/****************************************************************************
** COPYRIGHT (C):    1997 Cay S. Horstmann. All Rights Reserved.
** PROJECT:          Practical OO Development with C++ and Java
** FILE:             PrintfStream.java
** PURPOSE:          print stream with printf style formatting
** VERSION           1.0
** PROGRAMMERS:      Cay Horstmann (CSH)
** RELEASE DATE:     3-15-97 (CSH)
** UPDATE HISTORY:
****************************************************************************/

//package practicaloo;
import java.io.*;

public class PrintfStream extends PrintStream
{  public PrintfStream(OutputStream s)
   {  super(s);
   }

   public void printf(String fmt, double x)
   {  parseFormat(fmt);
      print(form(x));
   }
   public void printf(String fmt, long x)
   {  parseFormat(fmt);
      print(form(x));
   }
   public void printf(String fmt, char x)
   {  parseFormat(fmt);
      print(form(x));
   }
   public void printf(String fmt, String x)
   {  parseFormat(fmt);
      print(form(x));
   }

   private void parseFormat(String s)
   {  width = 0;
      precision = -1;
      pre = "";
      post = "";
      leading_zeroes = false;
      show_plus = false;
      alternate = false;
      show_space = false;
      left_align = false;
      fmt = ' ';

      int state = 0;
      int length = s.length();
      int parse_state = 0;
      // 0 = prefix, 1 = flags, 2 = width, 3 = precision,
      // 4 = format, 5 = end
      int i = 0;

      while (parse_state == 0)
      {  if (i >= length) parse_state = 5;
         else if (s.charAt(i) == '%')
         {  if (i < length - 1)
            {  if (s.charAt(i + 1) == '%')
               {  pre = pre + '%';
                  i++;
               }
               else
                  parse_state = 1;
            }
            else throw new java.lang.IllegalArgumentException();
         }
         else
            pre = pre + s.charAt(i);
         i++;
      }
      while (parse_state == 1)
      {  if (i >= length) parse_state = 5;
         else if (s.charAt(i) == ' ') show_space = true;
         else if (s.charAt(i) == '-') left_align = true;
         else if (s.charAt(i) == '+') show_plus = true;
         else if (s.charAt(i) == '0') leading_zeroes = true;
         else if (s.charAt(i) == '#') alternate = true;
         else { parse_state = 2; i--; }
         i++;
      }
      while (parse_state == 2)
      {  if (i >= length) parse_state = 5;
         else if ('0' <= s.charAt(i) && s.charAt(i) <= '9')
         {  width = width * 10 + s.charAt(i) - '0';
            i++;
         }
         else if (s.charAt(i) == '.')
         {  parse_state = 3;
            precision = 0;
            i++;
         }
         else
            parse_state = 4;
      }
      while (parse_state == 3)
      {  if (i >= length) parse_state = 5;
         else if ('0' <= s.charAt(i) && s.charAt(i) <= '9')
         {  precision = precision * 10 + s.charAt(i) - '0';
            i++;
         }
         else
            parse_state = 4;
      }
      if (parse_state == 4)
      {  if (i >= length) parse_state = 5;
         else fmt = s.charAt(i);
         i++;
      }
      if (i < length)
         post = s.substring(i, length);
   }

   private static String repeat(char c, int n)
   {  if (n <= 0) return "";
      StringBuffer s = new StringBuffer(n);
      for (int i = 0; i < n; i++) s.append(c);
      return s.toString();
   }

   private static String convert(long x, int n, int m, String d)
   {  if (x == 0) return "0";
      String r = "";
      while (x != 0)
      {  r = d.charAt((int)(x & m)) + r;
         x = x >>> n;
      }
      return r;
   }

   private String pad(String r)
   {  String p = repeat(' ', width - r.length());
      if (left_align) return pre + r + p + post;
      else return pre + p + r + post;
   }

   private String sign(int s, String r)
   {  String p = "";
      if (s < 0) p = "-";
      else if (s > 0)
      {  if (show_plus) p = "+";
         else if (show_space) p = " ";
      }
      else
      {  if (fmt == 'o' && alternate && r.length() > 0 && r.charAt(0) != '0') p = "0";
         else if (fmt == 'x' && alternate) p = "0x";
         else if (fmt == 'X' && alternate) p = "0X";
      }
      int w = 0;
      if (leading_zeroes)
         w = width;
      else if ((fmt == 'd' || fmt == 'i' || fmt == 'x' || fmt == 'X' || fmt == 'o')
         && precision > 0) w = precision;

      return p + repeat('0', w - p.length() - r.length()) + r;
   }

   private String fixed_format(double d)
   {  String f = "";

      if (d > 0x7FFFFFFFFFFFFFFFL) return exp_format(d);

      long l = (long)(precision == 0 ? d + 0.5 : d);
      f = f + l;

      double fr = d - l; // fractional part
      if (fr >= 1 || fr < 0) return exp_format(d);

      return f + frac_part(fr);
   }

   private String frac_part(double fr)
   // precondition: 0 <= fr < 1
   {  String z = "";
      if (precision > 0)
      {  double factor = 1;
         String leading_zeroes = "";
         for (int i = 1; i <= precision && factor <= 0x7FFFFFFFFFFFFFFFL; i++)
         {  factor *= 10;
            leading_zeroes = leading_zeroes + "0";
         }
         long l = (long) (factor * fr + 0.5);

         z = leading_zeroes + l;
         z = z.substring(z.length() - precision, z.length());
      }


      if (precision > 0 || alternate) z = "." + z;
      if ((fmt == 'G' || fmt == 'g') && !alternate)
      // remove trailing zeroes and decimal point
      {  int t = z.length() - 1;
         while (t >= 0 && z.charAt(t) == '0') t--;
         if (t >= 0 && z.charAt(t) == '.') t--;
         z = z.substring(0, t + 1);
      }
      return z;
   }

   private String exp_format(double d)
   {  String f = "";
      int e = 0;
      double dd = d;
      double factor = 1;
      while (dd > 10) { e++; factor /= 10; dd = dd / 10; }
      while (dd < 1) { e--; factor *= 10; dd = dd * 10; }
      if ((fmt == 'g' || fmt == 'G') && e >= -4 && e < precision)
         return fixed_format(d);

      d = d * factor;
      f = f + fixed_format(d);

      if (fmt == 'e' || fmt == 'g')
         f = f + "e";
      else
         f = f + "E";

      String p = "000";
      if (e >= 0)
      {  f = f + "+";
         p = p + e;
      }
      else
      {  f = f + "-";
         p = p + (-e);
      }

      return f + p.substring(p.length() - 3, p.length());
   }

   public String form(double x)
   {  String r;
      if (precision < 0) precision = 6;
      int s = 1;
      if (x < 0) { x = -x; s = -1; }
      if (fmt == 'f')
         r = fixed_format(x);
      else if (fmt == 'e' || fmt == 'E' || fmt == 'g' || fmt == 'G')
         r = exp_format(x);
      else throw new java.lang.IllegalArgumentException();

      return pad(sign(s, r));
   }

   public String form(long x)
   {  String r;
      int s = 0;
      if (fmt == 'd' || fmt == 'i')
      {  s = 1;
         if (x < 0) { x = -x; s = -1; }
         r = "" + x;
      }
      else if (fmt == 'o')
         r = convert(x, 3, 7, "01234567");
      else if (fmt == 'x')
         r = convert(x, 4, 15, "0123456789abcdef");
      else if (fmt == 'X')
         r = convert(x, 4, 15, "0123456789ABCDEF");
      else throw new java.lang.IllegalArgumentException();

      return pad(sign(s, r));
   }

   public String form(char c)
   {  if (fmt != 'c')
         throw new java.lang.IllegalArgumentException();

      String r = "" + c;
      return pad(r);
   }

  public String form(String s)
   {  if (fmt != 's')
         throw new java.lang.IllegalArgumentException();
      if (precision >= 0) s = s.substring(0, precision);
      return pad(s);
   }

   private int width;
   private int precision;
   private String pre;
   private String post;
   private boolean leading_zeroes;
   private boolean show_plus;
   private boolean alternate;
   private boolean show_space;
   private boolean left_align;
   private char fmt; // one of cdeEfgGiosxXos
}