;

 	typedef void *		ITERATOR;

 	/** 

 	 * @brief Encapsulates an IExtension.

 	 */

 	class IExtension

 	{

 	public:

 		/**

 		 * @brief Returns whether or not the extension is properly loaded.

 		 */

 		virtual bool IsLoaded() =0;

 		/**

 		 * @brief Returns the extension's API interface

 		 *

 		 * @return			An IExtensionInterface pointer.

 		 */

 		virtual IExtensionInterface *GetAPI() =0;

 		/**

 		 * @brief Returns the filename of the extension, relative to the

 		 * extension folder.

 		 *

 		 * @return			A string containing the extension file name.

 		 */

 		virtual const char *GetFilename() =0;

 		/**

 		 * @brief Returns the extension's identity token.

 		 *

 		 * @return			An IdentityToken_t pointer.

 		 */

 		virtual IdentityToken_t *GetIdentity() =0;

 		/**

 		 * @brief Retrieves the extension dependency list for this extension.

 		 *

 		 * @param pOwner		Optional pointer to store the first interface's owner.

 		 * @param pInterface	Optional pointer to store the first interface.

 		 * @return				An ITERATOR pointer for the results, or NULL if no results at all.

 		 */

 		virtual ITERATOR *FindFirstDependency(IExtension **pOwner, SMInterface **pInterface) =0;

 		/**

 		 * @brief Finds the next dependency in the dependency list.

 		 *

 		 * @param iter			Pointer to iterator from FindFirstDependency.

 		 * @param pOwner		Optional pointer to store the interface's owner.

 		 * @param pInterface	Optional pointer to store the interface.

 		 * @return				True if there are more results after this, false otherwise.

 		 */

 		virtual bool FindNextDependency(ITERATOR *iter, IExtension **pOwner, SMInterface **pInterface) =0;

 		/**

 		 * @brief Frees an ITERATOR handle from FindFirstDependency.

 		 *

 		 * @param iter			Pointer to iterator to free.

 		 */

 		virtual void FreeDependencyIterator(ITERATOR *iter) =0;

 	};

 	#define SMINTERFACE_EXTENSIONAPI_VERSION	1

 	/**

 	 * @brief The interface an extension must expose.

 	 */

 	class IExtensionInterface

 	{

 	public:

 		virtual unsigned int GetExtensionVersion()

 		{

 			return SMINTERFACE_EXTENSIONAPI_VERSION;

 		}

 	public:

 		/**

 		 * @brief Called when the extension is loaded.

 		 * 

 		 * @param me		Pointer back to extension.

 		 * @param sys		Pointer to interface sharing system of SourceMod.

 		 * @param error		Error buffer to print back to, if any.

 		 * @param err_max	Maximum size of error buffer.

 		 * @param late		If this extension was loaded "late" (i.e. manually).

 		 * @return			True if load should continue, false otherwise.

 		 */

 		virtual bool OnExtensionLoad(IExtension *me,

 								  IShareSys *sys, 

 								  char *error, 

 								  size_t err_max, 

 								  bool late) =0;

 		/**

 		 * @brief Called when the extension is about to be unloaded.

 		 */

 		virtual void OnExtensionUnload() =0;

 		/**

 		 * @brief Called when all extensions are loaded (loading cycle is done).

 		 * If loaded late, this will be called right after OnExtensionLoad().

 		 */

 		virtual void OnExtensionsAllLoaded() =0;

 		/**

 		 * @brief Called when your pause state is about to change.

 		 * 

 		 * @param pause		True if pausing, false if unpausing.

 		 */

 		virtual void OnExtensionPauseChange(bool pause) =0;

 		/**

 		 * @brief Asks the extension whether it's safe to remove an external interface it's using.

 		 * If it's not safe, return false, and the extension will be unloaded afterwards.

 		 * NOTE: It is important to also hook NotifyInterfaceDrop() in order to clean up resources.

 		 *

 		 * @param pInterface		Pointer to interface being dropped.

 		 * @return					True to continue, false to unload this extension afterwards.

 		 */

 		virtual bool QueryInterfaceDrop(SMInterface *pInterface)

 		{

 			return true;

 		}

 		/**

 		 * @brief Notifies the extension that an external interface it uses is being removed.

 		 *

 		 * @param pInterface		Pointer to interface being dropped.

 		 */

 		virtual void NotifyInterfaceDrop(SMInterface *pInterface)

 		{

 		}

 	public:

 		virtual bool IsMetamodExtension() =0;

 		virtual const char *GetExtensionName() =0;

 		virtual const char *GetExtensionURL() =0;

 		virtual const char *GetExtensionTag() =0;

 		virtual const char *GetExtensionAuthor() =0;

 		virtual const char *GetExtensionVerString() =0;

 		virtual const char *GetExtensionDescription() =0;

 		virtual const char *GetExtensionDateString() =0;

 	};

 	#define SMINTERFACE_EXTENSIONMANAGER_NAME			"IExtensionManager"

 	#define SMINTERFACE_EXTENSIONMANAGER_VERSION		1

 	enum ExtensionLifetime

 	{

 		ExtLifetime_Forever,			//Extension will never be unloaded automatically

 		ExtLifetime_Map,				//Extension will be unloaded at the end of the map

 	};

 	class IExtensionManager : public SMInterface

 	{

 	public:

 		virtual const char *GetInterfaceName()

 		{

 			return SMINTERFACE_EXTENSIONMANAGER_NAME;

 		}

 		virtual unsigned int GetInterfaceVersion()

 		{

 			return SMINTERFACE_EXTENSIONMANAGER_VERSION;

 		}

 	public:

 		/**

 		 * @brief Loads a extension into the extension system.

 		 *

 		 * @param path		Path to extension file, relative to the extensions folder.

 		 * @param lifetime	Lifetime of the extension.

 		 * @param error		Error buffer.

 		 * @param err_max	Maximum error buffer length.

 		 * @return			New IExtension on success, NULL on failure.

 		 */

 		virtual IExtension *LoadExtension(const char *path, 

 									ExtensionLifetime lifetime, 

 									char *error,

 									size_t err_max) =0;

 		/**

 		 * @brief Attempts to unload a module.

 		 *

 		 * @param pExt		IExtension pointer.

 		 * @return			True if successful, false otherwise.

 		 */

 		virtual bool UnloadExtension(IExtension *pExt) =0;

 	};

 };

 #endif //_INCLUDE_SOURCEMOD_MODULE_INTERFACE_H_