/**
 * vim: set ts=4 :
 * =============================================================================
 * SourceMod (C)2004-2008 AlliedModders LLC.  All rights reserved.
 * =============================================================================
 *
 * This file is part of the SourceMod/SourcePawn SDK.
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 3.0, as published by the
 * Free Software Foundation.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * As a special exception, AlliedModders LLC gives you permission to link the
 * code of this program (as well as its derivative works) to "Half-Life 2," the
 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
 * by the Valve Corporation.  You must obey the GNU General Public License in
 * all respects for all other code used.  Additionally, AlliedModders LLC grants
 * this exception to all derivative works.  AlliedModders LLC defines further
 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
 * or <http://www.sourcemod.net/license.php>.
 *
 * Version: $Id$
 */
 
#if defined _functions_included
 #endinput
#endif
#define _functions_included
 
#define SP_PARAMFLAG_BYREF	(1<<0)	/**< Internal use only. */

/**
 * Describes the various ways to pass parameters to functions or forwards.
 */
enum ParamType
{
	Param_Any			= 0,							/**< Any data type can be pushed */
	Param_Cell			= (1<<1),						/**< Only basic cells can be pushed */
	Param_Float			= (2<<1),						/**< Only floats can be pushed */
	Param_String		= (3<<1)|SP_PARAMFLAG_BYREF,	/**< Only strings can be pushed */
	Param_Array			= (4<<1)|SP_PARAMFLAG_BYREF,	/**< Only arrays can be pushed */
	Param_VarArgs		= (5<<1),						/**< Same as "..." in plugins, anything can be pushed, but it will always be byref */
	Param_CellByRef		= (1<<1)|SP_PARAMFLAG_BYREF,	/**< Only a cell by reference can be pushed */
	Param_FloatByRef	= (2<<1)|SP_PARAMFLAG_BYREF		/**< Only a float by reference can be pushed */
};

/**
 * Defines how a forward iterates through plugin functions.
 */
enum ExecType
{
	ET_Ignore	= 0,	/**< Ignore all return values, return 0 */
	ET_Single	= 1,	/**< Only return the last exec, ignore all others */
	ET_Event	= 2,	/**< Acts as an event with the Actions defined in core.inc, no mid-Stops allowed, returns highest */
	ET_Hook		= 3		/**< Acts as a hook with the Actions defined in core.inc, mid-Stops allowed, returns highest */
};

/**
 * @section Flags that are used with Call_PushArrayEx() and Call_PushStringEx()
 */
 
#define SM_PARAM_COPYBACK		(1<<0)		/**< Copy an array/reference back after call */

#define SM_PARAM_STRING_UTF8	(1<<0)		/**< String should be UTF-8 handled */
#define SM_PARAM_STRING_COPY	(1<<1)		/**< String should be copied into the plugin */
#define SM_PARAM_STRING_BINARY	(1<<2)		/**< Treat the string as a binary string */

/**
 * @endsection
 */

/**
 * @section Error codes
 */
#define SP_ERROR_NONE					0	/**< No error occurred */
#define SP_ERROR_FILE_FORMAT			1	/**< File format unrecognized */
#define SP_ERROR_DECOMPRESSOR			2	/**< A decompressor was not found */
#define SP_ERROR_HEAPLOW				3	/**< Not enough space left on the heap */
#define SP_ERROR_PARAM					4	/**< Invalid parameter or parameter type */
#define SP_ERROR_INVALID_ADDRESS		5	/**< A memory address was not valid */
#define SP_ERROR_NOT_FOUND				6	/**< The object in question was not found */
#define SP_ERROR_INDEX					7	/**< Invalid index parameter */
#define SP_ERROR_STACKLOW				8	/**< Not enough space left on the stack */
#define SP_ERROR_NOTDEBUGGING			9	/**< Debug mode was not on or debug section not found */
#define SP_ERROR_INVALID_INSTRUCTION	10	/**< Invalid instruction was encountered */
#define SP_ERROR_MEMACCESS				11	/**< Invalid memory access */
#define SP_ERROR_STACKMIN				12	/**< Stack went beyond its minimum value */
#define SP_ERROR_HEAPMIN				13  /**< Heap went beyond its minimum value */
#define SP_ERROR_DIVIDE_BY_ZERO			14	/**< Division by zero */
#define SP_ERROR_ARRAY_BOUNDS			15	/**< Array index is out of bounds */
#define SP_ERROR_INSTRUCTION_PARAM		16	/**< Instruction had an invalid parameter */
#define SP_ERROR_STACKLEAK				17  /**< A native leaked an item on the stack */
#define SP_ERROR_HEAPLEAK				18  /**< A native leaked an item on the heap */
#define SP_ERROR_ARRAY_TOO_BIG			19	/**< A dynamic array is too big */
#define SP_ERROR_TRACKER_BOUNDS			20	/**< Tracker stack is out of bounds */
#define SP_ERROR_INVALID_NATIVE			21	/**< Native was pending or invalid */
#define SP_ERROR_PARAMS_MAX				22	/**< Maximum number of parameters reached */
#define SP_ERROR_NATIVE					23	/**< Error originates from a native */
#define SP_ERROR_NOT_RUNNABLE			24	/**< Function or plugin is not runnable */
#define SP_ERROR_ABORTED				25	/**< Function call was aborted */

/**
 * @endsection
 */

/**
 * Gets a function id from a function name. 
 *
 * @param plugin			Handle of the plugin that contains the function.
							Pass INVALID_HANDLE to search in the calling plugin.
 * @param name				Name of the function.
 * @return 					Function id or INVALID_FUNCTION if not found.
 * @error					Invalid or corrupt plugin handle.
 */
native Function GetFunctionByName(Handle plugin, const char[] name);

/**
 * Creates a global forward.
 *
 * @note The name used to create the forward is used as its public function in all target plugins.
 * @note This is ideal for global, static forwards that are never changed.
 * @note Global forwards cannot be cloned.
 * @note Use CloseHandle() to destroy these.
 *
 * @param name				Name of public function to use in forward.
 * @param type				Execution type to be used.
 * @param ...				Variable number of parameter types (up to 32).
 * @return 					Handle to new global forward.
 * @error					More than 32 paramater types passed.
 */
native Handle CreateGlobalForward(const char[] name, ExecType type, ParamType ...);

/**
 * Creates a private forward.
 *
 * @note No functions are automatically added. Use AddToForward() to do this.
 * @note Private forwards can be cloned.
 * @note Use CloseHandle() to destroy these.
 *
 * @param type				Execution type to be used.
 * @param ...				Variable number of parameter types (up to 32).
 * @return 					Handle to new private forward.
 * @error					More than 32 paramater types passed.
 */
native Handle CreateForward(ExecType type, ParamType ...);

/**
 * Returns the number of functions in a global or private forward's call list.
 *
 * @param fwd				Handle to global or private forward.
 * @return					Number of functions in forward.
 * @error					Invalid or corrupt forward handle.
 */
native int GetForwardFunctionCount(Handle fwd);

/**
 * Adds a function to a private forward's call list.
 *
 * @note Cannot be used during an incomplete call.
 *
 * @param fwd				Handle to private forward.
 * @param plugin			Handle of the plugin that contains the function.
 *							Pass INVALID_HANDLE to specify the calling plugin.
 * @param func				Function to add to forward.
 * @return					True on success, false otherwise.
 * @error					Invalid or corrupt private forward handle, invalid or corrupt plugin handle, or invalid function.
 */
native bool AddToForward(Handle fwd, Handle plugin, Function func);

/**
 * Removes a function from a private forward's call list.
 *
 * @note Only removes one instance.
 * @note Functions will be removed automatically if their parent plugin is unloaded.
 *
 * @param fwd				Handle to private forward.
 * @param plugin			Handle of the plugin that contains the function.
 *							Pass INVALID_HANDLE to specify the calling plugin.
 * @param func				Function to remove from forward.
 * @return					True on success, false otherwise.
 * @error					Invalid or corrupt private forward handle, invalid or corrupt plugin handle, or invalid function.
 */
native bool RemoveFromForward(Handle fwd, Handle plugin, Function func);

/**
 * Removes all instances of a plugin from a private forward's call list.
 *
 * @note Functions will be removed automatically if their parent plugin is unloaded.
 *
 * @param fwd				Handle to private forward.
 * @param plugin			Handle of the plugin to remove instances of.
 *							Pass INVALID_HANDLE to specify the calling plugin.
 * @return					Number of functions removed from forward.
 * @error					Invalid or corrupt private forward handle or invalid or corrupt plugin handle.
 */
native int RemoveAllFromForward(Handle fwd, Handle plugin);

/**
 * Starts a call to functions in a forward's call list.
 *
 * @note Cannot be used during an incomplete call.
 *
 * @param fwd				Handle to global or private forward.
 * @error					Invalid or corrupt forward handle or called before another call has completed.
 */
native void Call_StartForward(Handle fwd);

/**
 * Starts a call to a function.
 *
 * @note Cannot be used during an incomplete call.
 *
 * @param plugin			Handle of the plugin that contains the function.
 *							Pass INVALID_HANDLE to specify the calling plugin.
 * @param func				Function to call.
 * @error					Invalid or corrupt plugin handle, invalid function, or called before another call has completed.
 */
native void Call_StartFunction(Handle plugin, Function func);

/**
 * Pushes a cell onto the current call.
 *
 * @note Cannot be used before a call has been started.
 *
 * @param value				Cell value to push.
 * @error					Called before a call has been started.
 */
native void Call_PushCell(any value);

/**
 * Pushes a cell by reference onto the current call.
 *
 * @note Cannot be used before a call has been started.
 *
 * @param value				Cell reference to push.
 * @error					Called before a call has been started.
 */
native void Call_PushCellRef(any &value);

/**
 * Pushes a float onto the current call.
 *
 * @note Cannot be used before a call has been started.
 *
 * @param value				Floating point value to push.
 * @error					Called before a call has been started.
 */
native void Call_PushFloat(float value);

/**
 * Pushes a float by reference onto the current call.
 *
 * @note Cannot be used before a call has been started.
 *
 * @param value				Floating point reference to push.
 * @error					Called before a call has been started.
 */
native void Call_PushFloatRef(float &value);

/**
 * Pushes an array onto the current call.
 *
 * @note Changes to array are not copied back to caller. Use PushArrayEx() to do this.
 * @note Cannot be used before a call has been started.
 *
 * @param value				Array to push.
 * @param size				Size of array.
 * @error					Called before a call has been started.
 */
native void Call_PushArray(const any[] value, int size);

/**
 * Pushes an array onto the current call.
 *
 * @note Cannot be used before a call has been started.
 *
 * @param value				Array to push.
 * @param size				Size of array.
 * @param cpflags			Whether or not changes should be copied back to the input array.
 *							See SP_PARAM_* constants for details.
 * @error					Called before a call has been started.
 */
native void Call_PushArrayEx(any[] value, int size, int cpflags);

/**
 * Pushes a string onto the current call.
 *
 * @note Changes to string are not copied back to caller. Use PushStringEx() to do this.
 * @note Cannot be used before a call has been started.
 *
 * @param value				String to push.
 * @error					Called before a call has been started.
 */
native void Call_PushString(const char[] value);

/**
 * Pushes a string onto the current call.
 *
 * @note Cannot be used before a call has been started.
 *
 * @param value				String to push.
 * @param length			Length of string buffer.
 * @param szflags			Flags determining how string should be handled.
 *							See SM_PARAM_STRING_* constants for details.
 *							The default (0) is to push ASCII.
 * @param cpflags			Whether or not changes should be copied back to the input array.
 *							See SM_PARAM_* constants for details.		
 * @error					Called before a call has been started.
 */
native void Call_PushStringEx(char[] value, int length, int szflags, int cpflags);

/**
 * Completes a call to a function or forward's call list.
 *
 * @note Cannot be used before a call has been started.
 *
 * @param result			Return value of function or forward's call list.		
 * @return					SP_ERROR_NONE on success, any other integer on failure.
 * @error					Called before a call has been started.
 */
native int Call_Finish(any &result=0);

/**
 * Cancels a call to a function or forward's call list.
 *
 * @note Cannot be used before a call has been started.
 *		
 * @error					Called before a call has been started.
 */
native void Call_Cancel();

/**
 * Defines a native function.
 *
 * It is not necessary to validate the parameter count 
 *
 * @param plugin			Handle of the calling plugin.
 * @param numParams			Number of parameters passed to the native.
 * @return 					Value for the native call to return.
 */
typedef NativeCall = function int (Handle plugin, int numParams);

/**
 * Creates a dynamic native.  This should only be called in AskPluginLoad(), or 
 * else you risk not having your native shared with other plugins.
 *
 * @param name				Name of the dynamic native; must be unique among
 *							all other registered dynamic natives.
 * @param func				Function to use as the dynamic native.
 */
native void CreateNative(const char[] name, NativeCall func);

/**
 * Throws an error in the calling plugin of a native, instead of your own plugin.
 *
 * @param error				Error code to use.
 * @param fmt				Error message format.
 * @param ...				Format arguments.
 */
native int ThrowNativeError(int error, const char[] fmt, any ...);

/**
 * Retrieves the string length from a native parameter string.  This is useful 
 * fetching the entire string using dynamic arrays.
 * @note If this function succeeds, Get/SetNativeString will also succeed.
 *
 * @param param				Parameter number, starting from 1.
 * @param length			Stores the length of the string.
 * @return					SP_ERROR_NONE on success, any other integer on failure.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native int GetNativeStringLength(int param, int &length);

/**
 * Retrieves a string from a native parameter.
 * @note Output conditions are undefined on failure.
 *
 * @param param				Parameter number, starting from 1.
 * @param buffer			Buffer to store the string in.
 * @param maxlength			Maximum length of the buffer.
 * @param bytes				Optionally store the number of bytes written.
 * @return					SP_ERROR_NONE on success, any other integer on failure.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native int GetNativeString(int param, char[] buffer, int maxlength, int &bytes=0);

/**
 * Sets a string in a native parameter.
 * @note Output conditions are undefined on failure.
 *
 * @param param				Parameter number, starting from 1.
 * @param source			Source string to use.
 * @param maxlength			Maximum number of bytes to write.
 * @param utf8				If false, string will not be written
 *							with UTF8 safety.
 * @param bytes				Optionally store the number of bytes written.
 * @return					SP_ERROR_NONE on success, any other integer on failure.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native int SetNativeString(int param, const char[] source, int maxlength, bool utf8=true, int &bytes=0);

/**
 * Gets a cell from a native parameter.
 *
 * @param param				Parameter number, starting from 1.
 * @return					Cell value at the parameter number.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native any GetNativeCell(int param);

/**
 * Gets a function pointer from a native parameter.
 *
 * @param param             Parameter number, starting from 1.
 * @return                  Function pointer at the given parameter number.
 * @error                   Invalid parameter number, or calling from a non-native function.
 */
native Function GetNativeFunction(int param);

/**
 * Gets a cell from a native parameter, by reference.
 *
 * @param param				Parameter number, starting from 1.
 * @return					Cell value at the parameter number.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native any GetNativeCellRef(int param);

/**
 * Sets a cell from a native parameter, by reference.
 *
 * @param param				Parameter number, starting from 1.
 * @param value				Cell value at the parameter number to set by reference.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native void SetNativeCellRef(int param, any value);

/**
 * Gets an array from a native parameter (always by reference).
 *
 * @param param				Parameter number, starting from 1.
 * @param local				Local array to copy into.
 * @param size				Maximum size of local array.
 * @return					SP_ERROR_NONE on success, anything else on failure.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native int GetNativeArray(int param, any[] local, int size);

/**
 * Copies a local array into a native parameter array (always by reference).
 * 
 * @param param				Parameter number, starting from 1.
 * @param local				Local array to copy from.
 * @param size				Size of the local array to copy.
 * @return					SP_ERROR_NONE on success, anything else on failure.
 * @error					Invalid parameter number or calling from a non-native function.
 */
native int SetNativeArray(int param, const any[] local, int size);

/**
 * Formats a string using parameters from a native.
 *
 * @note All parameter indexes start at 1.
 * @note If the input and output buffers overlap, the contents
 *  of the output buffer at the end is undefined.
 *
 * @param out_param			Output parameter number to write to.  If 0, out_string is used.
 * @param fmt_param			Format parameter number.  If 0, fmt_string is used.
 * @param vararg_param		First variable parameter number.
 * @param out_len			Output string buffer maximum length (always required).
 * @param written			Optionally stores the number of bytes written.
 * @param out_string		Output string buffer to use if out_param is not used.
 * @param fmt_string		Format string to use if fmt_param is not used.
 * @return					SP_ERROR_NONE on success, anything else on failure.
 */
native int FormatNativeString(int out_param, 
						  int fmt_param, 
						  int vararg_param, 
						  int out_len,
						  int &written=0,
						  char[] out_string="",
						  const char[] fmt_string="");

/**
 * Defines a RequestFrame Callback.
 *
 * @param data			Data passed to the RequestFrame native.
 */
typedef RequestFrameCallback = function void (any data);

/**
 * Creates a single use Next Frame hook.
 *
 * @param Function	Function to call on the next frame.
 * @param data			Value to be passed on the invocation of the Function.
 */
native void RequestFrame(RequestFrameCallback Function, any data=0);
