#include <kernel/fd.h>
#include <kernel/mem.h>
#include <kernel/panic.h>
#include <kernel/proc.h>

static int fdop_special_tty(enum fdop fdop, struct fd *fd, user_ptr ptr, size_t len);

int fdop_dispatch(enum fdop fdop, struct fd *fd, user_ptr ptr, size_t len) {
	switch(fd->type) {
		case FD_EMPTY:
			return -1;
		case FD_SPECIAL_TTY:
			return fdop_special_tty(fdop, fd, ptr, len);
		default:
			panic();
	}
}

static int fdop_special_tty(enum fdop fdop, struct fd *fd, user_ptr ptr, size_t len) {
	switch(fdop) {
		case FDOP_READ:
			return -1; // input not implemented yet

		case FDOP_WRITE: {
			 struct virt_iter iter;
			 virt_iter_new(&iter, ptr, len, process_current->pages, true, false);
			 while (virt_iter_next(&iter))
				 tty_write(iter.frag, iter.frag_len);
			 return iter.prior;
		}

		case FDOP_CLOSE:
			fd->type = FD_EMPTY;
			return 0;

		default: panic();
	}
}