/**
  ******************************************************************************
  * @file    cmd.c
  * @author  He Fahong
  * @version V1
  * @date    1/3/2012
  * @brief   封装的用于通讯具体处理的函数命令。 
  ******************************************************************************
  * @note 
  * @copy
  *
  */
enum CMDTYPE {CMDTYPE_SETTING, CMDTYPE_POLLING, CMDTYPE_SAVING, CMDTYPE_CHANGING, CMDTYPE_ERROR};
 
//inputcmdlength是实际经过rs232传输的命令字节的个数, 从命令开始到结束符'\r'结束, 长度包含结束符在内
uint8_t Cmd_CheckRS232Cmd(char * inputcmdstr, uint8_t inputcmdstrlength)
{	
	char modulestr[MaxComStrLength] = "\0";
	char paramstr[MaxComStrLength] = "\0";
	char valuestr[MaxComStrLength] = "\0";
	
	uint8_t addr = 0;
	uint8_t syntaxlevel = 0;

	enum CMDTYPE cmdtype = ProtocolAnalysis(inputcmdstr, inputcmdstrlength, modulestr, paramstr, valuestr, &addr, &syntaxlevel);	
				
	if(cmdtype == CMDTYPE_SETTING) //设置
	{		
		//这里写入自己的处理程序
	}
	else 	if(cmdtype == CMDTYPE_POLLING) //查询
	{		
		//这里写入自己的处理程序
	}
	else	if(cmdtype == CMDTYPE_SAVING) //保存
	{		
		//这里写入自己的处理程序
	}
	else	if(cmdtype == CMDTYPE_CHANGING) //改变
	{		
		//这里写入自己的处理程序
	}
	else
	{
		//这里写入自己的处理程序
	}
		
	return 1;
}

//通用的完善协议解析程序
//赋值三个字符串，地址，syntaxlevel（0，最简模式；1，带地址，2，带校验）
//返回，cmd_type
enum CMDTYPE ProtocolAnalysis(uint8_t * comstr, int comstrlength, uint8_t* modulestr, uint8_t* paramstr, uint8_t* valuestr, uint8_t * addr, uint8_t *syntaxlevel)
{
	int16_t ix;  //有符号数，防止负数变成正数，导致长度或定位计算错误
	
	uint8_t colonflag = 0; //是否有冒号的标志
	
	uint8_t modulelength = 0;
	uint8_t paramlength = 0;
	uint8_t valuelength = 0;
	
	uint8_t addrstartpos = 0; //地址字符串起始位置，@符号的下一个字符位置	
	uint8_t checkstartpos = 0; //校验字符串起始位置，#符号的下一个字符位置
	
	*syntaxlevel = 0;
	
	enum CMDTYPE cmdtype = CMDTYPE_ERROR;	

	//首先判断最后一位是否是'\r'
	if(comstr[comstrlength - 1] != '\r')
		return CMDTYPE_ERROR; 
	else comstr[comstrlength - 1] = '\0';

	//格式分析
	for (ix=0; ix<comstrlength; ix++)
	{
		switch (comstr[ix])
		{
			case ':':
			{
				modulelength = ix;
				colonflag = 1;
				break;
			}
			case '?':
			{
				paramlength = ix;
				cmdtype = CMDTYPE_POLLING;
				break;					
			}
			case '^':
			{
				paramlength = ix;
				cmdtype = CMDTYPE_CHANGING;
				break;
			}
			case '=':
			{
				paramlength = ix;
				cmdtype = CMDTYPE_SETTING;
				break;
			}
			case '!':
			{
				paramlength = ix;
				cmdtype = CMDTYPE_SAVING;
				break;
			}
			case '@':
			{
				addrstartpos = ix + 1;
				*syntaxlevel = 1;
				break;
			}
			case '#':
			{
				checkstartpos = ix + 1;
				*syntaxlevel = 2;
				break;
			}
		}
	}

	if(colonflag != 1)	//如果没有冒号，也是错误
	{
		return CMDTYPE_ERROR;
	}
	if(cmdtype == CMDTYPE_ERROR) //没有正确类型，也是错误
		return CMDTYPE_ERROR; 

	if(*syntaxlevel >= 1) //有地址
	{
		*addr = atoi(comstr + addrstartpos);  //遇到#符号或者\0或者\r都会停止转换，strtol同atoi
		
		
		if(*syntaxlevel >= 2) //不仅有目标地址，还有校验
		{		
			//进行校验
			if(CheckSum(comstr, checkstartpos) != strtol(comstr + checkstartpos, NULL, 16)) //校验不正确
			return CMDTYPE_ERROR;
		}
		
		//获取参数字符串的长度	
		valuelength = addrstartpos - paramlength - 2;
		paramlength = paramlength - modulelength - 1;			
	}
	else //无地址
	{
		//获取参数字符串的长度	
		valuelength = (comstrlength - 1) - paramlength - 1;
		paramlength = paramlength - modulelength - 1;
	}
	
	//根据字符串长度来赋值，是否可以改成字符串拷贝函数
	for (ix=0;ix<modulelength;ix++)
	{
		modulestr[ix] = comstr[ix];					
	}
	modulestr[ix] = '\0';
	for (ix=0;ix<paramlength;ix++)
	{
		paramstr[ix] = comstr[ix+1+modulelength];					
	}
	paramstr[ix] = '\0';
	
	if((cmdtype == CMDTYPE_CHANGING) || (cmdtype == CMDTYPE_SETTING))
	{
			for (ix=0;ix<valuelength;ix++)
			{
				valuestr[ix] = comstr[ix + 1 + modulelength + 1 + paramlength];					
			}
			valuestr[ix] = '\0';
	}																										   

	return cmdtype;
}

uint8_t CheckSum(char * str, uint8_t length)
{
	int i = 0;
	uint8_t checksum = 0;
	for(i=0;i<length;i++)
	{
		checksum = checksum^str[i];	
	}
	return checksum;
}