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

#define clear() printf("\033[H\033[J")
#define gotoxy(x,y) printf("\033[%d;%dH", (y), (x))

char fonth = 8;
int getch();
void enableRawMode();
void disableRawMode();
void drawWin();
int askHeight();
void resetCurPos();

char currchar = 'A';
char xpos=0, ypos=0;

struct termios orig_termios;

int main() {

	clear();
	enableRawMode();
	
	char c;
	while(1) {
		drawWin();
		c = getch();
		// Q to exit
		if (c == 'q') {
			break;
		}
		// Handle arrows and stuff
		if (c == '[') {
			c = getch();
			if (c == '6') { // PageUP
				if (currchar < 126) { currchar++; }
				continue;
			}
			if (c == '5') { // PageDOWN
				if (currchar >32) { currchar--; }
				continue;
			}
			
			if (c == 'A') {
				if (ypos > 0) { ypos--; }
				continue;
			}
			if (c == 'B') {
				if (ypos < fonth-1) { ypos++; }
				continue;
			}
			if (c == 'C') {
				if (xpos < 8-1) { xpos++; }
				continue;
			}
			if (c == 'D') {
				if (xpos > 0) { xpos--; }
				continue;
			}
		}
	}

	disableRawMode();
	clear();
	return 0;
}

void drawWin() {
	//clear();
	gotoxy(1, 1);
	printf("Kaari - Binarier font editor\r\n");
	printf("+--------+ Char \"%c\" / %d / 0x%X    \r\n", currchar, currchar, currchar);
	
	int cstart=32;
	int cperline=16;
	int cmax=126;
	for (int y=0; y<fonth; y++) {
		printf("|        | ");
		for (int c=y*cperline+cstart; c<(y+1)*cperline+cstart && c<=cmax; c++) {
			if (c == currchar) {
				printf("\033[7m%c\033[0m ", currchar);
			} else {
				printf("%c ", c);
			}
		}
		printf("\r\n");
	}
	
	printf("+--------+\r\nArrows:Move PgUP/DWN:Char Q:Quit");

	resetCurPos();
	
	return;
}

int askHeight() {
	printf("Enter desired font height: ");
	int fonth;
	scanf("%d", &fonth);
	if (fonth < 8 || fonth > 16) {
		printf("This should be 8 - 16.\r\n");
		return askHeight();
	}
	return fonth;
}

void disableRawMode() {
	tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios);
}

void enableRawMode() {
	tcgetattr(STDIN_FILENO, &orig_termios);
	atexit(disableRawMode);

	struct termios raw = orig_termios;
	raw.c_lflag &= ~(ECHO | ICANON);
	
	tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw);
}

int getch() {
	struct termios oldt, newt;
	int ch;
	
	tcgetattr(STDIN_FILENO, &oldt);
	newt = oldt;
	newt.c_lflag &= ~(ICANON | ECHO);
	tcsetattr(STDIN_FILENO, TCSANOW, &newt);
	
	ch = getchar();
	
	tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
	
	return ch;
}

void resetCurPos() {
	gotoxy(2+xpos, 3+ypos);
	return;
}