#ifndef _INCLUDE_SOURCEMOD_PLUGINFUNCTION_INTERFACE_H_

#define _INCLUDE_SOURCEMOD_PLUGINFUNCTION_INTERFACE_H_

#include <IPluginSys.h>

namespace SourceMod

{

	#define SM_FUNCFLAG_COPYBACK		(1<<0)		/* Copy an array/reference back after call */

	#define SP_STRING_UTF8				(1<<0)		/* String should be UTF-8 handled */

	#define SP_STRING_COPY				(1<<1)		/* String should be copied into the plugin */

	/**

	 * @brief Represents what a function needs to implement in order to be callable.

	 */

	class ICallable

	{

	public:

		/**

		 * @brief Pushes a cell onto the current call.

		 *

		 * @param cell		Parameter value to push.

		 * @return			Error code, if any.

		 */

		virtual int PushCell(cell_t cell) =0;

		/**

		 * @brief Pushes a cell by reference onto the current call.

		 * NOTE: On Execute, the pointer passed will be modified if copyback is enabled.

		 * NOTE: By reference parameters are cached and thus are not read until execution.

		 *		 This means you cannot push a pointer, change it, and push it again and expect

		 *       two different values to come out.

		 *

		 * @param cell		Address containing parameter value to push.

		 * @param flags		Copy-back flags.

		 * @return			Error code, if any.

		 */

		virtual int PushCellByRef(cell_t *cell, int flags) =0;

		/**

		 * @brief Pushes a float onto the current call.

		 *

		 * @param float		Parameter value to push.

		 * @return			Error code, if any.

		 */

		virtual int PushFloat(float number) =0;

		/**

		 * @brief Pushes a float onto the current call by reference.

		 * NOTE: On Execute, the pointer passed will be modified if copyback is enabled.

		 * NOTE: By reference parameters are cached and thus are not read until execution.

		 *		 This means you cannot push a pointer, change it, and push it again and expect

		 *       two different values to come out.

		 *

		 * @param float		Parameter value to push.

		 & @param flags		Copy-back flags.

		 * @return			Error code, if any.

		 */

		virtual int PushFloatByRef(float *number, int flags) =0;

		/**

		 * @brief Pushes an array of cells onto the current call.  

		 * NOTE: On Execute, the pointer passed will be modified if non-NULL and copy-back

		 * is enabled.

		 * NOTE: By reference parameters are cached and thus are not read until execution.

		 *		 This means you cannot push a pointer, change it, and push it again and expect

		 *       two different values to come out.

		 *

		 * @param inarray	Array to copy, NULL if no initial array should be copied.

		 * @param cells		Number of cells to allocate and optionally read from the input array.

		 * @param phys_addr	Optional return address for physical array, if one was made.

		 * @param flags		Whether or not changes should be copied back to the input array.

		 * @return			Error code, if any.

		 */

		virtual int PushArray(cell_t *inarray, 

								unsigned int cells, 

								cell_t **phys_addr, 

								int flags=0) =0;

		/**

		 * @brief Pushes a string onto the current call.

		 *

		 * @param string	String to push.

		 * @return			Error code, if any.

		 */

		virtual int PushString(const char *string) =0;

		/**

		 * @brief Pushes a string or string buffer.

		 * NOTE: On Execute, the pointer passed will be modified if copy-back is enabled.

		 *

		 * @param buffer	Pointer to string buffer.

		 * @param length	Length of buffer.

		 * @param sz_flags	String flags.

		 * @param cp_flags	Copy-back flags.

		 * @return			Error code, if any.

		 */

		virtual int PushStringEx(char *buffer, size_t length, int sz_flags, int cp_flags) =0;

		/**

		 * @brief Cancels a function call that is being pushed but not yet executed.

		 * This can be used be reset for CallFunction() use.

		 */

		virtual void Cancel() =0;

	};

	/**

	 * @brief Encapsulates a function call in a plugin.

	 * NOTE: Function calls must be atomic to one execution context.

	 * NOTE: This object should not be deleted.  It lives for the lifetime of the plugin.

	 */

	class IPluginFunction : public ICallable

	{

	public:

		/**

		 * @brief Executes the forward, resets the pushed parameter list, and performs any copybacks.

		 *

		 * @param result		Pointer to store return value in.

		 * @return				Error code, if any.

		 */

		virtual int Execute(cell_t *result) =0;

		/**

		 * @brief Executes the function with the given parameter array.

		 * Parameters are read in forward order (i.e. index 0 is parameter #1)

		 * NOTE: You will get an error if you attempt to use CallFunction() with

		 * previously pushed parameters.

		 *

		 * @param param			Array of cell parameters.

		 * @param num_params	Number of parameters to push.

		 * @param result		Pointer to store result of function on return.

		 * @return				SourcePawn error code (if any).

		 */

		virtual int CallFunction(const cell_t *params, unsigned int num_params, cell_t *result) =0;

		/**

		 * @brief Returns which plugin this function belongs to.

		 *

		 * @return				IPlugin pointer to parent plugin.

		 */

		virtual IPlugin *GetParentPlugin() =0;

		/**

		 * @brief Returns the physical address of a by-reference parameter.

		 *

		 * @param				Parameter index to read (beginning at 0).

		 * @return				Address, or NULL if invalid parameter specified.

		 */

		virtual cell_t *GetAddressOfPushedParam(unsigned int param) =0;

	};

};

#endif //_INCLUDE_SOURCEMOD_PLUGINFUNCTION_INTERFACE_H_