/**

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

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

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

 *

 * This file is not open source and may not be copied without explicit

 * written permission of AlliedModders LLC.  This file may not be redistributed 

 * in whole or significant part.

 * For information, see LICENSE.txt or http://www.sourcemod.net/license.php

 *

 * Version: $Id$

 */

#include <stdio.h>

#include <string.h>

#include "PluginSys.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)

{

	if (m_curparam >= SP_MAX_EXEC_PARAMS)

	{

		return SetError(SP_ERROR_PARAMS_MAX);

	}

	return PushArray(cell, 1, NULL, 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, cell_t **phys_addr, int copyback)

{

	if (m_curparam >= SP_MAX_EXEC_PARAMS)

	{

		return SetError(SP_ERROR_PARAMS_MAX);

	}

	ParamInfo *info = &m_info[m_curparam];

	int err;

	if ((err=m_pContext->HeapAlloc(cells, &info->local_addr, &info->phys_addr)) != SP_ERROR_NONE)

	{

		return SetError(err);

	}

	info->flags = inarray ? copyback : 0;

	info->marked = true;

	info->size = cells * sizeof(cell_t);

	m_params[m_curparam] = info->local_addr;

	m_curparam++;

	if (inarray)

	{

		memcpy(info->phys_addr, inarray, sizeof(cell_t) * cells);

		info->orig_addr = inarray;

	} else {

		info->orig_addr = info->phys_addr;

	}

	if (phys_addr)

	{

		*phys_addr = info->phys_addr;

	}

	return true;

}

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];

	size_t cells = (len + sizeof(cell_t) - 1) / sizeof(cell_t);

	int err;

	if ((err=m_pContext->HeapAlloc(cells, &info->local_addr, &info->phys_addr)) != SP_ERROR_NONE)

	{

		return SetError(err);

	}

	info->marked = true;

	m_params[m_curparam] = info->local_addr;

	m_curparam++;	/* Prevent a leak */

	if (!(sz_flags & SM_PARAM_STRING_COPY))

	{

		goto skip_localtostr;

	}

	if (sz_flags & SM_PARAM_STRING_UTF8)

	{

		if ((err=m_pContext->StringToLocalUTF8(info->local_addr, len, string, NULL)) != SP_ERROR_NONE)

		{

			return SetError(err);

		}

	} else {

		if ((err=m_pContext->StringToLocal(info->local_addr, len, string)) != SP_ERROR_NONE)

		{

			return SetError(err);

		}

	}

skip_localtostr:

	info->flags = cp_flags;

	info->orig_addr = (cell_t *)string;

	info->size = len;

	return SP_ERROR_NONE;

}

void CFunction::Cancel()

{

	if (!m_curparam)

	{

		return;

	}

	while (m_curparam--)

	{

		if (m_info[m_curparam].marked)

		{

			m_pContext->HeapRelease(m_info[m_curparam].local_addr);

			m_info[m_curparam].marked = false;

		}

	}

	m_errorstate = SP_ERROR_NONE;

}

int CFunction::Execute(cell_t *result)

{

	int err;

	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;

	bool docopies = true;

	if (numparams)

	{

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

		memcpy(temp_params, m_params, numparams * sizeof(cell_t));

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

	}

	m_curparam = 0;

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

	{

		docopies = false;

	}

	while (numparams--)

	{

		if (!temp_info[numparams].marked)

		{

			continue;

		}

		if (docopies && temp_info[numparams].flags)

		{

			if (temp_info[numparams].orig_addr)

			{

				if (temp_info[numparams].size == sizeof(cell_t))

				{

					*temp_info[numparams].orig_addr = *temp_info[numparams].phys_addr;

				} else {

					memcpy(temp_info[numparams].orig_addr, 

							temp_info[numparams].phys_addr, 

							temp_info[numparams].size);

				}

			}

		}

		m_pContext->HeapPop(temp_info[numparams].local_addr);

		temp_info[numparams].marked = false;

	}

	return err;

}

cell_t *CFunction::GetAddressOfPushedParam(unsigned int param)

{

	if (m_errorstate != SP_ERROR_NONE

		|| param >= m_curparam

		|| !m_info[param].marked)

	{

		return NULL;

	}

	return m_info[param].phys_addr;

}