import java.io.*;

/*************************************************************************
 *Class for data on endangered species. This is a new, improved definition
 *of the class Species, which replaces the definition in Chapter 4.
 *************************************************************************/
public class Species
{
   private String name;
   private int population;
   private double growthRate;

   public Species()
    {
        name = null;
        population = 0;
        growthRate = 0;
    }

    public Species(String initialName, int initialPopulation,
                                   double initialGrowthRate)
    {
        name = initialName;
        if (initialPopulation >= 0)
            population = initialPopulation;
        else
        {
            System.out.println("ERROR: Negative population.");
            System.exit(0);
        }
        growthRate = initialGrowthRate;
    }

    public void set(String newName, int newPopulation,
                                    double newGrowthRate)
    {
        name = newName;
        if (newPopulation >= 0)
            population = newPopulation;
        else
        {
            System.out.println("ERROR: Negative population.");
            System.exit(0);
        }
        growthRate = newGrowthRate;
    }

    /*******************************************************
     *Precondition: years is a nonnegative number.
     *Returns the projected population of the calling object
     *after the specified number of years.
     *******************************************************/
    public int projectedPopulation(int years)
    {
        double populationAmount = population;
        int count = years;

        while ((count > 0) && (populationAmount > 0))
        {
            populationAmount = (populationAmount +
                         (growthRate/100) * populationAmount);
            count--;
        }
        if (populationAmount > 0)
            return (int)populationAmount;
        else
            return 0;
    }

    public String getName()
    {
        return name;
    }

    public int getPopulation()
    {
        return population;
    }

    public double getGrowthRate()
    {
        return growthRate;
    }

    public boolean equals(Species otherObject)
    {
        return ((name.equalsIgnoreCase(otherObject.name))
                && (population == otherObject.population)
                && (growthRate == otherObject.growthRate));
    }

    /***************************
     *Sends output to the screen.
     ***************************/
    public void writeOutput()
    {
         System.out.println("Name = " + name);
         System.out.println("Population = " + population);
         System.out.println("Growth rate = " + growthRate + "%");
    }

    /*********************************************************
     *Precondition: The stream outputStream has been connected
     *to a file.
     *Action: A record of the species is written to the file
     *that is connected to outputStream. The record is written
     *as three items, IN THIS ORDER: a String for the name, an
     *int for the population, and a double for the growth rate.
     *********************************************************/
    public void writeOutput(DataOutputStream outputStream)
                                             throws IOException
    {
         outputStream.writeUTF(name);
         outputStream.writeInt(population);
         outputStream.writeDouble(growthRate);
    }


     /*******************************
      *Takes input from the keyboard.
      *******************************/
     public void readInput()
     {
        System.out.println("What is the species' name?");
        name = SavitchIn.readLine();
        System.out.println("What is the population of the species?");
        population = SavitchIn.readLineInt();
        System.out.println("Enter growth rate (percent increase per year):");
        growthRate = SavitchIn.readLineDouble();
    }

    /*************************************************************
     *Precondition: The stream inputStream is connected to a file.
     *Each species record appears in the file as three items,
     *IN THIS ORDER: a String for the name, an int for the
     *population, and a double for the growth rate.
     *Action: Reads a record from the stream and resets the data
     *for the calling object. An attempt to read past the end
     *of the file will throw an EOFException.
     ************************************************************/
    public void readInput(DataInputStream inputStream)
                                               throws IOException
    {
        name = inputStream.readUTF();
        population = inputStream.readInt();
        growthRate = inputStream.readDouble();
    }

}