/*
 * Copyright 2013 Garrett D'Amore <garrett@damore.org>
 * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2001 Alexey Zelkin <phantom@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#ifndef _LCONV_C99
#define _LCONV_C99
#endif

#include "lint.h"
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <monetary.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "localeimpl.h"
#include "lmonetary.h"
#include "lnumeric.h"

/* internal flags */
#define NEED_GROUPING           0x01    /* print digits grouped (default) */
#define SIGN_POSN_USED          0x02    /* '+' or '(' usage flag */
#define LOCALE_POSN             0x04    /* use locale defined +/- (default) */
#define PARENTH_POSN            0x08    /* enclose negative amount in () */
#define SUPRESS_CURR_SYMBOL     0x10    /* supress the currency from output */
#define LEFT_JUSTIFY            0x20    /* left justify */
#define USE_INTL_CURRENCY       0x40    /* use international currency symbol */
#define IS_NEGATIVE             0x80    /* is argument value negative ? */

/* internal macros */
#define PRINT(CH) {                                             \
        if (dst >= s + maxsize)                                 \
                goto e2big_error;                               \
        *dst++ = CH;                                            \
}

#define PRINTS(STR) {                                           \
        const char *tmps = STR;                                 \
        while (*tmps != '\0')                                   \
                PRINT(*tmps++);                                 \
}

#define GET_NUMBER(VAR) {                                       \
        VAR = 0;                                                \
        while (isdigit((unsigned char)*fmt)) {                  \
                if (VAR > INT_MAX / 10)                         \
                        goto e2big_error;                       \
                VAR *= 10;                                      \
                VAR += *fmt - '0';                              \
                if (VAR < 0)                                    \
                        goto e2big_error;                       \
                fmt++;                                          \
        }                                                       \
}

#define GRPCPY(howmany) {                                       \
        int i = howmany;                                        \
        while (i-- > 0) {                                       \
                avalue_size--;                                  \
                *--bufend = *(avalue+avalue_size+padded);       \
        }                                                       \
}

#define GRPSEP {                                                \
        bufend -= thousands_len;                                \
        (void) memcpy(bufend, thousands_sep, thousands_len);    \
        groups++;                                               \
}

static void setup_vars(const struct lc_monetary *, int, char *, char *, char *,
    const char **);
static int calc_left_pad(const struct lc_monetary *, int, const char *);
static char *format_grouped_double(const struct lc_monetary *,
    const struct lc_numeric *, double, int *, int, int, int);

ssize_t
strfmon_impl(char *_RESTRICT_KYWD s, size_t maxsize, locale_t loc,
    const char *_RESTRICT_KYWD format, va_list ap)
{
        char            *dst;           /* output destination pointer */
        const char      *fmt;           /* current format poistion pointer */
        char            *asciivalue;    /* formatted double pointer */

        int             flags;          /* formatting options */
        int             pad_char;       /* padding character */
        int             pad_size;       /* pad size */
        int             width;          /* field width */
        int             left_prec;      /* left precision */
        int             right_prec;     /* right precision */
        double          value;          /* just value */
        char            space_char = ' '; /* space after currency */

        char            cs_precedes;    /* values from struct lc_monetary */
        char            sep_by_space;
        char            sign_posn;
        const char      *signstr;
        const char      *currency_symbol;

        char            *tmpptr;        /* temporary vars */
        int             sverrno;
        const struct lc_monetary *lmon;         /* monetary structure */
        const struct lc_numeric *lnum;          /* numeric structure */

        lmon = loc->monetary;
        lnum = loc->numeric;

        dst = s;
        fmt = format;
        asciivalue = NULL;
        currency_symbol = NULL;
        pad_size = 0;

        while (*fmt) {
                /* pass nonformating characters AS IS */
                if (*fmt != '%')
                        goto literal;

                /* '%' found ! */

                /* "%%" mean just '%' */
                if (*(fmt+1) == '%') {
                        fmt++;
        literal:
                        PRINT(*fmt++);
                        continue;
                }

                /* set up initial values */
                flags = (NEED_GROUPING|LOCALE_POSN);
                pad_char = ' ';         /* padding character is "space" */
                left_prec = -1;         /* no left precision specified */
                right_prec = -1;        /* no right precision specified */
                width = -1;             /* no width specified */
                value = 0;              /* we have no value to print now */

                /* Flags */
                for (;;) {
                        switch (*++fmt) {
                                case '=':       /* fill character */
                                        pad_char = *++fmt;
                                        if (pad_char == '\0')
                                                goto format_error;
                                        continue;
                                case '^':       /* not group currency  */
                                        flags &= ~(NEED_GROUPING);
                                        continue;
                                case '+':       /* use locale defined signs */
                                        if (flags & SIGN_POSN_USED)
                                                goto format_error;
                                        flags |= (SIGN_POSN_USED|LOCALE_POSN);
                                        continue;
                                case '(':       /* enclose negatives with () */
                                        if (flags & SIGN_POSN_USED)
                                                goto format_error;
                                        flags |= (SIGN_POSN_USED|PARENTH_POSN);
                                        continue;
                                case '!':       /* suppress currency symbol */
                                        flags |= SUPRESS_CURR_SYMBOL;
                                        continue;
                                case '-':       /* alignment (left)  */
                                        flags |= LEFT_JUSTIFY;
                                        continue;
                                default:
                                        break;
                        }
                        break;
                }

                /* field Width */
                if (isdigit((unsigned char)*fmt)) {
                        GET_NUMBER(width);
                        /*
                         * Do we have enough space to put number with
                         * required width ?
                         */
                        if ((unsigned int)width >= maxsize - (dst - s))
                                goto e2big_error;
                }

                /* Left precision */
                if (*fmt == '#') {
                        if (!isdigit((unsigned char)*++fmt))
                                goto format_error;
                        GET_NUMBER(left_prec);
                        if ((unsigned int)left_prec >= maxsize - (dst - s))
                                goto e2big_error;
                }

                /* Right precision */
                if (*fmt == '.') {
                        if (!isdigit((unsigned char)*++fmt))
                                goto format_error;
                        GET_NUMBER(right_prec);
                        if ((unsigned int)right_prec >= maxsize - (dst - s) -
                            left_prec)
                                goto e2big_error;
                }

                /* Conversion Characters */
                switch (*fmt++) {
                        case 'i':       /* use internaltion currency format */
                                flags |= USE_INTL_CURRENCY;
                                break;
                        case 'n':       /* use national currency format */
                                flags &= ~(USE_INTL_CURRENCY);
                                break;
                        default:
                                /* required char missing or premature EOS */
                                goto format_error;
                }

                if (flags & USE_INTL_CURRENCY) {
                        currency_symbol = lmon->int_curr_symbol;
                        /* by definition three letters followed by a space */
                        if (currency_symbol != NULL)
                                space_char = currency_symbol[3];
                } else
                        currency_symbol = lmon->currency_symbol;

                /* value itself */
                value = va_arg(ap, double);

                /* detect sign */
                if (value < 0) {
                        flags |= IS_NEGATIVE;
                        value = -value;
                }

                /* fill left_prec with amount of padding chars */
                if (left_prec >= 0) {
                        pad_size = calc_left_pad(lmon, (flags ^ IS_NEGATIVE),
                            currency_symbol) -
                            calc_left_pad(lmon, flags, currency_symbol);
                        if (pad_size < 0)
                                pad_size = 0;
                }

                if (asciivalue != NULL)
                        free(asciivalue);
                asciivalue = format_grouped_double(lmon, lnum, value, &flags,
                    left_prec, right_prec, pad_char);
                if (asciivalue == NULL)
                        goto end_error;         /* errno already set */
                                                /* to ENOMEM by malloc() */

                /* set some variables for later use */
                setup_vars(lmon, flags, &cs_precedes, &sep_by_space,
                    &sign_posn, &signstr);

                /*
                 * Description of some LC_MONETARY's values:
                 *
                 * p_cs_precedes & n_cs_precedes
                 *
                 * = 1 - $currency_symbol precedes the value
                 *       for a monetary quantity with a non-negative value
                 * = 0 - symbol succeeds the value
                 *
                 * p_sep_by_space & n_sep_by_space
                 *
                 * = 0 - no space separates $currency_symbol
                 *       from the value for a monetary quantity with a
                 *       non-negative value
                 * = 1 - space separates the symbol from the value
                 * = 2 - space separates the symbol and the sign string,
                 *       if adjacent.
                 *
                 * p_sign_posn & n_sign_posn
                 *
                 * = 0 - parentheses enclose the quantity and the
                 *       $currency_symbol
                 * = 1 - the sign string precedes the quantity and the
                 *       $currency_symbol
                 * = 2 - the sign string succeeds the quantity and the
                 *       $currency_symbol
                 * = 3 - the sign string precedes the $currency_symbol
                 * = 4 - the sign string succeeds the $currency_symbol
                 *
                 */

                tmpptr = dst;

                while (pad_size-- > 0)
                        PRINT(' ');

                if (sign_posn == 0 && (flags & IS_NEGATIVE))
                        PRINT('(');

                if (cs_precedes == 1) {
                        if (sign_posn == 1 || sign_posn == 3) {
                                PRINTS(signstr);
                                if (sep_by_space == 2)
                                        PRINT(' ');
                        }

                        if (!(flags & SUPRESS_CURR_SYMBOL)) {
                                PRINTS(currency_symbol);

                                if (sign_posn == 4) {
                                        if (sep_by_space == 2)
                                                PRINT(space_char);
                                        PRINTS(signstr);
                                        if (sep_by_space == 1)
                                                PRINT(' ');
                                } else if (sep_by_space == 1)
                                        PRINT(space_char);
                        }
                } else if (sign_posn == 1)
                        PRINTS(signstr);

                PRINTS(asciivalue);

                if (cs_precedes == 0) {
                        if (sign_posn == 3) {
                                if (sep_by_space == 1)
                                        PRINT(' ');
                                PRINTS(signstr);
                        }

                        if (!(flags & SUPRESS_CURR_SYMBOL)) {
                                if ((sign_posn == 3 && sep_by_space == 2) ||
                                    (sep_by_space == 1 && (sign_posn == 0 ||
                                    sign_posn == 1 || sign_posn == 2 ||
                                    sign_posn == 4)))
                                        PRINT(space_char);
                                PRINTS(currency_symbol); /* XXX: len */
                                if (sign_posn == 4) {
                                        if (sep_by_space == 2)
                                                PRINT(' ');
                                        PRINTS(signstr);
                                }
                        }
                }

                if (sign_posn == 2) {
                        if (sep_by_space == 2)
                                PRINT(' ');
                        PRINTS(signstr);
                }

                if (sign_posn == 0 && (flags & IS_NEGATIVE))
                        PRINT(')');

                if (dst - tmpptr < width) {
                        if (flags & LEFT_JUSTIFY) {
                                while (dst - tmpptr < width)
                                        PRINT(' ');
                        } else {
                                pad_size = dst-tmpptr;
                                (void) memmove(tmpptr + width-pad_size, tmpptr,
                                    pad_size);
                                (void) memset(tmpptr, ' ', width-pad_size);
                                dst += width-pad_size;
                        }
                }
        }

        PRINT('\0');
        free(asciivalue);
        return (dst - s - 1);   /* size of put data except trailing '\0' */

e2big_error:
        errno = E2BIG;
        goto end_error;

format_error:
        errno = EINVAL;

end_error:
        sverrno = errno;
        if (asciivalue != NULL)
                free(asciivalue);
        errno = sverrno;
        return (-1);
}

ssize_t
strfmon(char *_RESTRICT_KYWD s, size_t maxsize,
    const char *_RESTRICT_KYWD format, ...)
{
        va_list ap;
        ssize_t ret;

        va_start(ap, format);
        ret = strfmon_impl(s, maxsize, uselocale(NULL), format, ap);
        va_end(ap);
        return (ret);
}

ssize_t
strfmon_l(char *_RESTRICT_KYWD s, size_t maxsize, locale_t loc,
    const char *_RESTRICT_KYWD format, ...)
{
        ssize_t ret;
        va_list ap;
        va_start(ap, format);
        ret = strfmon_impl(s, maxsize, loc, format, ap);
        va_end(ap);
        return (ret);
}

static void
setup_vars(const struct lc_monetary *lmon, int flags, char *cs_precedes,
    char *sep_by_space, char *sign_posn, const char **signstr)
{
        if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
                *cs_precedes = lmon->int_n_cs_precedes[0];
                *sep_by_space = lmon->int_n_sep_by_space[0];
                *sign_posn = (flags & PARENTH_POSN) ? 0 :
                    lmon->int_n_sign_posn[0];
                *signstr = (lmon->negative_sign[0] == '\0') ? "-" :
                    lmon->negative_sign;
        } else if (flags & USE_INTL_CURRENCY) {
                *cs_precedes = lmon->int_p_cs_precedes[0];
                *sep_by_space = lmon->int_p_sep_by_space[0];
                *sign_posn = (flags & PARENTH_POSN) ? 0 :
                    lmon->int_p_sign_posn[0];
                *signstr = lmon->positive_sign;
        } else if (flags & IS_NEGATIVE) {
                *cs_precedes = lmon->n_cs_precedes[0];
                *sep_by_space = lmon->n_sep_by_space[0];
                *sign_posn = (flags & PARENTH_POSN) ? 0 : lmon->n_sign_posn[0];
                *signstr = (lmon->negative_sign[0] == '\0') ? "-" :
                    lmon->negative_sign;
        } else {
                *cs_precedes = lmon->p_cs_precedes[0];
                *sep_by_space = lmon->p_sep_by_space[0];
                *sign_posn = (flags & PARENTH_POSN) ? 0 : lmon->p_sign_posn[0];
                *signstr = lmon->positive_sign;
        }

        /* Set default values for unspecified information. */
        if (*cs_precedes != 0)
                *cs_precedes = 1;
        if (*sep_by_space == CHAR_MAX)
                *sep_by_space = 0;
        if (*sign_posn == CHAR_MAX)
                *sign_posn = 0;
}

static int
calc_left_pad(const struct lc_monetary *lmon, int flags, const char *cur_symb)
{
        char cs_precedes, sep_by_space, sign_posn;
        const char *signstr;
        int left_chars = 0;

        setup_vars(lmon, flags, &cs_precedes, &sep_by_space, &sign_posn,
            &signstr);

        if (cs_precedes != 0) {
                left_chars += strlen(cur_symb);
                if (sep_by_space != 0)
                        left_chars++;
        }

        switch (sign_posn) {
                case 1:
                        left_chars += strlen(signstr);
                        break;
                case 3:
                case 4:
                        if (cs_precedes != 0)
                                left_chars += strlen(signstr);
        }
        return (left_chars);
}

static int
get_groups(int size, const char *grouping)
{

        int     chars = 0;

        if (*grouping == CHAR_MAX || *grouping <= 0)    /* no grouping ? */
                return (0);

        while (size > (int)*grouping) {
                chars++;
                size -= (int)*grouping++;
                /* no more grouping ? */
                if (*grouping == CHAR_MAX)
                        break;
                /* rest grouping with same value ? */
                if (*grouping == 0) {
                        chars += (size - 1) / *(grouping - 1);
                        break;
                }
        }
        return (chars);
}

/* convert double to ASCII */
static char *
format_grouped_double(const struct lc_monetary *lmon,
    const struct lc_numeric *lnum,
    double value, int *flags, int left_prec, int right_prec, int pad_char)
{

        char            *rslt;
        char            *avalue;
        int             avalue_size;
        char            fmt[32];

        size_t          bufsize;
        char            *bufend;

        int             padded;

        const char      *grouping;
        const char      *decimal_point;
        const char      *thousands_sep;
        int             decimal_len;
        int             thousands_len;

        int groups = 0;

        grouping = lmon->mon_grouping;
        decimal_point = lmon->mon_decimal_point;
        if (*decimal_point == '\0')
                decimal_point = lnum->decimal_point;
        thousands_sep = lmon->mon_thousands_sep;
        if (*thousands_sep == '\0')
                thousands_sep = lnum->thousands_sep;

        decimal_len = strlen(decimal_point);    /* usually 1 */
        thousands_len = strlen(thousands_sep);  /* 0 or 1 usually */

        /* fill left_prec with default value */
        if (left_prec == -1)
                left_prec = 0;

        /* fill right_prec with default value */
        if (right_prec == -1) {
                if (*flags & USE_INTL_CURRENCY)
                        right_prec = lmon->int_frac_digits[0];
                else
                        right_prec = lmon->frac_digits[0];

                if (right_prec == CHAR_MAX)     /* POSIX locale ? */
                        right_prec = 2;
        }

        if (*flags & NEED_GROUPING)
                left_prec += get_groups(left_prec, grouping);

        /* convert to string */
        (void) snprintf(fmt, sizeof (fmt), "%%%d.%df",
            left_prec + right_prec + 1, right_prec);
        avalue_size = asprintf(&avalue, fmt, value);
        if (avalue_size < 0)
                return (NULL);

        /*
         * Make sure that we've enough space for result string.
         * This assumes that digits take up at least much space as
         * grouping and radix characters.  The worst case currently known
         * is for Arabic, where two-byte UTF-8 sequences are used for both
         * decimal and thousands seperators, and groups can be a small as two
         * decimal digits.  This will do no worse than doubling the storage
         * requirement.
         */
        bufsize = strlen(avalue)*2+1;
        rslt = calloc(1, bufsize);
        if (rslt == NULL) {
                free(avalue);
                return (NULL);
        }
        bufend = rslt + bufsize - 1;    /* reserve space for trailing '\0' */

        /* skip spaces at beginning */
        padded = 0;
        while (avalue[padded] == ' ') {
                padded++;
                avalue_size--;
        }

        if (right_prec > 0) {
                bufend -= right_prec;
                (void) memcpy(bufend, avalue + avalue_size+padded-right_prec,
                    right_prec);
                bufend -= decimal_len;
                (void) memcpy(bufend, decimal_point, decimal_len);
                avalue_size -= (right_prec + decimal_len);
        }

        if ((*flags & NEED_GROUPING) &&
            thousands_len != 0 &&
            *grouping != CHAR_MAX &&
            *grouping > 0) {
                while (avalue_size > (int)*grouping) {
                        GRPCPY(*grouping);
                        GRPSEP;
                        grouping++;

                        /* no more grouping ? */
                        if (*grouping == CHAR_MAX)
                                break;

                        /* rest grouping with same value ? */
                        if (*grouping == 0) {
                                grouping--;
                                while (avalue_size > *grouping) {
                                        GRPCPY(*grouping);
                                        GRPSEP;
                                }
                        }
                }
                if (avalue_size != 0)
                        GRPCPY(avalue_size);
                padded -= groups;

        } else {
                bufend -= avalue_size;
                (void) memcpy(bufend, avalue+padded, avalue_size);
                if (right_prec == 0)
                        padded--;       /* decrease assumed $decimal_point */
        }

        /* do padding with pad_char */
        if (padded > 0) {
                bufend -= padded;
                (void) memset(bufend, pad_char, padded);
        }

        bufsize = bufsize - (bufend - rslt) + 1;
        (void) memmove(rslt, bufend, bufsize);
        free(avalue);
        return (rslt);
}