/*
*
* This is `gramscii`, a simple tool to create ascii box graphs
*
*/

#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>

#define MOVE   0x00
#define BOX    0x01
#define ARROW  0x02
#define TEXT   0x04
#define DEL    0x08

#define DIR_N  0x00
#define DIR_R  0x01
#define DIR_U  0x02
#define DIR_D  0x04
#define DIR_L  0x08

#define DIR_HOR (DIR_R | DIR_L)
#define DIR_VER (DIR_D | DIR_U)

#define WIDTH  100
#define HEIGHT  25

#define NOFIX 0x0
#define FIX   0x1

#define BG        ' '
#define PTR       '+'
#define UND       '_'
#define ARR_L     '<'
#define ARR_R     '>'
#define ARR_U     '^'
#define ARR_D     'v'


#define HOME   0x01
#define END    0x02
#define MIDDLE 0x04

#define MIN(x,y)  (x) < (y) ? (x) : (y)
#define MAX(x,y)  (x) > (y) ? (x) : (y)

char screen[HEIGHT][WIDTH+1];

int state;
int dir;
int x;
int y;
int step;
int force_new;
char cursor;
char corner;
char hlines[]  = {"-~=#@._ "};
char vlines[]  = {"|H#@:;i "};
char corners[] = {"+'H#@.\""};
char st_marks[] = {"+o-|<>^v"};
char end_marks[] = {">+o-|<^v"};

int hlines_sz= sizeof(hlines) -1;
int vlines_sz= sizeof(vlines) -1;
int corners_sz = sizeof(corners) -1;
int stmarks_sz = sizeof(st_marks) - 1;
int endmarks_sz = sizeof(st_marks) - 1;

int cur_hl, cur_vl, cur_corn, cur_start, cur_end;
char line_h;
char line_v;
char mark_st;
char mark_end;

char modified;
char fname[256];

struct termios t1, t2, t3;


void cleanup(int s){

	printf("\033[;H\033[2J");
	tcsetattr(0, TCSANOW, &t1);
	exit(0);
}

void show_cursor(){
	printf("\033[%d;%df", y+1, x+1);
}

void set(char c){
	screen[y][x] = c;
}

void set_xy(int x, int y, char c){
	/* FIXME: check if x and y are valid!!!! */
	screen[y][x] = c;
}

void draw_xy(int x, int y, char c){
	/* FIXME: check if x and y are valid!!!! */
	printf("\033[%d;%df",y+1,x+1);
	putchar(c);	
}

void init_screen(){
	int i;
	for(i=0; i<HEIGHT; i++){
		memset(screen[i], ' ', WIDTH);
		screen[i][WIDTH]='\0';
	}
	cur_corn = 0;
	corner = corners[0];
	cur_hl = cur_vl = 0;
	cur_start = cur_end = 0;
	line_h = hlines[cur_hl];
	line_v = vlines[cur_vl];
	mark_st = st_marks[cur_start];
	mark_end = end_marks[cur_end];
}

char* state_str(){
	switch(state){
		case MOVE:
			return "mov";
		case TEXT:
			return "txt";
		case BOX:
			return "box";
		case ARROW:
			return "arr";
		case DEL:
			return "del";
		default:
			return "ERR";
	}
	return "ERR";	
}


void status_bar(){
	
	printf("\033[%d;1f\033[7m", HEIGHT+1);
	printf("%100s", " ");
	printf("\033[%d;1f\033[7m", HEIGHT+1);
	printf(" x: %3d y: %3d -- mode: %4s hl: %c vl: %c cn: %c <: %c >: %c %10s", 
		x, y, state_str(), line_h, line_v, corner, mark_st, mark_end, "");
	printf(" [%s]", fname );
	printf("\033[0m");
}

void redraw(){
	int i;
	
	printf("\033[2J\033[1;1H");
	for (i=0;i<HEIGHT;i++){
		fprintf(stdout,"%s\n",screen[i]);
	}
	status_bar();
	show_cursor();
}

void update_current(){
	printf("\033[%d'%df",y+1,x+1);
	putchar(screen[y][x]);
}


void init(){

	signal(SIGHUP, cleanup);
	signal(SIGINT, cleanup);
	signal(SIGTERM, cleanup);
	signal(SIGQUIT, cleanup);
	
	tcgetattr(0, &t1);
	t2 = t1;
	t2.c_lflag &= ~(ICANON | ECHO);
	tcsetattr(0, TCSANOW, &t2);
	
	init_screen();
	x = WIDTH/2;
	y = HEIGHT/2;
	modified = 0;
	fname[0] = '\0';
	redraw();
}

void check_bound(){
	if (x<0) x=0;
	else if (x>=WIDTH) x = WIDTH-1;
	if (y<0) y=0;
	else if (y>=HEIGHT) y = HEIGHT -1; 
}


/*****  text, box, arrows  *****/

void get_text(){
	char c;
	int orig_x = x;
	
	redraw();
	while((c=getchar())!=EOF && c != 27){
		if(c=='\n'){
			set(BG);
			y += 1;
			x = orig_x;
		}
		else {
			set(c);
			update_current();
			x += 1;
			if (x >= WIDTH)
				x = orig_x;
		}
		check_bound();
		status_bar();
		show_cursor();
	}
	state=MOVE;
}


void draw_box(int x1, int y1, int fix){

	int xmin, ymin, xmax, ymax;
	int i;
	void (*f)(int, int, char);

	if (fix == FIX)
		f = set_xy;
	else
		f = draw_xy;
	
	xmin = MIN(x, x1);
	xmax = MAX(x, x1);
	ymin = MIN(y, y1);
	ymax = MAX(y, y1);

	for(i=xmin+1; i<=xmax; i++){
		f(i, ymin, line_h);
		f(i, ymax, line_h);
	}
	for(i=ymin+1; i<=ymax; i++){
		f(xmin, i, line_v);
		f(xmax, i, line_v);
	}
	f(xmin, ymin, corner);
	f(xmin, ymax, corner);
	f(xmax, ymin, corner);
	f(xmax, ymax, corner);
	show_cursor();
}


int move_around(char c){

	switch(c){
		case 'H': step = 5;
		case 'h': 
			dir = DIR_L;
			x -= step;
			break;	
		case 'J': step = 5;
		case 'j':
			dir = DIR_D;
			y += step;
			break;
		case 'K': step = 5;
		case 'k':
			dir = DIR_U;
			y -= step;
			break;
		case 'L': step = 5;
		case 'l':
			dir = DIR_R;
			x += step;
			break;
		default:
			return 1;
	}
	return 0;
}


void get_box(){
	char c;
	int orig_x=x, orig_y=y;
	redraw();
	step = 1;
	draw_box(x,y,NOFIX);
	while((c=getchar())!=EOF && c != 27 && c!= 'b'){
		if (move_around(c)) continue;
		check_bound();
		redraw();
		step = 1;
		draw_box(orig_x, orig_y, NOFIX);
		status_bar();
		show_cursor();
	}
	if (c == 'b'){
		draw_box(orig_x, orig_y, FIX);
		modified = 1;
	}
	redraw();
	state = MOVE;
}


int progr_x(int dir){
	return dir == DIR_L ? -1 : dir == DIR_R ? 1: 0;
}


int progr_y(int dir){
	return dir == DIR_U ? -1 : dir == DIR_D ? 1: 0;
}


void draw_arrow(int x, int y, char *a, int a_len, int fix){

	int i, j, cur_dir;
	char line;
	void (*f)(int, int, char);

		
	if (fix == FIX)
		f = set_xy;
	else
		f = draw_xy;

	f(x,y,mark_st);
	if (!a_len){
		show_cursor();
		return;
	}
	cur_dir=DIR_N;
	for (i=0; i<a_len; i+=2){
		if (i>0) {
			/* If we are switching between horizontal and vertical, put a "corner" */
			if (((cur_dir & DIR_HOR) && (a[i] & DIR_VER)) ||
			    ((cur_dir & DIR_VER) && (a[i] & DIR_HOR))){
				f(x,y,corner);
				show_cursor();
			}
		}
		for(j=0; j<a[i+1]; j++){
			line = (a[i] & DIR_L) || (a[i] & DIR_R) ? line_h : line_v;
			x += progr_x(a[i]);
			y += progr_y(a[i]);
			f(x, y, line); 
		}
		/* f(x,y,mark_end);*/
		cur_dir = a[i];
	}
	f(x,y,mark_end);
	show_cursor();
}

void get_arrow(){

	char c;
	int orig_x=x, orig_y=y, arrow_len;
	static char *arrow = NULL;
	static int arrow_sz;

	if (!arrow){
		arrow_sz = 100;
		arrow = malloc(arrow_sz * sizeof(char));
	}
	arrow_len = 0;
	dir = DIR_N;
	
	redraw();
	step = 1;
	draw_arrow(x,y, arrow, 0, NOFIX);
	while((c=getchar())!=EOF && c != 27 && c!= 'a'){
		if (move_around(c)) continue;
		check_bound();
		/* FIXME: if we are out of bound, do nothing? */
		if (arrow_len == arrow_sz){
			arrow_sz *=2;
			arrow = realloc(arrow, arrow_sz * sizeof(char));
		}
		arrow[arrow_len++] = dir;
		arrow[arrow_len++] = step;
		redraw();
		step = 1;
		draw_arrow(orig_x, orig_y, arrow, arrow_len, NOFIX);
		status_bar();
		show_cursor();
	}
	if (c == 'a'){
		draw_arrow(orig_x, orig_y, arrow, arrow_len, FIX);
		modified = 1;
	}
	redraw();
	state = MOVE;
}

char get_key(char *s){

	printf("\033[%d;1f\033[7m", HEIGHT+1);
	printf("%100s", " ");
	printf("\033[%d;1f\033[7m", HEIGHT+1);
	printf("%s ", s);
	printf("\033[0m");
	return getchar();
}

void get_string(char *s, int sz){

	printf("\033[%d;1f\033[7m", HEIGHT+1);
	printf("%100s", " ");
	printf("\033[%d;1f\033[7m", HEIGHT+1);
	/* We must activate echo now */
	t3 = t2;
	t3.c_lflag |= (ECHO | ICANON);
	tcsetattr(0, TCSANOW, &t3);
	printf("Write to: ");
	printf("\033[0m");
	fgets(s, sz, stdin);
	s[strlen(s)-1] = '\0';
	tcsetattr(0, TCSANOW, &t2);
}

int is_yes(char c){
	return c=='y' ? 1 : c == 'Y'? 1 : 0;
}

void write_file(){
	FILE *f;
	int i;
	
	if (!fname[0] || force_new){
		get_string(fname, 255);
		if (f=fopen(fname, "r")){
			if (!is_yes(get_key("File exists. Overwrite [y/n]?")) ){
				fclose(f);
				return;
			}
			fclose(f);
		}
	}
	if((f=fopen(fname, "w"))==NULL){
		get_key("Error opening file.");
		return;
	}
	for (i=0; i<HEIGHT; i++){
		fprintf(f, "%s\n", screen[i]);
	}
	fclose(f);
	modified = 0;
	get_key("File saved.");
}

void toggle_hline(){

	cur_hl = (cur_hl + 1) % hlines_sz;
	line_h = hlines[cur_hl];
	
}

void toggle_corner(){
	
	cur_corn = (cur_corn + 1 ) % corners_sz;
	corner = corners[cur_corn];

}

void toggle_vline(){

	cur_vl = (cur_vl + 1) % vlines_sz;
	line_v = vlines[cur_vl];

}

void toggle_st_mark(){
	
	cur_start = (cur_start + 1 ) % stmarks_sz;
	mark_st = st_marks[cur_start];
}

void toggle_end_mark(){
	
	cur_end = (cur_end+ 1 ) % endmarks_sz;
	mark_end = end_marks[cur_end];
}

void go_to(int where){
	switch(where){
		case HOME:
			x = y = 0;
			break;
		case END:
			x = WIDTH-1;
			y = HEIGHT-1;
			break;
		case MIDDLE:
			x = WIDTH/2;
			y = HEIGHT/2;
			break;
	}
	check_bound();
	show_cursor();
}

void do_delete(int x1, int y1){
	int i;
	switch(dir){
		case DIR_R:
			for(i=x1; i<=x; i++) set_xy(i,y,BG);
			break;
		case DIR_L:
			for(i=x1; i>=x; i--) set_xy(i,y,BG);
			break;
		case DIR_U:
			for(i=y1; i>=y; i--) set_xy(x,i,BG);
			break;
		case DIR_D:
			for(i=y1; i<=y; i++) set_xy(x,i,BG);
			break;
	}
}


void delete(){
	char c;
	int orig_x = x, orig_y = y;
	status_bar();
	show_cursor();
	while((c=getchar())!=EOF && c!=27 && c!= 'x'){
		if (move_around(c)) continue;
		check_bound();
		step = 1;
		do_delete(orig_x, orig_y);
		modified = 1;
		orig_x = x;
		orig_y = y;
		redraw();
		status_bar();
		show_cursor();
	}
	state = MOVE;
}

void check_modified(){

	if (modified){
		if (!is_yes(get_key("Unsaved changes. Write to file [y/n]?")) ){
			return;
		}
		write_file(0);
	}
}



void commands(){

	char c;
	while((c=getchar())!=EOF){
		//screen[y][x]=BG;
		switch(c){
			case 'H':
				step=5;
			case 'h':
				x-=step;
				break;
			case 'J':
				step=5;
			case 'j':
				y+=step;
				break;
			case 'K':
				step=5;
			case 'k':
				y-=step;
				break;
			case 'L':
				step=5;
			case 'l':
				x+=step;
				break;
			case 'i':
				state = TEXT;
				get_text();
				break;
			case 'r':
				redraw();
				break;
			case 'b':
				state = BOX;
				get_box();
				break;
			case 'a':
				state = ARROW;
				get_arrow();
				break;
			case 'W':
				force_new = 1;
			case 'w':
				write_file();
				break;
			case 'g':
				go_to(HOME);
				break;
			case 'G':
				go_to(END);
				break;
			case 'm':
				go_to(MIDDLE);
				break;
			case 'x':
				state = DEL;
				delete();
				break;
			case '-':
				toggle_hline();
				break;
			case '|':
				toggle_vline();
				break;
			case '+': 
				toggle_corner();
				break;
			case '<': 
				toggle_st_mark();
				break;
			case '>':
				toggle_end_mark();
				break;
			case 'q':
				check_modified();
			case 'Q':
				cleanup(0);
				exit(0);
				break;
			default:;
				//statu("got: %d\n", c);
		}
		check_bound();
		status_bar();
		show_cursor();
		step = 1;
		force_new = 0;
	}

}




int main(int argc, char *argv[]){

	init();

	commands();
	cleanup(0);
}