/****************************************************************************
 * [S]imulated [M]edieval [A]dventure multi[U]ser [G]ame      |   \\._.//   *
 * -----------------------------------------------------------|   (0...0)   *
 * SMAUG 1.0 (C) 1994, 1995, 1996 by Derek Snider             |    ).:.(    *
 * -----------------------------------------------------------|    {o o}    *
 * SMAUG code team: Thoric, Altrag, Blodkai, Narn, Haus,      |   / ' ' \   *
 * Scryn, Rennard, Swordbearer, Gorog, Grishnakh and Tricops  |~'~.VxvxV.~'~*
 * ------------------------------------------------------------------------ *
 *			 Tracking/hunting module			    *
 ****************************************************************************/

#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include "mud.h"

#define BFS_ERROR	   -1
#define BFS_ALREADY_THERE  -2
#define BFS_NO_PATH	   -3
#define BFS_MARK    536870912

#define TRACK_THROUGH_DOORS

extern sh_int	top_room;

/* You can define or not define TRACK_THOUGH_DOORS, above, depending on
   whether or not you want track to find paths which lead through closed
   or hidden doors.
*/

struct bfs_queue_struct {
   ROOM_INDEX_DATA *room;
   char   dir;
   struct bfs_queue_struct *next;
};

static struct bfs_queue_struct	*queue_head = NULL,
				*queue_tail = NULL,
				*room_queue = NULL;

/* Utility macros */
#define MARK(room)	(SET_BIT(	(room)->room_flags, BFS_MARK) )
#define UNMARK(room)	(REMOVE_BIT(	(room)->room_flags, BFS_MARK) )
#define IS_MARKED(room)	(IS_SET(	(room)->room_flags, BFS_MARK) )

ROOM_INDEX_DATA *toroom( ROOM_INDEX_DATA *room, sh_int door )
{
    return (get_exit( room, door )->to_room);
}

bool valid_edge( ROOM_INDEX_DATA *room, sh_int door )
{
    EXIT_DATA *pexit;
    ROOM_INDEX_DATA *to_room;

    pexit = get_exit( room, door );
    if ( pexit
    &&  (to_room = pexit->to_room) != NULL
#ifndef TRACK_THROUGH_DOORS
    &&  !IS_SET( pexit->exit_info, EX_CLOSED )
#endif
    &&  !IS_MARKED( to_room ) )
      return TRUE;
    else
      return FALSE;
}

void bfs_enqueue(ROOM_INDEX_DATA *room, char dir)
{
   struct bfs_queue_struct *curr;

   CREATE( curr, struct bfs_queue_struct, 1 );
   curr->room = room;
   curr->dir = dir;
   curr->next = NULL;

   if (queue_tail) {
      queue_tail->next = curr;
      queue_tail = curr;
   } else
      queue_head = queue_tail = curr;
}


void bfs_dequeue(void)
{
   struct bfs_queue_struct *curr;

   curr = queue_head;

   if (!(queue_head = queue_head->next))
      queue_tail = NULL;
   DISPOSE(curr);
}


void bfs_clear_queue(void) 
{
   while (queue_head)
      bfs_dequeue();
}

void room_enqueue(ROOM_INDEX_DATA *room)
{
   struct bfs_queue_struct *curr;

   CREATE( curr, struct bfs_queue_struct, 1 );
   curr->room = room;
   curr->next = room_queue;

   room_queue = curr;
}

void clean_room_queue(void) 
{
   struct bfs_queue_struct *curr, *curr_next;

   for (curr = room_queue; curr; curr = curr_next )
   {
      UNMARK( curr->room );
      curr_next = curr->next;
      DISPOSE( curr );
   }
   room_queue = NULL;
}


int find_first_step(ROOM_INDEX_DATA *src, ROOM_INDEX_DATA *target, int maxdist )
{
   int curr_dir, count;

   if ( !src || !target )
   {
      bug("Illegal value passed to find_first_step (track.c)", 0 );
      return BFS_ERROR;
   }

   if (src == target)
      return BFS_ALREADY_THERE;

   if ( src->area != target->area )
      return BFS_NO_PATH;

   room_enqueue( src );
   MARK(src);

   /* first, enqueue the first steps, saving which direction we're going. */
   for (curr_dir = 0; curr_dir < 10; curr_dir++)
      if (valid_edge(src, curr_dir))
      {
         MARK(toroom(src, curr_dir));
	 room_enqueue(toroom(src, curr_dir));
         bfs_enqueue(toroom(src, curr_dir), curr_dir);
      }

   count = 0;
   while (queue_head) {
      if ( ++count > maxdist )
      {
	bfs_clear_queue();
	clean_room_queue();
	return BFS_NO_PATH;
      }
      if (queue_head->room == target) {
	 curr_dir = queue_head->dir;
	 bfs_clear_queue();
	 clean_room_queue();
	 return curr_dir;
      } else {
         for (curr_dir = 0; curr_dir < 10; curr_dir++)
            if (valid_edge(queue_head->room, curr_dir)) {
               MARK(toroom(queue_head->room, curr_dir));
	       room_enqueue(toroom(queue_head->room, curr_dir));
	       bfs_enqueue(toroom(queue_head->room, curr_dir),queue_head->dir);
            }
         bfs_dequeue();
      }
   }
   clean_room_queue();

   return BFS_NO_PATH;
}


void do_track( CHAR_DATA *ch, char *argument )
{
   CHAR_DATA *vict;
   char arg[MAX_INPUT_LENGTH];
   char buf[MAX_STRING_LENGTH];
   int dir, maxdist;

   if ( !IS_NPC(ch) && !ch->pcdata->learned[gsn_track] )
   {
	send_to_char("You do not know of this skill yet.\n\r", ch );
	return;
   }

   one_argument(argument, arg);
   if ( arg[0]=='\0' ) {
      send_to_char("Whom are you trying to track?\n\r", ch);
      return;
   }

   WAIT_STATE( ch, skill_table[gsn_track]->beats );

   if (!(vict = get_char_world(ch, arg))) {
      send_to_char("You can't find a trail of anyone like that.\n\r", ch);
      return;
   }

   maxdist = 100 + ch->level * 30;

   if ( !IS_NPC(ch) )
     maxdist = (maxdist * ch->pcdata->learned[gsn_track]) / 100;

   dir = find_first_step(ch->in_room, vict->in_room, maxdist);

   switch(dir) {
      case BFS_ERROR:
         send_to_char("Hmm... something seems to be wrong.\n\r", ch);
         break;
      case BFS_ALREADY_THERE:
         send_to_char("You're already in the same room!\n\r", ch);
         break;
      case BFS_NO_PATH:
         sprintf(buf, "You can't sense a trail from here.\n\r" );
         send_to_char(buf, ch);
	 learn_from_failure( ch, gsn_track );
         break;
      default:
         ch_printf(ch, "You sense a trail %s from here...\n\r", dir_name[dir]);
	 learn_from_success( ch, gsn_track );
         break;
   }
}


void found_prey( CHAR_DATA *ch, CHAR_DATA *victim )
{
     char buf[MAX_STRING_LENGTH];
     char victname[MAX_STRING_LENGTH];

     if (victim == NULL)
     {
	bug("Found_prey: null victim", 0);
	return;
     }

     if ( victim->in_room == NULL )
     {
        bug( "Found_prey: null victim->in_room", 0 );
        return;
     }

     sprintf( victname, IS_NPC( victim ) ? victim->short_descr : victim->name );

     if ( !can_see(ch, victim) )
     {
        if ( number_percent( ) < 90 )
	  return;
	switch( number_bits( 2 ) )
 	{
	case 0: sprintf( buf, "Don't make me find you, %s!", victname );
		do_say( ch, buf );
	        break;
	case 1: act( AT_ACTION, "$n sniffs around the room for $N.", ch, NULL, victim, TO_NOTVICT );
		act( AT_ACTION, "You sniff around the room for $N.", ch, NULL, victim, TO_CHAR );
		act( AT_ACTION, "$n sniffs around the room for you.", ch, NULL, victim, TO_VICT );
		sprintf( buf, "I can smell your blood!" );
		do_say( ch, buf );
		break;
	case 2: sprintf( buf, "I'm going to tear %s apart!", victname );
		do_yell( ch, buf );
		break;
	case 3: do_say( ch, "Just wait until I find you...");
		break;
        }
	return;
     }

     if ( IS_SET( ch->in_room->room_flags, ROOM_SAFE ) )
     {
	if ( number_percent( ) < 90 )
	  return;
	switch( number_bits( 2 ) )
	{
	case 0:	do_say( ch, "C'mon out, you coward!" );
		sprintf( buf, "%s is a bloody coward!", victname );
		do_yell( ch, buf );
		break;
	case 1: sprintf( buf, "Let's take this outside, %s", victname );
		do_say( ch, buf );
		break;
	case 2: sprintf( buf, "%s is a yellow-bellied wimp!", victname );
		do_yell( ch, buf );
		break;
	case 3: act( AT_ACTION, "$n takes a few swipes at $N.", ch, NULL, victim, TO_NOTVICT );
		act( AT_ACTION, "You try to take a few swipes $N.", ch, NULL, victim, TO_CHAR );
		act( AT_ACTION, "$n takes a few swipes at you.", ch, NULL, victim, TO_VICT );
		break;
	}
	return;
     }

     switch( number_bits( 2 ) )
     {
     case 0: sprintf( buf, "Your blood is mine, %s!", victname );
	     do_yell( ch, buf);
	     break;
     case 1: sprintf( buf, "Alas, we meet again, %s!", victname );
     	     do_say( ch, buf );
     	     break;
     case 2: sprintf( buf, "What do you want on your tombstone, %s?", victname );
     	     do_say( ch, buf );
     	     break;
     case 3: act( AT_ACTION, "$n lunges at $N from out of nowhere!", ch, NULL, victim, TO_NOTVICT );
	     act( AT_ACTION, "You lunge at $N catching $M off guard!", ch, NULL, victim, TO_CHAR );
	     act( AT_ACTION, "$n lunges at you from out of nowhere!", ch, NULL, victim, TO_VICT );
     }
     stop_hunting( ch );
     set_fighting( ch, victim );
     multi_hit(ch, victim, TYPE_UNDEFINED);
     return;
} 

void hunt_victim( CHAR_DATA *ch )
{
   bool found;
   CHAR_DATA *tmp;
   sh_int ret;

   if (!ch || !ch->hunting)
      return;

   /* make sure the char still exists */
   for (found = FALSE, tmp = first_char; tmp && !found; tmp = tmp->next)
      if (ch->hunting->who == tmp)
         found = TRUE;

   if (!found)
   {
      do_say(ch, "Damn!  My prey is gone!!" );
      stop_hunting( ch );
      return;
   }

   if ( ch->in_room == ch->hunting->who->in_room )
   {
     if ( ch->fighting )
       return;
     found_prey( ch, ch->hunting->who );
     return;
   }
   
   ret = find_first_step(ch->in_room, ch->hunting->who->in_room, 500 + ch->level * 25);
   if (ret<0)
   {
      do_say( ch, "Damn!  Lost my prey!" );
      stop_hunting( ch );
      return;
   }
   else
   {
      move_char( ch, get_exit( ch->in_room, ret), FALSE );
      if ( !ch->hunting )
      {
        if ( !ch->in_room )
        {
          char buf[MAX_STRING_LENGTH];
          sprintf( buf, "Hunt_victim: no ch->in_room!  Mob #%d, name: %s.  Placing mob in limbo.",
                   ch->pIndexData->vnum, ch->name );
          bug( buf, 0 );
          char_to_room( ch, get_room_index( ROOM_VNUM_LIMBO ) );
          return;
        } 
	do_say( ch, "Damn!  Lost my prey!" );
	return;
      }
      if (ch->in_room == ch->hunting->who->in_room)
	found_prey( ch, ch->hunting->who );
      return;
   }
}