/*
 * Jalview - A Sequence Alignment Editor and Viewer (2.11.2.6)
 * Copyright (C) 2023 The Jalview Authors
 * 
 * This file is part of Jalview.
 * 
 * Jalview is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License 
 * as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *  
 * Jalview is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty 
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
 * PURPOSE.  See the GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Jalview.  If not, see <http://www.gnu.org/licenses/>.
 * The Jalview Authors are detailed in the 'AUTHORS' file.
 */
/**
 * A class for formatting numbers that follows printf conventions.
 * Also implements C-like atoi and atof functions
 * @version 1.03 25 Oct 1997
 * @author Cay Horstmann
 */
package jalview.util;

import java.util.Arrays;

/**
 * DOCUMENT ME!
 * 
 * @author $author$
 * @version $Revision$
 */
public class Format
{
  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

  private final String formatString;

  /**
   * Creates a new Format object.
   * 
   * @param s
   *          DOCUMENT ME!
   */
  public Format(String s)
  {
    formatString = s;
    width = 0;
    precision = -1;
    pre = "";
    post = "";
    leading_zeroes = false;
    show_plus = false;
    alternate = false;
    show_space = false;
    left_align = false;
    fmt = ' ';

    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);
    }
  }

  /**
   * Formats the number following printf conventions. Main limitation: Can only
   * handle one format parameter at a time Use multiple Format objects to format
   * more than one number
   * 
   * @param s
   *          the format string following printf conventions The string has a
   *          prefix, a format code and a suffix. The prefix and suffix become
   *          part of the formatted output. The format code directs the
   *          formatting of the (single) parameter to be formatted. The code has
   *          the following structure
   *          <ul>
   *          <li>a % (required)
   *          <li>a modifier (optional)
   *          <dl>
   *          <dt>+
   *          <dd>forces display of + for positive numbers
   *          <dt>0
   *          <dd>show leading zeroes
   *          <dt>-
   *          <dd>align left in the field
   *          <dt>space
   *          <dd>prepend a space in front of positive numbers
   *          <dt>#
   *          <dd>use "alternate" format. Add 0 or 0x for octal or hexadecimal
   *          numbers. Don't suppress trailing zeroes in general floating point
   *          format.
   *          </dl>
   *          <li>an integer denoting field width (optional)
   *          <li>a period followed by an integer denoting precision (optional)
   *          <li>a format descriptor (required)
   *          <dl>
   *          <dt>f
   *          <dd>floating point number in fixed format
   *          <dt>e, E
   *          <dd>floating point number in exponential notation (scientific
   *          format). The E format results in an uppercase E for the exponent
   *          (1.14130E+003), the e format in a lowercase e.
   *          <dt>g, G
   *          <dd>floating point number in general format (fixed format for
   *          small numbers, exponential format for large numbers). Trailing
   *          zeroes are suppressed. The G format results in an uppercase E for
   *          the exponent (if any), the g format in a lowercase e.
   *          <dt>d, i
   *          <dd>integer in decimal
   *          <dt>x
   *          <dd>integer in hexadecimal
   *          <dt>o
   *          <dd>integer in octal
   *          <dt>s
   *          <dd>string
   *          <dt>c
   *          <dd>character
   *          </dl>
   *          </ul>
   * @exception IllegalArgumentException
   *              if bad format
   * 
   */
  public static String getHexString(java.awt.Color color)
  {
    String r;
    String g;
    String b;
    r = Integer.toHexString(color.getRed());

    if (r.length() < 2)
    {
      r = "0" + r;
    }

    g = Integer.toHexString(color.getGreen());

    if (g.length() < 2)
    {
      g = "0" + g;
    }

    b = Integer.toHexString(color.getBlue());

    if (b.length() < 2)
    {
      b = "0" + b;
    }

    return r + g + b;
  }

  /**
   * prints a formatted number following printf conventions
   * 
   * @param s
   *          a PrintStream
   * @param fmt
   *          the format string
   * @param x
   *          the double to print
   */
  public static void print(java.io.PrintStream s, String fmt, double x)
  {
    s.print(new Format(fmt).form(x));
  }

  /**
   * prints a formatted number following printf conventions
   * 
   * @param s
   *          a PrintStream
   * @param fmt
   *          the format string
   * @param x
   *          the long to print
   */
  public static void print(java.io.PrintStream s, String fmt, long x)
  {
    s.print(new Format(fmt).form(x));
  }

  /**
   * prints a formatted number following printf conventions
   * 
   * @param s
   *          a PrintStream
   * @param fmt
   *          the format string
   * @param x
   *          the character to
   */
  public static void print(java.io.PrintStream s, String fmt, char x)
  {
    s.print(new Format(fmt).form(x));
  }

  /**
   * prints a formatted number following printf conventions
   * 
   * @param s
   *          a PrintStream, fmt the format string
   * @param x
   *          a string that represents the digits to print
   */
  public static void print(java.io.PrintStream s, String fmt, String x)
  {
    s.print(new Format(fmt).form(x));
  }

  /**
   * Converts a string of digits (decimal, octal or hex) to an integer
   * 
   * @param s
   *          a string
   * @return the numeric value of the prefix of s representing a base 10 integer
   */
  public static int atoi(String s)
  {
    return (int) atol(s);
  }

  /**
   * Converts a string of digits (decimal, octal or hex) to a long integer
   * 
   * @param s
   *          a string
   * @return the numeric value of the prefix of s representing a base 10 integer
   */
  public static long atol(String s)
  {
    int i = 0;

    while ((i < s.length()) && Character.isWhitespace(s.charAt(i)))
    {
      i++;
    }

    if ((i < s.length()) && (s.charAt(i) == '0'))
    {
      if (((i + 1) < s.length())
              && ((s.charAt(i + 1) == 'x') || (s.charAt(i + 1) == 'X')))
      {
        return parseLong(s.substring(i + 2), 16);
      }
      else
      {
        return parseLong(s, 8);
      }
    }
    else
    {
      return parseLong(s, 10);
    }
  }

  /**
   * DOCUMENT ME!
   * 
   * @param s
   *          DOCUMENT ME!
   * @param base
   *          DOCUMENT ME!
   * 
   * @return DOCUMENT ME!
   */
  private static long parseLong(String s, int base)
  {
    int i = 0;
    int sign = 1;
    long r = 0;

    while ((i < s.length()) && Character.isWhitespace(s.charAt(i)))
    {
      i++;
    }

    if ((i < s.length()) && (s.charAt(i) == '-'))
    {
      sign = -1;
      i++;
    }
    else if ((i < s.length()) && (s.charAt(i) == '+'))
    {
      i++;
    }

    while (i < s.length())
    {
      char ch = s.charAt(i);

      if (('0' <= ch) && (ch < ('0' + base)))
      {
        r = ((r * base) + ch) - '0';
      }
      else if (('A' <= ch) && (ch < (('A' + base) - 10)))
      {
        r = ((r * base) + ch) - 'A' + 10;
      }
      else if (('a' <= ch) && (ch < (('a' + base) - 10)))
      {
        r = ((r * base) + ch) - 'a' + 10;
      }
      else
      {
        return r * sign;
      }

      i++;
    }

    return r * sign;
  }

  /**
   * Converts a string of digits to an double
   * 
   * @param s
   *          a string
   */
  public static double atof(String s)
  {
    int i = 0;
    int sign = 1;
    double r = 0; // integer part
    // double f = 0; // fractional part
    double p = 1; // exponent of fractional part
    int state = 0; // 0 = int part, 1 = frac part

    while ((i < s.length()) && Character.isWhitespace(s.charAt(i)))
    {
      i++;
    }

    if ((i < s.length()) && (s.charAt(i) == '-'))
    {
      sign = -1;
      i++;
    }
    else if ((i < s.length()) && (s.charAt(i) == '+'))
    {
      i++;
    }

    while (i < s.length())
    {
      char ch = s.charAt(i);

      if (('0' <= ch) && (ch <= '9'))
      {
        if (state == 0)
        {
          r = ((r * 10) + ch) - '0';
        }
        else if (state == 1)
        {
          p = p / 10;
          r = r + (p * (ch - '0'));
        }
      }
      else if (ch == '.')
      {
        if (state == 0)
        {
          state = 1;
        }
        else
        {
          return sign * r;
        }
      }
      else if ((ch == 'e') || (ch == 'E'))
      {
        long e = (int) parseLong(s.substring(i + 1), 10);

        return sign * r * Math.pow(10, e);
      }
      else
      {
        return sign * r;
      }

      i++;
    }

    return sign * r;
  }

  /**
   * Formats a double into a string (like sprintf in C)
   * 
   * @param x
   *          the number to format
   * @return the formatted string
   * @exception IllegalArgumentException
   *              if bad argument
   */
  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));
  }

  /**
   * Formats a long integer into a string (like sprintf in C)
   * 
   * @param x
   *          the number to format
   * @return the formatted string
   */
  public String form(long x)
  {
    String r;
    int s = 0;

    if ((fmt == 'd') || (fmt == 'i'))
    {
      if (x < 0)
      {
        r = ("" + x).substring(1);
        s = -1;
      }
      else
      {
        r = "" + x;
        s = 1;
      }
    }
    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));
  }

  /**
   * Formats a character into a string (like sprintf in C)
   * 
   * @param debounceTrap
   *          the value to format
   * @return the formatted string
   */
  public String form(char c)
  {
    if (fmt != 'c')
    {
      throw new java.lang.IllegalArgumentException();
    }

    String r = "" + c;

    return pad(r);
  }

  /**
   * Formats a string into a larger string (like sprintf in C)
   * 
   * @param debounceTrap
   *          the value to format
   * @return the formatted string
   */
  public String form(String s)
  {
    if (fmt != 's')
    {
      throw new java.lang.IllegalArgumentException();
    }

    if (precision >= 0)
    {
      s = s.substring(0, precision);
    }

    return pad(s);
  }

  /**
   * Returns a string consisting of n repeats of character c
   * 
   * @param c
   * @param n
   * 
   * @return
   */
  static String repeat(char c, int n)
  {
    if (n <= 0)
    {
      return "";
    }
    char[] chars = new char[n];
    Arrays.fill(chars, c);
    return new String(chars);
  }

  /**
   * DOCUMENT ME!
   * 
   * @param x
   *          DOCUMENT ME!
   * @param n
   *          DOCUMENT ME!
   * @param m
   *          DOCUMENT ME!
   * @param d
   *          DOCUMENT ME!
   * 
   * @return DOCUMENT ME!
   */
  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;
  }

  /**
   * DOCUMENT ME!
   * 
   * @param r
   *          DOCUMENT ME!
   * 
   * @return DOCUMENT ME!
   */
  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;
    }
  }

  /**
   * DOCUMENT ME!
   * 
   * @param s
   *          DOCUMENT ME!
   * @param r
   *          DOCUMENT ME!
   * 
   * @return DOCUMENT ME!
   */
  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;
  }

  /**
   * DOCUMENT ME!
   * 
   * @param d
   *          DOCUMENT ME!
   * 
   * @return DOCUMENT ME!
   */
  private String fixed_format(double d)
  {
    boolean removeTrailing = ((fmt == 'G') || (fmt == 'g')) && !alternate;

    // remove trailing zeroes and decimal point
    if (d > 0x7FFFFFFFFFFFFFFFL)
    {
      return exp_format(d);
    }

    if (precision == 0)
    {
      return (long) (d + 0.5) + (removeTrailing ? "" : ".");
    }

    long whole = (long) d;
    double fr = d - whole; // fractional part

    if ((fr >= 1) || (fr < 0))
    {
      return exp_format(d);
    }

    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);

    if (l >= factor)
    {
      l = 0;
      whole++;
    }

    // CSH 10-25-97
    String z = leading_zeroes + l;
    z = "." + z.substring(z.length() - precision, z.length());

    if (removeTrailing)
    {
      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 whole + z;
  }

  /**
   * DOCUMENT ME!
   * 
   * @param d
   *          DOCUMENT ME!
   * 
   * @return DOCUMENT ME!
   */
  private String exp_format(double d)
  {
    String f = "";
    int e = 0;
    double dd = d;

    if (d != 0)
    {
      while (dd > 10)
      {
        e++;
        dd = dd / 10;
      }

      while (dd < 1)
      {
        e--;
        dd = dd * 10;
      }
    }

    if (((fmt == 'g') || (fmt == 'G')) && (e >= -4) && (e < precision))
    {
      return fixed_format(d);
    }

    f = f + fixed_format(dd);

    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());
  }

  @Override
  public String toString()
  {
    return formatString;
  }

  /**
   * Bespoke method to format percentage float value to the specified number of
   * decimal places. Avoids use of general-purpose format parsers as a
   * processing hotspot.
   * 
   * @param sb
   * @param value
   * @param dp
   */
  public static void appendPercentage(StringBuilder sb, float value, int dp)
  {
    /*
     * rounding first
     */
    double d = value;
    long factor = 1L;
    for (int i = 0; i < dp; i++)
    {
      factor *= 10;
    }
    d *= factor;
    d += 0.5;

    /*
     * integer part
     */
    value = (float) (d / factor);
    sb.append((long) value);

    /*
     * decimal places
     */
    if (dp > 0)
    {
      sb.append(".");
      while (dp > 0)
      {
        value = value - (int) value;
        value *= 10;
        sb.append((int) value);
        dp--;
      }
    }
  }
}
