#include "locale_impl.h"
#include <ctype.h>
#include <errno.h>
#include <monetary.h>
#include <stdarg.h>
#include <stdio.h>

static ssize_t vstrfmon_l(char* s, size_t n, locale_t loc, const char* fmt, va_list ap) {
    size_t l;
    double x;
    int left;
    int lp, rp, w, fw;
    char* s0 = s;
    for (; n && *fmt;) {
        if (*fmt != '%') {
        literal:
            *s++ = *fmt++;
            n--;
            continue;
        }
        fmt++;
        if (*fmt == '%')
            goto literal;

        left = 0;
        for (;; fmt++) {
            switch (*fmt) {
            case '=':
                ++fmt;
                continue;
            case '^':
                continue;
            case '(':
            case '+':
                continue;
            case '!':
                continue;
            case '-':
                left = 1;
                continue;
            }
            break;
        }

        for (fw = 0; isdigit(*fmt); fmt++)
            fw = 10 * fw + (*fmt - '0');
        lp = 0;
        rp = 2;
        if (*fmt == '#')
            for (lp = 0, fmt++; isdigit(*fmt); fmt++)
                lp = 10 * lp + (*fmt - '0');
        if (*fmt == '.')
            for (rp = 0, fmt++; isdigit(*fmt); fmt++)
                rp = 10 * rp + (*fmt - '0');

        w = lp + 1 + rp;
        if (!left && fw > w)
            w = fw;

        x = va_arg(ap, double);
        l = snprintf(s, n, "%*.*f", w, rp, x);
        if (l >= n) {
            errno = E2BIG;
            return -1;
        }
        s += l;
        n -= l;
    }
    return s - s0;
}

ssize_t strfmon_l(char* restrict s, size_t n, locale_t loc, const char* restrict fmt, ...) {
    va_list ap;
    ssize_t ret;

    va_start(ap, fmt);
    ret = vstrfmon_l(s, n, loc, fmt, ap);
    va_end(ap);

    return ret;
}

ssize_t strfmon(char* restrict s, size_t n, const char* restrict fmt, ...) {
    va_list ap;
    ssize_t ret;

    va_start(ap, fmt);
    ret = vstrfmon_l(s, n, CURRENT_LOCALE, fmt, ap);
    va_end(ap);

    return ret;
}