#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdarg.h>
#include <termios.h>
#include <sys/ioctl.h>

#include "tty.h"

void tty_reset(tty_t *tty){
	tcsetattr(tty->fdin, TCSANOW, &tty->original_termios);
}

void tty_init(tty_t *tty, const char *tty_filename){
	tty->fdin = open(tty_filename, O_RDONLY);
	tty->fout = fopen(tty_filename, "w");
	if(setvbuf(tty->fout, NULL, _IOFBF, 4096))
		perror("setvbuf");

	if(tcgetattr(tty->fdin, &tty->original_termios))
		perror("tcgetattr");

	struct termios new_termios = tty->original_termios;

	/*
	 * Disable both of
	 * ICANON  Canonical input (erase and kill processing).
	 * ECHO    Enable echo.
	 */
	new_termios.c_lflag &= ~(ICANON | ECHO);

	if(tcsetattr(tty->fdin, TCSANOW, &new_termios))
		perror("tcsetattr");

	tty_getwinsz(tty);

	tty_setnormal(tty);
}

void tty_getwinsz(tty_t *tty){
	struct winsize ws;
	if(ioctl(fileno(tty->fout), TIOCGWINSZ, &ws) == -1){
		tty->maxwidth = 80;
		tty->maxheight = 25;
	}else{
		tty->maxwidth = ws.ws_col;
		tty->maxheight = ws.ws_row;
	}
}

char tty_getchar(tty_t *tty){
	char ch;
	int size = read(tty->fdin, &ch, 1);
	if(size < 0){
		perror("error reading from tty");
		exit(EXIT_FAILURE);
	}else if(size == 0){
		/* EOF */
		exit(EXIT_FAILURE);
	}else{
		return ch;
	}
}

static void tty_sgr(tty_t *tty, int code){
	tty_printf(tty, "%c%c%im", 0x1b, '[', code);
}

void tty_setfg(tty_t *tty, int fg){
	if(tty->fgcolor != fg){
		tty_sgr(tty, 30 + fg);
		tty->fgcolor = fg;
	}
}

void tty_setinvert(tty_t *tty){
	tty_sgr(tty, 7);
}

void tty_setnormal(tty_t *tty){
	tty_sgr(tty, 0);
	tty->fgcolor = 9;
}

void tty_newline(tty_t *tty){
	tty_printf(tty, "%c%cK\n", 0x1b, '[');
}

void tty_clearline(tty_t *tty){
	tty_printf(tty, "%c%cK", 0x1b, '[');
}

void tty_setcol(tty_t *tty, int col){
	tty_printf(tty, "%c%c%iG", 0x1b, '[', col + 1);
}

void tty_moveup(tty_t *tty, int i){
	tty_printf(tty, "%c%c%iA", 0x1b, '[', i);
}

void tty_printf(tty_t *tty, const char *fmt, ...){
	va_list args;
	va_start(args, fmt);
	vfprintf(tty->fout, fmt, args);
	va_end(args);
}

void tty_flush(tty_t *tty){
	fflush(tty->fout);
}

size_t tty_getwidth(tty_t *tty){
	return tty->maxwidth;
}

size_t tty_getheight(tty_t *tty){
	return tty->maxheight;
}