import java.util.Random;
import java.text.NumberFormat;

public class CompanyStockSolution {
  
  private int index;
  private double record[];
  private Random random;
  private int shares;
  private final static int STOCKS_PER_DAY = 20;
  private boolean bankrupt = false;
  
  public CompanyStockSolution (int numDays)
  {
    random = new Random();
    record = new double[numDays*STOCKS_PER_DAY+1];
    record[0] = random.nextInt(201) + 100;
    shares = random.nextInt(5) + 50;
    index = 1;
  }
  
  public void monitorDay ()
  {
    for (int i=0; i<STOCKS_PER_DAY; i++)
    {
      int priceChange = (int) (random.nextInt(5)/10.0 * shares);
      if (random.nextBoolean())
      {
        prospers(priceChange);
      }
      else
      {
        slumps(priceChange);
      }
    }

  }
  
  private String determineTrend () 
  {
    String trend;
    if (!bankrupt)
    {
      final double MARGIN = 10;
      int minimum = (index>STOCKS_PER_DAY)?(index-STOCKS_PER_DAY-1):0;
      
      if (record[index-1]-MARGIN>record[minimum])
        trend = "rising";
      else if (record[index-1]<record[minimum]-MARGIN)
        trend = "falling";
      else 
        trend = "steady";
    }
    else 
      trend = "bankrupt";
    
    return trend;
  }
  
  public String reportResults ()
  {
    String result = "The company stock is ";
    result += determineTrend();
    int minimum = (index>STOCKS_PER_DAY)?(index-STOCKS_PER_DAY-1):0;
    
    // This formats the output into monetary form; it was not required. 
    NumberFormat moneyMaker = NumberFormat.getCurrencyInstance();
    
    double priceChange = (record[index-1]-record[minimum]);
    String dayPrice = moneyMaker.format(Math.abs(priceChange));
    result += "; the price changed by " + dayPrice + ".; Total value " + moneyMaker.format(record[index-1]);; 
    return result;
  }
  
  public void prospers (int priceRise)
  {
    if (!bankrupt)
      record[index] = record[index-1] + priceRise;
    else
      record[index] = 0;
    index++;
  }
  
  public void slumps (int priceDrop)
  {
    if (!bankrupt)
    {
      record[index] = record[index-1] - priceDrop;
      if (record[index] <= 0)
      {
        record[index] = 0;
        bankrupt = true;
      }
    }
    else
      record[index] = 0;
    index++;
  }
  
}