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

#include "util.h"
#include "ui.h"

#define MAX_STATUS	128

static char stbuf[MAX_STATUS];

static unsigned short rows;
static unsigned short cols;
static struct termios prevstate;
static int tty_fd;

int uiinit(const State *state)
{
	struct winsize w;
	struct termios t;

	if ((tty_fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC)) < 0)
		die("getpass: can't open /dev/tty for input");

	tcgetattr(tty_fd, &t);
	prevstate = t;
	if (state->flag & IGNORE_ISIG)
		t.c_lflag &= ~(ISIG);
	t.c_lflag &= ~(ECHO|INLCR|IGNCR|ICANON);
	t.c_iflag |= ICRNL;
	tcsetattr(tty_fd, TCSAFLUSH, &t);
	tcdrain(tty_fd);

	if (ioctl(STDIN_FILENO, TIOCGWINSZ, &w) == -1)
		die("ioctl() failed");

	rows = w.ws_row;
	cols = w.ws_col;

	printf("%c7", ESC); /* save cursor */
	printf("%c[?47h", ESC); /* use alt buffer */
	printf("%c[?25l", ESC); /* hide cursor */
	printf("%c[2J", ESC); /* clear vt */

	return tty_fd;
}

void pheader(const char *s)
{
	unsigned short col, row;

	row = rows / 2;
	col = (cols - strlen(s)) / 2;

	printf("%c[%d;%dH", ESC, row, col); /* pos curosr */
	printf("%c[2K", ESC); /* clear line */
	puts(s);
}

void pstatus(const char *s)
{
	unsigned short col, row;

	row = rows / 2 + 1;
	col = (cols - strlen(s)) / 2;

	printf("%c[%d;%dH", ESC, row, col); /* pos cursor */
	printf("%c[2K", ESC); /* clear line */
	puts(s);
}

void pstaticstat(const char *head, const char c)
{
	size_t stlen;

	if ((stlen = strlen(head)) > MAX_STATUS - 1)
		stlen = MAX_STATUS - 1;
	stbuf[stlen] = '\0';

	memset(stbuf, c, stlen);
	pstatus(stbuf);
}

void genrandstat(const char *head, const char *statstr)
{
	int entropy;
	size_t srlen, stlen, i;

	if ((stlen = strlen(head)) > MAX_STATUS - 1)
		stlen = MAX_STATUS - 1;
	srlen = strlen(statstr);

	for (entropy = i = 0; i < stlen; ++i, entropy /= srlen) {
		if (!entropy)
			entropy = rand();

		stbuf[i] = statstr[entropy % srlen];
	}

	stbuf[stlen] = '\0';
	pstatus(stbuf);
}

void uicleanup(void)
{
	printf("%c[2J", ESC); /* clear vt */
	printf("%c[?25h", ESC); /* show cursor */
	printf("%c[?47l", ESC); /* use normal buffer */
	printf("%c8", ESC); /* restore cursor */

	tcsetattr(tty_fd, TCSAFLUSH, &prevstate);
	close(tty_fd);
}

void pui(const char *head, const char stat)
{
	size_t stlen;

	if ((stlen = strlen(head)) > MAX_STATUS - 1)
		stlen = MAX_STATUS - 1;
	stbuf[stlen] = '\0';

	pheader(head);
	pstatus(memset(stbuf, stat, stlen));
}