/**
 * The class Consumer implements a consumer.
 * @author Stephan Fischli
 * @version 1.1
 */
public class Consumer extends Thread
{
   public static final int PAUSING = 0;
   public static final int READING = 1;
   public static final int CONSUMING = 2;

  /**
   * The buffer used by the consumer.
   */
   private Buffer buffer;

  /**
   * The state of the consumer.
   */
   private int state;

  /**
   * Constructs a Consumer object.
   * @param buffer the buffer to be used by the consumer
   */
   public Consumer( Buffer buffer )
   {
        this.buffer = buffer;
        state = PAUSING;
   }

  /**
   * Returns the state of the consumer.
   */
   public int state()
   {
        return state;
   }

  /**
   * Starts the consumer.
   */
   public void run()
   {
        while ( true ) {
             pause();
             Object data = read();
             consume( data );
        }
   }

  /**
   * Lets the consumer pause.
   */
   public void pause()
   {
        state = PAUSING;
        int time = (int)(20000*(0.5 + Math.random()));
        try { sleep( time ); }
        catch ( InterruptedException e ) {}
   }

  /**
   * Lets the consumer read data from the buffer.
   * @return the read data
   */
   public Object read()
   {
        state = READING;
        return buffer.get();
   }

  /**
   * Lets the consumer consume data.
   * @param the data to consume
   */
   public void consume( Object data )
   {
        state = CONSUMING;
        int time = (int)(10000*(0.5 + Math.random()));
        try { sleep( time ); }
        catch ( InterruptedException e ) {}
   }
}