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

#include "locale_impl.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;
}