/*
 * Copyright (c) 2017 Linaro Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#ifndef LWM2M_ENGINE_H
#define LWM2M_ENGINE_H

#include "lwm2m_object.h"

#define LWM2M_PROTOCOL_VERSION "1.0"

/* LWM2M / CoAP Content-Formats */
#define LWM2M_FORMAT_PLAIN_TEXT		0
#define LWM2M_FORMAT_APP_LINK_FORMAT	40
#define LWM2M_FORMAT_APP_OCTET_STREAM	42
#define LWM2M_FORMAT_APP_EXI		47
#define LWM2M_FORMAT_APP_JSON		50
#define LWM2M_FORMAT_OMA_PLAIN_TEXT	1541
#define LWM2M_FORMAT_OMA_OLD_TLV	1542
#define LWM2M_FORMAT_OMA_OLD_JSON	1543
#define LWM2M_FORMAT_OMA_OLD_OPAQUE	1544
#define LWM2M_FORMAT_OMA_TLV		11542
#define LWM2M_FORMAT_OMA_JSON		11543


#define ZOAP_RESPONSE_CODE_CLASS(x)	(x >> 5)
#define ZOAP_RESPONSE_CODE_DETAIL(x)	(x & 0x1F)

/* TODO: */
#define NOTIFY_OBSERVER(o, i, r)	lwm2m_notify_observer(o, i, r)
#define NOTIFY_OBSERVER_PATH(path)	lwm2m_notify_observer_path(path)

/* Use this value to skip token generation */
#define LWM2M_MSG_TOKEN_LEN_SKIP	0xFF

struct lwm2m_message;

/* Establish a message timeout callback */
typedef void (*lwm2m_message_timeout_cb_t)(struct lwm2m_message *msg);

/* Internal LwM2M message structure to track in-flight messages. */
struct lwm2m_message {
	/** LwM2M context related to this message */
	struct lwm2m_ctx *ctx;

	/** ZoAP packet data related to this message */
	struct zoap_packet zpkt;

	/** Message transmission handling for TYPE_CON */
	struct zoap_pending *pending;
	struct zoap_reply *reply;

	/** Message configuration */
	const u8_t *token;
	zoap_reply_t reply_cb;
	lwm2m_message_timeout_cb_t message_timeout_cb;
	u16_t mid;
	u8_t type;
	u8_t code;
	u8_t tkl;

	/** Counter for message re-send / abort handling */
	u8_t send_attempts;
};

/* Establish a request handler callback type */
typedef int (*udp_request_handler_cb_t)(struct zoap_packet *request,
					struct lwm2m_message *msg);

char *lwm2m_sprint_ip_addr(const struct sockaddr *addr);

int lwm2m_notify_observer(u16_t obj_id, u16_t obj_inst_id, u16_t res_id);
int lwm2m_notify_observer_path(struct lwm2m_obj_path *path);

void lwm2m_register_obj(struct lwm2m_engine_obj *obj);
void lwm2m_unregister_obj(struct lwm2m_engine_obj *obj);
struct lwm2m_engine_obj_field *
lwm2m_get_engine_obj_field(struct lwm2m_engine_obj *obj, int res_id);
int  lwm2m_create_obj_inst(u16_t obj_id, u16_t obj_inst_id,
			   struct lwm2m_engine_obj_inst **obj_inst);
int  lwm2m_delete_obj_inst(u16_t obj_id, u16_t obj_inst_id);
int  lwm2m_get_or_create_engine_obj(struct lwm2m_engine_context *context,
				    struct lwm2m_engine_obj_inst **obj_inst,
				    u8_t *created);

/* LwM2M message functions */
struct lwm2m_message *find_msg_from_pending(struct zoap_pending *pending);
struct lwm2m_message *lwm2m_get_message(struct lwm2m_ctx *client_ctx);
void lwm2m_release_message(struct lwm2m_message *msg);
int lwm2m_init_message(struct lwm2m_message *msg);
int lwm2m_send_message(struct lwm2m_message *msg);

u16_t lwm2m_get_rd_data(u8_t *client_data, u16_t size);

int lwm2m_write_handler(struct lwm2m_engine_obj_inst *obj_inst,
			struct lwm2m_engine_res_inst *res,
			struct lwm2m_engine_obj_field *obj_field,
			struct lwm2m_engine_context *context);

void lwm2m_udp_receive(struct lwm2m_ctx *client_ctx, struct net_pkt *pkt,
		       bool handle_separate_response,
		       udp_request_handler_cb_t udp_request_handler);

#endif /* LWM2M_ENGINE_H */