/*
 * 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 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 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>
 */

/* March 96 - Laid down original code. -b.t. thomas@astro.psu.edu */

#include <global.h>
#include <object.h>
#include <sproto.h>
#include <skills.h>
#include <spells.h>

/** define this for some helpful debuging information */
#if 0
# define ALCHEMY_DEBUG
#endif

/** define this for loads of (marginal) debuging information */
#if 0
# define EXTREME_ALCHEMY_DEBUG
#endif

/** Random cauldrons effects */
static const char *const cauldron_effect[] = {
  "vibrates briefly",
  "produces a cloud of steam",
  "emits bright flames",
  "pours forth heavy black smoke",
  "emits sparks",
  "shoots out small flames",
  "whines painfully",
  "hiccups loudly",
  "wheezes",
  "burps",
  "shakes",
  "rattles",
  "makes chugging sounds",
  "smokes heavily for a while"
};


static int is_defined_recipe (const recipe *rp, const object *cauldron, object *caster);
static recipe *find_recipe (recipelist * fl, int formula, object *ingredients);


/** Returns a random selection from cauldron_effect[] */
static const char *
cauldron_sound (void)
{
  int size = sizeof (cauldron_effect) / sizeof (char *);

  return cauldron_effect[rndm (0, size - 1)];
}

/**
 * Main part of the ALCHEMY code. From this we call fctns
 * that take a look at the contents of the 'cauldron' and, using these ingredients, 
 * we construct an integer formula value which is referenced (randomly) against a 
 * formula list (the formula list chosen is based on the # contents of the cauldron).
 *
 * If we get a match between the recipe indicated in cauldron contents and a 
 * randomly chosen one, an item is created and experience awarded. Otherwise 
 * various failure effects are possible (getting worse and worse w/ # cauldron 
 * ingredients). Note that the 'item' to be made can be *anything* listed on 
 * the artifacts list in lib/artifacts which has a recipe listed in lib/formulae.
 *
 * To those wondering why I am using the funky formula index method:
 *   1) I want to match recipe to ingredients regardless of ordering.
 *   2) I want a fast search for the 'right' recipe.
 * 
 * Note: it is just possible that a totally different combination of
 * ingredients will result in a match with a given recipe. This is not a bug!
 * There is no good reason (in my mind) why alchemical processes have to be
 * unique -- such a 'feature' is one reason why players might want to experiment
 * around. :)
 * -b.t.
 */

void
attempt_do_alchemy (object *caster, object *cauldron)
{
  recipelist *fl;
  recipe *rp = NULL;
  float success_chance;
  int numb, ability = 1;
  int formula = 0;
  float ave_chance;
  object *item, *skop;

  if (caster->type != PLAYER)
    return;                     /* only players for now */

  if (get_map_flags (caster->map, NULL, caster->x, caster->y, NULL, NULL) & P_SAFE)
    {
      new_draw_info (NDI_UNIQUE, 0, caster, "This is sacred ground, the gods prevent you from using this device.");
      return;
    }

  /* if no ingredients, no formula! lets forget it */
  if (!(formula = content_recipe_value (cauldron)))
    return;

  numb = numb_ob_inside (cauldron);
  if ((fl = get_formulalist (numb)))
    {
      if (QUERY_FLAG (caster, FLAG_WIZ))
        {
          rp = find_recipe (fl, formula, cauldron->inv);
          if (rp != NULL)
            {
#ifdef ALCHEMY_DEBUG
              if (strcmp (rp->title, "NONE"))
                LOG (llevDebug, "WIZ got formula: %s of %s\n", rp->arch_name[0], rp->title);
              else
                LOG (llevDebug, "WIZ got formula: %s (nbatches:%d)\n", rp->arch_name[0], formula / rp->index);
#endif
              attempt_recipe (caster, cauldron, ability, rp, formula / rp->index);
            }
          else
            LOG (llevDebug, "WIZ couldn't find formula for ingredients.\n");
          return;
        }                       /* End of WIZ alchemy */

      /* find the recipe */
      rp = find_recipe (fl, formula, cauldron->inv);
      if (rp)
        {
          uint64 value_ingredients;
          uint64 value_item;
          object *tmp;
          int attempt_shadow_alchemy;

          ave_chance = fl->total_chance / (float) fl->number;
          /* the caster gets an increase in ability based on thier skill lvl */
          if (rp->skill)
            {
              skop = find_skill_by_name (caster, rp->skill);
              if (!skop)
                new_draw_info (NDI_UNIQUE, 0, caster, "You do not have the proper skill for this recipe");
              else
                ability += (int) (skop->level * ((4.0 + cauldron->magic) / 4.0));
            }
          else
            {
              LOG (llevDebug, "Recipe %s has NULL skill!\n", &rp->title);
              return;
            }

          if (!rp->cauldron)
            {
              LOG (llevDebug, "Recipe %s has NULL cauldron!\n", &rp->title);
              return;
            }

          /* determine value of ingredients */
          value_ingredients = 0;
          for (tmp = cauldron->inv; tmp != NULL; tmp = tmp->below)
            value_ingredients += query_cost (tmp, NULL, F_TRUE);

          attempt_shadow_alchemy = !is_defined_recipe (rp, cauldron, caster);

          /* create the object **FIRST**, then decide whether to keep it.     */
          if ((item = attempt_recipe (caster, cauldron, ability, rp, formula / rp->index)) != NULL)
            {
              /*  compute base chance of recipe success */
              success_chance = ((float) ability / (float) (rp->diff * (item->level + 2)));
              if (ave_chance == 0)
                ave_chance = 1;

#ifdef ALCHEMY_DEBUG
              LOG (llevDebug, "percent success chance =  %f ab%d / diff%d*lev%d\n", success_chance, ability, rp->diff, item->level);
#endif

              value_item = query_cost (item, NULL, F_TRUE | F_IDENTIFIED | F_NOT_CURSED);
              if (attempt_shadow_alchemy && value_item > value_ingredients)
                {
#ifdef ALCHEMY_DEBUG
                  LOG (llevDebug,
                       "Forcing failure for shadow alchemy recipe because price of ingredients (%llu) is less than price of result (%llu).\n",
                       value_ingredients, value_item);
#endif
                }
              /* roll the dice */
              else if ((float) (random_roll (0, 101, caster, PREFER_LOW)) <= 100.0 * success_chance)
                {
                  change_exp (caster, rp->exp, rp->skill, SK_EXP_NONE);

                  // let alchemy consume some time, so that exploits are less easy
                  caster->speed_left -= 1.0;

                  return;
                }
            }
        }
    }

  /* if we get here, we failed!! */
  alchemy_failure_effect (caster, cauldron, rp, calc_alch_danger (caster, cauldron, rp));
}

/**
 * Recipe value of the entire contents of a container.
 * This appears to just generate a hash value, which I guess for now works
 * ok, but the possibility of duplicate hashes is certainly possible - msw
  */

int
content_recipe_value (object *op)
{
  char name[MAX_BUF];
  object *tmp = op->inv;
  int tval = 0, formula = 0;

  while (tmp)
    {
      tval = 0;
      assign (name, tmp->name);
      if (tmp->title)
        sprintf (name, "%s %s", &tmp->name, &tmp->title);
      tval = (strtoint (name) * (tmp->nrof ? tmp->nrof : 1));
#ifdef ALCHEMY_DEBUG
      LOG (llevDebug, "Got ingredient %d %s(%d)\n", tmp->nrof ? tmp->nrof : 1, name, tval);
#endif
      formula += tval;
      tmp = tmp->below;
    }
#ifdef ALCHEMY_DEBUG
  LOG (llevDebug, " Formula value=%d\n", formula);
#endif
  return formula;
}

/**
 * Returns total number of items in op
 */

int
numb_ob_inside (object *op)
{
  object *tmp = op->inv;
  int number = 0, o_number = 0;

  while (tmp)
    {
      if (tmp->nrof)
        number += tmp->nrof;
      else
        number++;
      o_number++;
      tmp = tmp->below;
    }
#ifdef ALCHEMY_DEBUG
  LOG (llevDebug, "numb_ob_inside(%s): found %d ingredients\n", op->name, o_number);
#endif
  return o_number;
}

/**
 * Essentially a wrapper for make_item_from_recipe() and 
 * insert_ob_in_ob. If the caster has some alchemy skill, then they might
 * gain some exp from (successfull) fabrication of the product. 
 * If nbatches==-1, don't give exp for this creation (random generation/
 * failed recipe)
 */

object *
attempt_recipe (object *caster, object *cauldron, int ability, recipe *rp, int nbatches)
{

  object *item = NULL, *skop;

  /* this should be passed to this fctn, not effiecent cpu use this way */
  int batches = abs (nbatches);


  /* is the cauldron the right type? */
  if (rp->cauldron != cauldron->arch->archname)
    {
      new_draw_info (NDI_UNIQUE, 0, caster, "You are not using the proper" " facilities for this formula.");
      return 0;
    }

  skop = find_skill_by_name (caster, rp->skill);
  /* does the caster have the skill? */
  if (!skop)
    return 0;

  /* code required for this recipe, search the caster */
  if (rp->keycode)
    {
      object *tmp;

      for (tmp = caster->inv; tmp; tmp = tmp->below)
        {
          if (tmp->type == FORCE && tmp->slaying && rp->keycode == tmp->slaying)
            break;
        }

      if (!tmp)
        {                       /* failure--no code found */
          new_draw_info (NDI_UNIQUE, 0, caster, "You know the ingredients, but not the technique. Go learn how to do this recipe.");
          return 0;
        }
    }

#ifdef EXTREME_ALCHEMY_DEBUG
  LOG (llevDebug, "attempt_recipe(): got %d nbatches\n", nbatches);
  LOG (llevDebug, "attempt_recipe(): using recipe %s\n", rp->title ? rp->title : "unknown");
#endif

  if ((item = make_item_from_recipe (cauldron, rp)) != NULL)
    {
      remove_contents (cauldron->inv, item);
      /* Recalc carrying of the cauldron, in case recipe did not conserve mass */
      cauldron->update_weight ();
      /* adj lvl, nrof on caster level */
      adjust_product (item, ability, rp->yield ? (rp->yield * batches) : batches);
      if (!item->env && (item = insert_ob_in_ob (item, cauldron)) == NULL)
        {
          new_draw_info (NDI_UNIQUE, 0, caster, "Nothing happened.");
          /* new_draw_info_format(NDI_UNIQUE, 0,caster,
             "Your spell causes the %s to explode!",&cauldron->name); */
          /* kaboom_cauldron(); */
        }
      else
        new_draw_info_format (NDI_UNIQUE, 0, caster, "The %s %s.", &cauldron->name, cauldron_sound ());
    }

  return item;
}



/**
 * We adjust the nrof, exp and level of the final product, based
 * on the item's default parameters, and the relevant caster skill level.
 */
void
adjust_product (object *item, int lvl, int yield)
{
  int nrof = 1;

  if (!yield)
    yield = 1;

  if (lvl <= 0)
    lvl = 1;                    /* lets avoid div by zero! */

  if (item->nrof)
    {
      nrof = (int) ((1.0 - 1.0 / (lvl / 10.0 + 1.0)) * (rndm (0, yield - 1) + rndm (0, yield - 1) + rndm (0, yield - 1)) + 1);

      if (nrof > yield)
        nrof = yield;

      item->nrof = nrof;
    }
}


/**
 * Using a list of items and a recipe to make an artifact.
 *
 * @param cauldron the cauldron (including the ingredients) used to make the item
 *
 * @param rp the recipe to make the artifact from
 *
 * @return the newly created object, NULL if something failed
 */

object *
make_item_from_recipe (object *cauldron, recipe *rp)
{
  artifact *art = NULL;
  object *item = NULL;
  size_t rp_arch_index;

  if (rp == NULL)
    return (object *) NULL;

  /* Find the appropriate object to transform... */
  if ((item = find_transmution_ob (cauldron->inv, rp, &rp_arch_index, 1)) == NULL)
    {
      LOG (llevDebug, "make_alchemy_item(): failed to create alchemical object.\n");
      return (object *) NULL;
    }

  /* Find the appropriate artifact template... */
  if (rp->title != shstr_NONE)
    {
      if ((art = locate_recipe_artifact (rp, rp_arch_index)) == NULL)
        {
          LOG (llevError, "make_alchemy_item(): failed to locate recipe artifact.\n");
          LOG (llevDebug, "  --requested recipe: %s of %s.\n", rp->arch_name[0], &rp->title);
          return (object *) NULL;
        }

      transmute_materialname (item, art->item);
      give_artifact_abilities (item, art->item);
    }

  if (QUERY_FLAG (cauldron, FLAG_CURSED))
    SET_FLAG (item, FLAG_CURSED);
  if (QUERY_FLAG (cauldron, FLAG_DAMNED))
    SET_FLAG (item, FLAG_DAMNED);

  return item;
}


/**
 * Looks through the ingredient list. If we find a
 * suitable object in it - we will use that to make the requested artifact.
 * Otherwise the code returns a 'generic' item if create_item is set. -b.t.
 *
 * @param rp_arch_index pointer to return value; set to arch index for recipe;
 * set to zero if not using a transmution formula
 */

object *
find_transmution_ob (object *first_ingred, recipe *rp, size_t * rp_arch_index, int create_item)
{
  object *item = NULL;

  *rp_arch_index = 0;

  if (rp->transmute)            /* look for matching ingredient/prod archs */
    for (item = first_ingred; item; item = item->below)
      {
        int i;

        for (int i = 0; i < rp->arch_names; i++)
          //TODO: should be a shstr comparison
          if (&item->arch->archname == rp->arch_name[i])
            {
              *rp_arch_index = i;
              break;
            }

        if (i < rp->arch_names)
          break;
      }

  /* failed, create a fresh object. Note no nrof>1 because that would
   * allow players to create massive amounts of artifacts easily */
  if (create_item && (!item || item->nrof > 1))
    {
      *rp_arch_index = rndm (rp->arch_names);
      item = get_archetype (rp->arch_name[*rp_arch_index]);
    }

#ifdef ALCHEMY_DEBUG
  LOG (llevDebug, "recipe calls for%stransmution.\n", rp->transmute ? " " : " no ");
  if (item != NULL)
    {
      LOG (llevDebug, " find_transmutable_ob(): returns arch %s(sp:%d)\n", item->arch->name, item->stats.sp);
    }
#endif

  return item;
}


/**
 * Ouch. We didnt get the formula we wanted.
 * This fctn simulates the backfire effects--worse effects as the level
 * increases. If SPELL_FAILURE_EFFECTS is defined some really evil things
 * can happen to the would be alchemist. This table probably needs some
 * adjustment for playbalance. -b.t.
 */

void
alchemy_failure_effect (object *op, object *cauldron, recipe *rp, int danger)
{
  int level = 0;

  if (!op || !cauldron)
    return;

  if (danger > 1)
    level = random_roll (1, danger, op, PREFER_LOW);

#ifdef ALCHEMY_DEBUG
  LOG (llevDebug, "Alchemy_failure_effect(): using level=%d\n", level);
#endif

  /* possible outcomes based on level */
  if (level < 25)
    {                           /* INGREDIENTS USED/SLAGGED */
      object *item = NULL;

      if (rndm (0, 2))
        {                       /* slag created */
          object *tmp = cauldron->inv;
          int weight = 0;

          tmp = get_archetype ("rock");
          tmp->weight = weight;
          tmp->value = 0;
          tmp->materialname = "stone";
          tmp->name = "slag";
          tmp->name_pl = "slags";
          item = insert_ob_in_ob (tmp, cauldron);
          CLEAR_FLAG (tmp, FLAG_CAN_ROLL);
          CLEAR_FLAG (tmp, FLAG_NO_PICK);
          tmp->move_block = 0;
        }

      remove_contents (cauldron->inv, item);
      new_draw_info_format (NDI_UNIQUE, 0, op, "The %s %s.", &cauldron->name, cauldron_sound ());
      return;
    }
  else if (level < 40)
    {                           /* MAKE TAINTED ITEM */
      object *tmp = NULL;

      if (!rp)
        if ((rp = get_random_recipe ((recipelist *) NULL)) == NULL)
          return;

      if ((tmp = attempt_recipe (op, cauldron, 1, rp, -1)))
        {
          if (!QUERY_FLAG (tmp, FLAG_CURSED))   /* curse it */
            SET_FLAG (tmp, FLAG_CURSED);

          /* the apply code for potions already deals with cursed
           * potions, so any code here is basically ignored.
           */
          if (tmp->type == FOOD)
            {
              tmp->stats.hp = random_roll (0, 149, op, PREFER_LOW);
            }
          tmp->value = 0;       /* unsaleable item */

          /* change stats downward */
          do
            {
              change_attr_value (&tmp->stats, rndm (0, 6), -1 * (rndm (1, 3)));
            }
          while (rndm (0, 2));
        }
      return;
    }

  if (level == 40)
    {                           /* MAKE RANDOM RECIPE */
      recipelist *fl;
      int numb = numb_ob_inside (cauldron);

      fl = get_formulalist (numb - 1);  /* take a lower recipe list */
      if (fl && (rp = get_random_recipe (fl)))
        /* even though random, don't grant user any EXP for it */
        (void) attempt_recipe (op, cauldron, 1, rp, -1);
      else
        alchemy_failure_effect (op, cauldron, rp, level - 1);
    }
  else if (level < 45)
    {                           /* INFURIATE NPC's */
      /* this is kind of kludgy I know... */
      cauldron->enemy = op;
      npc_call_help (cauldron);
      cauldron->enemy = NULL;

      alchemy_failure_effect (op, cauldron, rp, level - 5);
    }
  else if (level < 50)
    {                           /* MINOR EXPLOSION/FIREBALL */
      object *tmp;

      remove_contents (cauldron->inv, NULL);
      switch (rndm (0, 2))
        {
          case 0:
            tmp = get_archetype ("bomb");
            tmp->stats.dam = random_roll (1, level, op, PREFER_LOW);
            tmp->stats.hp = random_roll (1, level, op, PREFER_LOW);
            new_draw_info_format (NDI_UNIQUE, 0, op, "The %s creates a bomb!", &cauldron->name);
            break;

          default:
            tmp = get_archetype ("fireball");
            tmp->stats.dam = random_roll (1, level, op, PREFER_LOW) / 5 + 1;
            tmp->stats.hp = random_roll (1, level, op, PREFER_LOW) / 10 + 2;
            new_draw_info_format (NDI_UNIQUE, 0, op, "The %s erupts in flame!", &cauldron->name);
            break;
        }

      tmp->insert_at (cauldron);
    }
  else if (level < 60)
    {                           /* CREATE MONSTER */
      new_draw_info_format (NDI_UNIQUE, 0, op, "The %s %s.", &cauldron->name, cauldron_sound ());
      remove_contents (cauldron->inv, NULL);
    }
  else if (level < 80)
    {                           /* MAJOR FIRE */
      object *fb = get_archetype (SP_MED_FIREBALL);

      remove_contents (cauldron->inv, NULL);
      fire_arch_from_position (cauldron, cauldron, cauldron->x, cauldron->y, 0, fb);
      fb->destroy ();
      new_draw_info_format (NDI_UNIQUE, 0, op, "The %s erupts in flame!", &cauldron->name);
    }
  else if (level < 100)
    {                           /* WHAMMY the CAULDRON */
      if (!QUERY_FLAG (cauldron, FLAG_CURSED))
        SET_FLAG (cauldron, FLAG_CURSED);
      else
        cauldron->magic--;

      cauldron->magic -= random_roll (0, 4, op, PREFER_LOW);

      if (rndm (0, 1))
        {
          remove_contents (cauldron->inv, NULL);
          new_draw_info_format (NDI_UNIQUE, 0, op, "Your %s turns darker then makes a gulping sound!", &cauldron->name);
        }
      else
        new_draw_info_format (NDI_UNIQUE, 0, op, "Your %s becomes darker.", &cauldron->name);
    }
  else if (level < 110)
    {                           /* SUMMON EVIL MONSTERS */
      object *tmp = get_random_mon (level / 5);

      remove_contents (cauldron->inv, NULL);

      if (!tmp)
        alchemy_failure_effect (op, cauldron, rp, level);
      else if (summon_hostile_monsters (cauldron, random_roll (1, 10, op, PREFER_LOW), tmp->arch->archname))
        new_draw_info_format (NDI_UNIQUE, 0, op, "The %s %s and then pours forth monsters!", &cauldron->name, cauldron_sound ());
    }
  else if (level < 150)
    {                           /* COMBO EFFECT */
      int roll = rndm (1, 3);

      while (roll)
        {
          alchemy_failure_effect (op, cauldron, rp, level - 39);
          roll--;
        }
    }
  else if (level == 151)
    {                           /* CREATE RANDOM ARTIFACT */
      object *tmp;

      /* this is meant to be better than prior possiblity, 
       * in this one, we allow *any* valid alchemy artifact
       * to be made (rather than only those on the given
       * formulalist) */
      if (!rp)
        rp = get_random_recipe ((recipelist *) NULL);

      if (rp && (tmp = get_archetype (rp->arch_name [rndm (rp->arch_names)])))
        {
          generate_artifact (tmp, random_roll (1, op->level / 2 + 1, op, PREFER_HIGH) + 1);
          if ((tmp = insert_ob_in_ob (tmp, cauldron)))
            {
              remove_contents (cauldron->inv, tmp);
              new_draw_info_format (NDI_UNIQUE, 0, op, "The %s %s.", &cauldron->name, cauldron_sound ());
            }
        }
    }
  else
    {                           /* MANA STORM - watch out!! */
      object *tmp = get_archetype (LOOSE_MANA);

      new_draw_info (NDI_UNIQUE, 0, op, "You unwisely release potent forces!");
      remove_contents (cauldron->inv, NULL);
      cast_magic_storm (op, tmp, level);
    }
}

/*
 * All but object "save_item" are elimentated from
 * the container list. Note we have to becareful to remove the inventories
 * of objects in the cauldron inventory (ex icecube has stuff in it).  
 */
void
remove_contents (object *first_ob, object *save_item)
{
  // this cries for a cleaner rewrite, removing save_item first possibly
  object *next, *tmp = first_ob;

  while (tmp)
    {
      next = tmp->below;

      if (tmp == save_item)
        {
          if (!(tmp = next))
            break;
          else
            next = next->below;
        }

      if (tmp->inv)
        remove_contents (tmp->inv, NULL);

      tmp->destroy ();
      tmp = next;
    }
}

/**
 *"Danger" level, will determine how bad the backfire
 * could be if the user fails to concoct a recipe properly. Factors include
 * the number of ingredients, the length of the name of each ingredient,
 * the user's effective level, the user's Int and the enchantment on the
 * mixing device (aka "cauldron"). Higher values of 'danger' indicate more
 * danger. Note that we assume that we have had the caster ready the alchemy
 * skill *before* this routine is called. (no longer auto-readies that skill) 
 * -b.t. 
 */
int
calc_alch_danger (object *caster, object *cauldron, recipe *rp)
{
  object *item;
  char name[MAX_BUF];
  int danger = 0, nrofi = 0;

  /* Knowing alchemy skill reduces yer risk */
  danger -= caster->chosen_skill ? caster->chosen_skill->level : caster->level;

  if (!caster->chosen_skill)
    LOG (llevError | logBacktrace, "calc_alch_danger called without a chosen skill, caster %s, cauldron %s\n",
         caster->debug_desc (), cauldron->debug_desc ());

  /* better cauldrons reduce risk */
  danger -= cauldron->magic;

  /* Higher Int, lower the risk */
  danger -= 3 * (caster->stats.Int - 15);

  /* Ingredients. Longer names usually mean rarer stuff.
   * Thus the backfire is worse. Also, more ingredients
   * means we are attempting a more powerfull potion,
   * and thus the backfire will be worse.  */
  for (item = cauldron->inv; item; item = item->below)
    {
      assign (name, item->name);
      if (item->title)
        sprintf (name, "%s %s", &item->name, &item->title);
      danger += (strtoint (name) / 1000) + 3;
      nrofi++;
    }

  if (rp == NULL)
    danger += 110;
  else
    danger += rp->diff * 3;

  /* Using a bad device is *majorly* stupid */
  if (QUERY_FLAG (cauldron, FLAG_CURSED))
    danger += 80;
  if (QUERY_FLAG (cauldron, FLAG_DAMNED))
    danger += 200;

#ifdef ALCHEMY_DEBUG
  LOG (llevDebug, "calc_alch_danger() returned danger=%d\n", danger);
#endif

  return danger;
}

/**
 * Determines if ingredients in a container match the
 * proper ingredients for a recipe.
 *
 * rp is the recipe to check
 * cauldron is the container that holds the ingredients
 * returns 1 if the ingredients match the recipe, 0 if not
 *
 * This functions tries to find each defined ingredient in the container. It is
 * the defined recipe iff
 *  - the number of ingredients of the recipe and in the container is equal
 *  - all ingredients of the recipe are found in the container
 *  - the number of batches is the same for all ingredients
 */
static int
is_defined_recipe (const recipe *rp, const object *cauldron, object *caster)
{
  uint32 batches_in_cauldron;
  const linked_char *ingredient;
  int number;
  const object *ob;

  /* check for matching number of ingredients */
  number = 0;
  for (ingredient = rp->ingred; ingredient != NULL; ingredient = ingredient->next)
    number++;
  for (ob = cauldron->inv; ob != NULL; ob = ob->below)
    number--;
  if (number != 0)
    return 0;

  /* check for matching ingredients */
  batches_in_cauldron = 0;
  for (ingredient = rp->ingred; ingredient != NULL; ingredient = ingredient->next)
    {
      uint32 nrof;
      const char *name;
      int ok;

      /* determine and remove nrof from name */
      name = ingredient->name;
      nrof = 0;
      while (isdigit (*name))
        {
          nrof = 10 * nrof + (*name - '0');
          name++;
        }
      if (nrof == 0)
        nrof = 1;
      while (*name == ' ')
        name++;

      /* find the current ingredient in the cauldron */
      ok = 0;
      for (ob = cauldron->inv; ob != NULL; ob = ob->below)
        {
          char name_ob[MAX_BUF];
          const char *name2;

          if (!ob->title)
            name2 = ob->name;
          else
            {
              snprintf (name_ob, sizeof (name_ob), "%s %s", &ob->name, &ob->title);
              name2 = name_ob;
            }

          if (strcmp (name2, name) == 0)
            {
              if (ob->nrof % nrof == 0)
                {
                  uint32 batches;

                  batches = ob->nrof / nrof;
                  if (batches_in_cauldron == 0)
                    {
                      batches_in_cauldron = batches;
                      ok = 1;
                    }
                  else if (batches_in_cauldron == batches)
                    ok = 1;
                }
              break;
            }
        }
      if (!ok)
        return (0);
    }

  return (1);
}

/**
 * Find a recipe from a recipe list that matches the given formula. If there
 * is more than one matching recipe, it selects a random one. If at least one
 * transmuting recipe matches, it only considers matching transmuting recipes.
 *
 * @return one matching recipe, or NULL if no recipe matches
 */
static recipe *
find_recipe (recipelist * fl, int formula, object *ingredients)
{
  recipe *rp;
  recipe *result;               /* winning recipe, or NULL if no recipe found */
  int recipes_matching;         /* total number of matching recipes so far */
  int transmute_found;          /* records whether a transmuting recipe was found so far */
  size_t rp_arch_index;

#ifdef EXTREME_ALCHEMY_DEBUG
  LOG (llevDebug, "looking for formula %d:\n", formula);
#endif
  result = NULL;
  recipes_matching = 0;
  transmute_found = 0;

  for (rp = fl->items; rp; rp = rp->next)
    {
      /* check if recipe matches at all */
      if (formula % rp->index != 0)
        {
#ifdef EXTREME_ALCHEMY_DEBUG
          LOG (llevDebug, " formula %s of %s (%d) does not match\n", rp->arch_name[0], rp->title, rp->index);
#endif
          continue;
        }

      if (rp->transmute && find_transmution_ob (ingredients, rp, &rp_arch_index, 0) != NULL)
        {
#ifdef EXTREME_ALCHEMY_DEBUG
          LOG (llevDebug, " formula %s of %s (%d) is a matching transmuting formula\n", rp->arch_name[rp_arch_index], rp->title, rp->index);
#endif
          /* transmution recipe with matching base ingredient */
          if (!transmute_found)
            {
              transmute_found = 1;
              recipes_matching = 0;
            }
        }
      else if (transmute_found)
        {
#ifdef EXTREME_ALCHEMY_DEBUG
          LOG (llevDebug, " formula %s of %s (%d) matches but is not a matching transmuting formula\n", rp->arch_name[0], rp->title,
               rp->index);
#endif
          /* "normal" recipe found after previous transmution recipe => ignore this recipe */
          continue;
        }
#ifdef EXTREME_ALCHEMY_DEBUG
      else
        {
          LOG (llevDebug, " formula %s of %s (%d) matches\n", rp->arch_name[0], rp->title, rp->index);
        }
#endif

      if (rndm (0, recipes_matching) == 0)
        result = rp;

      recipes_matching++;
    }

  if (result == NULL)
    {
#ifdef ALCHEMY_DEBUG
      LOG (llevDebug, "couldn't find formula for ingredients.\n");
#endif
      return NULL;
    }

#ifdef ALCHEMY_DEBUG
  if (strcmp (result->title, "NONE") != 0)
    LOG (llevDebug, "got formula: %s of %s (nbatches:%d)\n", result->arch_name[0], result->title, formula / result->index);
  else
    LOG (llevDebug, "got formula: %s (nbatches:%d)\n", result->arch_name[0], formula / result->index);
#endif
  return result;
}