#include <getopt.h>
#include <curses.h>
#include <unistd.h>
#include <stdlib.h>
#include <malloc_np.h>
#include <string.h>
#include <time.h>

/* cc pepper2.c -lncurses -o p2 -O2 */

typedef struct {
	size_t len;
	char *items[10];
} truc_array;

enum dirs {
	R, /* right */
	L, /* left */
	U, /* up */
	D /* down */	
};

static size_t delay = 150;

/* result window */
static WINDOW * winR;

/* sprite */
static void worm(WINDOW *win, int x, int y, char c0, char repl)
{
	static int ax, ay;
	static char ac = '*';

	wattron(win, A_REVERSE);
	mvwaddch(win, y + 1, x + 1, c0);
	wattroff(win, A_REVERSE);
	if (ac != '*') {
		int colnum = 4;

		if (ac != '.')
			colnum = 1;
		wattron(win, COLOR_PAIR(colnum));
		mvwaddch(win, ay, ax, ac);
		wattroff(win, COLOR_PAIR(colnum));
	}
	wrefresh(win);
	ax = x + 1;
	ay = y + 1;
	ac = repl;
	usleep(delay * 1000);
}

/* path lookup */
static __attribute((malloc)) __attribute__((nonnull)) char *get_it(truc_array const *src)
{
	char *r = mallocx(src->len, MALLOCX_ZERO);
	size_t n = 0;
	enum dirs dir = R;
	int x = 0, y = 0;
	char c0 = '<';

	WINDOW * win = newwin(12, 17, 1, 49);

	curs_set(0);
	box(win, 0, 0);


	while (src->len && (n < src->len)) {
		char c;

		while((c = src->items[y][x]) != ' ') {
			/* store */
			if (c != '*') {
				worm(win, x, y, c0, c);
				if (n > 0)
					mvwaddch(winR, 1, n , r[n - 1]);
				r[n++] = c;
				wattron (winR, COLOR_PAIR(2));
				mvwaddch(winR, 1, n, c);
				wattroff(winR, COLOR_PAIR(2));
				wrefresh(winR);
			} else
				worm(win, x, y, c0, '.');


			if (n == src->len) {
				break;
			}

			/* test next one */
			int tx = x;
			int ty = y;
			switch (dir) {
				case R:
					tx++;
					break;
				case L:
					tx--;
					break;
				case U:
					ty--;
					break;
				case D:
					ty++;
					break;
				default:
					fprintf(stderr, "Bug!\n");
					break;
			}

			/* ouch */
			if (tx > 14 || tx < 0 || ty <0 || ty > 9)
				break;
			if ((c = src->items[ty][tx]) == ' ') {
				wattron(win,COLOR_PAIR(3));
				mvwaddch(win, ty + 1, tx + 1, c);
				wattroff(win, COLOR_PAIR(3));
				break;
			}
			/* valid next */
			x = tx;
			y = ty;
		}

		switch (dir) {
			char c_up, c_down, c_left, c_right;
			case R:
			case L:
			/* cover up and down */
			c_up   = ' ';
			c_down = ' ';

			if (y > 1)
				c_up   = src->items[y - 1][x];
			if (y < 9)
				c_down = src->items[y + 1][x];
			if (c_up != ' ') {
				y = y - 1;
				dir = U;
				c0 = '^';
			}
			else if (c_down != ' ') {
				y = y + 1;
				dir = D;
				c0 = ';';
			}
			else
				goto end;
			break;
			case U:
			case D:

			/* cover left and right */
			c_left   = ' ';
			c_right = ' ';

			if (x > 1)
				c_left  = src->items[y][x - 1];
			if (y < 14)
				c_right = src->items[y][x + 1];

			if (c_left != ' ') {
				x = x - 1;
				dir = L;
				c0 = '>';
			}
			else if (c_right != ' ') {
				x = x + 1;
				dir = R;
				c0 = '<';
			} else
				goto end;
			break;
		}
	}

end:
	worm(win, x , y , ' ', ' ');
	if (n > 1) {
		mvwaddch(winR, 1, n, r[n -1]);
		wrefresh(winR);
	}
	delwin(win);
	return r;
}

/* puzzle display */
static void print_it(truc_array src)
{
	WINDOW * win = newwin(12, 17, 1, 1);
	box(win, 0, 0);
	for (size_t j= 0; j < 10; ++j) {
		mvwprintw(win, j + 1, 1, "%s", src.items[j]);
	}
	wrefresh(win);
	delwin(win);
}

int main(int argc, char *argv[])
{
	truc_array a= {60, };
	char *r = NULL;
	static struct option longopts[] = {
		{ "delay",   required_argument,      NULL, 'd' },
		{ NULL,	0, NULL, 0 }
	};
	int ch;
	while ((ch = getopt_long(argc, argv, "d:", longopts, NULL)) != -1) {
		switch (ch) {
			case 'd':
				delay = strtoul(optarg, NULL, 10);
				break;
			case 0:
				/* long option */
				break;
			default:
				break;
		}
	}

	/*            012345789ABCDEF */
	a.items[0] = "*01**         $";
	a.items[1] = "edcBA          ";
	a.items[2] = "*  *       X   ";
	a.items[3] = "*  !       *   ";
	a.items[4] = "****F**        ";
	a.items[5] = "      *  *H*   ";
	a.items[6] = "      *G** *   ";
	a.items[7] = "   X       I   ";
	a.items[8] = "   X **J****   ";
	a.items[9] = "X    Z        $";

	initscr();
	nonl();
	noecho();
	winR = newwin(3, 65, 13, 1);
	box(winR, 0, 0);
	wrefresh(winR);

	start_color();
	init_pair(1, COLOR_RED, COLOR_GREEN);
	init_pair(2, COLOR_BLACK, COLOR_MAGENTA);
	init_pair(3, COLOR_BLUE, COLOR_BLUE);
	init_pair(4, COLOR_YELLOW, COLOR_GREEN);
	print_it(a);
	r = get_it(&a);
	dallocx(r, 0);
	delwin(winR);
	endwin();
}