#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>

#include "vip.h"

extern editor vip;

void die(const char *s)
{
	write(STDOUT_FILENO, "\x1b[2J", 4);
	write(STDOUT_FILENO, "\x1b[H", 3);
	perror(s);
	exit(1);
}

void reset_term()
{
	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &vip.termios) == -1) {
		die("tcsetattr");
	}
}

/*
 * Setup terminal
 */
void setup_term()
{
	if (tcgetattr(STDIN_FILENO, &vip.termios) == -1) {
		die("tcgetattr");
	}
	atexit(reset_term);

	struct termios raw = vip.termios;
	/* disbable echo, line output and signals */
	raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
	raw.c_oflag &= ~(OPOST);
	raw.c_cflag |= (CS8);
	raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
	raw.c_cc[VMIN] = 0;
	raw.c_cc[VTIME] = 1;
	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1) {
		die("tcsetattr");
	}
}

int get_cursor_position(int *rows, int *cols)
{
	char buf[32];
	unsigned int i = 0;
	if (write(STDOUT_FILENO, "\x1b[6n", 4) != 4) {
		return -1;
	}
	while (i < sizeof(buf) - 1) {
		if (read(STDIN_FILENO, &buf[i], 1) != 1) {
			break;
		}
		if (buf[i] == 'R') {
			break;
		}
		i++;
	}
	buf[i] = '\0';
	if (buf[0] != '\x1b' || buf[1] != '[') {
		return -1;
	}
	if (sscanf(&buf[2], "%d;%d", rows, cols) != 2) {
		return -1;
	}
	return 0;
}

int get_window_size(int *rows, int *cols)
{
	struct winsize ws;
	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
		/* Can't get window size */
		if (write(STDOUT_FILENO, "\x1b[999C\x1b[999B", 12) != 12) {
			return -1;
		}
		return get_cursor_position(rows, cols);
	} else {
		*cols = ws.ws_col;
		*rows = ws.ws_row;
		return 0;
	}
}