int GetCheckDigit(char *src);
void CopyString(char *src, char *dst, int pos, int length);
void UPCE2UPCA(char *src, char *dst);

extern void EAN13(char *src, char *res);
extern void EAN8(char *src, char *res);
extern void UPCA(char *src, char *res);
extern void UPCE(char *src, char *res);

int GetCheckDigit(char *src)
{
	int len = strlen(src);
	int CheckSum = 0;

	for (int i = 1; i <= len; i++)
	{
		if (i % 2 == 1)
			CheckSum = CheckSum + (src[len - i] - '0') * 3;
		else
			CheckSum = CheckSum + (src[len - i] - '0');
	}
    
	CheckSum = CheckSum % 10;
	if (CheckSum != 0)
		CheckSum = 10 - CheckSum;
    
	return CheckSum;
}
 
void CopyString(char *src, char *dst, int pos, int length)
{
	int DstLen = strlen(dst);
	for (int i = 0; i < length; i++)
	{
		dst[DstLen++] = src[pos + i];
	}
	dst[DstLen] = '\0';
}
   
void UPCE2UPCA(char *src, char *dst)
{
	switch (src[6])
	{
		case '0':
		case '1':
		case '2':
			CopyString(src, dst, 0, 3);
			CopyString(src, dst, 6, 1);
			strcat(dst, "0000");
			CopyString(src, dst, 3, 3);
			break;

		case '3':
			CopyString(src, dst, 0, 4);
			strcat(dst, "00000");
			CopyString(src, dst, 4, 2);
			break;

		case '4':
			CopyString(src, dst, 0, 5);
			strcat(dst, "00000");
			CopyString(src, dst, 5, 1);
			break;

		case '5':
		case '6':
		case '7':
		case '8':
		case '9':
			CopyString(src, dst, 0, 6);
			strcat(dst, "0000");
			CopyString(src, dst, 6, 1);
			break;
	}
}

extern void EAN13(char *src, char *res)
{
	int len;
	char Message[256];
	char CharSet[6];
	int index;

	strcpy(Message, src);
	len = strlen(Message);

	// check length to make sure Data has 12 characters
	if (len < 12)
	{
		while(strlen(Message) < 12)
		{
			strcat(Message, "0");
		}
	}
	else if (len > 12)
	{
		for(int i = 0; i < 12; i++)
			Message[i] = src[i];
		Message[12] = '\0';
	}

	// choose character set depending on the first character of string
	switch(Message[0] - '0')
	{
		case 0: 
			strcpy(CharSet, "AAAAAA");
			break;

		case 1: 
			strcpy(CharSet, "AABABB");
			break;

		case 2: 
			strcpy(CharSet, "AABBAB");
			break;

		case 3: 
			strcpy(CharSet, "AABBBA");
			break;

		case 4: 
			strcpy(CharSet, "ABAABB");
			break;

		case 5: 
			strcpy(CharSet, "ABBAAB");
			break;

		case 6: 
			strcpy(CharSet, "ABBBAA");
			break;

		case 7: 
			strcpy(CharSet, "ABABAB");
			break;

		case 8: 
			strcpy(CharSet, "ABABBA");
			break;

		case 9: 
			strcpy(CharSet, "ABBABA");
			break;
	}

	index = 0;
	res[index++] = Message[0] - '0' + 192;
	res[index++] = '(';

	for (int i = 2; i <= 7; i++)
	{
		char ch = CharSet[i - 2];
		if (ch == 'A')
			res[index++] = Message[i - 1];
		else if (ch == 'B')
			res[index++] = Message[i - 1] - '0' + 'Q';
	}
    
	res[index++] = '*';
	for (i = 8; i <= 12; i++)
	{
		res[index++] = Message[i - 1] - '0' + 'A';
	}
    
	res[index++] = GetCheckDigit(Message) + 'A';
	res[index++] = ')';
	res[index++] = '\0';
}

extern void EAN8(char *src, char *res)
{
	int len;
	char Message[256];
	int index;

	strcpy(Message, src);
	len = strlen(Message);

	// check length to make sure Data has 7 characters
	if (len < 7)
	{
		while(strlen(Message) < 7)
		{
			strcat(Message, "0");
		}
	}
	else if (len > 7)
	{
		for(int i = 0; i < 7; i++)
			Message[i] = src[i];
		Message[7] = '\0';
	}

	index = 0;
	res[index++] = '(';

	for (int i = 1; i <= 4; i++)
	{
		res[index++] = Message[i - 1];
	}
    
	res[index++] = '*';
	for (i = 5; i <= 7; i++)
	{
		res[index++] = Message[i - 1] - '0' + 'A';
	}
    
	res[index++] = GetCheckDigit(Message) + 'A';
	res[index++] = ')';
	res[index++] = '\0';
}

extern void UPCA(char *src, char *res)
{
	int len;
	char Message[256];
	int index;

	strcpy(Message, src);
	len = strlen(Message);

	// check length to make sure Data has 11 characters
	if (len < 11)
	{
		while(strlen(Message) < 11)
		{
			strcat(Message, "0");
		}
	}
	else if (len > 11)
	{
		for(int i = 0; i < 11; i++)
			Message[i] = src[i];
		Message[11] = '\0';
	}

	index = 0;
	res[index++] = Message[0]- '0' + 192;
	res[index++] = '(';
	res[index++] = Message[0]- '0' + 'a';

	for (int i = 2; i <= 6; i++)
	{
		res[index++] = Message[i - 1];
	}
    
	res[index++] = '*';
	for (i = 7; i <= 11; i++)
	{
		res[index++] = Message[i - 1] - '0' + 'A';
	}
    
	int CheckDigit = GetCheckDigit(Message);
	res[index++] = CheckDigit + 'q';
	res[index++] = ')';
	res[index++] = CheckDigit + 192;
	
	res[index++] = '\0';
}

extern void UPCE(char *src, char *res)
{
	int len;
	char Message[256];
	char CharSet[6];
	char tmp[100];
	int index;

	strcpy(Message, src);
	len = strlen(Message);

	// check length to make sure Data has 6 characters
	if (len < 6)
	{
		while(strlen(Message) < 6)
		{
			strcat(Message, "0");
		}
	}
	else if (len > 6)
	{
		for(int i = 0; i < 6; i++)
			Message[i] = src[i];
		Message[6] = '\0';
	}
	strcpy(tmp, "0");
	strcat(tmp, Message);
	strcpy(Message, tmp);

	strcpy(tmp, "");
	UPCE2UPCA(Message, tmp);
	int CheckDigit = GetCheckDigit(tmp);

	// choose character set depending on the check digit value
	switch(CheckDigit)
	{
		case 0: 
			strcpy(CharSet, "BBBAAA");
			break;

		case 1: 
			strcpy(CharSet, "BBABAA");
			break;

		case 2: 
			strcpy(CharSet, "BBAABA");
			break;

		case 3: 
			strcpy(CharSet, "BBAAAB");
			break;

		case 4: 
			strcpy(CharSet, "BABBAA");
			break;

		case 5: 
			strcpy(CharSet, "BAABBA");
			break;

		case 6: 
			strcpy(CharSet, "BAAABB");
			break;

		case 7: 
			strcpy(CharSet, "BABABA");
			break;

		case 8: 
			strcpy(CharSet, "BABAAB");
			break;

		case 9: 
			strcpy(CharSet, "BAABAB");
			break;
	}

	index = 0;
	res[index++] = Message[0]- '0' + 192;
	res[index++] = '(';

	for (int i = 2; i <= 7; i++)
	{
		char ch = CharSet[i - 2];
		if (ch == 'A')
			res[index++] = Message[i - 1];
		else if (ch == 'B')
			res[index++] = Message[i - 1] - '0' + 'Q';
	}
    
	res[index++] = '+';
	res[index++] = GetCheckDigit(Message) + 192;
	res[index++] = '\0';
}