/**

 * vim: set ts=4 :

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

 * SourcePawn

 * Copyright (C) 2004-2007 AlliedModders LLC.  All rights reserved.

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

 *

 * 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: $Id$

 */

#include <stdio.h>

#include <string.h>

#include "sp_vm_function.h"

/********************

* FUNCTION CALLING *

********************/

void CFunction::Set(uint32_t code_addr, IPluginContext *plugin)

{

	m_codeaddr = code_addr;

	m_pContext = plugin;

	m_curparam = 0;

	m_errorstate = SP_ERROR_NONE;

	m_Invalid = false;

	m_pCtx = plugin ? plugin->GetContext() : NULL;

}

bool CFunction::IsRunnable()

{

	return ((m_pCtx->flags & SPFLAG_PLUGIN_PAUSED) != SPFLAG_PLUGIN_PAUSED);

}

int CFunction::CallFunction(const cell_t *params, unsigned int num_params, cell_t *result)

{

	if (!IsRunnable())

	{

		return SP_ERROR_NOT_RUNNABLE;

	}

	while (num_params--)

	{

		m_pContext->PushCell(params[num_params]);

	}

	return m_pContext->Execute(m_codeaddr, result);

}

IPluginContext *CFunction::GetParentContext()

{

	return m_pContext;

}

CFunction::CFunction(uint32_t code_addr, IPluginContext *plugin) : 

	m_codeaddr(code_addr), m_pContext(plugin), m_curparam(0), 

	m_errorstate(SP_ERROR_NONE)

{

	m_Invalid = false;

	if (plugin)

	{

		m_pCtx = plugin->GetContext();

	}

}

int CFunction::PushCell(cell_t cell)

{

	if (m_curparam >= SP_MAX_EXEC_PARAMS)

	{

		return SetError(SP_ERROR_PARAMS_MAX);

	}

	m_info[m_curparam].marked = false;

	m_params[m_curparam] = cell;

	m_curparam++;

	return SP_ERROR_NONE;

}

int CFunction::PushCellByRef(cell_t *cell, int flags)

{

	return PushArray(cell, 1, flags);

}

int CFunction::PushFloat(float number)

{

	cell_t val = *(cell_t *)&number;

	return PushCell(val);

}

int CFunction::PushFloatByRef(float *number, int flags)

{

	return PushCellByRef((cell_t *)number, flags);

}

int CFunction::PushArray(cell_t *inarray, unsigned int cells, int copyback)

{

	if (m_curparam >= SP_MAX_EXEC_PARAMS)

	{

		return SetError(SP_ERROR_PARAMS_MAX);

	}

	ParamInfo *info = &m_info[m_curparam];

	info->flags = inarray ? copyback : 0;

	info->marked = true;

	info->size = cells;

	info->str.is_sz = false;

	info->orig_addr = inarray;

	m_curparam++;

	return SP_ERROR_NONE;

}

int CFunction::PushString(const char *string)

{

	return _PushString(string, SM_PARAM_STRING_COPY, 0, strlen(string)+1);

}

int CFunction::PushStringEx(char *buffer, size_t length, int sz_flags, int cp_flags)

{

	return _PushString(buffer, sz_flags, cp_flags, length);

}

int CFunction::_PushString(const char *string, int sz_flags, int cp_flags, size_t len)

{

	if (m_curparam >= SP_MAX_EXEC_PARAMS)

	{

		return SetError(SP_ERROR_PARAMS_MAX);

	}

	ParamInfo *info = &m_info[m_curparam];

	info->marked = true;

	info->orig_addr = (cell_t *)string;

	info->flags = cp_flags;

	info->size = len;

	info->str.sz_flags = sz_flags;

	info->str.is_sz = true;

	m_curparam++;

	return SP_ERROR_NONE;

}

void CFunction::Cancel()

{

	if (!m_curparam)

	{

		return;

	}

	m_errorstate = SP_ERROR_NONE;

	m_curparam = 0;

}

int CFunction::Execute(cell_t *result)

{

	int err = SP_ERROR_NONE;

	if (!IsRunnable())

	{

		m_errorstate = SP_ERROR_NOT_RUNNABLE;

	}

	if (m_errorstate != SP_ERROR_NONE)

	{

		err = m_errorstate;

		Cancel();

		return err;

	}

	//This is for re-entrancy!

	cell_t temp_params[SP_MAX_EXEC_PARAMS];

	ParamInfo temp_info[SP_MAX_EXEC_PARAMS];

	unsigned int numparams = m_curparam;

	unsigned int i;

	bool docopies = true;

	if (numparams)

	{

		//Save the info locally, then reset it for re-entrant calls.

		memcpy(temp_info, m_info, numparams * sizeof(ParamInfo));

	}

	m_curparam = 0;

	/* Browse the parameters and build arrays */

	for (i=0; i<numparams; i++)

	{

		/* Is this marked as an array? */

		if (temp_info[i].marked)

		{

			if (!temp_info[i].str.is_sz)

			{

				/* Allocate a normal/generic array */

				if ((err=m_pContext->HeapAlloc(temp_info[i].size, 

											   &(temp_info[i].local_addr),

											   &(temp_info[i].phys_addr)))

					!= SP_ERROR_NONE)

				{

					break;

				}

				if (temp_info[i].orig_addr)

				{

					memcpy(temp_info[i].phys_addr, temp_info[i].orig_addr, sizeof(cell_t) * temp_info[i].size);

				}

			} else {

				/* Calculate cells required for the string */

				size_t cells = (temp_info[i].size + sizeof(cell_t) - 1) / sizeof(cell_t);

				/* Allocate the buffer */

				if ((err=m_pContext->HeapAlloc(cells,

												&(temp_info[i].local_addr),

												&(temp_info[i].phys_addr)))

					!= SP_ERROR_NONE)

				{

					break;

				}

				/* Copy original string if necessary */

				if ((temp_info[i].str.sz_flags & SM_PARAM_STRING_COPY) && (temp_info[i].orig_addr != NULL))

				{

					if (temp_info[i].str.sz_flags & SM_PARAM_STRING_UTF8)

					{

						if ((err=m_pContext->StringToLocalUTF8(temp_info[i].local_addr, 

																temp_info[i].size, 

																(const char *)temp_info[i].orig_addr,

																NULL))

							!= SP_ERROR_NONE)

						{

							break;

						}

					} else {

						if ((err=m_pContext->StringToLocal(temp_info[i].local_addr,

															temp_info[i].size,

															(const char *)temp_info[i].orig_addr))

							!= SP_ERROR_NONE)

						{

							break;

						}

					}

				}

			} /* End array/string calculation */

			/* Update the pushed parameter with the byref local address */

			temp_params[i] = temp_info[i].local_addr;

		} else {

			/* Just copy the value normally */

			temp_params[i] = m_params[i];

		}

	}

	/* Make the call if we can */

	if (err == SP_ERROR_NONE)

	{

		if ((err = CallFunction(temp_params, numparams, result)) != SP_ERROR_NONE)

		{

			docopies = false;

		}

	} else {

		docopies = false;

	}

	/* i should be equal to the last valid parameter + 1 */

	while (i--)

	{

		if (!temp_info[i].marked)

		{

			continue;

		}

		if (docopies && (temp_info[i].flags & SM_PARAM_COPYBACK))

		{

			if (temp_info[i].orig_addr)

			{

				if (temp_info[i].str.is_sz)

				{

					memcpy(temp_info[i].orig_addr, temp_info[i].phys_addr, temp_info[i].size);

				} else {

					if (temp_info[i].size == 1)

					{

						*temp_info[i].orig_addr = *(temp_info[i].phys_addr);

					} else {

						memcpy(temp_info[i].orig_addr, 

								temp_info[i].phys_addr, 

								temp_info[i].size * sizeof(cell_t));

					}

				}

			}

		}

		if ((err=m_pContext->HeapPop(temp_info[i].local_addr)) != SP_ERROR_NONE)

		{

			return err;

		}

	}

	return err;

}