import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class Payroll extends Frame
{
  private static Frame outputDisplay;             //Declare a Frame for total

  static double CalcPay(/* in */ double payRate,  //Employee's pay rate
                        /* in */ double hours)    //Hours worked

  // CalcPay computes wages from the employee's pay rate
  // and the hours worked, taking overtime into account

  {
    final double MAX_HOURS = 40.0;                  //Maximum normal work hours
    final double OVERTIME = 1.5;                    //Overtime pay rate factor
    if (hours > MAX_HOURS)                          //Is there overtime?
      return (MAX_HOURS * payRate) +                //Yes
          (hours - MAX_HOURS) * payRate * OVERTIME;
    else
      return hours * payRate;                       //No
  }
      

  public static void main(String args[]) throws IOException, NumberFormatException
  // Main is where excution starts. It opens the DataFile and PayFile, and processes 
  // the data file. After that, it shows the total in a Frame on the screen and exits
  // when the user closes the window
  {
    String empNum;                                //Employee ID Number
    double payRate;                               //Employee's pay rate
    double hours;                                 //Hours worked
    double wages;                                 //Wages earned
    double total = 0.0;                           //Total company payroll
    BufferedReader dataFile;                      //Declare dataFile for input
    PrintWriter payFile;                          //Declare payFile for printing
    //Open company payroll files
    dataFile = new BufferedReader(new FileReader("datafile.dat"));
    payFile = new PrintWriter(new FileWriter("payfile.dat"));  
    //Process the input on dataFile, outputting results on payFile
    empNum = dataFile.readLine();                 //Read employee ID number
    while (empNum != null)
    {    
      payRate = Double.valueOf(dataFile.readLine()).doubleValue(); //Read payRate
      hours = Double.valueOf(dataFile.readLine()).doubleValue();   //Read hours
      wages = CalcPay(payRate, hours);            //Compute wages
      total = total + wages;                      //Add wages to total
      //Put results into payFile 
      payFile.println(empNum + " " + payRate + " " + hours + " " + wages + " ");  
      empNum = dataFile.readLine();               //Get next ID number
    } 
     
    dataFile.close();                             //Close input file
    payFile.close();                              //Close output file
    
    //Create a Frame and display it on the screen
    outputDisplay = new Frame();                  //Instantiate a Frame object
    outputDisplay.setLayout(new FlowLayout());    //Specify layout manager for frame
    outputDisplay.add(new Label("Total payroll for the week is $" + total));
    outputDisplay.add(new Label("Close window to exit program."));
    outputDisplay.pack();                         //Pack the frame 
    outputDisplay.show();                         //Show the frame on the screen
    //Event handler for window closing
    outputDisplay.addWindowListener(new WindowAdapter() //Create a WindowAdapter
      {
        public void windowClosing(WindowEvent event)  //Method to handle event
        {
          outputDisplay.dispose();                    //Remove frame from the screen
          System.exit(0);                             //Quit the program
        }
      });
  }

}