extern void Code128Auto(char *src, char *res);
extern void UCCEAN128(char *src, char *res);
extern void Code128A(char *src, char *res);
extern void Code128B(char *src, char *res);
extern void Code128C(char *src, char *res);
void GeneralEncode(char *src, char *res, int StartIndex, int StartWeight);

void GeneralEncode(char *src, char *res, int StartIndex, int StartWeight, int StartSum, int StartSet)
{
	int tmp;
	int i;
	bool CurrDone;	
	int StrLen;
	char CurrChar;
	char NextChar;

	int index = StartIndex;
	int Weight = StartWeight;
	int Sum = StartSum;
	int CurrSet = StartSet;

	StrLen = strlen(src);
	i = 0;
	while (i < StrLen)
	{
		CurrChar = src[i];
		CurrDone = false;

		if ((i + 1) < StrLen)
		{
			NextChar = src[i + 1];

			if (CurrChar >= '0' && CurrChar <= '9' &&
				NextChar >= '0' && NextChar <= '9') 
			{
				tmp = (CurrChar - '0') * 10 + (NextChar - '0');
                
				// 2 digits
				if (CurrSet != 3)
				{
					// the previous set is not Set C
					res[index++] = (char)(99 + 98);
					Sum = Sum + Weight * 99;
					Weight = Weight + 1;
					CurrSet = 3;
				}
                
				if (tmp == 0) 
					res[index++] = (char)192;
				else if (tmp > 0 && tmp < 95)
					res[index++] = (char)(tmp + 32);
				else
					res[index++] = (char)(tmp + 98);
    
				Sum = Sum + Weight * tmp;
				i = i + 2;

				CurrDone = true;
			}
		}
        
		 if (!CurrDone)
		{
			if (CurrChar >= 0 && CurrChar <= 31)
			{
				// choose Set A
				if (CurrSet != 1)
				{
					// the previous set is not Set A
					res[index++] = (char)(101 + 98);
					Sum = Sum + Weight * 101;
					Weight = Weight + 1;
					CurrSet = 1;
				}
                
				if (CurrChar == 31)
				{
					res[index++] = (char)193;
					Sum = Sum + Weight * 95;
				}
				else
				{
					res[index++] = (char)(CurrChar + 96);
					Sum = Sum + Weight * (CurrChar + 64);
				}
			}
			else
			{
				// choose Set B
				if (CurrSet != 2)
				{ 
					// the previous set is not Set B
					res[index++] = (char)(100 + 98);
					Sum = Sum + Weight * 100;
					Weight = Weight + 1;
					CurrSet = 2;
				}
                
                
				if (CurrChar == 32)
				{
					res[index++] = (char)192;
				}
				else if (CurrChar == 127)
				{
					res[index++] = (char)193;
					Sum = Sum + Weight * 95;
				}
				else if (CurrChar < 127 && CurrChar > 32)
				{
					res[index++] = (char)CurrChar;
					Sum = Sum + Weight * (CurrChar - 32);
				}
			}
            
			i = i + 1;
		}
        
		Weight = Weight + 1;
	}
    
	// add CheckDigit
	Sum = Sum % 103;
	if (Sum == 0)
		res[index++] = (char)192;
	else if (Sum <= 94) 
		res[index++] = (char)(Sum + 32);
	else
		res[index++] = (char)(Sum + 98);

	// add stop character (204)
	res[index++] = (char)204;

	res[index++] = '\0';
}


extern void Code128Auto(char *src, char *res)
{
	int Sum;
	int CurrSet;
	int Weight;
	char Message[256];

	Sum = 104;

	// 2 indicates Set B
	CurrSet = 2;

	// start character with value 202 for Set B
	Message[0] = (char)202;

	char CurrChar = src[0];
	if (CurrChar <= 31 && CurrChar >= 0)
	{
		// switch to Set A
		// 1 indicates Set A
		CurrSet = 1;

		// start character with value 201 for Set A
		Message[0] = (char)201;
		Sum = 103;
	}
    
	Weight = 1;
	GeneralEncode(src, Message, 1, Weight, Sum, CurrSet);

	strcpy(res, Message);
}

extern void UCCEAN128(char *src, char *res)
{
	int Sum;
	int CurrSet;
	int Weight;
	char Message[256];

	Sum = 105;

	// 3 indicates Set C
	CurrSet = 3;

	// start character (203) + FNC1 (200)
	Message[0] = (char)203;
	Message[1] = (char)200;
	Sum = Sum + 102;
	Weight = 2;
	GeneralEncode(src, Message, 2, Weight, Sum, CurrSet);

	strcpy(res, Message);
}

extern void Code128A(char *src, char *res)
{
	int StrLen;
	char CurrChar;
	char Message[256];

	int index;
	int Weight;
	int Sum;

	StrLen = strlen(src);
	Sum = 103;

	// start character (201) for Set A
	index = 0;
	res[index++] = (char)201;

	Weight = 1;
	for (int i = 0 ; i < StrLen; i++)
	{
		CurrChar = src[i];
		if (CurrChar == 32)
			res[index++] = (char)192;
		else if (CurrChar == 31)
		{
			res[index++] = (char)193;
			Sum = Sum + Weight * 95;
		}
		else if (CurrChar <= 95 && CurrChar > 32)
		{
			res[index++] = (char)CurrChar;
			Sum = Sum + Weight * (CurrChar - 32);
		}
		else if (CurrChar >= 0 && CurrChar <= 31)
		{
			res[index++] = (char)(CurrChar + 96);
			Sum = Sum + Weight * (CurrChar + 64);
		}
		else
		{
			Code128Auto(src, Message);
			strcpy(res, Message);
			return;
		}
		Weight = Weight + 1;
	}
    
	// add CheckDigit
	Sum = Sum % 103;
	if (Sum == 0)
		res[index++] = (char)192;
	else if (Sum <= 94)
		res[index++] = (char)(Sum + 32);
	else
		res[index++] = (char)(Sum + 98);

	// add stop character (204)
	res[index++] = (char)204;

	res[index++] = '\0';
    
}

extern void Code128B(char *src, char *res)
{
	int StrLen;
	char CurrChar;
	char Message[256];

	int index;
	int Weight;
	int Sum;

	StrLen = strlen(src);
	Sum = 104;

	// start character (202) for Set B
	index = 0;
	res[index++] = (char)202;

	Weight = 1;
	for (int i = 0; i < StrLen; i++)
	{
		CurrChar = src[i];
		if (CurrChar == 32)
			res[index++] = (char)192;
		else if (CurrChar == 127)
		{
			res[index++] = (char)193;
			Sum = Sum + Weight * 95;
		}
		else if (CurrChar < 127 && CurrChar > 32)
		{
			res[index++] = (char)CurrChar;
			Sum = Sum + Weight * (CurrChar - 32);
		}
		else
		{
			Code128Auto(src, Message);
			strcpy(res, Message);
			return;
		}

		Weight = Weight + 1;
	}
    
	// add CheckDigit
	Sum = Sum % 103;
	if (Sum == 0)
		res[index++] = (char)192;
	else if (Sum <= 94)
		res[index++] = (char)(Sum + 32);
	else
		res[index++] = (char)(Sum + 98);

	// add stop character (204)
	res[index++] = (char)204;
	res[index++] = '\0';   
}

extern void Code128C(char *src, char *res)
{
	int tmp;
	int i;
	int StrLen;
	char CurrChar;
	char NextChar;
	char Message[256];
	int index;
	int Weight;
	int Sum;

	StrLen = strlen(src);
	Sum = 105;

	// start character (203) for Set C
	index = 0;
	res[index++] = (char)203;

	Weight = 1;
	i = 0;
	while (i < StrLen)
	{
		CurrChar = src[i];
		if ((i + 1) < StrLen)
		{
			NextChar = src[i + 1];

			if (CurrChar >= '0' && CurrChar <= '9' &&
				NextChar >= '0' && NextChar <= '9')
			{
				//2 digits
				tmp = (CurrChar - '0') * 10 + (NextChar - '0');

				if (tmp == 0)
					res[index++] = (char)192;
				else if (tmp > 0 && tmp < 95)
					res[index++] = (char)(tmp + 32);
				else
					res[index++] = (char)(tmp + 98);

				Sum = Sum + Weight * tmp;
				i = i + 2;
			}
			else
			{
				Code128Auto(src, Message);
				strcpy(res, Message);
				return;
			}
		}
		else	
		{
			res[index++] = (char)198;
			Sum = Sum + Weight * 100;
			Weight = Weight + 1;

			if (CurrChar == 32)
				res[index++] = (char)192;
			else if (CurrChar == 127)
			{
				res[index++] = (char)193;
				Sum = Sum + Weight * 95;
			}
			else if (CurrChar < 127 && CurrChar > 32) 
			{
				res[index++] = (char)CurrChar;
				Sum = Sum + Weight * (CurrChar - 32);
			}
			else
			{
				Code128Auto(src, Message);
				strcpy(res, Message);
				return;
			}
			i = i + 1;
		}
        
		Weight = Weight + 1;
	}
    
	// add CheckDigit
	Sum = Sum % 103;
	if (Sum == 0)
		res[index++] = (char)192;
	else if (Sum <= 94) 
		res[index++] = (char)(Sum + 32);
	else
		res[index++] = (char)(Sum + 98);

	// add stop character (204)
	res[index++] = (char)204;
	res[index++] = '\0';
}