import java.awt.*;
import java.awt.event.*;
import java.io.*;
/**
* Example application that stores Biscuit's in an array
* 
* @author Mr J 
* @version 1.0
*/
public class BiscuitWindow extends Frame implements ActionListener
{ 
  // Filename to load and save records from
  private static final String FILENAME = "c:\\biscuits.txt";
  private static final String EOF = "XXXX";
  // GUI objects
  private BiscuitDisplay display = new BiscuitDisplay();
  private Button add = new Button("add");
  private Button del = new Button("delete");
  private Button find = new Button("find"); 
  private Button next = new Button("next");
  private Button prev = new Button("previous");
  private Label messages = new Label("Any system messages will appear here...."); 
  // We'll need an array to keep track of our collection
  private static final int MAX = 10; 
  private Biscuit2[] biscuits = new Biscuit2[MAX];
  // pointers into the biscuit collection
  int lastBiscuit = -1;
  int current = -1;
  /**
  * Constructor
  */
  public BiscuitWindow() 
  {
    // inner class to intercept window events
    addWindowListener ( new WindowAdapter()
    {
      // we are only interested in window closing
      public void windowClosing(WindowEvent e) 
      {
        // save the array contents
        saveToFile();
        // Exit the system, 0 is a normal exit code
        System.exit(0);
      }
    } ); 
    // Helper method to set up the display
    makeDisplay();
    // load the array contents
    readFromFile();
  }
  /**
  * Helper method to set up the display
  */
  private void makeDisplay()
  {
    // set up the Biscuit display
    setLayout(new FlowLayout());
    add(display.getPanel());
    // Make a Panel for the buttons
    Panel buttonPanel = new Panel();
    buttonPanel.setLayout(new GridLayout(5,1));
    buttonPanel.add(add); 
    buttonPanel.add(del); 
    buttonPanel.add(find); 
    buttonPanel.add(next);
    buttonPanel.add(prev);
    add(buttonPanel);
    // set up the button listeners
    add.addActionListener(this);
    del.addActionListener(this);
    find.addActionListener(this);
    next.addActionListener(this);
    prev.addActionListener(this);
    add(messages);
    setSize(500,200);
    setTitle("Biscuit Collection Manager v 1.0");
    setVisible(true);
  }
  /**  
  * main method to call the Constructor
  */
  public static void main(String[] args)
  {
    BiscuitWindow theApp = new BiscuitWindow();
  }
  /**
  * Our old buddy, actionPerformed will detect the button presses
  * 
  * @param the object that caused the event to occur
  */
  public void actionPerformed(ActionEvent e)
  {
    if (e.getSource() == add)
    {
      addBiscuit();
    }
    else if (e.getSource() == del)
    {
      //messages.setText("My students will try their best");
    }
    else if (e.getSource() == find)
    {
      messages.setText("My brilliant programmers will whizz through this");
    }
    else if (e.getSource() == next)
    {
      messages.setText("My serfs will try to do this");
    }
    else if (e.getSource() == prev)
    {
      messages.setText("My best and brightest will have a go at this");
    }
  } 
  /**
  * add a Biscuit object to the array
  * 
  */
  public void addBiscuit()
  {
    // Check if the array is full
    if ( lastBiscuit < (MAX-1) )
    {
      lastBiscuit = lastBiscuit + 1;
      Biscuit2 b = display.getBiscuit();
      // check if a valid biscuit was got from display 
      if (b != null)
      {
        biscuits[lastBiscuit] = b;
        messages.setText("Biscuit added " + lastBiscuit);
        current = lastBiscuit;
        display.showBiscuit(biscuits[current]);
      }
      else
      {
        messages.setText("Could not add the biscuit, check details");
      }
    }
    else
    {
      messages.setText("No more space to add biscuits");
    }
  }
  /**
  * Save the array contents to a text file
  */
  private void saveToFile()
  {
    try
    {
      SimpleWriter writer = new SimpleWriter(FILENAME); 
      for(int x = 0; x <= lastBiscuit; x++)
      {
        writer.writeLine(biscuits[x].toString());
      }
      writer.writeLine(EOF);
      writer.close();
    }
    catch(IOException io)
    {
      messages.setText("Some error writing to file");
      System.exit(1);
    }
  }
  /**
  * load the array contents from text file 
  */
  private void readFromFile()
  {
    try
    {
      SimpleReader reader = new SimpleReader(FILENAME);
      // read first line of file, if file is empty should be EOF
      String next = reader.readLine();       
      while (!next.equals(EOF)) 
      {
        lastBiscuit = lastBiscuit + 1;
        biscuits[lastBiscuit] = new Biscuit2(next);
        next = reader.readLine(); 
      } 
      // show the last one, check for none
      if (lastBiscuit >=0)
      {
        current = lastBiscuit;
        display.showBiscuit(biscuits[current]);
        messages.setText("File opened with " + lastBiscuit + 1 + " records");
      }
      else
      {
        messages.setText("The file is empty");
      }
    }
    catch(IOException io)
    {
      messages.setText("Error reading from file");
    }
  }
}