#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))

int getch();
void enableRawMode();
void disableRawMode();
void drawWin(int fonth);
int askHeight();
void limitCurrChar();

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

struct termios orig_termios;

int main() {
	int fonth = askHeight();
	clear();
	drawWin(fonth);
	
	enableRawMode();
	
	char c;
	limitCurrChar();
	while(1) {
		c = getch();
		// Q to exit
		if (c == 'q') {
			break;
		}
		// Handle arrows and stuff
		if (c == '[') {
			c = getch();
			if (c == '5') { // PageUP
				currchar++;
				limitCurrChar();
				continue;
			}
			if (c == '6') { // PageDOWN
				currchar--;
				limitCurrChar();
				continue;
			}
			
			if (c == 'A') {
				printf("^");
				continue;
			}
			if (c == 'B') {
				printf("v");
				continue;
			}
			if (c == 'C') {
				printf(">");
				continue;
			}
			if (c == 'D') {
				printf("<");
				continue;
			}
		}
	}
	
	disableRawMode();
	return 0;
}

void drawWin(int fonth) {
	clear();
	printf("Kaari - Binarier font editor\r\n");
	printf("+--------+\r\n");
	
	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++) {
			printf("%c ", c);
		}
		printf("\r\n");
	}
	
	printf("+--------+\r\nQ:Quit PgUP/DWN:Switch char\r\n");
	
	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 limitCurrChar() {
	if (currchar < 32) {
		currchar = 32;
	} else if (currchar > 126) {
		currchar = 126;
	}
	
	gotoxy(12+currchar%16*2, 3+(currchar-32)/16);
	printf("\033[7m%c", currchar);

	gotoxy(12+(currchar-1)%16*2, 3+(currchar-1-32)/16);
	printf("\033[0m%c", currchar-1);

	gotoxy(12+(currchar+1)%16*2, 3+(currchar+1-32)/16);
	printf("\033[0m%c", currchar+1);

	gotoxy(12, 2);
	printf("\033[0mEditing \"%c\" / %d / 0x%X", currchar, currchar, currchar);

	gotoxy(0, 21);
	
	return;
}