/**
 * \file netconf.h
 * \author Radek Krejci <rkrejci@cesnet.cz>
 * \brief libnetconf2's general public functions and structures definitions.
 *
 * Copyright (c) 2015 CESNET, z.s.p.o.
 *
 * This source code is licensed under BSD 3-Clause License (the "License").
 * You may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://opensource.org/licenses/BSD-3-Clause
 */

#ifndef NC_NETCONF_H_
#define NC_NETCONF_H_

#include <time.h>

#ifdef __cplusplus
extern "C" {
#endif

#define NC_NS_BASE  "urn:ietf:params:xml:ns:netconf:base:1.0"
#define NC_NS_NOTIF "urn:ietf:params:xml:ns:netconf:notification:1.0"

/** @brief Default NETCONF over SSH port */
#define NC_PORT_SSH 830
/** @brief Default NETCONF over SSH Call Home port */
#define NC_PORT_CH_SSH 6666

/** @brief Default NETCONF over TLS port */
#define NC_PORT_TLS 6513
/** @brief Default NETCONF over TLS Call Home port */
#define NC_PORT_CH_TLS 6667

/** @brief Microseconds after which tasks are repeated until the full timeout elapses.
 *         A second (1000 000) should be divisible by this number without remain.
 */
#define NC_TIMEOUT_STEP 20

/**
 * @brief Set RPC callback to a schema node.
 *
 * @param[in] node const struct lys_node *node
 * @param[in] cb nc_rpc_clb cb
 */
#define nc_set_rpc_callback(node, cb) lys_set_private(node, cb)

/**
 * @brief Enumeration of reasons of the NETCONF session termination as defined in RFC 6470.
 */
typedef enum NC_SESSION_TERM_REASON {
    NC_SESSION_TERM_NONE = 0,     /**< session still running */
    NC_SESSION_TERM_CLOSED,       /**< closed by client in a normal fashion */
    NC_SESSION_TERM_KILLED,       /**< session was terminated by \<kill-session\> operation */
    NC_SESSION_TERM_DROPPED,      /**< transport layer connection was unexpectedly closed */
    NC_SESSION_TERM_TIMEOUT,      /**< terminated because of inactivity */
    NC_SESSION_TERM_BADHELLO,     /**< \<hello\> message was invalid */
    NC_SESSION_TERM_OTHER         /**< terminated for some other reason */
} NC_SESSION_TERM_REASON;

/**
 * @brief Enumeration of NETCONF message types.
 */
typedef enum NC_MSG_TYPE {
    NC_MSG_ERROR,           /**< error return value */
    NC_MSG_WOULDBLOCK,      /**< timeout return value */
    NC_MSG_NONE,            /**< no message at input or message was processed internally */
    NC_MSG_HELLO,           /**< \<hello\> message */
    NC_MSG_BAD_HELLO,       /**< \<hello\> message parsing failed */
    NC_MSG_RPC,             /**< \<rpc\> message */
    NC_MSG_REPLY,           /**< \<rpc-reply\> message */
    NC_MSG_REPLY_ERR_MSGID, /**< \<rpc-reply\> message with missing or wrong message-id attribute value */
    NC_MSG_NOTIF            /**< \<notification\> message */
} NC_MSG_TYPE;

/**
 * @brief Enumeration of the supported types of datastores defined by NETCONF
 */
typedef enum NC_DATASTORE_TYPE {
    NC_DATASTORE_ERROR = 0, /**< error state of functions returning the datastore type */
    NC_DATASTORE_CONFIG,    /**< value describing that the datastore is set as config */
    NC_DATASTORE_URL,       /**< value describing that the datastore data should be given from the URL */
    NC_DATASTORE_RUNNING,   /**< base NETCONF's datastore containing the current device configuration */
    NC_DATASTORE_STARTUP,   /**< separated startup datastore as defined in Distinct Startup Capability */
    NC_DATASTORE_CANDIDATE  /**< separated working datastore as defined in Candidate Configuration Capability */
} NC_DATASTORE;

/**
 * @brief Enumeration of NETCONF with-defaults capability modes.
 */
typedef enum NC_WITHDEFAULTS_MODE {
    NC_WD_UNKNOWN = 0,    /**< invalid mode */
    NC_WD_ALL,            /**< report-all mode */
    NC_WD_ALL_TAG,        /**< report-all-tagged mode */
    NC_WD_TRIM,           /**< trim mode */
    NC_WD_EXPLICIT        /**< explicit mode */
} NC_WD_MODE;

/**
 * @brief Enumeration of NETCONF (both server and client) rpc-reply types.
 */
typedef enum NC_REPLY {
    NC_RPL_OK,    /**< OK rpc-reply */
    NC_RPL_DATA,  /**< DATA rpc-reply */
    NC_RPL_ERROR, /**< ERROR rpc-reply */
    NC_RPL_NOTIF  /**< notification (client-only) */
} NC_RPL;

/**
 * @brief Enumeration of function parameter treatments.
 */
typedef enum NC_PARAMTYPE {
    NC_PARAMTYPE_CONST,       /**< use the parameter directly, do not free */
    NC_PARAMTYPE_FREE,        /**< use the parameter directly, free afterwards */
    NC_PARAMTYPE_DUP_AND_FREE /**< make a copy of the argument, free afterwards */
} NC_PARAMTYPE;

#if defined(NC_ENABLED_SSH) || defined(NC_ENABLED_TLS)

/**
 * @brief Free all the dynamically allocated thread-specific libssl/libcrypto
 *        resources.
 *
 *        This function should be called only if init was called. Call it in every
 *        thread your application creates just before the thread exits. In the last thread
 *        (usually the main one) call only nc_destroy().
 */
void nc_thread_destroy(void);

#endif /* NC_ENABLED_SSH || NC_ENABLED_TLS */

/**
 * @brief Transform given time_t (seconds since the epoch) into the RFC 3339 format
 * accepted by NETCONF functions.
 *
 * This is a reverse function to nc_datetime2time().
 *
 * @param[in] time Time to convert.
 * @param[in] tz Timezone name for the result. See tzselect(1) for list of
 * correct values. If not specified (NULL) or unknown/invalid, the result is provided in UTC (Zulu).
 * @param[in] buf Optional buffer to print the datetime into, should be at least 26 characters long!
 * @return Printed string in a format compliant to RFC 3339 stored in \p buf if provided,
 * otherwise it is up to the caller to free the returned string. NULL on error.
 */
char* nc_time2datetime(time_t time, const char* tz, char *buf);

/**
 * @brief Transform given string in RFC 3339 compliant format to the time_t
 * (seconds since the epoch) accepted by most Linux functions.
 *
 * This is a reverse function to nc_time2datetime().
 *
 * @param[in] datetime Time structure returned e.g. by localtime().
 * @return time_t value of the given string, -1 on error.
 */
time_t nc_datetime2time(const char* datetime);

#ifdef __cplusplus
}
#endif

#endif /* NC_NETCONF_H_ */