/* -*-comment-start: "//";comment-end:""-*-
 * Mes --- Maxwell Equations of Software
 * Copyright © 2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
 * Copyright (C) 2018 Han-Wen Nienhuys <hanwen@xs4all.nl>
 *
 * This file is part of Mes.
 *
 * Mes is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or (at
 * your option) any later version.
 *
 * Mes is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Mes.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <setjmp.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>

#include <libc.c>

#if __MESC__

#include <linux+tcc-mes.c>
#include <libc+tcc-mes.c>

#else // !__MESC__

#include <linux+tcc-gcc.c>
#include <libc+tcc-gcc.c>

#endif // !__MESC__

int
dlclose (void *handle)
{
  return 0;
}

void *
dlopen (char const *filename, int flags)
{
  return 0;
}

int
execvp (char const *file, char *const argv[])
{
  eputs ("execvp stub\n");
  return 0;
}

int
fclose (FILE *stream)
{
  int fd = (int)stream;
  return close (fd);
}

FILE *
fdopen (int fd, char const *mode)
{
  return (FILE*)fd;
}

int
ferror (FILE *stream)
{
  int fd = (int)stream;
  if (fd == -1) return -1;
  return 0;
}

int
fflush (FILE *stream)
{
  return 0;
}

int
fprintf (FILE *stream, char const *format, ...)
{
  va_list ap;
  va_start (ap, format);
  int r = vfprintf (stream, format, ap);
  va_end (ap);
  return r;
}

size_t
fread (void *data, size_t size, size_t count, FILE *stream)
{
  if (! size || !count)
    return 0;
  int bytes = read ((int)stream, data, size * count);
  if (bytes > 0)
    return bytes/size;

  return bytes;
}

long
ftell (FILE *stream)
{
  return lseek ((int)stream, 0, SEEK_CUR);
}

int
fseek (FILE *stream, long offset, int whence)
{
  int pos = lseek ((int)stream, offset, whence);
  if (pos >= 0)
    return 0;
  return -1;
}

int
gettimeofday (struct timeval *tv, struct timezone *tz)
{
  return 0;
}

double
ldexp (double x, int exp)
{
  eputs ("ldexp stub\n");
  return 0;
}

struct tm *
localtime (time_t const *timep)
{
  eputs ("localtime stub\n");
  return 0;
}

void *
memmove (void *dest, void const *src, size_t n)
{
  if (dest < src)
    return memcpy (dest, src, n);
  char *p = dest + n;
  char const *q = src +n;
  while (n--)
    *--p = *--q;
  return dest;
}

void *
memset (void *s, int c, size_t n)
{
  char *p = s;
  while (n--) *p++ = c;
  return s;
}

int
memcmp (void const *s1, void const *s2, size_t n)
{
  char *a = s1;
  char *b = s2;
  while (*a == *b && --n) {a++;b++;}
  return *a - *b;
}

int
mprotect (void *addr, size_t len, int prot)
{
  return 0;
}

void
qswap (void *a, void *b, size_t size)
{
  char *buf[8];
  memcpy (buf, a, size);
  memcpy (a, b, size);
  memcpy (b, buf, size);
}

size_t
qpart (void *base, size_t count, size_t size, int (*compare)(void const *, void const *))
{
  void* p = base + count*size;
  size_t i = 0;
  for (size_t j = 0; j < count; j++)
    {
      if (compare (base+j*size, p) < 0)
        {
          qswap (base+i*size, base+j*size, size);
          i++;
        }
    }
  if (compare (base+count*size, base+i*size) < 0)
    qswap (base+i*size, base+count*size, size);
  return i;
}

void
qsort (void *base, size_t count, size_t size, int (*compare)(void const *, void const *))
{
  if (count > 1)
    {
      int p = qpart (base, count-1, size, compare);
      qsort (base, p, size, compare);
      qsort (base+p*size, count-p, size, compare);
    }
}

int
remove (char const *file_name)
{
  struct stat buf;
  if (stat (file_name, &buf) < 0)
    return -1;
  if (S_ISDIR (buf.st_mode))
    return rmdir (file_name);
  return unlink (file_name);
}

int
sigaction (int signum, struct sigaction const *act, struct sigaction *oldact)
{
  return 0;
}

int
sigemptyset (sigset_t *set)
{
  return 0;
}

int
snprintf(char *str,  size_t size,  char const *format, ...)
{
  va_list ap;
  va_start (ap, format);
  int r = vsprintf (str, format, ap);
  va_end (ap);
  return r;
}

int
sscanf (char const *str, const char *template, ...)
{
  va_list ap;
  va_start (ap, template);
  int r = vsscanf (str, template, ap);
  va_end (ap);
  return r;
  return 0;
}

char *
strcat (char *to, char const *from)
{
  char *p = strchr (to, '\0');
  while (*from)
    *p++ = *from++;
  *p = 0;
  return to;
}

char *
strchr (char const *s, int c)
{
  char const *p = s;
  while (*p || !c)
    {
      if (c == *p)
        return p;
      *p++;
    }
  return 0;
}

char *
strncpy (char *dest, char const *src, size_t length)
{
  char *p = dest;
  while (*src && length--)
    *p++ = *src++;
  if (*src)
    length++;
  while (length--)
    *p++ = 0;
  return dest;
}

char *
strrchr (char const *s, int c)
{
  int n = strlen (s);
  if (!n) return 0;
  char const *p = s + n - 1;
  while (*p || !c)
    {
      if (c == *p) return p;
      *p--;
    }
  return 0;
}

/** locate a substring. #memmem# finds the first occurrence of
    #needle# in #haystack#.  This is not ANSI-C.

    The prototype is not in accordance with the Linux Programmer's
    Manual v1.15, but it is with /usr/include/string.h   */

unsigned char *
_memmem (unsigned char const *haystack, int haystack_len,
         unsigned char const *needle, int needle_len)
{
  unsigned char const *end_haystack = haystack + haystack_len - needle_len + 1;
  unsigned char const *end_needle = needle + needle_len;

  /* Ahhh ... Some minimal lowlevel stuff. This *is* nice; Varation
     is the spice of life */
  while (haystack < end_haystack)
    {
      unsigned char const *subneedle = needle;
      unsigned char const *subhaystack = haystack;
      while (subneedle < end_needle)
        if (*subneedle++ != *subhaystack++)
          goto next;

      /* Completed the needle.  Gotcha.  */
      return (unsigned char *) haystack;
    next:
      haystack++;
    }
  return 0;
}

void *
memmem (void const *haystack, int haystack_len,
        void const *needle, int needle_len)
{
  unsigned char const *haystack_byte_c = (unsigned char const *)haystack;
  unsigned char const *needle_byte_c = (unsigned char const *)needle;
  return _memmem (haystack_byte_c, haystack_len, needle_byte_c, needle_len);
}

char *
strstr (char const *haystack, char const *needle)
{
  return memmem (haystack, strlen (haystack), needle, strlen (needle));
}

double
strtod (char const *nptr, char **endptr)
{
  eputs ("strtod stub\n");
}

float
strtof (char const *nptr, char **endptr)
{
  return strtod (nptr, endptr);
}

long double
strtold (char const *nptr, char **endptr)
{
  return strtod (nptr, endptr);
}

long
strtol (char const *nptr, char **endptr, int base)
{
  if (!strncmp (nptr, "0x", 2))
    {
      char const *p = nptr + 2;
      return abtoi (&p, 16);
    }
  return abtoi (&nptr, base);
}

long long int
strtoll (char const *nptr, char **endptr, int base)
{
  eputs ("strtoll stub\n");
  return 0;
}

unsigned long
strtoul (char const *nptr, char **endptr, int base)
{
  eputs ("strtoul stub\n");
  return 0;
}

unsigned long long
strtoull (char const *p, char **endptr, int base)
{
  *endptr = p;
  return abtoi (endptr, base);
}

time_t time (time_t *tloc)
{
  return 0;
}

int
vsnprintf (char *str, size_t size, char const *format, va_list ap)
{
  return vsprintf (str, format, ap);
}

void *
calloc (size_t nmemb, size_t size)
{
  size_t count = nmemb * size;
  void *p = malloc (count);
  memset (p, 0, count);
  return p;
}

int
vfprintf (FILE* f, char const* format, va_list ap)
{
  int fd = (int)f;
  char const *p = format;
  while (*p)
    if (*p != '%')
      fputc (*p++, fd);
    else
      {
        p++;
        char c = *p;
        switch (c)
          {
          case '%': {fputc (*p, fd); break;}
          case 'c': {char c; c = va_arg (ap, char); fputc (c, fd); break;}
          case 'd': {int d; d = va_arg (ap, int); fputs (itoa (d), fd); break;}
          case 's': {char *s; s = va_arg (ap, char *); fputs (s, fd); break;}
          default:
            {
              eputs ("vfprintf: not supported: %");
              eputc (c);
              eputs ("\n");
              p++;
            }
          }
        p++;
      }
  va_end (ap);
  return 0;
}

int
vprintf (char const* format, va_list ap)
{
  return vfprintf (STDOUT, format, ap);
}

int
vsscanf (char const *s, char const *template, va_list ap)
{
  char const *p = s;
  char const *t = template;
  while (*t && *p)
    if (*t != '%')
      {
        t++;
        p++;
      }
    else
      {
        t++;
        char c = *t;
        switch (c)
          {
          case '%': {p++; break;}
          case 'c': {char *c = va_arg (ap, char*); *c = *p++; break;}
          case 'd':
          case 'i':
          case 'u': {int *d = va_arg (ap, int*); *d = abtoi (&p, 10); break;}
          default:
            {
              eputs ("vsscanf: not supported: %");
              eputc (c);
              eputs ("\n");
              t++;
              p++;
            }
          }
        t++;
      }
  va_end (ap);
  return 0;
}

int
vsprintf (char *str, char const* format, va_list ap)
{
  char const *p = format;
  while (*p)
    if (*p != '%')
      *str++ = *p++;
    else
      {
        p++;
        char c = *p;
        int left_p = 0;
        int width = -1;
        if (c == '-')
          {
            left_p = 1;
            c = *++p;
          }
        char pad = ' ';
        if (c == '0')
          {
            pad = c;
            c = *p++;
          }
        if (c >= '0' && c <= '9')
          {
            width = abtoi (&p, 10);
            c = *p;
          }
        switch (c)
          {
          case '%': {*str++ = *p; break;}
          case 'c': {char c; c = va_arg (ap, char); *str++ = c; break;}
          case 'd':
          case 'i':
          case 'u':
            {
              int d = va_arg (ap, int);
              char const *s = itoa (d);
              if (width >= 0)
                width = width - strlen (s);
              if (!left_p)
                while (width-- > 0)
                  *str++ = pad;
              while (*s)
                *str++ = *s++;
              while (width-- > 0)
                *str++ = pad;
              break;
            }
          case 's': {char *s; s = va_arg (ap, char *); while (*s) *str++ = *s++; break;}
          default:
            {
              eputs ("vsprintf: not supported: %");
              eputc (c);
              eputs ("\n");
              p++;
            }
          }
        p++;
      }
  va_end (ap);
  *str = 0;
  return strlen (str);
}

int
sprintf (char *str, char const* format, ...)
{
  va_list ap;
  va_start (ap, format);
  int r = vsprintf (str, format, ap);
  va_end (ap);
  return r;
}

int
printf (char const* format, ...)
{
  va_list ap;
  va_start (ap, format);
  int r = vprintf (format, ap);
  va_end (ap);
  return r;
}