#include <socks/tty.h>
#include <socks/input.h>
#include <socks/printk.h>

static void newline(struct device *tty)
{
	struct tty_device *ttydev = TTY_DEVICE(tty);
	struct tty_driver *tty_driver = TTY_DRIVER(tty->dev_owner);
	struct tty_driver_ops *ops = tty_driver->tty_ops;

	ttydev->tty_xcur = 0;
	ttydev->tty_ycur++;

	if (ttydev->tty_ycur >= ttydev->tty_ycells) {
		ttydev->tty_xcur = 0;
		ttydev->tty_ycur = ttydev->tty_ycells - 1;

		if (ops->tty_scroll) {
			ops->tty_scroll(tty, TTY_SCROLL_DOWN, 1);
		}
	}

	ops->tty_move_cursor(tty, ttydev->tty_xcur, ttydev->tty_ycur);
}

static void __putchar(struct device *tty, int c)
{
	struct tty_device *ttydev = TTY_DEVICE(tty);
	struct tty_driver *tty_driver = TTY_DRIVER(tty->dev_owner);
	struct tty_driver_ops *ops = tty_driver->tty_ops;

	ops->tty_putc(tty, c, ttydev->tty_xcur, ttydev->tty_ycur, ttydev->tty_curattrib);
	ttydev->tty_xcur++;

	if (ttydev->tty_xcur >= ttydev->tty_xcells) {
		ttydev->tty_xcur = 0;
		ttydev->tty_ycur++;
	}

	if (ttydev->tty_ycur >= ttydev->tty_ycells) {
		ttydev->tty_xcur = 0;
		ttydev->tty_ycur = ttydev->tty_ycells - 1;

		if (ops->tty_scroll) {
			ops->tty_scroll(tty, TTY_SCROLL_DOWN, 1);
		}
	}

	ops->tty_move_cursor(tty, ttydev->tty_xcur, ttydev->tty_ycur);
}

static void putchar(struct device *tty, int c)
{
	struct tty_driver *tty_driver = TTY_DRIVER(tty->dev_owner);
	struct tty_driver_ops *ops = tty_driver->tty_ops;

	if (!ops->tty_putc) {
		return;
	}

	if (tty_driver->tty_type == TTY_DRIVER_SIMPLE) {
		ops->tty_putc(tty, c, -1, -1, 0);
		return;
	}

	switch (c) {
	case '\n':
		newline(tty);
		break;
	default:
		__putchar(tty, c);
		break;
	}
}

kern_status_t tty_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags)
{
	printk("tty_read");
	return KERN_OK;
}

kern_status_t tty_write(struct device *tty, const void *buf, size_t len, size_t *nr_written, socks_flags_t flags)
{
	size_t r = 0;
	const char *s = buf;
	for (size_t i = 0; i < len; i++) {
		putchar(tty, s[i]);
		r++;
	}

	*nr_written = r;
	return KERN_OK;
}

static void process_events(struct device *tty)
{
	struct tty_device *ttydev = TTY_DEVICE(tty);

	if (!ttydev->tty_ldisc || !ttydev->tty_ldisc->process_events) {
		struct input_event ev;
		while (ringbuffer_unread(&ttydev->tty_events)) {
			ringbuffer_read(&ttydev->tty_events, sizeof ev, &ev, S_NOBLOCK);
		}

		return;
	}

	ttydev->tty_ldisc->process_events(tty);
}

kern_status_t tty_report_event(struct device *tty, const struct input_event *ev)
{
	struct tty_device *ttydev = TTY_DEVICE(tty);
	size_t w = ringbuffer_write(&ttydev->tty_events, sizeof *ev, ev, S_NOBLOCK);

	if (w != sizeof *ev) {
		return KERN_WOULD_BLOCK;
	}

	if (ringbuffer_unread(&ttydev->tty_events) > 0) {
		process_events(tty);

	}

	return KERN_OK;
}