/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009 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>
 */

/*
 * compatibility functions for older (GPL) source code parts
 */

#include <cstring>
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>

#include <global.h>
#include "define.h"
#include "path.h"


/* buf_overflow() - we don't want to exceed the buffer size of 
 * buf1 by adding on buf2! Returns true if overflow will occur.
 */
int
buf_overflow (const char *buf1, const char *buf2, int bufsize)
{
  int len1 = 0, len2 = 0;

  if (buf1)
    len1 = strlen (buf1);

  if (buf2)
    len2 = strlen (buf2);

  if ((len1 + len2) >= bufsize)
    return 1;

  return 0;
}

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

static const char *const fatalmsgs[80] = {
  "Failed to allocate memory",
  "Failed repeatedly to load maps",
  "Hashtable for archetypes is too small",
  "Too many errors"
};

/*
 * fatal() is meant to be called whenever a fatal signal is intercepted.
 * It will call the emergency_save and the clean_tmp_files functions.
 */
void
fatal (int err)
{
  LOG (llevError, "Fatal: %s\n", fatalmsgs [err]);
  cleanup (fatalmsgs[err], 1);
}

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

/*
 * 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;
}

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

#ifndef PATH_MAX
# define PATH_MAX 8192
#endif

char *
path_combine (const char *src, const char *dst)
{
  char *p;
  static char path[PATH_MAX];

  if (*dst == '/')
    {
      /* absolute destination path => ignore source path */
      strcpy (path, dst);
    }
  else
    {
      /* relative destination path => add after last '/' of source */
      strcpy (path, src);
      p = strrchr (path, '/');
      if (p)
        p++;
      else
        {
          p = path;
          if (*src == '/')
            *p++ = '/';
        }

      strcpy (p, dst);
    }

  return path;
}

void
path_normalize (char *path)
{
  char *p;                      /* points to the beginning of the path not yet processed; this is
                                   either a path component or a path separator character */
  char *q;                      /* points to the end of the path component p points to */
  char *w;                      /* points to the end of the already normalized path; w <= p is
                                   maintained */
  size_t len;                   /* length of current component (which p points to) */

  p = path;
  w = p;
  while (*p != '\0')
    {
      if (*p == '/')
        {
          if ((w == path && *path == '/') || (w > path && w[-1] != '/'))
            *w++ = '/';

          p++;
          continue;
        }

      q = strchr (p, '/');
      if (q == NULL)
        q = p + strlen (p);
      len = q - p;
      assert (len > 0);

      if (len == 1 && *p == '.')
        {
          /* remove current component */
        }
      else if (len == 2 && memcmp (p, "..", 2) == 0)
        {
          if (w == path || (w == path + 3 && memcmp (path, "../", 3) == 0))
            {
              /* keep ".." at beginning of relative path ("../x" => "../x") */
              memmove (w, p, len);
              w += len;
            }
          else if (w == path + 1 && *path == '/')
            {
              /* remove ".." at beginning of absolute path ("/../x" => "/x") */
            }
          else
            {
              /* remove both current component ".." and preceding one */
              if (w > path && w[-1] == '/')
                w--;
              while (w > path && w[-1] != '/')
                w--;
            }
        }
      else
        {
          /* normal component ==> add it */
          memmove (w, p, len);
          w += len;
        }

      p = q;
    }

  /* remove trailing slashes, but keep the one at the start of the path */
  while (w > path + 1 && w[-1] == '/')
    w--;

  *w = '\0';
}

char *
path_combine_and_normalize (const char *src, const char *dst)
{
  char *path;

  path = path_combine (src, dst);
  path_normalize (path);
  return (path);
}

char *
strcasestr_local (const char *s, const char *find)
{
  char c, sc;
  size_t len;

  if ((c = *find++) != 0)
    {
      c = tolower (c);
      len = strlen (find);
      do
        {
          do
            {
              if ((sc = *s++) == 0)
                return NULL;
            }
          while (tolower (sc) != c);
        }
      while (strncasecmp (s, find, len) != 0);
      s--;
    }
  return (char *) s;
}

/**
 * open_and_uncompress() first searches for the original filename. If it exist,
 * then it opens it and returns the file-pointer.
 */
FILE *
open_and_uncompress (const char *name, int flag, int *compressed)
{
  *compressed = 0;
  return fopen (name, "r");
}

/*
 * See open_and_uncompress().
 */

void
close_and_delete (FILE * fp, int compressed)
{
  fclose (fp);
}

/*
 * 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';
}