/*
  webid-oidc, implementation of the Solid specification
  Copyright (C) 2020, 2021  Vivien Kraus

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU Affero General Public License as
  published by the Free Software Foundation, either version 3 of the
  License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License
  along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

#ifndef H_RANDOM_INCLUDED
#define H_RANDOM_INCLUDED

struct webid_oidc_random_context;
typedef struct webid_oidc_random_context webid_oidc_random_context;

/* These functions allocate data, they are not reentrant. */
struct webid_oidc_random_context *webid_oidc_random_context_alloc (void);
void webid_oidc_random_context_free (struct webid_oidc_random_context *ctx);

enum webid_oidc_random_context_state
{
  WEBID_OIDC_RANDOM_CONTEXT_READY = 0,
  WEBID_OIDC_RANDOM_CONTEXT_WAIT_LOCK_FILE,
  WEBID_OIDC_RANDOM_CONTEXT_WAIT_FILE_READ,
  WEBID_OIDC_RANDOM_CONTEXT_WAIT_FILE_WRITE,
  WEBID_OIDC_RANDOM_CONTEXT_WAIT_UNLOCK_FILE
};

typedef enum webid_oidc_random_context_state webid_oidc_random_context_state;

enum webid_oidc_random_context_state
webid_oidc_random_context_get_state (const struct webid_oidc_random_context
				     *ctx);
int webid_oidc_random_context_get_wait_bytes (const struct
					      webid_oidc_random_context *ctx,
					      size_t max, size_t start,
					      uint8_t * bytes,
					      size_t *n_bytes);
int webid_oidc_random_context_ok (struct webid_oidc_random_context *ctx);
int webid_oidc_random_context_bytes (struct webid_oidc_random_context *ctx,
				     size_t n_bytes, const uint8_t * bytes);

enum webid_oidc_random_context_spawn_flags
{
  WEBID_OIDC_RANDOM_CONTEXT_THREAD_UNSAFE = 1
};
typedef enum webid_oidc_random_context_spawn_flags
  webid_oidc_random_context_spawn_flags;

int webid_oidc_random_context_spawn (struct webid_oidc_random_context *parent,
				     struct webid_oidc_random_context *child,
				     enum
				     webid_oidc_random_context_spawn_flags
				     flags);

int webid_oidc_random_context_get (struct webid_oidc_random_context *ctx,
				   size_t request_size, uint8_t * data);

/* These functions set up and use a global state. Neither are
   reentrant. */
void webid_oidc_random_init (void);

/* This function is thread-safe. */
void webid_oidc_random (size_t request_size, uint8_t * data);

#endif /* not H_RANDOM_INCLUDED */