#ifndef _INCLUDE_SOURCEMOD_PLUGINSYSTEM_H_

#define _INCLUDE_SOURCEMOD_PLUGINSYSTEM_H_

#include <time.h>

#include <IPluginSys.h>

#include <IHandleSys.h>

#include <sh_list.h>

#include <sh_stack.h>

#include "sm_globals.h"

#include "vm/sp_vm_basecontext.h"

#include "CFunction.h"

#include "PluginInfoDatabase.h"

#include "sm_trie.h"

#include "sourcemod.h"

using namespace SourceHook;

/**

 * NOTES:

 *

 *  Currently this system needs a lot of work but it's good skeletally.  Plugin creation 

 * is done without actually compiling anything.  This is done by Load functions in the 

 * manager.  This will need a rewrite when we add context switching.

 *

 *  The plugin object itself has a few things to note.  The most important is that it stores

 * a table of function objects.  The manager marshals allocation and freeing of these objects.

 * The plugin object can be in erroneous states, they are:

 *   Plugin_Error   --> Some error occurred any time during or after compilation.

 *						This error can be cleared since the plugin itself is valid.

 *						However, the state itself being set prevents any runtime action.

 *   Plugin_BadLoad	--> The plugin failed to load entirely and nothing can be done to save it.

 *

 *  If a plugin fails to load externally, it is never added to the internal tracker.  However, 

 * plugins that failed to load from the internal loading mechanism are always tracked.  This 

 * allows users to see which automatically loaded plugins failed, and makes the interface a bit

 * more flexible.

 *

 *  Once a plugin is compiled, it sets its own state to Plugin_Created.  This state is still invalid

 * for execution.  SourceMod is a two pass system, and even though the second pass is not implemented

 * yet, it is structured so Plugin_Created must be switched to Plugin_Running in the second pass.  When

 * implemented, a Created plugin will be switched to Error in the second pass if it not loadable.

 *

 *  The two pass loading mechanism is described below.  Modules/natives are not implemented yet.

 * PASS ONE: All loadable plugins are found and have the following steps performed:

 *			 1.  Loading and compilation is attempted.

 *			 2.  If successful, all natives from Core are added.

 *			 3.  OnPluginLoad() is called.

 *			 4.  If failed, any user natives are scrapped and the process halts here.

 *			 5.  If successful, the plugin is ready for Pass 2.

 * INTERMEDIATE:

 *			 1.  All forced modules are loaded.

 * PASS TWO: All loaded plugins are found and have these steps performed:

 *			 1. Any modules referenced in the plugin that are not already loaded, are loaded.

 *			 2. If any module fails to load and the plugin requires it, load fails and jump to step 6.

 *			 3. If any natives are unresolved, check if they are found in the user-natives pool.

 *			 4. If yes, load succeeds.  If not, natives are passed through a native acceptance filter.

 *			 5. If the filter fails, the plugin is marked as failed.

 *			 6. If the plugin has failed to load at this point, any dynamic natives it has added are scrapped.

 *			    Furthermore, any plugin that referenced these natives must now have pass 2 re-ran.

 * PASS THREE (not a real pass):

 *			 7. Once all plugins are deemed to be loaded, OnPluginInit() is called

 */

#define SM_CONTEXTVAR_MYSELF	0

struct ContextPair

{

	ContextPair() : base(NULL), ctx(NULL), co(NULL)

	{

	};

	BaseContext *base;

	sp_context_t *ctx;

	ICompilation *co;

	IVirtualMachine *vm;

};

class CPlugin : public IPlugin

{

	friend class CPluginManager;

	friend class CFunction;

public:

	CPlugin(const char *file);

	~CPlugin();

public:

	virtual PluginType GetType() const;

	virtual SourcePawn::IPluginContext *GetBaseContext() const;

	virtual sp_context_t *GetContext() const;

	virtual const sm_plugininfo_t *GetPublicInfo() const;

	virtual const char *GetFilename() const;

	virtual bool IsDebugging() const;

	virtual PluginStatus GetStatus() const;

	virtual bool SetPauseState(bool paused);

	virtual unsigned int GetSerial() const;

	virtual const sp_plugin_t *GetPluginStructure() const;

	virtual IPluginFunction *GetFunctionByName(const char *public_name);

	virtual IPluginFunction *GetFunctionById(funcid_t func_id);

	virtual IdentityToken_t *GetIdentity() const;

public:

	/**

	 * Creates a plugin object with default values.

	 *   If an error buffer is specified, and an error occurs, the error will be copied to the buffer

	 * and NULL will be returned.

	 *   If an error buffer is not specified, the error will be copied to an internal buffer and 

	 * a valid (but error-stated) CPlugin will be returned.

	 */

	static CPlugin *CreatePlugin(const char *file, char *error, size_t maxlength);

public:

	/**

	 * Starts the initial compilation of a plugin.

	 * Returns false if another compilation exists or there is a current context set.

	 */

	ICompilation *StartMyCompile(IVirtualMachine *vm);

	/** 

	 * Finalizes a compilation.  If error buffer is NULL, the error is saved locally.

	 */

	bool FinishMyCompile(char *error, size_t maxlength);

	void CancelMyCompile();

	/**

	 * Sets an error state on the plugin

	 */

	void SetErrorState(PluginStatus status, const char *error_fmt, ...);

	/**

	 * Initializes the plugin's identity information

	 */

	void InitIdentity();

	/**

	 * Calls the OnPluginLoad function, and sets any failed states if necessary.

	 * NOTE: Valid pre-states are: Plugin_Created

	 * NOTE: If validated, plugin state is changed to Plugin_Loaded

	 *

	 * If the error buffer is NULL, the error message is cached locally.

	 */

	bool Call_AskPluginLoad(char *error, size_t maxlength);

	/**

	 * Calls the OnPluginInit function.

	 * NOTE: Valid pre-states are: Plugin_Created

	 * NOTE: Post-state will be Plugin_Running

	 */

	void Call_OnPluginInit();

	/**

	 * Calls the OnPluginUnload function.

	 */

	void Call_OnPluginUnload();

	/**

	* Toggles debug mode in the plugin

	*/

	bool ToggleDebugMode(bool debug);

	/**

	* Returns true if a plugin is usable.

	*/

	bool IsRunnable() const;

public:

	time_t HasUpdatedFile();

	/** 

	 * Returns true if the plugin was running, but is now invalid.

	 */

	bool WasRunning();

protected:

	void UpdateInfo();

private:

	ContextPair m_ctx;

	PluginType m_type;

	char m_filename[PLATFORM_MAX_PATH+1];

	PluginStatus m_status;

	unsigned int m_serial;

	sm_plugininfo_t m_info;

	sp_plugin_t *m_plugin;

	unsigned int m_funcsnum;

	CFunction **m_priv_funcs;

	CFunction **m_pub_funcs;

	char m_errormsg[256];

	time_t m_LastAccess;

	IdentityToken_t *m_ident;

	Handle_t m_handle;

	bool m_WasRunning;

};

class CPluginManager : 

	public IPluginManager,

	public SMGlobalClass,

	public IHandleTypeDispatch

{

	friend class CPlugin;

public:

	CPluginManager();

	~CPluginManager();

public:

	/* Implements iterator class */

	class CPluginIterator : public IPluginIterator

	{

	public:

		CPluginIterator(List<CPlugin *> *mylist);

		virtual ~CPluginIterator();

		virtual bool MorePlugins();

		virtual IPlugin *GetPlugin();

		virtual void NextPlugin();

		void Release();

	public:

		void Reset();

	private:

		List<CPlugin *> *mylist;

		List<CPlugin *>::iterator current;

	};

	friend class CPluginManager::CPluginIterator;

public: //IPluginManager

	IPlugin *LoadPlugin(const char *path, 

								bool debug,

								PluginType type,

								char error[],

								size_t err_max);

	bool UnloadPlugin(IPlugin *plugin);

	IPlugin *FindPluginByContext(const sp_context_t *ctx);

	unsigned int GetPluginCount();

	IPluginIterator *GetPluginIterator();

	void AddPluginsListener(IPluginsListener *listener);

	void RemovePluginsListener(IPluginsListener *listener);

public: //SMGlobalClass

	void OnSourceModAllInitialized();

	void OnSourceModShutdown();

public: //IHandleTypeDispatch

	void OnHandleDestroy(HandleType_t type, void *object);

public:

	/**

	 * Loads all plugins not yet loaded

	 */

	void LoadAll_FirstPass(const char *config, const char *basedir);

	/**

	 * Runs the second loading pass for all plugins

	 */

	void LoadAll_SecondPass();

	/**

	 * Tests a plugin file mask against a local folder.

	 * The alias is searched backwards from localdir - i.e., given this input:

	 *   csdm/ban        csdm/ban

	 *   ban             csdm/ban

	 *   csdm/ban        optional/csdm/ban

	 * All of these will return true for an alias match.  

	 * Wildcards are allowed in the filename.

	 */

	bool TestAliasMatch(const char *alias, const char *localdir);

	/** 

	 * Returns whether anything loaded will be a late load.

	 */

	bool IsLateLoadTime() const;

	/**

	 * Adds natives from core into the native pool.

	 */

	void RegisterNativesFromCore(sp_nativeinfo_t *natives);

	/**

	 * Converts a Handle to an IPlugin if possible.

	 */

	IPlugin *PluginFromHandle(Handle_t handle, HandleError *err);

	/**

	* Finds a plugin based on its index. (starts on index 1)

	*/

	CPlugin *GetPluginByOrder(int num);

private:

	bool _LoadPlugin(CPlugin **pPlugin, const char *path, bool debug, PluginType type, char error[], size_t err_max);

	void LoadAutoPlugin(const char *plugin);

	/**

	 * Recursively loads all plugins in the given directory.

	 */

	void LoadPluginsFromDir(const char *basedir, const char *localdir);

	/**

	 * Adds a plugin object.  This is wrapped by LoadPlugin functions.

	 */

	void AddPlugin(CPlugin *pPlugin);

	/**

	 * Runs the second loading pass on a plugin.

	 */

	bool RunSecondPass(CPlugin *pPlugin, char *error, size_t maxlength);

	/**

	 * Adds any globally registered natives to a plugin

	 */

	void AddCoreNativesToPlugin(CPlugin *pPlugin);

protected:

	/**

	 * Caching internal objects

	 */

	void ReleaseIterator(CPluginIterator *iter);

	CFunction *GetFunctionFromPool(funcid_t f, CPlugin *plugin);

	void ReleaseFunctionToPool(CFunction *func);

	inline IdentityToken_t *GetIdentity()

	{

		return m_MyIdent;

	}

private:

	List<IPluginsListener *> m_listeners;

	List<CPlugin *> m_plugins;

	List<sp_nativeinfo_t *> m_natives;

	CStack<CPluginManager::CPluginIterator *> m_iters;

	CStack<CFunction *> m_funcpool;

	CPluginInfoDatabase m_PluginInfo;

	Trie *m_LoadLookup;

	bool m_AllPluginsLoaded;

	IdentityToken_t *m_MyIdent;

};

extern CPluginManager g_PluginSys;

#endif //_INCLUDE_SOURCEMOD_PLUGINSYSTEM_H_