package pr02;

public class FibonacciListSimple {
   
   private int[] values;
   
   public FibonacciListSimple(int n) {
      int maxLength = getMaxLength();
      if (n < 0)
         n = 0;
      if (n > maxLength)
         n = maxLength;
      fillValues(n);
   }
   
   public static int getMaxLength() {
      int fib1 = 0;
      int fib2 = 1;
      int fibNew = fib1 + fib2;
      int count = 2;
      while (fibNew > 0) {
         fib1 = fib2;
         fib2 = fibNew;
         fibNew = fib1 + fib2;
         count++;
      }
      return count;
   }
   
   private void fillValues(int n) {
      int fib1 = 0;
      int fib2 = 1;
      int fibNew = fib1 + fib2;
      values = new int[n];
      if (n == 0)
         return;
      values[0] = fib1;
      if (n == 1)
         return;
      values[1] = fib2;
      for (int i=2;i<values.length;i++) {
         values[i] = fibNew;
         fib1 = fib2;
         fib2 = fibNew;
         fibNew = fib1 + fib2;
      }
   }
   
   public int getLength() {
      return values.length;
   }
   
   public int getAsInt(int n) {
      if ((n < 0) || (n >= values.length))
         return -1;
      return values[n];
   }
   
   public double getAsDouble(int n) {
      if ((n < 0) || (n >= values.length))
         return -1;
      return (double)values[n];
   }
   
   public String getAsString(int n) {
      if ((n < 0) || (n >= values.length))
         return null;
      String s = ""+values[n];
      String result = "";
      while (s.length() > 3) {
         result = "," + s.substring(s.length()-3) + result;
         s = s.substring(0,s.length()-3);
      }
      result = s + result;
      return result;
   }
   
   public int[] getAllAsInt() {
      int[] newValues = new int[values.length];
      for (int i=0;i<values.length;i++)
         newValues[i] = values[i];
      return newValues;
   }
   
   // if mod is 0, get the even ones
   // if mod is 1, get the odd ones
   private int[] getSomeAsInt(int mod) {
      int count = 0;
      for (int i=0;i<values.length;i++)
         if (values[i]%2 == mod)
            count++;
      int[] result = new int[count];
      count = 0;
      for (int i=0;i<values.length;i++)
         if (values[i]%2 == mod)
            result[count++] = values[i];
      return result;
   }
   
   public int[] getOddAsInt() {
      return getSomeAsInt(1);
   }
   
   public int[] getEvenAsInt() {
      return getSomeAsInt(0);
   }
   
   public String toStringOriginal() {
      String s = "";
      for (int i=0;i<values.length;i++)
         s = s + "F["+i+"]: " + values[i] + "\n";
      return s;
   }
   
   public String toString() {
      StringBuilder s = new StringBuilder();
      for (int i=0;i<values.length;i++)
         s.append("F["+i+"]: " + values[i] + "\n");
      return s.toString();
   }

}