// Orginal source:
// https://git.musl-libc.org/cgit/musl/tree/src/monetary/strfmon.c
//
// ----------------------------------------------------------------------
// Copyright © 2005-2020 Rich Felker, et al.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// ----------------------------------------------------------------------

#include <libc.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdarg.h>
#include <monetary.h>

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

		fill = ' ';
		nogrp = 0;
		negpar = 0;
		nosym = 0;
		left = 0;
		for (;; fmt++) {
			switch (*fmt) {
			case '=':
				fill = *++fmt;
				continue;
			case '^':
				nogrp = 1;
				continue;
			case '(':
				negpar = 1;
			case '+':
				continue;
			case '!':
				nosym = 1;
				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');

		intl = *fmt++ == 'i';

		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(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, fmt, ap);
	va_end(ap);

	return ret;
}

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

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

	return ret;
}