// FILE: Payroll.cpp
// COMPUTES AND PRINTS GROSS PAY AND NET PAY GIVEN AN HOURLY
//    RATE AND NUMBER OF HOURS WORKED.  DEDUCTS UNION DUES OF $15
//    IF GROSS SALARY EXCEEDS $100; OTHERWISE, DEDUCTS NO DUES.

#include <iostream.h>	// needed for cin and cout
#include "money.h"	// needed for money data type

   // Functions used ...
   // DISPLAYS USER INSTRUCTIONS
   void instruct_user
   (const money,	// IN: max earnings (dollars) before paying Union dues
    const money,	// IN: Union dues (dollars)
    const double,	// IN: max number of hours without overtime pay
    const double);	// IN: overtime rate

    // FIND THE GROSS SALARY
   money compute_gross
   (double,		// IN: number of hours worked
    money,		// IN: hourly pay rate (dollars)
    const double,	// IN: max number of hours without overtime pay
    const double);	// IN: overtime rate

   // FIND THE NET SALARY
   money compute_net
   (money,		// IN: gross pay (dollars)
    const money,	// IN: max earnings (dollars) before paying Union dues
    const money);	// IN: Union dues (dollars)

int main ()
{
   // Local data ...
   const money max_no_dues = 100.00;	// max earnings before dues (dollars)
   const money dues = 15.00;			// dues amount (dollars)
   const double max_no_overtime = 40.0;	// max hours before overtime
   const double overtime_rate = 1.5;	// overtime rate

   double hours;					// input: hours worked
   double rate;					// input: hourly pay rate (dollars)
   money gross;					// output: gross pay (dollars) 
   money net;					// output: net pay (dollars)

   // Display user instructions.
   instruct_user (max_no_dues, dues, max_no_overtime, overtime_rate);

   // Enter hours and rate.
   cout << "Hours worked: ";
   cin  >> hours;
   cout << "Hourly rate: ";
   cin  >> rate;

   // Compute gross salary.
   gross = compute_gross (hours, rate, max_no_overtime, overtime_rate);

   // Compute net salary.
   net = compute_net (gross, max_no_dues, dues);

   // Print gross and net.
   cout << "Gross salary is " << gross << endl;
   cout << "Net salary is " << net << endl;

   return 0;
}

// DISPLAYS USER INSTRUCTIONS
void instruct_user
  (const money max_no_dues,	// IN: max earnings (dollars) before paying dues   
   const money dues,			// IN: dues amount (dollars)
   const double max_no_overtime,	// IN: max number of hours without overtime pay
   const double overtime_rate)	// IN: overtime rate
{
   cout << "This program computes gross and net salary." << endl;
   cout << "A dues amount of " << dues << " is deducted for" << endl;
   cout << "an employee who earns more than " << max_no_dues << endl << endl;
   cout << "Overtime is paid at the rate of " << overtime_rate << endl;
   cout << "times the regular rate for hours worked over " << max_no_overtime
        << endl << endl;
   cout << "Enter hours worked and hourly rate" << endl;
   cout << "on separate lines after the prompts." << endl;
   cout << "Press <return> after typing each number." << endl << endl;
}  // end instruct_user

// FIND THE GROSS SALARY
money compute_gross
  (double hours,				// IN: number of hours worked
   money rate,				// IN: hourly pay rate (dollars)
   const double max_no_overtime, // IN: max number of hours without overtime pay
   const double overtime_rate)	// IN: overtime rate

{
   // Local data ...
   money gross;				// RESULT: gross pay (dollars)
   money regular_pay;			// pay for first 40 hours
   money overtime_pay;		// pay for hours in excess of 40

   // Compute gross pay.
   if (hours > max_no_overtime)
   {
      regular_pay = max_no_overtime * rate;
      overtime_pay = (hours - max_no_overtime) * overtime_rate * rate;
      gross = regular_pay + overtime_pay;
   }
   else
       gross = hours * rate;

   return gross;
}  // end compute_gross

// FIND THE NET SALARY
money compute_net
  (money gross,				// IN: gross salary (dollars)
   const money max_no_dues,	// IN: max salary for no deduction (dollars)
   const money dues)			// IN: dues amount (dollars)
{
   // Local data ...
   money net;				// RESULT: net pay (dollars)

   // Compute net pay.
   if (gross > max_no_dues)
      net = gross - dues;                // deduct dues amount
   else
      net = gross;

   return net;
} // end compute_net