/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * Copyright (©) 2002,2007 Mark Wedel & Crossfire Development Team
 * Copyright (©) 1992,2007 Frank Tore Johansen
 * 
 * Deliantra is free software: you can redistribute it and/or modify it under
 * the terms of the Affero GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program 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 Affero GNU General Public License
 * and the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <support@deliantra.net>
 */

/*
 * General convenience functions for crossfire.
 */

#include <cstdlib>
#include <sys/types.h>
#include <unistd.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>

#include <global.h>
#include <material.h>
#include <object.h>

#include <sys/time.h>
#include <sys/resource.h>

#include <glib.h>

refcnt_base::refcnt_t refcnt_dummy;
ssize_t slice_alloc;
rand_gen rndm, rmg_rndm;

void
tausworthe_random_generator::seed (uint32_t seed)
{
  state [0] = seed      * 69069U; if (state [0] <   2U) state [0] +=   2U;
  state [1] = state [0] * 69069U; if (state [0] <   8U) state [0] +=   8U;
  state [2] = state [1] * 69069U; if (state [0] <  16U) state [0] +=  16U;
  state [3] = state [2] * 69069U; if (state [0] < 128U) state [0] += 128U;

  for (int i = 11; --i; )
    next ();
}

uint32_t
tausworthe_random_generator::next ()
{
  state [0] = ((state [0] & 0xFFFFFFFEU) << 18U) ^ (((state [0] <<  6U) ^ state [0]) >> 13U);
  state [1] = ((state [1] & 0xFFFFFFF8U) <<  2U) ^ (((state [1] <<  2U) ^ state [1]) >> 27U);
  state [2] = ((state [2] & 0xFFFFFFF0U) <<  7U) ^ (((state [2] << 13U) ^ state [2]) >> 21U);
  state [3] = ((state [3] & 0xFFFFFF80U) << 13U) ^ (((state [3] <<  3U) ^ state [3]) >> 12U);

  return state [0] ^ state [1] ^ state [2] ^ state [3];
}

template<class generator>
uint32_t
random_number_generator<generator>::get_range (uint32_t num)
{
  return (this->next () * (uint64_t)num) >> 32U;
}

// return a number within (min .. max)
template<class generator>
int 
random_number_generator<generator>::get_range (int r_min, int r_max)
{
  return r_min + get_range (max (r_max - r_min + 1, 0));
}

template struct random_number_generator<tausworthe_random_generator>;
template struct random_number_generator<xorshift_random_generator>;

/*
 * The random functions here take luck into account when rolling random
 * dice or numbers.  This function has less of an impact the larger the
 * difference becomes in the random numbers.  IE, the effect is lessened
 * on a 1-1000 roll, vs a 1-6 roll.  This can be used by crafty programmers,
 * to specifically disable luck in certain rolls, simply by making the
 * numbers larger (ie, 1d1000 > 500 vs 1d6 > 3)
 */

/*
 * Roll a random number between min and max.  Uses op to determine luck,
 * and if goodbad is non-zero, luck increases the roll, if zero, it decreases.
 * Generally, op should be the player/caster/hitter requesting the roll,
 * not the recipient (ie, the poor slob getting hit). [garbled 20010916]
 */
int
random_roll (int r_min, int r_max, const object *op, int goodbad)
{
  r_max = max (r_min, r_max);

  int base = r_max - r_min > 1 ? 20 : 50;     /* d2 and d3 are corner cases */

  if (op->type == PLAYER)
    {
      int luck = op->stats.luck;

      if (rndm (base) < min (10, abs (luck)))
        {
          //TODO: take luck into account
        }
    }

  return rndm (r_min, r_max);
}

/*
 * This is a 64 bit version of random_roll above.  This is needed
 * for exp loss calculations for players changing religions.
 */
sint64
random_roll64 (sint64 r_min, sint64 r_max, const object *op, int goodbad)
{
  sint64 omin = r_min;
  sint64 range = max (0, r_max - r_min + 1);
  int base = range > 2 ? 20 : 50;     /* d2 and d3 are corner cases */

  /* 
   * Make a call to get two 32 bit unsigned random numbers, and just to
   * a little bitshifting.
   */
  sint64 ran = (sint64) rndm.next () ^ ((sint64) rndm.next () << 31);

  if (op->type != PLAYER)
    return ((ran % range) + r_min);

  int luck = op->stats.luck;

  if (rndm (base) < min (10, abs (luck)))
    {
      /* we have a winner */
      ((luck > 0) ? (luck = 1) : (luck = -1));
      range -= luck;
      if (range < 1)
        return (omin);          /*check again */

      ((goodbad) ? (r_min += luck) : (range));

      return (max (omin, min (r_max, (ran % range) + r_min)));
    }

  return ran % range + r_min;
}

/*
 * Roll a number of dice (2d3, 4d6).  Uses op to determine luck,
 * If goodbad is non-zero, luck increases the roll, if zero, it decreases.
 * Generally, op should be the player/caster/hitter requesting the roll,
 * not the recipient (ie, the poor slob getting hit).
 * The args are num D size (ie 4d6)  [garbled 20010916]
 */
int
die_roll (int num, int size, const object *op, int goodbad)
{
  int min, luck, total, i, gotlucky;

  int diff = size;
  min = 1;
  luck = total = gotlucky = 0;
  int base = diff > 2 ? 20 : 50;     /* d2 and d3 are corner cases */

  if (size < 2 || diff < 1)
    {
      LOG (llevError, "Calling die_roll with num=%d size=%d\n", num, size);
      return num;             /* avoids a float exception */
    }

  if (op->type == PLAYER)
    luck = op->stats.luck;

  for (i = 0; i < num; i++)
    {
      if (rndm (base) < MIN (10, abs (luck)) && !gotlucky)
        {
          /* we have a winner */
          gotlucky++;
          ((luck > 0) ? (luck = 1) : (luck = -1));
          diff -= luck;
          if (diff < 1)
            return (num);       /*check again */
          ((goodbad) ? (min += luck) : (diff));
          total += MAX (1, MIN (size, rndm (diff) + min));
        }
      else
        total += rndm (size) + 1;
    }

  return total;
}

/* convert materialname to materialtype_t */

materialtype_t *
name_to_material (const shstr_cmp name)
{
  for (materialtype_t *mt = materialt; mt; mt = mt->next)
    if (name == mt->name)
      return mt;

  return 0;
}

/* when doing transmutation of objects, we have to recheck the resistances,
 * as some that did not apply previously, may apply now.
 */
void
transmute_materialname (object *op, const object *change)
{
  materialtype_t *mt;
  int j;

  if (!op->materialname)
    return;

  if (op->materialname != change->materialname)
    return;

  if (!op->is_armor ())
    return;

  mt = name_to_material (op->materialname);
  if (!mt)
    {
      LOG (llevError, "archetype '%s>%s' uses nonexistent material '%s'\n", &op->arch->archname, &op->name, &op->materialname);
      return;
    }

  for (j = 0; j < NROFATTACKS; j++)
    if (op->resist[j] == 0 && change->resist[j] != 0)
      {
        op->resist[j] += mt->mod[j];
        if (op->resist[j] > 100)
          op->resist[j] = 100;
        if (op->resist[j] < -100)
          op->resist[j] = -100;
      }
}

/* set the materialname and type for an item */
void
set_materialname (object *op, int difficulty, materialtype_t *nmt)
{
  materialtype_t *mt, *lmt;

  if (!op->materialname)
    return;

  if (nmt)
    lmt = nmt;
  else
    {
      lmt = 0;

      for (mt = materialt; mt; mt = mt->next)
        if (op->materials & mt->material && rndm (1, 100) <= mt->chance &&
            difficulty >= mt->difficulty && (op->magic >= mt->magic || mt->magic == 0))
          {
            lmt = mt;
            if (!(op->is_weapon () || op->is_armor ()))
              break;
          }
    }

  if (lmt)
    {
      if (op->stats.dam && op->is_weapon ())
        {
          op->stats.dam += lmt->damage;
          if (op->stats.dam < 1)
            op->stats.dam = 1;
        }

      if (op->stats.sp && op->type == BOW)
        op->stats.sp += lmt->sp;
      if (op->stats.wc && op->is_weapon ())
        op->stats.wc += lmt->wc;
      if (op->is_armor ())
        {
          if (op->stats.ac)
            op->stats.ac += lmt->ac;

          for (int j = 0; j < NROFATTACKS; j++)
            if (op->resist[j] != 0)
              {
                op->resist[j] += lmt->mod[j];
                if (op->resist[j] > 100)
                  op->resist[j] = 100;
                if (op->resist[j] < -100)
                  op->resist[j] = -100;
              }
        }

      op->materialname = lmt->name;
      /* dont make it unstackable if it doesn't need to be */
      if (op->is_weapon () || op->is_armor ())
        {
          op->weight = (op->weight * lmt->weight) / 100;
          op->value = (op->value * lmt->value) / 100;
        }
    }
}

/*
 * Strip out the media tags from a String.
 * Warning the input string will contain the result string
 */
void
strip_media_tag (char *message)
{
  int in_tag = 0;
  char *dest;
  char *src;

  src = dest = message;
  while (*src != '\0')
    {
      if (*src == '[')
        {
          in_tag = 1;
        }
      else if (in_tag && (*src == ']'))
        in_tag = 0;
      else if (!in_tag)
        {
          *dest = *src;
          dest++;
        }
      src++;
    }
  *dest = '\0';
}

const char *
strrstr (const char *haystack, const char *needle)
{
  const char *lastneedle;

  lastneedle = NULL;
  while ((haystack = strstr (haystack, needle)) != NULL)
    {
      lastneedle = haystack;
      haystack++;
    }
  return lastneedle;

}

#define EOL_SIZE (sizeof("\n")-1)
void
strip_endline (char *buf)
{
  if (strlen (buf) < sizeof ("\n"))
    {
      return;
    }
  if (!strcmp (buf + strlen (buf) - EOL_SIZE, "\n"))
    buf[strlen (buf) - EOL_SIZE] = '\0';
}

/**
 * Replace in string src all occurrences of key by replacement. The resulting
 * string is put into result; at most resultsize characters (including the
 * terminating null character) will be written to result.
 */
void
replace (const char *src, const char *key, const char *replacement, char *result, size_t resultsize)
{
  size_t resultlen;
  size_t keylen;

  /* special case to prevent infinite loop if key==replacement=="" */
  if (strcmp (key, replacement) == 0)
    {
      snprintf (result, resultsize, "%s", src);
      return;
    }

  keylen = strlen (key);

  resultlen = 0;
  while (*src != '\0' && resultlen + 1 < resultsize)
    {
      if (strncmp (src, key, keylen) == 0)
        {
          snprintf (result + resultlen, resultsize - resultlen, "%s", replacement);
          resultlen += strlen (result + resultlen);
          src += keylen;
        }
      else
        {
          result[resultlen++] = *src++;
        }
    }
  result[resultlen] = '\0';
}

/******************************************************************************/

/* Checks a player-provided string which will become the msg property of
 * an object for dangerous input.
 */
bool 
msg_is_safe (const char *msg)
{
  bool safe = true;

  /* Trying to cheat by getting data into the object */
  if (!strncmp (msg, "endmsg", sizeof ("endmsg") - 1)
      || strstr (msg, "\nendmsg"))
    safe = false;

  /* Trying to make the object talk, and potentially access arbitrary code */
  if (object::msg_has_dialogue (msg))
    safe = false;

  return safe;
}

/////////////////////////////////////////////////////////////////////////////

void
fork_abort (const char *msg)
{
  if (!fork ())
    {
      signal (SIGINT , SIG_IGN);
      signal (SIGTERM, SIG_IGN);
      signal (SIGABRT, SIG_IGN);

      signal (SIGSEGV, SIG_DFL);
      signal (SIGBUS , SIG_DFL);
      signal (SIGILL , SIG_DFL);
      signal (SIGTRAP, SIG_DFL);

      // try to put corefiles into a subdirectory, if existing, to allow
      // an administrator to reduce the I/O load.
      chdir ("cores");

      // try to detach us from as many external dependencies as possible
      // as coredumping can take time by closing all fd's.
      {
        struct rlimit lim;

        if (getrlimit (RLIMIT_NOFILE, &lim))
          lim.rlim_cur = 1024;

        for (int i = 0; i < lim.rlim_cur; ++i)
          close (i);
      }

      {
        sigset_t empty;
        sigemptyset (&empty);
        sigprocmask (SIG_SETMASK, &empty, 0);
      }

      // try to coredump with SIGTRAP
      kill (getpid (), SIGTRAP);
      abort ();
    }

  LOG (llevError, "fork abort: %s\n", msg);
}

void *salloc_ (int n) throw (std::bad_alloc)
{
  void *ptr = g_slice_alloc (n);

  if (!ptr)
    throw std::bad_alloc ();

  slice_alloc += n;
  return ptr;
}

void *salloc_ (int n, void *src) throw (std::bad_alloc)
{
  void *ptr = salloc_ (n);

  if (src)
    memcpy (ptr, src, n);
  else
    memset (ptr, 0, n);

  return ptr;
}

/******************************************************************************/

#if DEBUG_SALLOC

#define MAGIC 0xa1b2c35543deadLL

void *g_slice_alloc (unsigned long size)
{
  unsigned long *p = (unsigned long *) (g_slice_alloc)(size + sizeof (unsigned long));
  *p++ = size ^ MAGIC;
  //fprintf (stderr, "g_slice_alloc %ld %p\n", size, p);//D
  return (void *)p;
}

void *g_slice_alloc0 (unsigned long size)
{
  return memset (g_slice_alloc (size), 0, size);
}

void g_slice_free1 (unsigned long size, void *ptr)
{
  //fprintf (stderr, "g_slice_free %ld %p\n", size, ptr);//D
  if (expect_true (ptr))
    {
      unsigned long *p = (unsigned long *)ptr;
      unsigned long s = *--p ^ MAGIC;

      if (size != (unsigned long)(*p ^ MAGIC))
        {
          LOG (logBacktrace | llevError, "slice free size (%lx) doesn't match alloc size (%lx)\n", size, s);
          abort ();
        }

      *p = MAGIC;

      (g_slice_free1)(s + sizeof (unsigned long), p);
    }
}

#endif

/******************************************************************************/

int
assign (char *dst, const char *src, int maxsize)
{
  if (!src)
    src = "";

  int len = strlen (src);

  if (len >= maxsize)
    {
      if (maxsize <= 4)
        {
          memset (dst, '.', maxsize - 2);
          dst [maxsize - 1] = 0;
        }
      else
        {
          memcpy (dst, src, maxsize - 4);
          memcpy (dst + maxsize - 4, "...", 4);
        }

      len = maxsize;
    }
  else
    memcpy (dst, src, ++len);

  return len;
}

char *
vformat (const char *format, va_list ap)
{
  static dynbuf_text buf; buf.clear ();
  buf.vprintf (format, ap);
  return buf;
}

char *
format (const char *format, ...)
{
  va_list ap;
  va_start (ap, format);
  char *buf = vformat (format, ap);
  va_end (ap);

  return buf;
}

tstamp now ()
{
  struct timeval tv;

  gettimeofday (&tv, 0);
  return tstamp (tv.tv_sec) + tstamp (tv.tv_usec) * tstamp (1e-6);
}

int
similar_direction (int a, int b)
{
  if (!a || !b)
    return 0;

  int diff = (b - a) & 7;
  return diff <= 1 || diff >= 7;
}

/* crc32 0xdebb20e3 table and supplementary functions.  */
extern const uint32_t crc_32_tab[256] =
{
    0x00000000UL, 0x77073096UL, 0xee0e612cUL, 0x990951baUL, 0x076dc419UL,
    0x706af48fUL, 0xe963a535UL, 0x9e6495a3UL, 0x0edb8832UL, 0x79dcb8a4UL,
    0xe0d5e91eUL, 0x97d2d988UL, 0x09b64c2bUL, 0x7eb17cbdUL, 0xe7b82d07UL,
    0x90bf1d91UL, 0x1db71064UL, 0x6ab020f2UL, 0xf3b97148UL, 0x84be41deUL,
    0x1adad47dUL, 0x6ddde4ebUL, 0xf4d4b551UL, 0x83d385c7UL, 0x136c9856UL,
    0x646ba8c0UL, 0xfd62f97aUL, 0x8a65c9ecUL, 0x14015c4fUL, 0x63066cd9UL,
    0xfa0f3d63UL, 0x8d080df5UL, 0x3b6e20c8UL, 0x4c69105eUL, 0xd56041e4UL,
    0xa2677172UL, 0x3c03e4d1UL, 0x4b04d447UL, 0xd20d85fdUL, 0xa50ab56bUL,
    0x35b5a8faUL, 0x42b2986cUL, 0xdbbbc9d6UL, 0xacbcf940UL, 0x32d86ce3UL,
    0x45df5c75UL, 0xdcd60dcfUL, 0xabd13d59UL, 0x26d930acUL, 0x51de003aUL,
    0xc8d75180UL, 0xbfd06116UL, 0x21b4f4b5UL, 0x56b3c423UL, 0xcfba9599UL,
    0xb8bda50fUL, 0x2802b89eUL, 0x5f058808UL, 0xc60cd9b2UL, 0xb10be924UL,
    0x2f6f7c87UL, 0x58684c11UL, 0xc1611dabUL, 0xb6662d3dUL, 0x76dc4190UL,
    0x01db7106UL, 0x98d220bcUL, 0xefd5102aUL, 0x71b18589UL, 0x06b6b51fUL,
    0x9fbfe4a5UL, 0xe8b8d433UL, 0x7807c9a2UL, 0x0f00f934UL, 0x9609a88eUL,
    0xe10e9818UL, 0x7f6a0dbbUL, 0x086d3d2dUL, 0x91646c97UL, 0xe6635c01UL,
    0x6b6b51f4UL, 0x1c6c6162UL, 0x856530d8UL, 0xf262004eUL, 0x6c0695edUL,
    0x1b01a57bUL, 0x8208f4c1UL, 0xf50fc457UL, 0x65b0d9c6UL, 0x12b7e950UL,
    0x8bbeb8eaUL, 0xfcb9887cUL, 0x62dd1ddfUL, 0x15da2d49UL, 0x8cd37cf3UL,
    0xfbd44c65UL, 0x4db26158UL, 0x3ab551ceUL, 0xa3bc0074UL, 0xd4bb30e2UL,
    0x4adfa541UL, 0x3dd895d7UL, 0xa4d1c46dUL, 0xd3d6f4fbUL, 0x4369e96aUL,
    0x346ed9fcUL, 0xad678846UL, 0xda60b8d0UL, 0x44042d73UL, 0x33031de5UL,
    0xaa0a4c5fUL, 0xdd0d7cc9UL, 0x5005713cUL, 0x270241aaUL, 0xbe0b1010UL,
    0xc90c2086UL, 0x5768b525UL, 0x206f85b3UL, 0xb966d409UL, 0xce61e49fUL,
    0x5edef90eUL, 0x29d9c998UL, 0xb0d09822UL, 0xc7d7a8b4UL, 0x59b33d17UL,
    0x2eb40d81UL, 0xb7bd5c3bUL, 0xc0ba6cadUL, 0xedb88320UL, 0x9abfb3b6UL,
    0x03b6e20cUL, 0x74b1d29aUL, 0xead54739UL, 0x9dd277afUL, 0x04db2615UL,
    0x73dc1683UL, 0xe3630b12UL, 0x94643b84UL, 0x0d6d6a3eUL, 0x7a6a5aa8UL,
    0xe40ecf0bUL, 0x9309ff9dUL, 0x0a00ae27UL, 0x7d079eb1UL, 0xf00f9344UL,
    0x8708a3d2UL, 0x1e01f268UL, 0x6906c2feUL, 0xf762575dUL, 0x806567cbUL,
    0x196c3671UL, 0x6e6b06e7UL, 0xfed41b76UL, 0x89d32be0UL, 0x10da7a5aUL,
    0x67dd4accUL, 0xf9b9df6fUL, 0x8ebeeff9UL, 0x17b7be43UL, 0x60b08ed5UL,
    0xd6d6a3e8UL, 0xa1d1937eUL, 0x38d8c2c4UL, 0x4fdff252UL, 0xd1bb67f1UL,
    0xa6bc5767UL, 0x3fb506ddUL, 0x48b2364bUL, 0xd80d2bdaUL, 0xaf0a1b4cUL,
    0x36034af6UL, 0x41047a60UL, 0xdf60efc3UL, 0xa867df55UL, 0x316e8eefUL,
    0x4669be79UL, 0xcb61b38cUL, 0xbc66831aUL, 0x256fd2a0UL, 0x5268e236UL,
    0xcc0c7795UL, 0xbb0b4703UL, 0x220216b9UL, 0x5505262fUL, 0xc5ba3bbeUL,
    0xb2bd0b28UL, 0x2bb45a92UL, 0x5cb36a04UL, 0xc2d7ffa7UL, 0xb5d0cf31UL,
    0x2cd99e8bUL, 0x5bdeae1dUL, 0x9b64c2b0UL, 0xec63f226UL, 0x756aa39cUL,
    0x026d930aUL, 0x9c0906a9UL, 0xeb0e363fUL, 0x72076785UL, 0x05005713UL,
    0x95bf4a82UL, 0xe2b87a14UL, 0x7bb12baeUL, 0x0cb61b38UL, 0x92d28e9bUL,
    0xe5d5be0dUL, 0x7cdcefb7UL, 0x0bdbdf21UL, 0x86d3d2d4UL, 0xf1d4e242UL,
    0x68ddb3f8UL, 0x1fda836eUL, 0x81be16cdUL, 0xf6b9265bUL, 0x6fb077e1UL,
    0x18b74777UL, 0x88085ae6UL, 0xff0f6a70UL, 0x66063bcaUL, 0x11010b5cUL,
    0x8f659effUL, 0xf862ae69UL, 0x616bffd3UL, 0x166ccf45UL, 0xa00ae278UL,
    0xd70dd2eeUL, 0x4e048354UL, 0x3903b3c2UL, 0xa7672661UL, 0xd06016f7UL,
    0x4969474dUL, 0x3e6e77dbUL, 0xaed16a4aUL, 0xd9d65adcUL, 0x40df0b66UL,
    0x37d83bf0UL, 0xa9bcae53UL, 0xdebb9ec5UL, 0x47b2cf7fUL, 0x30b5ffe9UL,
    0xbdbdf21cUL, 0xcabac28aUL, 0x53b39330UL, 0x24b4a3a6UL, 0xbad03605UL,
    0xcdd70693UL, 0x54de5729UL, 0x23d967bfUL, 0xb3667a2eUL, 0xc4614ab8UL,
    0x5d681b02UL, 0x2a6f2b94UL, 0xb40bbe37UL, 0xc30c8ea1UL, 0x5a05df1bUL,
    0x2d02ef8dL
};

void thread::start (void *(*start_routine)(void *), void *arg)
{
  pthread_attr_t attr;

  pthread_attr_init (&attr);
  pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
  pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN < sizeof (long) * 4096
                                    ? sizeof (long) * 4096 : PTHREAD_STACK_MIN);
#ifdef PTHREAD_SCOPE_PROCESS
  pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
#endif

  sigset_t fullsigset, oldsigset;
  sigfillset (&fullsigset);

  pthread_sigmask (SIG_SETMASK, &fullsigset, &oldsigset);

  if (pthread_create (&id, &attr, start_routine, arg))
    cleanup ("unable to create a new thread");

  pthread_sigmask (SIG_SETMASK, &oldsigset, 0);
}