/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 *
 * Copyright (©) 2017,2018 Marc Alexander Lehmann / the Deliantra team
 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * Copyright (©) 2002 Mark Wedel & Crossfire Development Team
 * Copyright (©) 1992 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>
 */

#include <global.h>
#include <util.h>
#include <rmg.h>
#include <rproto.h>

/*  Put in the walls and autojoin them.  */

/* given a maze and a coordinate, tell me which squares up/down/right/left
        are occupied. */
int
surround_flag (const layout &maze, int i, int j)
{
  /* 1 = wall to left,
     2 = wall to right,
     4 = wall above
     8 = wall below */
  int surround_index = 0;

  if (i >          0 && maze[i - 1][j] != 0) surround_index |= 1;
  if (i < maze.w - 1 && maze[i + 1][j] != 0) surround_index |= 2;
  if (j >          0 && maze[i][j - 1] != 0) surround_index |= 4;
  if (j < maze.h - 1 && maze[i][j + 1] != 0) surround_index |= 8;

  return surround_index;
}

/* like surround_flag, but only walls count.  */
int
surround_flag2 (const layout &maze, int i, int j)
{
  /* 1 = wall to left,
     2 = wall to right,
     4 = wall above
     8 = wall below */
  int surround_index = 0;

  if (i >          0 && maze[i - 1][j] == '#') surround_index |= 1;
  if (i < maze.w - 1 && maze[i + 1][j] == '#') surround_index |= 2;
  if (j >          0 && maze[i][j - 1] == '#') surround_index |= 4;
  if (j < maze.h - 1 && maze[i][j + 1] == '#') surround_index |= 8;

  return surround_index;
}

/* like surround_flag, except it checks  a map, not a maze.
 * Since this is part of the random map code, presumption
 * is that this is not a tiled map.
 * What is considered blocking and not is somewhat hard coded.
 */
int
surround_flag3 (maptile *map, int i, int j)
{
  /*
   * 1 = blocked to left,
   * 2 = blocked to right,
   * 4 = blocked above
   * 8 = blocked below
   */
  int surround_index = 0;

  // don't forget to update the mapspace!
  if (i >               0) map->at (i - 1, j    ).update ();
  if (i < map->width  - 1) map->at (i + 1, j    ).update ();
  if (j >               0) map->at (i    , j - 1).update ();
  if (j < map->height - 1) map->at (i    , j + 1).update ();

  if (i >               0 && (GET_MAP_MOVE_BLOCK (map, i - 1, j) & MOVE_WALK)) surround_index |= 1;
  if (i < map->width  - 1 && (GET_MAP_MOVE_BLOCK (map, i + 1, j) & MOVE_WALK)) surround_index |= 2;
  if (j >               0 && (GET_MAP_MOVE_BLOCK (map, i, j - 1) & MOVE_WALK)) surround_index |= 4;
  if (j < map->height - 1 && (GET_MAP_MOVE_BLOCK (map, i, j + 1) & MOVE_WALK)) surround_index |= 8;

  return surround_index;
}

/* like surround_flag2, except it checks a map, not a maze. */
static int
surround_flag4 (maptile *map, int i, int j)
{
  /* 1 = blocked to left,
     2 = blocked to right,
     4 = blocked above
     8 = blocked below */
  int surround_index = 0;

  if (i >               0 && wall_blocked (map, i - 1, j)) surround_index |= 1;
  if (i < map->width  - 1 && wall_blocked (map, i + 1, j)) surround_index |= 2;
  if (j >               0 && wall_blocked (map, i, j - 1)) surround_index |= 4;
  if (j < map->height - 1 && wall_blocked (map, i, j + 1)) surround_index |= 8;

  return surround_index;
}

/* picks the right wall type for this square, to make it look nice,
        and have everything nicely joined.  It uses the maze.  */
static object *
pick_joined_wall (object *the_wall, const layout &maze, int i, int j, random_map_params *RP)
{
  int l;
  char wall_name[1024];
  archetype *wall_arch = 0;

  assign (wall_name, the_wall->arch->archname);

  /* conventionally, walls are named like this:
     wallname_wallcode, where wallcode indicates
     a joinedness, and wallname is the wall.
     this code depends on the convention for
     finding the right wall. */

  /* extract the wall name, which is the text up to the leading _ */
  for (l = 0; l < 64; l++)
    {
      if (wall_name[l] == '_')
        {
          wall_name[l] = 0;
          break;
        }
    }

  strcat (wall_name, "_");
  strcat (wall_name, wall_suffix [surround_flag2 (maze, i, j)]);

  wall_arch = archetype::find (wall_name);

  return wall_arch ? wall_arch->instance () : the_wall->arch->instance ();
}

// checks whether the layout has a "reachable" space at a given point, i.e.
// not a wall that is completely surrounded by walls.
static bool inline
is_visible (layout &maze, int i, int j)
{
  for (int dx = -1; dx <= 1; ++dx)
    for (int dy = -1; dy <= 1; ++dy)
      {
        int x = i + dx;
        int y = j + dy;

        if (IN_RANGE_EXC (x, 0, maze.w)
            && IN_RANGE_EXC (y, 0, maze.h)
            && maze [x][y] != '#')
          return true;
      }

  return false;
}

/* takes a map and a maze, and puts walls in the map (picked from
        w_style) at '#' marks. */
void
make_map_walls (maptile *map, layout &maze, const char *w_style, const char *m_style, random_map_params *RP)
{
  object *the_wall;

  /* get the style map */
  if (!strcmp (w_style, "none"))
    return;

  maptile *style_map = find_style ("/styles/wallstyles", w_style, RP->difficulty);
  if (!style_map)
    return;

  maptile *mining_map = m_style && *m_style
      ? find_style ("/styles/miningstyles", m_style, RP->difficulty)
      : 0;

  if ((the_wall = style_map->pick_random_object (rmg_rndm)))
    {
      // first pass, remove all "unreachable" (in-rock) walls
      // and replace them by "blocked" spaces.

      layout clean_maze (maze);

      if (archetype *blocked = archetype::find ("blocked"))
        for (int x = 0; x < maze.w; ++x)
          for (int y = 0; y < maze.h; ++y)
            if (maze [x][y] == '#' && !is_visible (maze, x, y))
              {
                clean_maze [x][y] = 'X';

                // erase everything on this space ad replace it by blocked
                mapspace &ms = map->at (x, y);

                while (ms.top)
                  ms.top->destroy ();

                map->insert (blocked->instance (), x, y, 0, INS_NO_MERGE | INS_NO_WALK_ON);
              }

      // second pass, add in walls

      int joinedwalls = 0;

      assign (RP->wall_name, the_wall->arch->archname);
      if (char *cp = strchr (RP->wall_name, '_'))
        {
          *cp = 0;
          joinedwalls = 1;
        }

      for (int i = 0; i < RP->Xsize; i++)
        for (int j = 0; j < RP->Ysize; j++)
          if (clean_maze [i][j] == '#')
            {
              object *thiswall = joinedwalls ? pick_joined_wall (the_wall, clean_maze, i, j, RP)
                                             : the_wall->arch->instance ();

              thiswall->move_block = MOVE_ALL;
              map->insert (thiswall, i, j, thiswall, INS_NO_MERGE | INS_NO_WALK_ON);

              if (mining_map)
                if (object *vein = mining_map->at (rmg_rndm (mining_map->width), rmg_rndm (mining_map->height)).bot)
                  map->insert (vein->clone (), i, j, thiswall, INS_NO_MERGE | INS_NO_WALK_ON);
            }
    }
}

/* this takes a map, and changes an existing wall to match what's blocked
 * around it, counting only doors and walls as blocked.  If insert_flag is
 * 1, it will go ahead and insert the wall into the map.  If not, it
 * will only return the wall which would belong there, and doesn't
 * remove anything.  It depends on the
 * global, previously-set variable, "wall_name"
 */
object *
retrofit_joined_wall (maptile *the_map, int i, int j, int insert_flag, random_map_params *RP)
{
  int l;
  object *the_wall = 0;
  object *new_wall = 0;
  archetype *wall_arch = 0;

  /* first find the wall */
  for (the_wall = GET_MAP_OB (the_map, i, j); the_wall; the_wall = the_wall->above)
    if ((the_wall->move_type & MOVE_WALK) && the_wall->type != EXIT && the_wall->type != TELEPORTER)
      break;

  /* if what we found is a door, don't remove it, set the_wall to NULL to
   * signal that later.
   */
  if (the_wall && (the_wall->type == DOOR || the_wall->type == LOCKED_DOOR))
    {
      the_wall = NULL;
      /* if we're not supposed to insert a new wall where there wasn't one,
       * we've gotta leave.
       */
      if (insert_flag == 0)
        return 0;
    }
  else if (the_wall == NULL)
    return NULL;

  /* canonicalize the wall name */
  for (l = 0; l < 64; l++)
    {
      if (RP->wall_name[l] == '_')
        {
          RP->wall_name[l] = 0;
          break;
        }
    }

  strcat (RP->wall_name, "_");
  strcat (RP->wall_name, wall_suffix [surround_flag4 (the_map, i, j)]);

  wall_arch = archetype::find (RP->wall_name);

  if (!wall_arch)
    {
      new_wall = wall_arch->instance ();
      new_wall->x = i;
      new_wall->y = j;

      if (the_wall->map)
        the_wall->destroy ();

      the_wall->move_block = MOVE_ALL;
      insert_ob_in_map (new_wall, the_map, new_wall, INS_NO_MERGE | INS_NO_WALK_ON);
    }

  return new_wall;
}