/*
 * CrossFire, A Multiplayer game for X-windows
 * 
 * Copyright (C) 2005, 2006, 2007 Marc Lehmann & Crossfire+ Development Team
 * Copyright (C) 2002 Mark Wedel & Crossfire Development Team
 * Copyright (C) 1992 Frank Tore Johansen
 * 
 * This program 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 2 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 GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * The authors can be reached via e-mail at <crossfire@schmorp.de>
 */

/*
 * 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 <funcpoint.h>
#include <material.h>

#include <glib.h>

rand_gen rndm (time (0));

tausworthe_random_generator::tausworthe_random_generator (uint32_t seed)
{
  state [0] = max (  2, seed      * 69069U);
  state [1] = max (  8, state [0] * 69069U);
  state [2] = max ( 16, state [1] * 69069U);
  state [3] = max (128, state [2] * 69069U);

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

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];
}

/*
 * 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 min, int max, const object *op, int goodbad)
{
  int omin, diff, luck, base, ran;

  omin = min;
  diff = max - min + 1;
  ((diff > 2) ? (base = 20) : (base = 50));     /* d2 and d3 are corner cases */

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

  ran = RANDOM ();

  if (op->type != PLAYER)
    return ((ran % diff) + min);

  luck = op->stats.luck;
  if (RANDOM () % base < MIN (10, abs (luck)))
    {
      /* we have a winner */
      ((luck > 0) ? (luck = 1) : (luck = -1));
      diff -= luck;
      if (diff < 1)
        return (omin);          /*check again */
      ((goodbad) ? (min += luck) : (diff));

      return (MAX (omin, MIN (max, (ran % diff) + min)));
    }
  return ((ran % diff) + min);
}

/*
 * 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 min, sint64 max, const object *op, int goodbad)
{
  sint64 omin, diff, luck, ran;
  int base;

  omin = min;
  diff = max - min + 1;
  ((diff > 2) ? (base = 20) : (base = 50));     /* d2 and d3 are corner cases */

  if (max < 1 || diff < 1)
    {
      LOG (llevError, "Calling random_roll with min=%" PRId64 " max=%" PRId64 "\n", min, max);
      return (min);             /* avoids a float exception */
    }

  /* Don't know of a portable call to get 64 bit random values.
   * So make a call to get two 32 bit random numbers, and just to
   * a little byteshifting.  Do make sure the first one is only
   * 32 bit, so we don't get skewed results
   */
  ran = (RANDOM () & 0xffffffff) | ((sint64) RANDOM () << 32);

  if (op->type != PLAYER)
    return ((ran % diff) + min);

  luck = op->stats.luck;
  if (RANDOM () % base < MIN (10, abs (luck)))
    {
      /* we have a winner */
      ((luck > 0) ? (luck = 1) : (luck = -1));
      diff -= luck;
      if (diff < 1)
        return (omin);          /*check again */
      ((goodbad) ? (min += luck) : (diff));

      return (MAX (omin, MIN (max, (ran % diff) + min)));
    }
  return ((ran % diff) + 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, diff, luck, total, i, gotlucky, base, ran;

  diff = size;
  min = 1;
  luck = total = gotlucky = 0;
  ((diff > 2) ? (base = 20) : (base = 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 (RANDOM () % 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));
          ran = RANDOM ();
          total += MAX (1, MIN (size, (ran % diff) + min));
        }
      else
        {
          total += RANDOM () % size + 1;
        }
    }
  return (total);
}

/* decay and destroy perishable items in a map */
void
maptile::decay_objects ()
{
  if (!spaces)
    return;

  for (mapspace *ms = spaces + size (); ms-- > spaces; )
    for (object *above, *op = ms->bot; op; op = above)
      {
        above = op->above;

        bool destroy = 0;

        // do not decay anything above unique floor tiles (yet :)
        if (QUERY_FLAG (op, FLAG_IS_FLOOR) && QUERY_FLAG (op, FLAG_UNIQUE))
          break;

        if (QUERY_FLAG (op, FLAG_IS_FLOOR)
            || QUERY_FLAG (op, FLAG_OBJ_ORIGINAL)
            || QUERY_FLAG (op, FLAG_OBJ_SAVE_ON_OVL)
            || QUERY_FLAG (op, FLAG_UNIQUE)
            || QUERY_FLAG (op, FLAG_OVERLAY_FLOOR)
            || QUERY_FLAG (op, FLAG_UNPAID)
            || op->is_alive ())
          ; // do not decay
        else if (op->is_weapon ())
          {
            op->stats.dam--;
            if (op->stats.dam < 0)
              destroy = 1;
          }
        else if (op->is_armor ())
          {
            op->stats.ac--;
            if (op->stats.ac < 0)
              destroy = 1;
          }
        else if (op->type == FOOD)
          {
            op->stats.food -= rndm (5, 20);
            if (op->stats.food < 0)
              destroy = 1;
          }
        else
          {
            int mat = op->material;

            if (mat & M_PAPER
                || mat & M_LEATHER
                || mat & M_WOOD
                || mat & M_ORGANIC
                || mat & M_CLOTH
                || mat & M_LIQUID
                || (mat & M_IRON  && rndm (1, 5) == 1)
                || (mat & M_GLASS && rndm (1, 2) == 1)
                || ((mat & M_STONE      || mat & M_ADAMANT) && rndm (1, 10) == 1)
                || ((mat & M_SOFT_METAL || mat & M_BONE)    && rndm (1, 3)  == 1)
                || (mat & M_ICE && temp > 32))
              destroy = 1;
          }

        /* adjust overall chance below */
        if (destroy && rndm (0, 1))
          op->destroy ();
      }
}

/* convert materialname to materialtype_t */

materialtype_t *
name_to_material (const char *name)
{
  materialtype_t *mt, *nmt;

  mt = NULL;
  for (nmt = materialt; nmt != NULL && nmt->next != NULL; nmt = nmt->next)
    {
      if (strcmp (name, nmt->name) == 0)
        {
          mt = nmt;
          break;
        }
    }
  return mt;
}

/* 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 == NULL)
    return;

  if (change->materialname != NULL && strcmp (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->name, &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;

#ifdef NEW_MATERIAL_CODE
  int j;
#endif

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



  if (nmt == NULL)
    {
      lmt = NULL;
#ifndef NEW_MATERIAL_CODE
      for (mt = materialt; mt != NULL && mt->next != NULL; mt = mt->next)
        {
          if (op->material & mt->material)
            {
              lmt = mt;
              break;
            }
        }

#else
      for (mt = materialt; mt != NULL && mt->next != NULL; mt = mt->next)
        {
          if (op->material & 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;
            }
        }
#endif
    }
  else
    {
      lmt = nmt;
    }

  if (lmt != NULL)
    {
#ifndef NEW_MATERIAL_CODE
      op->materialname = lmt->name;
      return;
#else

      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 (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 = add_string (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;
        }
#endif
    }
}

/*
 * 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';
}

/**
 * Taking a string as an argument, mutate it into a string that looks like a list.
 * a 'list' for the purposes here, is a string of items, seperated by commas, except
 * for the last entry, which has an 'and' before it, and a full stop (period) after it.
 * This function will also strip all trailing non alphanumeric characters.
 * It does not insert an oxford comma.
 */

void
make_list_like (char *input)
{
  char *p, tmp[MAX_BUF];
  int i;

  if (!input || strlen (input) > MAX_BUF - 5)
    return;
  /* bad stuff would happen if we continued here, the -5 is to make space for ' and ' */

  strncpy (tmp, input, MAX_BUF - 5);
  /*trim all trailing commas, spaces etc. */
  for (i = strlen (tmp); !isalnum (tmp[i]) && i >= 0; i--)
    tmp[i] = '\0';

  strcat (tmp, ".");

  p = strrchr (tmp, ',');
  if (p)
    {
      *p = '\0';
      strcpy (input, tmp);
      p++;
      strcat (input, " and");
      strcat (input, p);
    }
  else
    strcpy (input, tmp);

  return;
}

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

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

  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;
}

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

  int len = strlen (src);

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

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;
}