/*
 * Copyright (C) 2016, 2017 "IoT.bzh"
 * Author: José Bollo <jose.bollo@iot.bzh>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

struct afb_binding_interface;
struct json_object;
struct afb_service;

/*
 * Function for registering the binding
 *
 * A binding V1 MUST have an exported function of name
 *
 *              afbBindingV1Register
 *
 * This function is called during loading of the binding. It
 * receives an 'interface' that should be recorded for later access to
 * functions provided by the framework.
 *
 * This function MUST return the address of a structure that describes
 * the binding and its implemented verbs.
 *
 * In case of initialisation error, NULL must be returned.
 *
 * Be aware that the given 'interface' is not fully functionnal
 * because no provision is given to the name and description
 * of the binding. Check the function 'afbBindingV1ServiceInit'
 * defined in the file <afb/afb-service-itf.h> because when
 * the function 'afbBindingV1ServiceInit' is called, the 'interface'
 * is fully functionnal.
 */
extern const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *interface);

/*
 * When a binding have an exported implementation of the
 * function 'afbBindingV1ServiceInit', defined below,
 * the framework calls it for initialising the service after
 * registration of all bindings.
 *
 * The object 'service' should be recorded. It has functions that
 * allows the binding to call features with its own personality.
 *
 * The function should return 0 in case of success or, else, should return
 * a negative value.
 */
extern int afbBindingV1ServiceInit(struct afb_service service);

/*
 * When a binding have an implementation of the function 'afbBindingV1ServiceEvent',
 * defined below, the framework calls that function for any broadcasted event or for
 * events that the service subscribed to in its name.
 *
 * It receive the 'event' name and its related data in 'object' (be aware that 'object'
 * might be NULL).
 */
extern void afbBindingV1ServiceEvent(const char *event, struct json_object *object);


/*
 * Enum for Session/Token/Assurance middleware.
 * This enumeration is valid for bindings of type 1
 */
enum afb_session_v1
{
       AFB_SESSION_NONE = 0,   /* nothing required */
       AFB_SESSION_CREATE = 1, /* Obsolete */
       AFB_SESSION_CLOSE = 2,  /* After token authentification, closes the session at end */
       AFB_SESSION_RENEW = 4,  /* After token authentification, refreshes the token at end */
       AFB_SESSION_CHECK = 8,  /* Requires token authentification */

       AFB_SESSION_LOA_GE = 16, /* check that the LOA is greater or equal to the given value */
       AFB_SESSION_LOA_LE = 32, /* check that the LOA is lesser or equal to the given value */
       AFB_SESSION_LOA_EQ = 48, /* check that the LOA is equal to the given value */

       AFB_SESSION_LOA_SHIFT = 6, /* shift for LOA */
       AFB_SESSION_LOA_MASK = 7,  /* mask for LOA */

       AFB_SESSION_LOA_0 = 0,   /* value for LOA of 0 */
       AFB_SESSION_LOA_1 = 64,  /* value for LOA of 1 */
       AFB_SESSION_LOA_2 = 128, /* value for LOA of 2 */
       AFB_SESSION_LOA_3 = 192, /* value for LOA of 3 */
       AFB_SESSION_LOA_4 = 256, /* value for LOA of 4 */

       AFB_SESSION_LOA_LE_0 = AFB_SESSION_LOA_LE | AFB_SESSION_LOA_0, /* check LOA <= 0 */
       AFB_SESSION_LOA_LE_1 = AFB_SESSION_LOA_LE | AFB_SESSION_LOA_1, /* check LOA <= 1 */
       AFB_SESSION_LOA_LE_2 = AFB_SESSION_LOA_LE | AFB_SESSION_LOA_2, /* check LOA <= 2 */
       AFB_SESSION_LOA_LE_3 = AFB_SESSION_LOA_LE | AFB_SESSION_LOA_3, /* check LOA <= 3 */

       AFB_SESSION_LOA_GE_0 = AFB_SESSION_LOA_GE | AFB_SESSION_LOA_0, /* check LOA >= 0 */
       AFB_SESSION_LOA_GE_1 = AFB_SESSION_LOA_GE | AFB_SESSION_LOA_1, /* check LOA >= 1 */
       AFB_SESSION_LOA_GE_2 = AFB_SESSION_LOA_GE | AFB_SESSION_LOA_2, /* check LOA >= 2 */
       AFB_SESSION_LOA_GE_3 = AFB_SESSION_LOA_GE | AFB_SESSION_LOA_3, /* check LOA >= 3 */

       AFB_SESSION_LOA_EQ_0 = AFB_SESSION_LOA_EQ | AFB_SESSION_LOA_0, /* check LOA == 0 */
       AFB_SESSION_LOA_EQ_1 = AFB_SESSION_LOA_EQ | AFB_SESSION_LOA_1, /* check LOA == 1 */
       AFB_SESSION_LOA_EQ_2 = AFB_SESSION_LOA_EQ | AFB_SESSION_LOA_2, /* check LOA == 2 */
       AFB_SESSION_LOA_EQ_3 = AFB_SESSION_LOA_EQ | AFB_SESSION_LOA_3  /* check LOA == 3 */
};

/*
 * Description of one verb of the API provided by the binding
 * This enumeration is valid for bindings of type version 1
 */
struct afb_verb_desc_v1
{
       const char *name;                       /* name of the verb */
       enum afb_session_v1 session;            /* authorisation and session requirements of the verb */
       void (*callback)(struct afb_req req);   /* callback function implementing the verb */
       const char *info;                       /* textual description of the verb */
};

/*
 * Description of the bindings of type version 1
 */
struct afb_binding_desc_v1
{
       const char *info;                       /* textual information about the binding */
       const char *prefix;                     /* required prefix name for the binding */
       const struct afb_verb_desc_v1 *verbs;   /* array of descriptions of verbs terminated by a NULL name */
};

/*
 * Definition of the type+versions of the binding.
 * The definition uses hashes.
 */
enum  afb_binding_type
{
       AFB_BINDING_VERSION_1 = 123456789
};

/*
 * Description of a binding
 */
struct afb_binding
{
       enum afb_binding_type type; /* type of the binding */
       union {
               struct afb_binding_desc_v1 v1;   /* description of the binding of type 1 */
       };
};