/**
 * @file
 * Snake-like layout generator.
 * @author peterm@langmuir.eecs.berkeley.edu
 */
#include <stdio.h>
#include <global.h>
#include <time.h>

/**
 * Generate a snake-like layout.
 * @param xsize
 * @param ysize
 * layout size.
 * @return
 * generated layout.
 */
char **make_snake_layout(int xsize, int ysize) {
    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;
}