/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * Copyright (©) 2003,2007 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>
 */

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

#ifndef sqr
# define sqr(x) ((x)*(x))
#endif

/*  peterm:  
 *  write_rune:
 *  op:  rune writer
 *  skop: skill object used for casting this rune
 *  dir:  orientation of rune, direction rune's contained spell will
 *	    be cast in, if applicable
 *  inspell: spell object to put into the rune, can be null if doing
 *    a marking rune.
 *  level:  level of casting of the rune
 *  runename:  name of the rune or message displayed by the rune for
 *		a rune of marking 
 */

int
write_rune (object *op, object *caster, object *spell, int dir, const char *runename)
{
  object *tmp, *rune_spell, *rune;
  char buf[MAX_BUF];
  maptile *m;
  sint16 nx, ny;

  if (!dir)
    dir = 1;

  nx = op->x + freearr_x[dir];
  ny = op->y + freearr_y[dir];
  m = op->map;

  if (get_map_flags (m, &m, nx, ny, &nx, &ny) & (P_OUT_OF_MAP | P_SAFE | P_NO_MAGIC | P_NO_CLERIC))
    {
      new_draw_info (NDI_UNIQUE, 0, op, "Can't make a rune there!");
      return 0;
    }

  for (tmp = m->at (nx, ny).bot; tmp; tmp = tmp->above)
    if (tmp->type == RUNE)
      break;

  if (tmp)
    {
      new_draw_info (NDI_UNIQUE, 0, op, "You can't write a rune on top of another rune.");
      return 0;
    }

  if (spell->other_arch)
    rune_spell = arch_to_object (spell->other_arch);
  else
    {
      /* Player specified spell.  The player has to know the spell, so
       * lets just look through the players inventory see if they know it
       * use the item_matched_string for our typical matching method.
       */
      int bestmatch = 0, ms;

      if (!runename || *runename == 0)
        {
          new_draw_info (NDI_UNIQUE, 0, op, "Write a rune of what?");
          return 0;
        }

      rune_spell = NULL;
      for (tmp = op->inv; tmp; tmp = tmp->below)
        if (tmp->type == SPELL)
          {
            ms = item_matched_string (op, tmp, runename);
            if (ms > bestmatch)
              {
                bestmatch = ms;
                rune_spell = tmp;
              }
          }

      if (!rune_spell)
        {
          new_draw_info_format (NDI_UNIQUE, 0, op, "You don't know any spell named %s", runename);
          return 0;
        }

      if (rune_spell->skill != spell->skill)
        {
          new_draw_info_format (NDI_UNIQUE, 0, op, "You can't cast %s with %s", &rune_spell->name, &spell->name);
          return 0;
        }

      if (caster->path_denied & spell->path_attuned && !caster->flag [FLAG_WIZCAST])
        {
          new_draw_info_format (NDI_UNIQUE, 0, op, "%s belongs to a spell path denied to you.", &rune_spell->name);
          return 0;
        }

      if (casting_level (caster, rune_spell) < rune_spell->level && !caster->flag [FLAG_WIZCAST])
        {
          new_draw_info_format (NDI_UNIQUE, 0, op, "%s is beyond your ability to cast!", &rune_spell->name);
          return 0;
        }

      if (SP_level_spellpoint_cost (caster, rune_spell, SPELL_MANA) > op->stats.sp)
        {
          new_draw_info (NDI_UNIQUE, 0, op, "You don't have enough mana.");
          return 0;
        }

      if (SP_level_spellpoint_cost (caster, rune_spell, SPELL_GRACE) > op->stats.grace)
        {
          new_draw_info (NDI_UNIQUE, 0, op, "You don't have enough grace.");
          return 0;
        }

      op->stats.grace -= SP_level_spellpoint_cost (caster, rune_spell, SPELL_GRACE);
      op->stats.sp -= SP_level_spellpoint_cost (caster, rune_spell, SPELL_MANA);
    }

  /* already proper rune.  Note this should only be the case if other_arch was set */
  if (rune_spell->type == RUNE)
    rune = rune_spell;
  else
    {
      rune = get_archetype (GENERIC_RUNE);
      sprintf (buf, "You set off a rune of %s\n", &rune_spell->name);
      rune->msg = buf;
      rune->insert (rune_spell->clone ());

      if (spell->face != blank_face)
        rune->face = spell->face;
    }

  rune->level = casting_level (caster, spell);
  rune->stats.Cha = rune->level / 2;    /* the invisibility parameter */
  rune->direction = dir;        /* where any spell will go upon detonation */
  rune->set_owner (op);         /* runes without need no owner */
  set_spell_skill (op, caster, spell, rune);

  m->insert (rune, nx, ny, op);
  return 1;
}

/*  move_rune:  peterm
  comments on runes:
    rune->level	    :	    level at which rune will cast its spell.
    rune->hp	    :	    number of detonations before rune goes away
    rune->msg	    :	    message the rune displays when it goes off
    rune->direction :	    direction it will cast a spell in
    rune->dam	    :	    damage the rune will do if it doesn't cast spells
    rune->attacktype:	    type of damage it does, if not casting spells
    rune->other_arch:       spell in the rune
    rune->Cha       :       how hidden the rune is
    rune->maxhp     :       number of spells the rune casts
*/
void
move_rune (object *op)
{
  /* runes of level zero cannot detonate. */
  if (!op->level)
    return;

  int det = op->invisible;

  if (!(rndm (0, MAX (1, (op->stats.Cha)) - 1)))
    {
      op->invisible = 0;
      op->speed_left -= 1;
    }
  else
    op->invisible = 1;

  if (op->invisible != det)
    update_object (op, UP_OBJ_CHANGE);
}

/*  peterm: rune_attack
 * function handles those runes which detonate but do not cast spells.  
 */
void
rune_attack (object *op, object *victim)
{
  if (victim)
    {
      hit_player (victim, op->stats.dam, op, op->attacktype, 1);

      if (victim->destroyed ())
        return;

      /*  if there's a disease in the needle, put it in the player */
      if (op->has_random_items ())
        create_treasure (op->randomitems, op, 0, (victim->map ? victim->map->difficulty : 1), 0);

      if (op->inv && op->inv->type == DISEASE)
        {
          object *disease = op->inv;

          infect_object (victim, disease, 1);
          disease->destroy (true);
        }
    }
  else
    hit_map (op, 0, op->attacktype, 1);
}

/*  This function generalizes attacks by runes/traps.  This ought to make
 *  it possible for runes to attack from the inventory, 
 *  it'll spring the trap on the victim.
 */
void
spring_trap (object *trap, object *victim)
{
  object *env;
  rv_vector rv;
  int i;

  /* Prevent recursion */
  if (trap->stats.hp <= 0)
    return;

  if (QUERY_FLAG (trap, FLAG_IS_LINKED))
    use_trigger (trap);

  /* Only living objects can trigger runes that don't cast spells, as
   * doing direct damage to a non-living object doesn't work anyway.
   * Typical example is an arrow attacking a door.
   */
  if (!QUERY_FLAG (victim, FLAG_ALIVE) && !trap->inv && !trap->other_arch)
    return;

  trap->stats.hp--;             /*decrement detcount */

  if (victim && victim->type == PLAYER)
    new_draw_info (NDI_UNIQUE, 0, victim, trap->msg);

  /*  Flash an image of the trap on the map so the poor sod
   *   knows what hit him.  
   */
  env = trap->outer_env ();

  /* If the victim is not next to this trap, don't set it off.
   * players shouldn't get hit by firing arrows at a door for example.
   * At the same time, the trap will stick around until detonated
   */
  get_rangevector (env, victim, &rv, 0);
  if (rv.distance > 1)
    return;

  env->play_sound (trap->sound ? trap->sound : sound_find ("trap_spring"));

  trap_show (trap, env);

  if (victim->type == PLAYER) // only count players as enemies
    trap->enemy = victim; // set the victim as the traps enemy, so that summoned
                          // creatures know who to attack.

  /* Only if it is a spell do we proceed here */
  if ((trap->inv && trap->inv->type == SPELL) || (trap->other_arch && trap->other_arch->type == SPELL))
    {
      if (trap->destroyed ())
        return;

      // breaks summon golem spells, which, for inexplicable reasons,
      // do not work like summon golem spells at all but still require
      // direction "0" to work at all.
      //if (trap->direction)
      //  rv.direction = trap->direction;

      for (i = 0; i < MAX (1, trap->stats.maxhp); i++)
        {
          if (trap->inv)
            cast_spell (env, trap, trap->direction, trap->inv, NULL);
          else
            {
              object *spell = arch_to_object (trap->other_arch);

              cast_spell (env, trap, trap->direction, spell, NULL);
              spell->destroy (true);
            }
        }
    }
  else
    {
      rune_attack (trap, victim);
      if (trap->destroyed ())
        return;
    }

  if (trap->stats.hp <= 0)
    {
      trap->type = SIGN;        /* make the trap impotent */
      trap->stats.food = 20;    /* make it stick around until its spells are gone */
      SET_FLAG (trap, FLAG_IS_USED_UP);
    }
}

/* dispel_rune:  by peterm  
 * dispels the target rune, depending on the level of the actor
 * and the level of the rune  risk flag, if true, means that there is
 * a chance that the trap/rune will detonate 
 */
int
dispel_rune (object *op, object *caster, object *spell, object *skill, int dir)
{
  object *tmp, *tmp2;
  int searchflag = 1, mflags;
  sint16 x, y;
  maptile *m;

  x = op->x + freearr_x[dir];
  y = op->y + freearr_y[dir];
  m = op->map;

  mflags = get_map_flags (m, &m, x, y, &x, &y);

  /* Should we perhaps not allow player to disable traps if a monster/
   * player is standing on top? 
   */
  if (mflags & P_OUT_OF_MAP)
    {
      new_draw_info (NDI_UNIQUE, 0, op, "There's nothing there!");
      return 0;
    }

  for (tmp = GET_MAP_OB (m, x, y); tmp != NULL; tmp = tmp->above)
    {
      if (tmp->type == RUNE || tmp->type == TRAP)
        break;

      /* we could put a probability chance here, but since nothing happens
       * if you fail, no point on that.  I suppose we could do a level
       * comparison so low level players can't erase high level players runes.
       */
      if (tmp->type == SIGN && !strcmp (tmp->arch->archname, "rune_mark"))
        {
          tmp->destroy (true);
          new_draw_info (NDI_UNIQUE, 0, op, "You wipe out the rune of marking!");
          return 1;
        }

      /* now search tmp's inventory for traps
       * This is for chests, where the rune is in the chests inventory.
       */
      for (tmp2 = tmp->inv; tmp2 != NULL; tmp2 = tmp2->below)
        {
          if (tmp2->type == RUNE || tmp2->type == TRAP)
            {
              tmp = tmp2;
              searchflag = 0;
              break;
            }
        }
      if (!searchflag)
        break;
    }

  /* no rune there. */
  if (tmp == NULL)
    {
      new_draw_info (NDI_UNIQUE, 0, op, "There's nothing there!");
      return 0;
    }

  trap_disarm (op, tmp, 0, skill);
  return 1;
}

int
trap_see (object *op, object *trap)
{
  int chance;

  chance = random_roll (0, 99, op, PREFER_HIGH);;

  /*  decide if we see the rune or not */
  if ((trap->stats.Cha == 1) || (chance > MIN (95, MAX (5, ((int) ((float) (op->map->difficulty
                                                                            + trap->level + trap->stats.Cha - op->level) / 10.0 * 50.0))))))
    {
      new_draw_info_format (NDI_UNIQUE, 0, op, "You spot a %s!", &trap->name);
      return 1;
    }

  return 0;
}

int
trap_show (object *trap, object *where)
{
  if (where == NULL)
    return 0;

  object *tmp = get_archetype ("runedet");
  tmp->face = GET_ANIMATION (trap, 0);
  tmp->insert_at (where, 0);

  return 1;
}

int
trap_disarm (object *disarmer, object *trap, int risk, object *skill)
{
  int trapworth; /* need to compute the experience worth of the trap before we kill it */

  /* this formula awards a more reasonable amount of exp */
  trapworth = MAX (1, trap->level)
            * disarmer->map->difficulty
            * sqr (MAX (trap->stats.dam, trap->inv ? trap->inv->level : 1))
            / skill->level;

  if (!(random_roll (0, (MAX (2, MIN (20, trap->level - skill->level + 5 - disarmer->stats.Dex / 2)) - 1), disarmer, PREFER_LOW)))
    {
      new_draw_info_format (NDI_UNIQUE, 0, disarmer, "You successfully disarm the %s!", &trap->name);
      trap->destroy (true);

      /* If it is your own trap, (or any players trap), don't you don't
       * get exp for it.
       */
      if (trap->owner && trap->owner->type != PLAYER && risk)
        return trapworth;
      else
        return 1;               /* give minimal exp and say success */
    }
  else
    {
      new_draw_info_format (NDI_UNIQUE, 0, disarmer, "You fail to disarm the %s.", &trap->name);
      if (!(random_roll (0, (MAX (2, skill->level - trap->level + disarmer->stats.Dex / 2 - 6)) - 1, disarmer, PREFER_LOW)) && risk)
        {
          new_draw_info (NDI_UNIQUE, 0, disarmer, "In fact, you set it off!");
          spring_trap (trap, disarmer);
        }
      return 0;
    }
}

/*  traps need to be adjusted for the difficulty of the map.  The
 * default traps are too strong for wimpy level 1 players, and 
 * unthreatening to anyone of high level 
 */
void
trap_adjust (object *trap, int difficulty)
{
  int i;

  /* now we set the trap level to match the difficulty of the level
   * the formula below will give a level from 1 to (2*difficulty) with 
   * a peak probability at difficulty 
   */

  trap->level = rndm (0, difficulty - 1) + rndm (0, difficulty - 1);
  if (trap->level < 1)
    trap->level = 1;

  /* set the hiddenness of the trap, similar formula to above */
  trap->stats.Cha = rndm (0, 19) + rndm (0, difficulty - 1) + rndm (0, difficulty - 1);

  if (!trap->other_arch && !trap->inv)
    {
      /* set the damage of the trap.
       * we get 0-4 pts of damage per level of difficulty of the map in
       * the trap
       */

      trap->stats.dam = 0;
      for (i = 0; i < difficulty; i++)
        trap->stats.dam += rndm (0, 4);

      /*  the poison trap special case */
      if (trap->attacktype & AT_POISON)
        {
          trap->stats.dam = rndm (0, difficulty - 1);
          if (trap->stats.dam < 1)
            trap->stats.dam = 1;
        }

      /*  so we get an appropriate amnt of exp for AT_DEATH traps */
      if (trap->attacktype & AT_DEATH)
        trap->stats.dam = 127;
    }

}