import java.util.*;
import java.io.*;
/**
 * class <code>Zoo</code> simulates storing animals in a collection.
 *
 * @author D Newton
 * */
public class Zoo
{
   private ArrayList<Animal> animalCollection;
   private int lionCount;
   private int tigerCount;
   private int elephantCount;
   private int otherCount;

   /**
    * Create an "empty" zoo
    */
   public Zoo()
   {
      animalCollection = new ArrayList<Animal>();
      lionCount = 0;
      tigerCount = 0;
      elephantCount = 0;
      otherCount = 0;
   }

   /**
    * Create a zoo and populate it using data from a text file
    */
   public Zoo(String fileName) throws FileNotFoundException
   {
      this();
      readAnimalData(fileName);
   }
   
   /**
    * Adds an animal to the zoo
    *
    * @param   <code>animal</code> an <code>Animal</code> object, the animal to be added
    */
   public void storeAnimal(Animal animal)
   {
      animalCollection.add(animal);
   }

   /**
    * Shows an animal by printing it's details.  This includes
    * it's position in the collection.
    *
    * @param  <code>listPosition</code> the position of the animal
    */
   public void showAnimal(int listPosition)
   {
      Animal animal;
      if( listPosition < animalCollection.size() )
      {
         animal = animalCollection.get(listPosition);
         System.out.println("Position " + listPosition  + ": " + animal);
      }
   }

   /**
    * Returns how many animals are stored in the collection
    *
    * @return   the number of animals in the collection
    */
   public int numberOfAnimals()
   {
      return animalCollection.size();
   }

   /**
    * Displays all the animals in the collection
    *
    */
   public void showAllAnimals()
   {
      System.out.println("Zoo");
      System.out.println("===");

      int listPosition = 0;
      while( listPosition<animalCollection.size() )
      {
         showAnimal(listPosition);
         listPosition++;
      }
      System.out.println(listPosition + " animals shown" );    // display number of animals shown  
   }

    /**
    * Remove an animal from the collection
    *
    * @param  <code>listPosition</code> the position of the animal
    */
   public void removeAnimal(int listPosition)
   {
       if( listPosition>=0 && listPosition<animalCollection.size() )
       {
          animalCollection.remove(listPosition);
       }
       else
       {
          System.out.println("Invalid position");
       }
   }

  /**
    * Adds a pre-defined set of animals to the current collection
    *
    */
   public void populate()
   {
      storeAnimal( new Animal("lion", "Leo") );
      storeAnimal( new Animal("tiger", "Tommy") );
      storeAnimal( new Animal("elephant", "Ollie") );
      storeAnimal( new Animal("rat", "Roland") );
      storeAnimal( new Animal("reindeer", "Rudolph") );
      storeAnimal( new Animal("Lion", "Lenny") );
      storeAnimal( new Animal("Elephant", "Nellie") );
      storeAnimal( new Animal("tiger", "Tessa") );
      storeAnimal( new Animal("eLephant", "Hetty") );
      storeAnimal( new Animal("LION", "Leslie") );      
   }

   /**
    * Counts the number of lions, tigers and elephants
    *
    */
   public void countAnimals( )
   {
       lionCount = 0; tigerCount = 0; 
       elephantCount= 0; otherCount = 0;
       Iterator<Animal> it = animalCollection.iterator();
       while( it.hasNext() )
       {
           Animal currentAnimal = it.next();
           String species = currentAnimal.getSpecies();
           if( species.equalsIgnoreCase("lion") )
              lionCount++;
           else if( species.equalsIgnoreCase("tiger") )
              tigerCount++;
           else if( species.equalsIgnoreCase("elephant") )
              elephantCount++;
           else
              otherCount++;
       }
   }

   /**
    * Writes animal data to a file
    *
    * @param   <code>fileName</code> a <code>String</code>, the name of the 
    *          text file in which the data will be stored.
    * 
    * @throws  FileNotFoundException
    */
   public void writeAnimalData(String fileName) throws FileNotFoundException
   {
      PrintWriter pWriter = new PrintWriter(fileName);
      
      for(Animal a: animalCollection)
      {
         String lineOfOutput = a.getName() + "," + a.getSpecies();
         pWriter.println(lineOfOutput);
      }
      pWriter.close();
   }

   /**
    * Reads animal data from a file and adds corresponding animals to the zoo
    *
    * @param   <code>fileName</code> a <code>String</code>, the name of the 
    *          text file in which the data is stored.
    * 
    * @throws  FileNotFoundException
    */   
   public void readAnimalData(String fileName) throws FileNotFoundException
   {
	  File dataFile = new File(fileName);
      Scanner scanner = new Scanner(dataFile);
      scanner.useDelimiter("[,\n]");

      while( scanner.hasNext() )
      {
         String name = scanner.next();
         name.trim();
         String species = scanner.next();
         species.trim();
         storeAnimal( new Animal(species, name) );
      }
      scanner.close();
   }
}