/*
 * Gary Cornell and Cay S. Horstmann, Core Java (Book/CD-ROM) Published By
 * SunSoft Press/Prentice-Hall Copyright (C) 1996 Sun Microsystems Inc. All
 * Rights Reserved. ISBN 0-13-565755-5
 * 
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for NON-COMMERCIAL purposes and without fee is hereby granted
 * provided that this copyright notice appears in all copies.
 * 
 * THE AUTHORS AND PUBLISHER MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT THE
 * SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT
 * LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHORS AND PUBLISHER SHALL NOT
 * BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING,
 * MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
/**
 * A class for formatting numbers that follows printf conventions. Also
 * implements C-like atoi and atof functions
 * 
 * @version 1.1.3 Wed Jul 18 15:00:35 GMT 2001
 * 
 * 
 * 
 * @author Cay Horstmann
 */
package edu.sc.seis.TauP;

/*
 * was package corejava; but changed to the TauP package to avoid namespace
 * conflicts. HPC 8/27/98
 * 
 * fixed_format does rounding incorrectly, fixed Oct 27, 1998, HPC
 * 
 */
public class Format {

    /**
     * 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 Format(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);
    }

    /**
     * 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);
    }

    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') {
            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));
    }

    /**
     * Formats a character into a string (like sprintf in C)
     * 
     * @param c
     *            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 s
     *            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);
    }

    /**
     * a test stub for the format class
     */
    public static void main(String[] a) {
        double x = 1.23456789012;
        double y = 123;
        double z = 1.2345e30;
        double w = 1.02;
        double u = 1.234e-5;
        int d = 0xCAFE;
        Format.print(System.out, "x = |%f|\n", x);
        Format.print(System.out, "u = |%20f|\n", u);
        Format.print(System.out, "x = |% .5f|\n", x);
        Format.print(System.out, "w = |%20.5f|\n", w);
        Format.print(System.out, "x = |%020.5f|\n", x);
        Format.print(System.out, "x = |%+20.5f|\n", x);
        Format.print(System.out, "x = |%+020.5f|\n", x);
        Format.print(System.out, "x = |% 020.5f|\n", x);
        Format.print(System.out, "y = |%#+20.5f|\n", y);
        Format.print(System.out, "y = |%-+20.5f|\n", y);
        Format.print(System.out, "z = |%20.5f|\n", z);
        Format.print(System.out, "x = |%e|\n", x);
        Format.print(System.out, "u = |%20e|\n", u);
        Format.print(System.out, "x = |% .5e|\n", x);
        Format.print(System.out, "w = |%20.5e|\n", w);
        Format.print(System.out, "x = |%020.5e|\n", x);
        Format.print(System.out, "x = |%+20.5e|\n", x);
        Format.print(System.out, "x = |%+020.5e|\n", x);
        Format.print(System.out, "x = |% 020.5e|\n", x);
        Format.print(System.out, "y = |%#+20.5e|\n", y);
        Format.print(System.out, "y = |%-+20.5e|\n", y);
        Format.print(System.out, "x = |%g|\n", x);
        Format.print(System.out, "z = |%g|\n", z);
        Format.print(System.out, "w = |%g|\n", w);
        Format.print(System.out, "u = |%g|\n", u);
        Format.print(System.out, "y = |%.2g|\n", y);
        Format.print(System.out, "y = |%#.2g|\n", y);
        Format.print(System.out, "d = |%d|\n", d);
        Format.print(System.out, "d = |%20d|\n", d);
        Format.print(System.out, "d = |%020d|\n", d);
        Format.print(System.out, "d = |%+20d|\n", d);
        Format.print(System.out, "d = |% 020d|\n", d);
        Format.print(System.out, "d = |%-20d|\n", d);
        Format.print(System.out, "d = |%20.8d|\n", d);
        Format.print(System.out, "d = |%x|\n", d);
        Format.print(System.out, "d = |%20X|\n", d);
        Format.print(System.out, "d = |%#20x|\n", d);
        Format.print(System.out, "d = |%020X|\n", d);
        Format.print(System.out, "d = |%20.8x|\n", d);
        Format.print(System.out, "d = |%o|\n", d);
        Format.print(System.out, "d = |%020o|\n", d);
        Format.print(System.out, "d = |%#20o|\n", d);
        Format.print(System.out, "d = |%#020o|\n", d);
        Format.print(System.out, "d = |%20.12o|\n", d);
        Format.print(System.out, "s = |%-20s|\n", "Hello");
        Format.print(System.out, "s = |%-20c|\n", '!');
    }

    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);
        if(precision > 0) {
            d = Math.rint(d * Math.pow(10, precision))
                    / Math.pow(10, precision);
        }
        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;
        if ( ! Double.isFinite(d)) {
        	return ""+d;
        }
        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());
    }

    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
}
