//--------------------------------------------------------------------------
//  Assignment #2 - VWC Service Station and Car Wash
//
//  Written by B M Massie
//  September 2008
//
//  Purpose:  To calculate the cost of gasoline, the price of a wash,  
//            the total cost of gasoline and the wash, and the number
//            of discount points earned.
//--------------------------------------------------------------------------

// ----------- Preprocessor Section -----------

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

// --------------- Main Function ---------------

int main ()
{

// ----- Variables and Constants

   int
      numdispts,         // number of discount points earned
      gallons;           // number of gallons 

   float
      numgals,           // number of gallons purchased
      pricewash,         // cost of the car wash
      costofgas,         // cost of the gasoline
      totalcost;         // total cost of the gasoline and the car wash
    
   char
      gradesofgas;       // regular, premium, or super      


// ----- Input Phase
   cout << "\n\n   Welcome to the VWC Service Station and Car Wash! \n\n" << endl;
   cout << "\n\n          Enter your amount of gasoline --> ";
   cin >> numgals;
   cout << "\n          Enter your grade of gasoline (R,r for regular, P,p for premium, S,s for super) --------> ";
   cin >> gradesofgas;

// ----- Processing Phase

gallons = static_cast <int> (numgals);

if (gallons <= 5)
  pricewash = 6;

else
  if (5 < gallons && gallons < 15)
    pricewash = 6 - (gallons - 5) / .10 / 100 * 6;
  
  else
    if (gallons >= 15)
      pricewash = 0;

if (gradesofgas == 'r' || gradesofgas == 'R')
  costofgas = 3.399 * numgals;

else
  if (gradesofgas == 'p' || gradesofgas == 'P')
    costofgas = 3.539 * numgals;

  else
    if (gradesofgas == 's' || gradesofgas == 'S') 
       costofgas = 3.679 * numgals;

totalcost = costofgas + pricewash;

if (gradesofgas == 'r' || gradesofgas == 'R')
  numdispts = 3 * gallons;

else
  if (gradesofgas == 'p' || gradesofgas == 'P')
    numdispts = 4 * gallons;
 
  else 
    if (gradesofgas == 's' || gradesofgas == 'S')
      numdispts = 5 * gallons;


// ----- Output Phase
   
   cout << fixed << setprecision(2);    // force fixed point format for floats
    
   cout << "\n\n~~~~~~~~~~~~~~~VWC Service Station Summary~~~~~~~~~~~~~~~~"<< endl;
   cout << "\n     Grade of Gasoline:                 " ;
  
    if (gradesofgas == 'r' || gradesofgas == 'R')
       cout << "Regular ";
    else if (gradesofgas == 'p' || gradesofgas == 'P')
              cout << "Premium ";
         else 
              cout << "Super ";  

   cout << "\n     Number of gallons purchased:       " << setw(5) << numgals;
   cout << "\n     Cost of Gasoline:                $ " << setw(5) << costofgas << endl;
   cout << "\n     Price of Car Wash:               $ " << setw(5);

   if (pricewash == 0)
     cout << "FREE WASH!";
   else
     cout << pricewash; 

   cout << "\n     Total Cost:                      $ " << setw(5) << totalcost << endl;
   cout << "\n     Number of Discount Points:         " << numdispts << endl;

   return 0;
}