/** Let's make a zoo -- the other files in this program define various
 *  animals, and here we can create and play with them.
 *  Because a zoo has several animals, and we don't know how many in advance,
 *  we use an ArrayList instead of an array of animals.  An ArrayList has all
 *  the functionality and is more flexible than an array:  it allows you to
 *  grow or shrink whenever needed.
 */
import java.util.*;              // where the ArrayList class is defined
import java.io.*;

public class Driver
{
  public static void main(String [] args) throws IOException
  {
    ArrayList zoo = new ArrayList();
    BufferedReader kbd = new BufferedReader(new InputStreamReader(System.in));

    // This loop will interactively get input concerning
    // what the user wants to do with the animals.
    while (true)
    {
      System.out.println("\nCurrently we have " + zoo.size() + " animals.");
      System.out.print("(p)rint zoo, (a)dd animal, (d)elete, ");
      System.out.println("(e)xercise, (f)eed, (w)eigh, (q)uit program");
      System.out.print("Enter your selection:  ");
      char input = kbd.readLine().charAt(0);

      // A series of if/else statements will handle the individual commands.
      // It would be more efficient to read both the command and the
      // respective animal at the same time, rather than have separate prompts,
      // but it would be more difficult for the user to remember exactly
      // how to enter the commands.  This implementation makes it easy to run.
      if (input == 'a')
      {
	System.out.print("(b)ird, (p)enguin, (f)ish, (r)eptile, (s)nake?  ");  
        char type = kbd.readLine().charAt(0);
        switch(type)
	{
  	  case 'b' : zoo.add(new Bird()); break;
	  case 'f' : zoo.add(new Fish()); break;
	  case 'p' : zoo.add(new Penguin()); break;
	  case 'r' : zoo.add(new Reptile()); break;
	  case 's' : zoo.add(new Snake()); break;
	  default: System.out.println("Invalid animal type, sorry.");
	}
      }
      else if (input == 'd')
      {
        System.out.print("Enter number of animal to delete:  ");
        int num = Integer.parseInt(kbd.readLine());
	zoo.remove(num);
      }
      else if (input == 'p')
      {
	for (int i = 0; i < zoo.size(); ++i)
	  System.out.println("#" + i + " --> " + zoo.get(i));
      }

      // Take a close look at the calls to exercise() and feed() below.
      // It turns out that the ArrayList get() function returns simply
      // an Object, and we need to cast it to Animal, because exercise()
      // and feed() belong to the Animal class.  This cast is not a problem,
      // because the ArrayList consists of animal objects (or specialized
      // versions of animals, which also have the ability to exercise and eat).
      else if (input == 'e')
      {
	System.out.print("Which animal do you want to exercise?  ");
        int num = Integer.parseInt(kbd.readLine());
	((Animal)(zoo.get(num))).exercise();
      }
      else if (input == 'f')
      {
	System.out.print("Which animal do you want to feed?  ");
        int num = Integer.parseInt(kbd.readLine());
        ((Animal)(zoo.get(num))).feed();
      }
      else if (input == 'w')
      {
        System.out.print("Which animal do you want to weigh?  ");
	int num = Integer.parseInt(kbd.readLine());
        System.out.println(zoo.get(num) + " weighs " +
                           ((Animal)(zoo.get(num))).getWeight());
      }
      else if (input == 'q')
        break;
      else
	System.out.println("Invalid option.  Try again.");
    }
  }
}