///////////////////////////////////////////////////////////////
// MT4Q1b - Convert to and from Hexadecimal the hard way     //
//                                                           //
// Jim Fawcett, CSE687 - OOD Midterm, Spring 2013            //
///////////////////////////////////////////////////////////////

#include <string>
#include <iostream>
#include "../MTutility/MTutility.h"

std::string HexToString(int i)
{
  std::string temp;
  do
  {
    char a = i%16 + '0'; 
    if(!isdigit(a))
      a += ('a' - '0' - 10);
    ////////////////////////////////////////////////////////////
    //The lines below are equivalent to the previous line.
    //switch(a)  // convert chars after '9' in ASCII to alphas
    //{
    //case ':' : a = 'a'; break;
    //case ';' : a = 'b'; break;
    //case '<' : a = 'c'; break;
    //case '=' : a = 'd'; break;
    //case '>' : a = 'e'; break;
    //case '?' : a = 'f'; break;
    //}
    temp += a;
    i /= 16;
  } while(i != 0);
  std::string out;
  for(size_t i=0; i<temp.size(); ++i)  // reverse string
    out += temp[temp.size() -i -1];
  out = "0x" + out;
  return out;
}

long int StringToHex(const std::string& hexStrMaster)
{
  std::string hexStr = hexStrMaster.substr(2);  // remove 0x
  long int out = 0, base = 1;
  for(size_t i=0; i<hexStr.size(); ++i)
  {
    int temp;
    char ch = hexStr[hexStr.size() -i -1];
    temp = ch - '0';
    if(!isdigit(ch))
      temp = ch - 'a' + 10;
    ////////////////////////////////////////////////////////
    //The next few lines are equvalent to the previous line
    //switch(ch)
    //{
    //case 'a' : temp = 10; break;
    //case 'b' : temp = 11; break;
    //case 'c' : temp = 12; break;
    //case 'd' : temp = 13; break;
    //case 'e' : temp = 14; break;
    //case 'f' : temp = 15; break;
    //default  : temp = ch - '0';
    //}
    out += base * temp;
    base *= 16;
  }
  return out;
}

int main()
{
  Title("MT4Q1b - Convert To and From Hex the harder way");

  for(int i=0; i<32; ++i)
  {
    std::string hexStr = HexToString(i);
    std::cout << "\n  " << StringToHex(hexStr) << " : " << HexToString(i) << " ";
  }
  std::cout << "\n\n";
	return 0;
}