/**

 * vim: set ts=4 :

 * ================================================================

 * SourcePawn, 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_SOURCEPAWN_VM_API_H_

#define _INCLUDE_SOURCEPAWN_VM_API_H_

/**

 * @file sp_vm_api.h

 * @brief Contains all of the object structures used in the SourcePawn API.

 */

#include <stdio.h>

#include "sp_vm_types.h"

/** SourcePawn VM API Version */

#define SOURCEPAWN_VM_API_VERSION		1

#if defined SOURCEMOD_BUILD

namespace SourceMod

{

	struct IdentityToken_t;

};

#endif

namespace SourcePawn

{

	class IVirtualMachine;

	#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 */

	/**

	 * @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 number	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 number	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 params		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				IPluginContext pointer to parent plugin.

		 */

		virtual IPluginContext *GetParentContext() =0;

		/**

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

		 *

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

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

		 */

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

	};

	/**

	 * @brief Interface to managing a debug context at runtime.

	 */

	class IPluginDebugInfo

	{

	public:

		/**

		 * @brief Given a code pointer, finds the file it is associated with.

		 * 

		 * @param addr		Code address offset.

		 * @param filename	Pointer to store filename pointer in.

		 */

		virtual int LookupFile(ucell_t addr, const char **filename) =0;

		/**

		 * @brief Given a code pointer, finds the function it is associated with.

		 *

		 * @param addr		Code address offset.

		 * @param name		Pointer to store function name pointer in.

		 */

		virtual int LookupFunction(ucell_t addr, const char **name) =0;

		/**

		 * @brief Given a code pointer, finds the line it is associated with.

		 *

		 * @param addr		Code address offset.

		 * @param line		Pointer to store line number in.

		 */

		virtual int LookupLine(ucell_t addr, uint32_t *line) =0;

	};

	/**

	 * @brief Interface to managing a context at runtime.

	 */

	class IPluginContext

	{

	public:

		/** Virtual destructor */

		virtual ~IPluginContext() { };

	public:

		/** 

		 * @brief Returns the parent IVirtualMachine.

		 *

		 * @return				Parent virtual machine pointer.

		 */

		virtual IVirtualMachine *GetVirtualMachine() =0;

		/**

		 * @brief Returns the child sp_context_t structure.

		 *

		 * @return				Child sp_context_t structure.

		 */

		virtual sp_context_t *GetContext() =0;

		/**

		 * @brief Returns true if the plugin is in debug mode.

		 *

		 * @return				True if in debug mode, false otherwise.

		 */

		virtual bool IsDebugging() =0;

		/**

		 * @brief Installs a debug break and returns the old one, if any.

		 * This will fail if the plugin is not debugging.

		 *

		 * @param newpfn		New function pointer.

		 * @param oldpfn		Pointer to retrieve old function pointer.

		 */

		virtual int SetDebugBreak(SPVM_DEBUGBREAK newpfn, SPVM_DEBUGBREAK *oldpfn) =0;

		/**

		 * @brief Returns debug info.

		 *

		 * @return				IPluginDebugInfo, or NULL if no debug info found.

		 */

		virtual IPluginDebugInfo *GetDebugInfo() =0;

		/**

		 * @brief Allocates memory on the secondary stack of a plugin.

		 * Note that although called a heap, it is in fact a stack.

		 * 

		 * @param cells			Number of cells to allocate.

		 * @param local_addr	Will be filled with data offset to heap.

		 * @param phys_addr		Physical address to heap memory.

		 */

		virtual int HeapAlloc(unsigned int cells, cell_t *local_addr, cell_t **phys_addr) =0;

		/**

		 * @brief Pops a heap address off the heap stack.  Use this to free memory allocated with

		 *  SP_HeapAlloc().  

		 * Note that in SourcePawn, the heap is in fact a bottom-up stack.  Deallocations

		 *  with this native should be performed in precisely the REVERSE order.

		 *

		 * @param local_addr	Local address to free.

 		 */

		virtual int HeapPop(cell_t local_addr) =0;

		/**

		 * @brief Releases a heap address using a different method than SP_HeapPop().

		 * This allows you to release in any order.  However, if you allocate N 

		 *  objects, release only some of them, then begin allocating again, 

		 *  you cannot go back and starting freeing the originals.  

		 * In other words, for each chain of allocations, if you start deallocating,

		 *  then allocating more in a chain, you must only deallocate from the current 

		 *  allocation chain.  This is basically HeapPop() except on a larger scale.

		 *

		 * @param local_addr	Local address to free.

 		 */

		virtual int HeapRelease(cell_t local_addr) =0;

		/**

		 * @brief Finds a native by name.

		 *

		 * @param name			Name of native.

		 * @param index			Optionally filled with native index number.

		 */

		virtual int FindNativeByName(const char *name, uint32_t *index) =0;

		/**

		 * @brief Gets native info by index.

		 *

		 * @param index			Index number of native.

		 * @param native		Optionally filled with pointer to native structure.

		 */

		virtual int GetNativeByIndex(uint32_t index, sp_native_t **native) =0;

		/**

		 * @brief Gets the number of natives.

		 * 

		 * @return				Filled with the number of natives.

		 */

		virtual uint32_t GetNativesNum() =0;

		/**

		 * @brief Finds a public function by name.

		 *

		 * @param name			Name of public

		 * @param index			Optionally filled with public index number.

		 */

		virtual int FindPublicByName(const char *name, uint32_t *index) =0;

		/**

		 * @brief Gets public function info by index.

		 * 

		 * @param index			Public function index number.

		 * @param publicptr		Optionally filled with pointer to public structure.

		 */

		virtual int GetPublicByIndex(uint32_t index, sp_public_t **publicptr) =0;

		/**

		 * @brief Gets the number of public functions.

		 *

		 * @return				Filled with the number of public functions.

		 */

		virtual uint32_t GetPublicsNum() =0;

		/**

		 * @brief Gets public variable info by index.

		 * 

		 * @param index			Public variable index number.

		 * @param pubvar		Optionally filled with pointer to pubvar structure.

		 */

		virtual int GetPubvarByIndex(uint32_t index, sp_pubvar_t **pubvar) =0;

		/**

		 * @brief Finds a public variable by name.

		 *

		 * @param name			Name of pubvar

		 * @param index			Optionally filled with pubvar index number.

		 */

		virtual int FindPubvarByName(const char *name, uint32_t *index) =0;

		/**

		 * @brief Gets the addresses of a public variable.

		 * 

		 * @param index			Index of public variable.

		 * @param local_addr		Address to store local address in.

		 * @param phys_addr		Address to store physically relocated in.

		 */

		virtual int GetPubvarAddrs(uint32_t index, cell_t *local_addr, cell_t **phys_addr) =0;

		/**

		 * @brief Returns the number of public variables.

		 *

		 * @return				Number of public variables.

		 */

		virtual uint32_t GetPubVarsNum() =0;

		/**

		 * @brief Round-about method of converting a plugin reference to a physical address

		 *

		 * @param local_addr	Local address in plugin.

		 * @param phys_addr		Optionally filled with relocated physical address.

		 */

		virtual int LocalToPhysAddr(cell_t local_addr, cell_t **phys_addr) =0;

		/**

		 * @brief Converts a local address to a physical string.

		 *

		 * @param local_addr	Local address in plugin.

		 * @param addr			Destination output pointer.

		 */

		virtual int LocalToString(cell_t local_addr, char **addr) =0;

		/**

		 * @brief Converts a physical string to a local address.

		 *

		 * @param local_addr	Local address in plugin.

		 * @param bytes			Number of chars to write, including NULL terminator.

		 * @param source		Source string to copy.

		 */

		virtual int StringToLocal(cell_t local_addr, size_t bytes, const char *source) =0;

		/**

		 * @brief Converts a physical UTF-8 string to a local address.

		 * This function is the same as the ANSI version, except it will copy the maximum number of characters possible 

		 *  without accidentally chopping a multi-byte character.

		 *

		 * @param local_addr		Local address in plugin.

		 * @param maxbytes		Number of bytes to write, including NULL terminator.

		 * @param source			Source string to copy.

		 * @param wrtnbytes		Optionally set to the number of actual bytes written.

		 */

		virtual int StringToLocalUTF8(cell_t local_addr, 

									  size_t maxbytes, 

									  const char *source, 

									  size_t *wrtnbytes) =0;

		/**

		 * @brief Pushes a cell onto the stack.  Increases the parameter count by one.

		 *

		 * @param value			Cell value.

		 */

		virtual int PushCell(cell_t value) =0;

		/** 

		 * @brief Pushes an array of cells onto the stack.  Increases the parameter count by one.

		 * If the function returns an error it will fail entirely, releasing anything allocated in the process.

		 * Note that this does not release the heap, so you should release it after

		 *  calling Execute().

		 *

		 * @param local_addr	Filled with local address to release.

		 * @param phys_addr		Optionally filled with physical address of new array.

		 * @param array			Cell array to copy.

		 * @param numcells		Number of cells in the array to copy.

		 */

		virtual int PushCellArray(cell_t *local_addr, cell_t **phys_addr, cell_t array[], unsigned int numcells) =0;

		/**

		 * @brief Pushes a string onto the stack (by reference) and increases the parameter count by one.

		 * Note that this does not release the heap, so you should release it after

		 *  calling Execute().

		 *

		 * @param local_addr	Filled with local address to release.

		 * @param phys_addr		Optionally filled with physical address of new array.

		 * @param string		Source string to push.

		 */

		virtual int PushString(cell_t *local_addr, char **phys_addr, const char *string) =0;

		/**

		 * @brief Individually pushes each cell of an array of cells onto the stack.  Increases the 

		 *  parameter count by the number of cells pushed.

		 * If the function returns an error it will fail entirely, releasing anything allocated in the process.

		 *

		 * @param array			Array of cells to read from.

		 * @param numcells		Number of cells to read.

		 */

		virtual int PushCellsFromArray(cell_t array[], unsigned int numcells) =0;

		/** 

		 * @brief Binds a list of native names and their function pointers to a context.

		 * If num is 0, the list is read until an entry with a NULL name is reached.

		 * If overwrite is non-zero, already registered natives will be overwritten.

		 * 

		 * @param natives		Array of natives.

		 * @param num			Number of natives in array.

		 * @param overwrite		Toggles overwrite.

		 */

		virtual int BindNatives(const sp_nativeinfo_t *natives, unsigned int num, int overwrite) =0;

		/**

		 * @brief Binds a single native.  Overwrites any existing bind.

		 * If the context does not contain the native that will be binded the function will return

		 *  with a SP_ERROR_NOT_FOUND error.

		 *

		 * @param native		Pointer to native.

		 */

		virtual int BindNative(const sp_nativeinfo_t *native) =0;

		/**

		 * @brief Binds a single native to any non-registered native.

		 *

		 * @param native		Native to bind.

		 */

		virtual int BindNativeToAny(SPVM_NATIVE_FUNC native) =0;

		/**

		 * @brief Executes a function ID located in this context.

		 *

		 * @param code_addr		Address to execute at.

		 * @param result		Pointer to store the return value (required).

		 * @return				Error code (if any) from the VM.

		 */

		virtual int Execute(uint32_t code_addr, cell_t *result) =0;

		/**

		 * @brief Throws a error and halts any current execution.

		 *

		 * @param error		The error number to set.

		 * @param msg		Custom error message format.  NULL to use default.

		 * @param ...		Message format arguments, if any.

		 */

		virtual void ThrowNativeErrorEx(int error, const char *msg, ...) =0;

		/**

		 * @brief Throws a generic native error and halts any current execution.

		 *

		 * @param msg		Custom error message format.  NULL to set no message.

		 * @param ...		Message format arguments, if any.

		 * @return			0 for convenience.

		 */

		virtual cell_t ThrowNativeError(const char *msg, ...) =0;

		/**

		 * @brief Returns a function by name.

		 *

		 * @param public_name		Name of the function.

		 * @return					A new IPluginFunction pointer, NULL if not found.

		 */

		virtual IPluginFunction *GetFunctionByName(const char *public_name) =0;

		/**

		 * @brief Returns a function by its id.

		 *

		 * @param func_id			Function ID.

		 * @return					A new IPluginFunction pointer, NULL if not found.

		 */

		virtual IPluginFunction *GetFunctionById(funcid_t func_id) =0;

#if defined SOURCEMOD_BUILD

		/**

		 * @brief Returns the identity token for this context.

		 * Note: This is a helper function for native calls and the Handle System.

		 *

		 * @return			Identity token.

		 */

		virtual SourceMod::IdentityToken_t *GetIdentity() =0;

		/**

		 * @brief Returns whether the identity is runnable.

		 *

		 * @return			True if runnable, false otherwise.

		 */

		virtual bool IsRunnable() =0;

#endif

	};

	/**

	 * @brief Information about a position in a call stack.

	 */

	struct CallStackInfo

	{

		const char *filename;		/**< NULL if not found */

		unsigned int line;			/**< 0 if not found */

		const char *function;		/**< NULL if not found */

	};

	/**

	 * @brief Retrieves error information from a debug hook.

	 */

	class IContextTrace

	{

	public:

		/**

		 * @brief Returns the integer error code.

		 *

		 * @return			Integer error code.

		 */

		virtual int GetErrorCode() =0;

		/**

		 * @brief Returns a string describing the error.

		 *

		 * @return			Error string.

		 */

		virtual const char *GetErrorString() =0;

		/**

		 * @brief Returns whether debug info is available.

		 *

		 * @return			True if debug info is available, false otherwise.

		 */

		virtual bool DebugInfoAvailable() =0;

		/**

		 * @brief Returns a custom error message.

		 *

		 * @return			A pointer to a custom error message, or NULL otherwise.

		 */

		virtual const char *GetCustomErrorString() =0;

		/**

		 * @brief Returns trace info for a specific point in the backtrace, if any.

		 * The next subsequent call to GetTraceInfo() will return the next item in the call stack.

		 * Calls are retrieved in descending order (i.e. the first item is at the top of the stack/call sequence).

		 *

		 * @param trace		An ErrorTraceInfo buffer to store information (NULL to ignore).

		 * @return			True if successful, false if there are no more traces.

		 */

		virtual bool GetTraceInfo(CallStackInfo *trace) =0;

		/**

		 * @brief Resets the trace to its original position (the call on the top of the stack).

		 */

		virtual void ResetTrace() =0;

		/**

		 * @brief Retrieves the name of the last native called.

		 * Returns NULL if there was no native that caused the error.

		 *

		 * @param index		Optional pointer to store index.

		 * @return			Native name, or NULL if none.

		 */

		virtual const char *GetLastNative(uint32_t *index) =0;

	};

	/**

	 * @brief Provides callbacks for debug information.

	 */

	class IDebugListener

	{

	public:

		virtual void OnContextExecuteError(IPluginContext *ctx, IContextTrace *error) =0;

	};

	/**

	 * @brief Contains helper functions used by VMs and the host app

	 */

	class ISourcePawnEngine

	{

	public:

		/**

		 * @brief Loads a named file from a file pointer.  

		 * Note: Using this means the memory will be allocated by the VM.

		 * 

		 * @param fp			File pointer.  May be at any offset.  Not closed on return.

		 * @param err		Optional error code pointer.

		 * @return			A new plugin structure.

		 */	

		virtual sp_plugin_t *LoadFromFilePointer(FILE *fp, int *err) =0;

		/**

		 * @brief Loads a file from a base memory address.

		 *	

		 * @param base		Base address of the plugin's memory region.

		 * @param plugin	If NULL, a new plugin pointer is returned.

		 *                  Otherwise, the passed pointer is used.

		 * @param err		Optional error code pointer.

		 * @return			The resulting plugin pointer.

		 */

		virtual sp_plugin_t *LoadFromMemory(void *base, sp_plugin_t *plugin, int *err) =0;

		/**

		 * Frees all of the memory associated with a plugin file.

		 * If allocated using SP_LoadFromMemory, the base and plugin pointer 

		 *  itself are not freed (so this may end up doing nothing).

		 */

		virtual int FreeFromMemory(sp_plugin_t *plugin) =0;

		/**

		 * @brief Allocates large blocks of temporary memory.

		 * 

		 * @param size		Size of memory to allocate.

		 * @return			Pointer to memory, NULL if allocation failed.

		 */

		virtual void *BaseAlloc(size_t size) =0;

		/**

		 * @brief Frees memory allocated with BaseAlloc.

		 *

		 * @param memory	Memory address to free.

		 */

		virtual void BaseFree(void *memory) =0;

		/**

		 * @brief Allocates executable memory.

		 *

		 * @param size		Size of memory to allocate.

		 * @return			Pointer to memory, NULL if allocation failed.

		 */

		virtual void *ExecAlloc(size_t size) =0;

		/**

		 * @brief Frees executable memory.

		 *

		 * @param address	Address to free.

		 */

		virtual void ExecFree(void *address) =0;

		/**

		 * @brief Sets the debug listener.  This should only be called once.

		 * If called successively (using manual chaining), only the last function should

		 * attempt to call back into the same plugin.  Otherwise, globally cached states

		 * can be accidentally overwritten.

		 *

		 * @param listener	Pointer to an IDebugListener.

		 * @return			Old IDebugListener, or NULL if none.

		 */

		virtual IDebugListener *SetDebugListener(IDebugListener *listener) =0;

		/**

		 * @brief Returns the number of plugins on the call stack.

		 *

		 * @return			Number of contexts in the call stack.

		 */

		virtual unsigned int GetContextCallCount() =0;

	};

	/**

	 * @brief Dummy class for encapsulating private compilation data.

	 */

	class ICompilation

	{

	public:

		/** Virtual destructor */

		virtual ~ICompilation() { };

	};

	/** 

	 * @brief Outlines the interface a Virtual Machine (JIT) must expose

	 */

	class IVirtualMachine

	{

	public:

		/**

		 * @brief Returns the current API version.