/* peterm@langmuir.eecs.berkeley.edu:  this function generates a random
snake-type layout.

input:  xsize, ysize;
output:  a char** array with # and . for closed and open respectively.

a char value of 0 represents a blank space:  a '#' is
a wall.

*/


#include <stdio.h>
#include <global.h>
#include <time.h>




char **
make_snake_layout (int xsize, int ysize, int options)
{
  int i, j;

  /* allocate that array, set it up */
  char **maze = (char **) calloc (sizeof (char *), xsize);

  for (i = 0; i < xsize; i++)
    {
      maze[i] = (char *) calloc (sizeof (char), ysize);
    }

  /* write the outer walls */
  for (i = 0; i < xsize; i++)
    maze[i][0] = maze[i][ysize - 1] = '#';
  for (j = 0; j < ysize; j++)
    maze[0][j] = maze[xsize - 1][j] = '#';

  /* Bail out if the size is too small to make a snake. */
  if (xsize < 8 || ysize < 8)
    return maze;

  /* decide snake orientation--vertical or horizontal , and
     make the walls and place the doors. */

  if (RANDOM () % 2)
    {                           /* vertical orientation */
      int n_walls = RANDOM () % ((xsize - 5) / 3) + 1;
      int spacing = xsize / (n_walls + 1);
      int orientation = 1;

      for (i = spacing; i < xsize - 3; i += spacing)
        {
          if (orientation)
            {
              for (j = 1; j < ysize - 2; j++)
                {
                  maze[i][j] = '#';
                }
              maze[i][j] = 'D';
            }
          else
            {
              for (j = 2; j < ysize; j++)
                {
                  maze[i][j] = '#';
                }
              maze[i][1] = 'D';
            }
          orientation ^= 1;     /* toggle the value of orientation */
        }
    }
  else
    {                           /* horizontal orientation */
      int n_walls = RANDOM () % ((ysize - 5) / 3) + 1;
      int spacing = ysize / (n_walls + 1);
      int orientation = 1;

      for (i = spacing; i < ysize - 3; i += spacing)
        {
          if (orientation)
            {
              for (j = 1; j < xsize - 2; j++)
                {
                  maze[j][i] = '#';
                }
              maze[j][i] = 'D';
            }
          else
            {
              for (j = 2; j < xsize; j++)
                {
                  maze[j][i] = '#';
                }
              maze[1][i] = 'D';
            }
          orientation ^= 1;     /* toggle the value of orientation */
        }
    }

  /* place the exit up/down */
  if (RANDOM () % 2)
    {
      maze[1][1] = '<';
      maze[xsize - 2][ysize - 2] = '>';
    }
  else
    {
      maze[1][1] = '>';
      maze[xsize - 2][ysize - 2] = '<';
    }


  return maze;
}