/*******************************************************************************
 minesviiper 0.4
 By Tobias Girstmair, 2015 - 2018

 ./minesviiper 16x16x40
 (see ./minesviiper -h for full list of options)

 MOUSE MODE: - left click to open and choord
             - right click to flag/unflag
 VI MODE:    - hjkl to move cursor left/down/up/right
             - o/space to open and choord
             - i to flag/unflag
             - (see `./minesviiper -h' for all keybindings)

 GNU GPL v3, see LICENSE or https://www.gnu.org/licenses/gpl-3.0.txt
*******************************************************************************/


#define _POSIX_C_SOURCE 2 /*for getopt, sigaction in c99*/
#include <ctype.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

#include "mines.h"
#include "schemes.h"

#define LINE_OFFSET 3
#define LINES_AFTER 2
#define COL_OFFSET 2
#define BIG_MOVE 5
#define MOUSE_MAX 231

#define MIN(a,b) (a>b?b:a)
#define MAX(a,b) (a>b?a:b)
#define CLAMP(a,m,M) (a<m?m:(a>M?M:a))
#define printm(n, s) for (int _loop = 0; _loop < n; _loop++) fputs (s, stdout)
#define print(str) fputs (str?str:"", stdout)
#define EMOT(e) op.scheme->emoticons[EMOT_ ## e]
#define BORDER(l, c) op.scheme->border[B_ ## l][B_ ## c]
#define CW op.scheme->cell_width /* for brevity */
#define HI_CELL f.c[g.p[0]][g.p[1]]
#define CTRL_ 0x1F &

#define AR_CELL f.c[ROW][COL] /* helper for AROUND() */
#define AROUND(l, c) /* gives us loop-variables ROW, COL, AR_CELL */ \
	for (int ROW = MAX(l-1, 0); ROW <= MIN(l+1, f.h-1); ROW++) \
		for (int COL = MAX(c-1, 0); COL <= MIN(c+1, f.w-1); COL++) \
			if (!(ROW == l && COL == c)) /* skip itself */

struct minefield f;
struct game g;
struct opt op;

int main (int argc, char** argv) {
	/* defaults: */
	f.w = 30;
	f.h = 16;
	f.m = 99;
	op.scheme = &symbols_mono;
	op.mode = FLAG;

	int optget;
	opterr = 0; /* don't print message on unrecognized option */
	while ((optget = getopt (argc, argv, "+hnfqcdx")) != -1) {
		switch (optget) {
		case 'n': op.mode    = NOFLAG; break;
		case 'f': op.mode    = FLAG; break; /*default*/
		case 'q': op.mode    = QUESM; break; /*WARN:implicitly sets -f*/
		case 'c': op.scheme  = &symbols_col1; break;
		case 'd': op.scheme  = &symbols_doublewidth; break;
		case 'h':
		default: 
			fprintf (stderr, SHORTHELP LONGHELP, argv[0]);
			return !(optget=='h');
		}
	} if (optind < argc) { /* parse Fieldspec */
		if (parse_fieldspec (argv[optind])) {
			fprintf (stderr, "FIELDSPEC: WxH[xM]"
			" (width 'x' height 'x' mines)\n");
			return 1;
		}
	}

	signal_setup();
	screen_setup(1);
	atexit (*quit);

newgame:
	switch (minesviiper()) {
	case GAME_NEW: goto newgame;
	case GAME_WON: g.o = GAME_WON; break;
	case GAME_LOST:g.o = GAME_LOST;break;
	case GAME_QUIT:goto quit;
	}

	timer_setup(0); /* stop timer */
	show_minefield (SHOWMINES);
	for(;;) {
		switch(getch_wrapper()) {
		case WRAPPER_EMOTICON:
		case 'r': goto newgame;
		case 'q': goto quit;
		case CTRL_'R':
			interactive_resize();
			goto newgame;
		}
	}

quit:
	return 0;
}

int minesviiper(void) {
	f.c = alloc_array (f.h, f.w);
	g = (const struct game){0}; /* reset all game-specific parameters */

	show_minefield (NORMAL);

	for(;;) {
		switch (getch_wrapper()) {
		case ' ':
			if (HI_CELL.o == OPENED) goto open_cell;
			if (g.s == MODE_OPEN)  goto open_cell;
			if (g.s == MODE_FLAG)  goto flag_cell;
			if (g.s == MODE_QUESM) goto quesm_cell;
			break;
		case 'a':
			g.s = (g.s+1)%(op.mode+1);
			show_minefield (g.c?SHOWMINES:NORMAL);
			break;
		open_cell:
		case CTRSEQ_MOUSE_LEFT:
		case 'o':
			switch (do_uncover(&(g.n))) {
				case GAME_LOST: return GAME_LOST;
				case GAME_WON:  return GAME_WON;
			}
			break;
		flag_cell:
		case CTRSEQ_MOUSE_RIGHT:
		case 'i': flag_square (g.p[0], g.p[1]); break;
		quesm_cell:
		case '?':quesm_square (g.p[0], g.p[1]); break;
		case CTRSEQ_CURSOR_LEFT:
		case 'h': move_hi (g.p[0],   g.p[1]-1); break;
		case CTRSEQ_CURSOR_DOWN:
		case 'j': move_hi (g.p[0]+1, g.p[1]  ); break;
		case CTRSEQ_CURSOR_UP:
		case 'k': move_hi (g.p[0]-1, g.p[1]  ); break;
		case CTRSEQ_CURSOR_RIGHT:
		case 'l': move_hi (g.p[0],   g.p[1]+1); break;
		case 'w': to_next_boundary (g.p[0], g.p[1], '>'); break;
		case 'b': to_next_boundary (g.p[0], g.p[1], '<'); break;
		case 'u': to_next_boundary (g.p[0], g.p[1], '^'); break;
		case 'd': to_next_boundary (g.p[0], g.p[1], 'v'); break;
		case '0': /* fallthrough */
		case '^': move_hi (g.p[0],    0        ); break;
		case '$': move_hi (g.p[0],    f.w-1    ); break;
		case 'g': move_hi (0,         g.p[1]   ); break;
		case 'G': move_hi (f.h-1,     g.p[1]   ); break;
		case 'z': move_hi (f.h/2, f.w/2); break;
		case 'm': set_mark(); break;
		case'\'': /* fallthrough */
		case '`': jump_mark(); break;
		case WRAPPER_EMOTICON:
		case 'r': return GAME_NEW;
		case 'q': return GAME_QUIT;
		case CTRL_'L':
			screen_setup(1);
			show_minefield (NORMAL);
			break;
		case CTRL_'R':
			interactive_resize();
			return GAME_NEW;
		case '\\':
			if (g.n == GAME_NEW) break; /* must open a cell first */
			g.c = !g.c;
			show_minefield (g.c?SHOWMINES:NORMAL);
			break;
		}
	}

}

void quit (void) {
	screen_setup(0);
	free_field ();
}

/* I haven't won as long as a cell exists, that
    - I haven't opened, and
    - is not a mine */
int everything_opened (void) {
	for (int row = 0; row < f.h; row++)
		for (int col = 0; col < f.w; col++)
			if (f.c[row][col].o == CLOSED &&
			    f.c[row][col].m == NO_MINE  ) return 0;
	return 1;
}

int wait_mouse_up (int l, int c) { /* TODO: should not take minefield-coords but absolute ones */
	unsigned char mouse2[3];
	int level = 1;
	int l2, c2;

	/* show :o face */
	move_ph (1, field2screen_c (f.w/2)-1); print (EMOT(OHH));

	if (!(l < 0 || l >= f.h || c < 0 || c >= f.w)) {
		/* show a pushed-in button if cursor is on minefield */
		partial_show_minefield (l, c, HIGHLIGHT);
	}

	while (level > 0) {
		if (getctrlseq (mouse2) == CTRSEQ_MOUSE) {
			/* ignore mouse wheel events: */
			if (mouse2[0] & 0x40) continue;

			else if (mouse2[0]&3 == 3) level--; /* release event */
			else level++; /* another button pressed */
		}
	}

	move_ph (1, field2screen_c (f.w/2)-1); print (get_emoticon());

	if (!(l < 0 || l >= f.h || c < 0 || c >= f.w)) {
		partial_show_minefield (l, c, NORMAL);
	}
	c2 = screen2field_c(mouse2[1]);
	l2 = screen2field_l(mouse2[2]);
	return ((l2 == l) && (c2 == c));
}

int choord_square (int line, int col) {
	if (uncover_square (line, col)) return 1;
	AROUND(line,col)
		if (AR_CELL.f != FLAG) {
			if (uncover_square (ROW, COL))
				 return 1;
		}

	return 0;
}

int uncover_square (int l, int c) {
	if (f.c[l][c].o == OPENED)
		return 0; /* nothing to do */

	f.c[l][c].o = OPENED;
	f.c[l][c].f = NOFLAG; /*must not be QUESM, otherwise rendering issues*/
	partial_show_minefield (l, c, NORMAL);

	if (f.c[l][c].m) {
		f.c[l][c].m = DEATH_MINE;
		return 1;
	}

	/* check for chording */
	if (f.c[l][c].n == 0) {
		AROUND(l, c)
			if (uncover_square (ROW, COL)) return 1;
	}

	return 0;
}

void flag_square (int l, int c) {
	static char modechar[] = {'*', '!', '?'};

	if (f.c[l][c].o != CLOSED) return;
	/* cycle through flag/quesm/noflag: */
	f.c[l][c].f = (f.c[l][c].f + 1) % (op.mode + 1);
	if (f.c[l][c].f==FLAG) g.f++;
	else if ((op.mode==FLAG  && f.c[l][c].f==NOFLAG) ||
	         (op.mode==QUESM && f.c[l][c].f==QUESM)) g.f--;
	partial_show_minefield (l, c, NORMAL);
	move_ph (1, op.scheme->cell_width);
	printf ("[%03d%c]", f.m - g.f, modechar[g.s]);
}

void quesm_square (int l, int c) {
	/* toggle question mark / none. won't turn flags into question marks.
	unlike flag_square, this function doesn't respect `-q'. */
	if      (f.c[l][c].o != CLOSED) return;
	else if (f.c[l][c].f == NOFLAG) f.c[l][c].f = QUESM;
	else if (f.c[l][c].f == QUESM)  f.c[l][c].f = NOFLAG;
	partial_show_minefield (l, c, NORMAL);
}

int do_uncover (int* is_newgame) {
	if (*is_newgame == GAME_NEW) {
		*is_newgame = GAME_INPROGRESS;
		fill_minefield (g.p[0], g.p[1]);
		timer_setup(1);
	}

	if (HI_CELL.f == FLAG  ) return GAME_INPROGRESS;
	if (HI_CELL.o == CLOSED) {
		if (uncover_square (g.p[0], g.p[1])) return GAME_LOST;
	} else if (get_neighbours (g.p[0], g.p[1], 1) == 0) {
		if (choord_square (g.p[0], g.p[1])) return GAME_LOST;
	} else {
		/* show the stomp radius if we aren't fully flagged */
		AROUND(g.p[0], g.p[1])
			if (AR_CELL.o == CLOSED && AR_CELL.f !=FLAG)
				partial_show_minefield (ROW, COL, HIGHLIGHT);
		/* TODO: save g.p, then in ~.1s execute:
		AROUND(saved_l, saved_r) partial_show_minefield (ROW, COL, NORMAL);
		using setitimer is tricky, because we already use SIGALRM; and it
		should also trigger when a key is pressed. maybe a getchar() with
		a read(2)-timeout + ungetch()? (usleep did not show the stomp at all?!) */
	}
	if (everything_opened()) return GAME_WON;

	return GAME_INPROGRESS;
}

void set_mark(void) {
	int mark = tolower(getch_wrapper());
	if (mark < 'a' || mark > 'z') return; /*out of bound*/

	g.m[mark-'a'].l = g.p[0];
	g.m[mark-'a'].c = g.p[1];
	g.m[mark-'a'].s = 1;
}

void jump_mark(void) {
	int mark = tolower(getch_wrapper());
	/* check bounds and if set: */
	if (mark < 'a' || mark > 'z' || !g.m[mark-'a'].s) return;
	move_hi (g.m[mark-'a'].l, g.m[mark-'a'].c);
}

void fill_minefield (int l, int c) {
	srand (time(0));
	int mines_set = f.m;
	while (mines_set) {
		int line = rand() % f.h;
		int col = rand() % f.w;

		if (f.c[line][col].m) {
		/* skip if field already has a mine */
			continue;
		} else if ((line == l) && (col == c)) {
		/* don't put a mine on the already opened (first click) field */
			continue;
		} else {
			mines_set--;
			f.c[line][col].m = STD_MINE;
		}
	}

	/* precalculate neighbours */
	for (int l=0; l < f.h; l++)
		for (int c=0; c < f.w; c++)
			f.c[l][c].n = get_neighbours (l, c, NORMAL);
}

void move_ph (int line, int col) {
	/* move printhead to zero-indexed position */
	printf ("\033[%d;%dH", line+1, col+1);
}

void move_hi (int l, int c) {
	/* move cursor and highlight to absolute coordinates */

	partial_show_minefield (g.p[0], g.p[1], NORMAL);
	/* update g.p */
	g.p[0] = CLAMP(l, 0, f.h-1);
	g.p[1] = CLAMP(c, 0, f.w-1);
	move_ph (g.p[0]+LINE_OFFSET, field2screen_c(g.p[1]));

	partial_show_minefield (g.p[0], g.p[1], HIGHLIGHT);
}

/* to_next_boundary(): move into the supplied direction until a change in open-
state or flag-state is found and move there. falls back to BIG_MOVE. */
#define FIND_NEXT(X, L, C, L1, C1, MAX, OP) do {\
	new_ ## X OP ## = BIG_MOVE;\
	for (int i = X OP 1; i > 0 && i < f.MAX-1; i OP ## OP)\
		if (((f.c[L ][C ].o<<2) + f.c[L ][C ].f) \
		 != ((f.c[L1][C1].o<<2) + f.c[L1][C1].f)) {\
			new_ ## X = i OP 1;\
			break;\
		}\
	} while(0)
void to_next_boundary (int l, int c, char direction) {
	int new_l = l;
	int new_c = c;
	switch (direction) {
	case '>': FIND_NEXT(c, l, i, l, i+1, w, +); break;
	case '<': FIND_NEXT(c, l, i, l, i-1, w, -); break;
	case '^': FIND_NEXT(l, i, c, i-1, c, h, -); break;
	case 'v': FIND_NEXT(l, i, c, i+1, c, h, +); break;
	}

	move_hi (new_l, new_c);
}
#undef FIND_NEXT

char* cell2schema (int l, int c, int mode) {
	struct minecell cell = f.c[l][c];

	if (mode == SHOWMINES) return (
		cell.f == FLAG &&  cell.m ? op.scheme->field_flagged:
		cell.f == FLAG && !cell.m ? op.scheme->mine_wrongf:
		cell.m == STD_MINE        ? op.scheme->mine_normal:
		cell.m == DEATH_MINE      ? op.scheme->mine_death:
		cell.o == CLOSED          ? op.scheme->field_closed:
		/*.......................*/ op.scheme->number[f.c[l][c].n]);
	 else return (
		cell.f == FLAG            ? op.scheme->field_flagged:
		cell.f == QUESM           ? op.scheme->field_question:
		cell.o == CLOSED          ? op.scheme->field_closed:
		cell.m == STD_MINE        ? op.scheme->mine_normal:
		cell.m == DEATH_MINE      ? op.scheme->mine_death:
		/*.......................*/ op.scheme->number[f.c[l][c].n]);
}

void partial_show_minefield (int l, int c, int mode) {
	move_ph (l+LINE_OFFSET, field2screen_c(c));
	if (mode == HIGHLIGHT) printf ("\033[7m"); /* reverse video */
	print (cell2schema(l, c, mode));
	if (mode == HIGHLIGHT) printf ("\033[0m"); /* reset all */
}

char* get_emoticon(void) {
	return g.o==GAME_WON ? EMOT(WON):
	       g.o==GAME_LOST? EMOT(DEAD):
		EMOT(SMILE);
}

/* https://zserge.com/blog/c-for-loop-tricks.html */
#define print_line(which) \
	for (int _break = (printf("%s", BORDER(which,LEFT)), 1); _break; \
		_break = 0, printf("%s\r\n", BORDER(which,RIGHT)))
#define print_border(which, width) \
	print_line(which) printm (width, BORDER(which,MIDDLE))
void show_minefield (int mode) {
	int dtime = difftime (time(NULL), g.t)*!!g.t;
	int half_spaces = f.w*op.scheme->cell_width/2;
	int left_spaces = MAX(0,half_spaces-7-(f.m-g.f>999));
	int right_spaces = MAX(0,half_spaces-6-(dtime>999));
	static char modechar[] = {'*', '!', '?'};

	move_ph (0,0);

	print_border(TOP, f.w);
	print_line(STATUS) {
		if (mode == RESIZEMODE) printf ("%-*s", 2*half_spaces,
		  f.w>20?"Resize Mode: HJKL to resize, Enter to set":
		  f.w>11?"Resize Mode: HJKL/Enter":"HJKL/Enter");
		else printf("[%03d%c]%*s%s%*s[%03d]",
		  /* [ */ f.m - g.f, modechar[g.s], /* ] */
		  left_spaces,"", get_emoticon(), right_spaces,"",
		  /* [ */ dtime /* ] */);
	}
	print_border(DIVIDER, f.w);
	/* main body */
	for (int l = 0; l < f.h; l++) print_line(FIELD)
		printm (f.w, cell2schema(l, _loop, mode));
	print_border(BOTTOM, f.w);
}

int get_neighbours (int line, int col, int reduced_mode) {
	/* counts mines surrounding a square
	   modes: 0=normal; 1=reduced */

	int count = 0;
	AROUND(line, col) {
		count += !!AR_CELL.m;
		count -= reduced_mode * AR_CELL.f==FLAG;
	}
	return count;
}

void interactive_resize(void) {
	unsigned char buf[3];
	for(;;) {
		screen_setup(1); /* clears the screen */
		show_minefield (RESIZEMODE);
		/* show the new field size in the corner: */
		move_ph(f.h+LINE_OFFSET-1,COL_OFFSET);
		printf("%d x %d", f.w, f.h);

		free_field(); /* must free before resizing! */
		switch (getctrlseq(buf)) {
		case 'h': f.w--; break;
		case 'j': f.h++; break;
		case 'k': f.h--; break;
		case 'l': f.w++; break;
		case 0xa: /* enter, fallthrough */
		case 'q': return;
		}

		clamp_fieldsize();
		f.m = mines_percentage(f.w, f.h);
		f.c = alloc_array (f.h, f.w);
	}
}

struct minecell** alloc_array (int lines, int cols) {
	free_field (); /* NOTE: this feels like a hack :| */
	struct minecell** a = malloc (lines * sizeof(struct minecell*));
	if (a == NULL) return NULL;
	for (int l = 0; l < lines; l++) {
		a[l] = calloc (cols, sizeof(struct minecell));
		if (a[l] == NULL) goto unalloc;
	}

	return a;
unalloc:
	for (int l = 0; l < lines; l++)
		free (a[l]);
	return NULL;
}

void free_field (void) {
	if (f.c == NULL) return;
	for (int l = 0; l < f.h; l++) {
		free (f.c[l]);
	}

	free (f.c);
	f.c = NULL;
}

int screen2field_l (int l) {
	return (l-LINE_OFFSET) - 1;
}
int screen2field_c (int c) {
	/* this depends on the cell width and only works when it is 1 or 2. */
	return (c-COL_OFFSET+1 - 2*(CW%2))/2 - CW/2;
}
int field2screen_c (int c) {
	return (CW*c+COL_OFFSET - (CW%2));
}
int clicked_emoticon (unsigned char* mouse) {
	return (mouse[2] == LINE_OFFSET-1 && (
		mouse[1] == f.w+COL_OFFSET ||
		mouse[1] == f.w+COL_OFFSET+1));
}

enum esc_states {
	START,
	ESC_SENT,
	CSI_SENT,
	MOUSE_EVENT,
};
int getctrlseq (unsigned char* buf) {
	int c;
	int state = START;
	int offset = 0x20; /* never sends control chars as data */
	while ((c = getchar()) != EOF) {
		switch (state) {
		case START:
			switch (c) {
			case '\033': state=ESC_SENT; break;
			default: return c;
			}
			break;
		case ESC_SENT:
			switch (c) {
			case '[': state=CSI_SENT; break;
			default: return CTRSEQ_INVALID;
			}
			break;
		case CSI_SENT:
			switch (c) {
			case 'A': return CTRSEQ_CURSOR_UP;
			case 'B': return CTRSEQ_CURSOR_DOWN;
			case 'C': return CTRSEQ_CURSOR_RIGHT;
			case 'D': return CTRSEQ_CURSOR_LEFT;
			case 'M': state=MOUSE_EVENT; break;
			default: return CTRSEQ_INVALID;
			}
			break;
		case MOUSE_EVENT:
			buf[0] = c - offset;
			buf[1] = getchar() - offset;
			buf[2] = getchar() - offset;
			return CTRSEQ_MOUSE;
		default:
			return CTRSEQ_INVALID;
		}
	}
	return 2;
}

int getch(unsigned char* buf) {
/* returns a character, EOF, or constant for an escape/control sequence - NOT
compatible with the ncurses implementation of same name */
	int action = getctrlseq(buf);
	int l, c;
	switch (action) {
	case CTRSEQ_MOUSE:
		l = screen2field_l (buf[2]);
		c = screen2field_c (buf[1]);

		if (buf[0] > 3) break; /* ignore all but left/middle/right/up */
		int success = wait_mouse_up(l, c);

		/* mouse moved while pressed: */
		if (!success) return CTRSEQ_INVALID;

		switch (buf[0]) {
		case 0: return CTRSEQ_MOUSE_LEFT;
		case 1: return CTRSEQ_MOUSE_MIDDLE;
		case 2: return CTRSEQ_MOUSE_RIGHT;
		}
	}

	return action;
}

int getch_wrapper (void) {
	unsigned char mouse[3];
	int c = getch(mouse);

	if (c == CTRSEQ_MOUSE_LEFT || c == CTRSEQ_MOUSE_RIGHT) {
		if (clicked_emoticon(mouse))
			return WRAPPER_EMOTICON;

		if (screen2field_c (mouse[1]) < 0
		 || screen2field_c (mouse[1]) >= f.w
		 || screen2field_l (mouse[2]) < 0
		 || screen2field_l (mouse[2]) >= f.h)
			return CTRSEQ_INVALID;

		g.p[0] = screen2field_l (mouse[2]);
		g.p[1] = screen2field_c (mouse[1]);

		return c; /* CTRSEQ_MOUSE_LEFT || CTRSEQ_MOUSE_RIGHT */
	}

	return c;
}

void clamp_fieldsize (void) {
	/* clamp field size to terminal size and mouse maximum: */
	struct winsize w;
	ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);

	if (COL_OFFSET + f.w*CW + COL_OFFSET > w.ws_col)
		f.w = w.ws_col/CW - (COL_OFFSET+COL_OFFSET);
	if (LINE_OFFSET + f.h + LINES_AFTER > w.ws_row)
		f.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
	if (COL_OFFSET + f.w*CW > MOUSE_MAX)
		f.w = MOUSE_MAX/CW - COL_OFFSET;
	if (LINE_OFFSET + f.h > MOUSE_MAX)
		f.h = MOUSE_MAX - LINE_OFFSET;
}

int mines_percentage(int w, int h) {
	return w*h*(w*h<30*16?.15625:.20625);
}

int parse_fieldspec(char* str) {
	/* parses the FIELDSPEC (WxHxM); returns 1 on error */
	int n = sscanf (str, "%dx%dx%d", &f.w, &f.h, &f.m);

	clamp_fieldsize();

	if (n < 2) {
		return 1; /* error */
	} else if (n == 2) {
		f.m = mines_percentage(f.w, f.h);
	}

	f.m = MIN(f.m, (f.w-1) * (f.h-1)); /* limit mines */

	return 0;
}

void timer_setup (int enable) {
	static struct itimerval tbuf;
	tbuf.it_interval.tv_sec  = 1;
	tbuf.it_interval.tv_usec = 0;

	if (enable) {
		g.t = time(NULL);
		tbuf.it_value.tv_sec  = 1;
		tbuf.it_value.tv_usec = 0;
		if (setitimer(ITIMER_REAL, &tbuf, NULL) == -1) {
			perror("setitimer");
			exit(1);
		}
	} else {
		tbuf.it_value.tv_sec  = 0;
		tbuf.it_value.tv_usec = 0;
		if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
			perror("setitimer");
			exit(1);
		}
	}

}

void signal_setup (void) {
	struct sigaction saction;

	saction.sa_handler = signal_handler;
	sigemptyset(&saction.sa_mask);
	saction.sa_flags   = 0;
	if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
		perror("SIGALRM");
		exit(1);
	}

	if (sigaction(SIGINT, &saction, NULL) < 0 ) {
		perror ("SIGINT");
		exit (1);
	}
}

void signal_handler (int signum) {
	int dtime;
	switch (signum) {
	case SIGALRM:
		dtime = difftime (time(NULL), g.t);
		move_ph (1, f.w*CW-(CW%2)-3-(dtime>999));
		printf ("[%03d]", g.t?dtime:0);
		break;
	case SIGINT:
		exit(128+SIGINT);
	}
}

void screen_setup (int enable) {
	if (enable) {
		raw_mode(1);
		printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
		printf ("\033[H\033[J"); /* reset cursor, clear screen */
		printf ("\033[?1000h\033[?25l"); /* enable mouse, hide cursor */
		print (op.scheme->init_seq); /* swich charset, if necessary */
	} else {
		print (op.scheme->reset_seq); /* reset charset, if necessary */
		printf ("\033[?9l\033[?25h"); /* disable mouse, show cursor */
		printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
		raw_mode(0);
	}
}

/* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
void raw_mode(int enable) {
	static struct termios saved_term_mode;
	struct termios raw_term_mode;

	if (enable) {
		tcgetattr(STDIN_FILENO, &saved_term_mode);
		raw_term_mode = saved_term_mode;
		raw_term_mode.c_lflag &= ~(ICANON | ECHO);
		raw_term_mode.c_cc[VMIN] = 1 ;
		raw_term_mode.c_cc[VTIME] = 0;
		tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
	} else {
		tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
	}
}