/* using http://sourceforge.net/projects/libserial/
 */


#include <string>
#include <sstream>




#include "util.h"


using namespace std;


namespace SmsPdu
{


vector<unsigned char> BcdEncode(string input)
{
	char buf[2] = " ";
	vector<unsigned char> result;

	unsigned char current;
	for (unsigned int i=0; i<input.length(); ++i)
	{
		buf[0] = input.at(i);
		unsigned char tmp = atoi(buf);

		if ( (i%2) == 0)
		{
			current = tmp;
		}
		else
		{
			current |= (tmp<<4);
			result.push_back(current);
		}
	}

	return result;
}

string HexformatVector(vector<unsigned char> vec)
{
	ostringstream os;

	for (unsigned int i=0; i<vec.size(); ++i)
	{
		os.width(2);
		os.fill('0');
		os << hex << uppercase << static_cast<unsigned int>(vec.at(i));
	}


	return os.str();
}

vector<unsigned char> Encode7to8bit(std::string str)
{
	vector<unsigned char> buf;

	int shift = 0;
	for (unsigned int i=0; i<str.size(); ++i)
	{
		unsigned char current = str.at(i) & 0x7F;
		unsigned char next = ( (i+1)<str.size()) ? str.at(i+1) : 0;
		next &= 0x7F;

		current >>= shift;
		next <<= (7-shift);

		unsigned char byte = current | next;
		buf.push_back(byte);

		if (shift == 6)
			i++;

		shift = (shift+1) % 7;

	}

	return buf;
}

string CreateSmsPdu(string to, string message, int& len)
{
	message = message.substr(0,160); //truncate to 160

	vector<unsigned char> pdu;

	pdu.push_back(0x00); // use SMSC from phone
	pdu.push_back(0x01); // first octet -- no timeout
	pdu.push_back(0x00); // TP-MR message reference
	pdu.push_back(to.length() ); //length of phone nr
	pdu.push_back(0x91); // type of address (international nr  + ISDN/telephone range) - else try 0x81

	vector<unsigned char> phone = BcdEncode(to);
	pdu.insert( pdu.end(), phone.begin(), phone.end());

	pdu.push_back(0x00); // Protocol identifier
	pdu.push_back(0x00); // Data coding scheme
	pdu.push_back( message.length() ); //UserDataLength

	vector<unsigned char> userData = Encode7to8bit(message);
	pdu.insert( pdu.end(), userData.begin(), userData.end());

	len = pdu.size()-1;
	return HexformatVector(pdu);
}

}