/*
 *  gensio - A library for abstracting stream I/O
 *  Copyright (C) 2018  Corey Minyard <minyard@acm.org>
 *
 *  SPDX-License-Identifier: LGPL-2.1-only
 */

#ifndef GENSIO_LL_FD_H
#define GENSIO_LL_FD_H

#include <gensio/gensio_dllvisibility.h>
#include <gensio/gensio_base.h>

enum gensio_ll_close_state {
    GENSIO_LL_CLOSE_STATE_START,
    GENSIO_LL_CLOSE_STATE_DONE
};

struct gensio_iod;

struct gensio_fd_ll_ops {
    int (*sub_open)(void *handler_data, struct gensio_iod **iod);

    int (*check_open)(void *handler_data, struct gensio_iod *iod);

    int (*retry_open)(void *handler_data, struct gensio_iod **iod);

    /*
     * When GENSIO_LL_CLOSE_STATE_START, timeout will be NULL and the
     * return value is ignored.  Return 0.  When
     * GENSIO_LL_CLOSE_STATE_DONE, return EINPROGRESS to get called
     * again after next_timeout microseconds, zero to continue the
     * close.  If this returns 0, it must close the file, either with
     * gensio_fd_ll_close_now() or directly.
     */
    int (*check_close)(void *handler_data, struct gensio_iod *iod,
		       enum gensio_ll_close_state state,
		       gensio_time *next_timeout);

    void (*free)(void *handler_data);

    int (*control)(void *handler_data, struct gensio_iod *iod, bool get,
		   unsigned int option, char *data, gensiods *datalen);

    void (*read_ready)(void *handler_data, struct gensio_iod *iod);

    void (*write_ready)(void *handler_data, struct gensio_iod *iod);

    int (*except_ready)(void *handler_data, struct gensio_iod *iod);

    int (*write)(void *handler_data, struct gensio_iod *iod, gensiods *count,
		 const struct gensio_sg *sg, gensiods sglen,
		 const char *const *auxdata);
};

GENSIO_DLL_PUBLIC
gensiods gensio_fd_ll_callback(struct gensio_ll *ll, int op, int val,
			       void *buf, gensiods buflen, const void *data);

/*
 * For calling from the check_close() callback only, and only when
 * GENSIO_LL_CLOSE_STATE_DONE is the state.  This will immediately
 * close the file descriptor.  Some gensios (like pty) require that
 * the fd gets closed before they can finish the close operation
 * (waiting for the process to exit when stdin closes).
 */
GENSIO_DLL_PUBLIC
void gensio_fd_ll_close_now(struct gensio_ll *ll);

GENSIO_DLL_PUBLIC
void gensio_fd_ll_handle_incoming(struct gensio_ll *ll,
				  int (*doread)(struct gensio_iod *iod,
						void *buf,
						gensiods count,
						gensiods *rcount,
						const char ***auxdata,
						void *cb_data),
				  const char **auxdata,
				  void *cb_data);

GENSIO_DLL_PUBLIC
void *gensio_fd_ll_get_handler_data(struct gensio_ll *ll);

GENSIO_DLL_PUBLIC
struct gensio_ll *fd_gensio_ll_alloc(struct gensio_os_funcs *o,
				     struct gensio_iod *iod,
				     const struct gensio_fd_ll_ops *ops,
				     void *handler_data,
				     gensiods max_read_size,
				     bool write_only, bool read_only);


#endif /* GENSIO_LL_FD_H */
