/*
 * Copyright (c) 2017 Linaro Limited
 * Copyright (c) 2018 Foundries.io
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/*
 * Copyright (c) 2015, Yanzi Networks AB.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Original Authors:
 *         Joakim Eriksson <joakime@sics.se>
 *         Niclas Finne <nfi@sics.se>
 */

#ifndef LWM2M_OBJECT_H_
#define LWM2M_OBJECT_H_

/* stdint conversions */
#include <zephyr/types.h>
#include <stddef.h>
#include <net/net_ip.h>
#include <net/coap.h>
#include <net/lwm2m.h>
#include <misc/printk.h>
#include <misc/util.h>
#include <kernel.h>

/* #####/###/#####/### + NULL */
#define MAX_RESOURCE_LEN	20

/* operations / permissions */
/* values from 0 to 7 can be used as permission checks */
#define LWM2M_OP_READ		0
#define LWM2M_OP_WRITE		1
#define LWM2M_OP_CREATE		2
#define LWM2M_OP_DELETE		3
#define LWM2M_OP_EXECUTE	4
#define LWM2M_FLAG_OPTIONAL	7
/* values >7 aren't used for permission checks */
#define LWM2M_OP_DISCOVER	8
#define LWM2M_OP_WRITE_ATTR	9

/* resource permissions */
#define LWM2M_PERM_R		BIT(LWM2M_OP_READ)
#define LWM2M_PERM_R_OPT	(BIT(LWM2M_OP_READ) | \
				 BIT(LWM2M_FLAG_OPTIONAL))
#define LWM2M_PERM_W		(BIT(LWM2M_OP_WRITE) | \
				 BIT(LWM2M_OP_CREATE))
#define LWM2M_PERM_W_OPT	(BIT(LWM2M_OP_WRITE) | \
				 BIT(LWM2M_OP_CREATE) | \
				 BIT(LWM2M_FLAG_OPTIONAL))
#define LWM2M_PERM_X		BIT(LWM2M_OP_EXECUTE)
#define LWM2M_PERM_X_OPT	(BIT(LWM2M_OP_EXECUTE) | \
				 BIT(LWM2M_FLAG_OPTIONAL))
#define LWM2M_PERM_RW		(BIT(LWM2M_OP_READ) | \
				 BIT(LWM2M_OP_WRITE) | \
				 BIT(LWM2M_OP_CREATE))
#define LWM2M_PERM_RW_OPT	(BIT(LWM2M_OP_READ) | \
				 BIT(LWM2M_OP_WRITE) | \
				 BIT(LWM2M_OP_CREATE) | \
				 BIT(LWM2M_FLAG_OPTIONAL))
#define LWM2M_PERM_RWX		(BIT(LWM2M_OP_READ) | \
				 BIT(LWM2M_OP_WRITE) | \
				 BIT(LWM2M_OP_CREATE) | \
				 BIT(LWM2M_OP_EXECUTE))
#define LWM2M_PERM_RWX_OPT	(BIT(LWM2M_OP_READ) | \
				 BIT(LWM2M_OP_WRITE) | \
				 BIT(LWM2M_OP_CREATE) | \
				 BIT(LWM2M_OP_EXECUTE) | \
				 BIT(LWM2M_FLAG_OPTIONAL))

#define LWM2M_HAS_PERM(of, p)	((of->permissions & p) == p)

/* resource types */
#define LWM2M_RES_TYPE_NONE	0
#define LWM2M_RES_TYPE_OPAQUE	1
#define LWM2M_RES_TYPE_STRING	2
#define LWM2M_RES_TYPE_UINT64	3
#define LWM2M_RES_TYPE_U64	3
#define LWM2M_RES_TYPE_UINT	4
#define LWM2M_RES_TYPE_U32	4
#define LWM2M_RES_TYPE_U16	5
#define LWM2M_RES_TYPE_U8	6
#define LWM2M_RES_TYPE_INT64	7
#define LWM2M_RES_TYPE_S64	7
#define LWM2M_RES_TYPE_INT	8
#define LWM2M_RES_TYPE_S32	8
#define LWM2M_RES_TYPE_S16	9
#define LWM2M_RES_TYPE_S8	10
#define LWM2M_RES_TYPE_BOOL	11
#define LWM2M_RES_TYPE_TIME	12
#define LWM2M_RES_TYPE_FLOAT32	13
#define LWM2M_RES_TYPE_FLOAT64	14

/* remember that we have already output a value - can be between two block's */
#define WRITER_OUTPUT_VALUE      1
#define WRITER_RESOURCE_INSTANCE 2

struct lwm2m_engine_obj;
struct lwm2m_engine_context;

/* path representing object instances */
struct lwm2m_obj_path {
	u16_t obj_id;
	u16_t obj_inst_id;
	u16_t res_id;
	u16_t res_inst_id;
	u8_t  level;  /* 0/1/2/3 = 3 = resource */
};

#define OBJ_FIELD(res_id, perm, type, multi_max) \
	{ res_id, LWM2M_PERM_ ## perm, LWM2M_RES_TYPE_ ## type, multi_max }

#define OBJ_FIELD_DATA(res_id, perm, type) \
	OBJ_FIELD(res_id, perm, type, 1)

#define OBJ_FIELD_EXECUTE(res_id) \
	OBJ_FIELD(res_id, X, NONE, 0)

#define OBJ_FIELD_EXECUTE_OPT(res_id) \
	OBJ_FIELD(res_id, X_OPT, NONE, 0)

struct lwm2m_engine_obj_field {
	u16_t  res_id;
	u8_t   permissions;
	u8_t   data_type;
	u8_t   multi_max_count;
};

typedef struct lwm2m_engine_obj_inst *
	(*lwm2m_engine_obj_create_cb_t)(u16_t obj_inst_id);
typedef int (*lwm2m_engine_obj_delete_cb_t)(u16_t obj_inst_id);

struct lwm2m_engine_obj {
	/* object list */
	sys_snode_t node;

	/* object field definitions */
	struct lwm2m_engine_obj_field *fields;

	/* object event callbacks */
	lwm2m_engine_obj_create_cb_t create_cb;
	lwm2m_engine_obj_delete_cb_t delete_cb;
	lwm2m_engine_user_cb_t user_create_cb;
	lwm2m_engine_user_cb_t user_delete_cb;

	/* object member data */
	u16_t obj_id;
	u16_t field_count;
	u16_t instance_count;
	u16_t max_instance_count;
};

#define INIT_OBJ_RES(res_var, index_var, id_val, multi_var, \
		     data_val, data_val_len, r_cb, pre_w_cb, post_w_cb, ex_cb) \
	res_var[index_var].res_id = id_val; \
	res_var[index_var].multi_count_var = multi_var; \
	res_var[index_var].data_ptr = data_val; \
	res_var[index_var].data_len = data_val_len; \
	res_var[index_var].read_cb = r_cb; \
	res_var[index_var].pre_write_cb = pre_w_cb; \
	res_var[index_var].post_write_cb = post_w_cb; \
	res_var[index_var++].execute_cb = ex_cb

#define INIT_OBJ_RES_MULTI_DATA(res_var, index_var, id_val, multi_var, \
				data_val, data_val_len) \
	INIT_OBJ_RES(res_var, index_var, id_val, multi_var, data_val, \
		     data_val_len, NULL, NULL, NULL, NULL)

#define INIT_OBJ_RES_DATA(res_var, index_var, id_val, data_val, data_val_len) \
	INIT_OBJ_RES_MULTI_DATA(res_var, index_var, id_val, NULL, \
				data_val, data_val_len)

#define INIT_OBJ_RES_DUMMY(res_var, index_var, id_val) \
	INIT_OBJ_RES_MULTI_DATA(res_var, index_var, id_val, NULL, NULL, 0)

#define INIT_OBJ_RES_EXECUTE(res_var, index_var, id_val, ex_cb) \
	INIT_OBJ_RES(res_var, index_var, id_val, NULL, NULL, 0, \
		     NULL, NULL, NULL, ex_cb)


#define LWM2M_ATTR_PMIN	0
#define LWM2M_ATTR_PMAX	1
#define LWM2M_ATTR_GT	2
#define LWM2M_ATTR_LT	3
#define LWM2M_ATTR_STEP	4
#define NR_LWM2M_ATTR	5

/* TODO: support multiple server (sec 5.4.2) */
struct lwm2m_attr {
	void *ref;

	/* values */
	union {
		float32_value_t float_val;
		s32_t int_val;
	};

	u8_t type;
};

struct lwm2m_engine_res_inst {
	/* callbacks set by user code on obj instance */
	lwm2m_engine_get_data_cb_t	read_cb;
	lwm2m_engine_get_data_cb_t	pre_write_cb;
	lwm2m_engine_set_data_cb_t	post_write_cb;
	lwm2m_engine_user_cb_t		execute_cb;

	u8_t  *multi_count_var;
	void  *data_ptr;
	u16_t data_len;
	u16_t res_id;
	u8_t  data_flags;
};

struct lwm2m_engine_obj_inst {
	/* instance list */
	sys_snode_t node;

	struct lwm2m_engine_obj *obj;
	struct lwm2m_engine_res_inst *resources;

	/* object instance member data */
	u16_t obj_inst_id;
	u16_t resource_count;
};

struct lwm2m_output_context {
	const struct lwm2m_writer *writer;
	struct coap_packet *out_cpkt;

	/* current write fragment in net_buf chain */
	struct net_buf *frag;

	/* current write position in net_buf chain */
	u16_t offset;

	/* private output data */
	void *user_data;
};

struct lwm2m_input_context {
	const struct lwm2m_reader *reader;
	struct coap_packet *in_cpkt;

	/* current read position in net_buf chain */
	struct net_buf *frag;
	u16_t offset;

	/* length of incoming coap/lwm2m payload */
	u16_t payload_len;

	/* length of incoming opaque */
	u16_t opaque_len;
};

/* LWM2M format writer for the various formats supported */
struct lwm2m_writer {
	size_t (*put_begin)(struct lwm2m_output_context *out,
			    struct lwm2m_obj_path *path);
	size_t (*put_end)(struct lwm2m_output_context *out,
			  struct lwm2m_obj_path *path);
	size_t (*put_begin_oi)(struct lwm2m_output_context *out,
			       struct lwm2m_obj_path *path);
	size_t (*put_end_oi)(struct lwm2m_output_context *out,
			     struct lwm2m_obj_path *path);
	size_t (*put_begin_r)(struct lwm2m_output_context *out,
			      struct lwm2m_obj_path *path);
	size_t (*put_end_r)(struct lwm2m_output_context *out,
			    struct lwm2m_obj_path *path);
	size_t (*put_begin_ri)(struct lwm2m_output_context *out,
			       struct lwm2m_obj_path *path);
	size_t (*put_end_ri)(struct lwm2m_output_context *out,
			     struct lwm2m_obj_path *path);
	size_t (*put_s8)(struct lwm2m_output_context *out,
			 struct lwm2m_obj_path *path,
			 s8_t value);
	size_t (*put_s16)(struct lwm2m_output_context *out,
			  struct lwm2m_obj_path *path,
			  s16_t value);
	size_t (*put_s32)(struct lwm2m_output_context *out,
			  struct lwm2m_obj_path *path,
			  s32_t value);
	size_t (*put_s64)(struct lwm2m_output_context *out,
			  struct lwm2m_obj_path *path,
			  s64_t value);
	size_t (*put_string)(struct lwm2m_output_context *out,
			     struct lwm2m_obj_path *path,
			     char *buf, size_t buflen);
	size_t (*put_float32fix)(struct lwm2m_output_context *out,
				 struct lwm2m_obj_path *path,
				 float32_value_t *value);
	size_t (*put_float64fix)(struct lwm2m_output_context *out,
				 struct lwm2m_obj_path *path,
				 float64_value_t *value);
	size_t (*put_bool)(struct lwm2m_output_context *out,
			   struct lwm2m_obj_path *path,
			   bool value);
	size_t (*put_opaque)(struct lwm2m_output_context *out,
			     struct lwm2m_obj_path *path,
			     char *buf, size_t buflen);
};

struct lwm2m_reader {
	size_t (*get_s32)(struct lwm2m_input_context *in,
			  s32_t *value);
	size_t (*get_s64)(struct lwm2m_input_context *in,
			  s64_t *value);
	size_t (*get_string)(struct lwm2m_input_context *in,
			     u8_t *buf, size_t buflen);
	size_t (*get_float32fix)(struct lwm2m_input_context *in,
				 float32_value_t *value);
	size_t (*get_float64fix)(struct lwm2m_input_context *in,
				 float64_value_t *value);
	size_t (*get_bool)(struct lwm2m_input_context *in,
			   bool *value);
	size_t (*get_opaque)(struct lwm2m_input_context *in,
			     u8_t *buf, size_t buflen, bool *last_block);
};

/* LWM2M engine context */
struct lwm2m_engine_context {
	struct lwm2m_input_context *in;
	struct lwm2m_output_context *out;
	struct lwm2m_obj_path *path;
	u8_t operation;
};

/* output user_data management functions */

static inline void engine_set_out_user_data(struct lwm2m_output_context *out,
					    void *user_data)
{
	out->user_data = user_data;
}

static inline void *engine_get_out_user_data(struct lwm2m_output_context *out)
{
	return out->user_data;
}

static inline void
engine_clear_out_user_data(struct lwm2m_output_context *out)
{
	out->user_data = NULL;
}

/* inline multi-format write / read functions */

static inline size_t engine_put_begin(struct lwm2m_output_context *out,
				      struct lwm2m_obj_path *path)
{
	if (out->writer->put_begin) {
		return out->writer->put_begin(out, path);
	}

	return 0;
}

static inline size_t engine_put_end(struct lwm2m_output_context *out,
				    struct lwm2m_obj_path *path)
{
	if (out->writer->put_end) {
		return out->writer->put_end(out, path);
	}

	return 0;
}

static inline size_t engine_put_begin_oi(struct lwm2m_output_context *out,
					 struct lwm2m_obj_path *path)
{
	if (out->writer->put_begin_oi) {
		return out->writer->put_begin_oi(out, path);
	}

	return 0;
}

static inline size_t engine_put_end_oi(struct lwm2m_output_context *out,
				       struct lwm2m_obj_path *path)
{
	if (out->writer->put_end_oi) {
		return out->writer->put_end_oi(out, path);
	}

	return 0;
}

static inline size_t engine_put_begin_r(struct lwm2m_output_context *out,
					struct lwm2m_obj_path *path)
{
	if (out->writer->put_begin_r) {
		return out->writer->put_begin_r(out, path);
	}

	return 0;
}

static inline size_t engine_put_end_r(struct lwm2m_output_context *out,
				      struct lwm2m_obj_path *path)
{
	if (out->writer->put_end_r) {
		return out->writer->put_end_r(out, path);
	}

	return 0;
}

static inline size_t engine_put_begin_ri(struct lwm2m_output_context *out,
					 struct lwm2m_obj_path *path)
{
	if (out->writer->put_begin_ri) {
		return out->writer->put_begin_ri(out, path);
	}

	return 0;
}

static inline size_t engine_put_end_ri(struct lwm2m_output_context *out,
				       struct lwm2m_obj_path *path)
{
	if (out->writer->put_end_ri) {
		return out->writer->put_end_ri(out, path);
	}

	return 0;
}

static inline size_t engine_put_s8(struct lwm2m_output_context *out,
				   struct lwm2m_obj_path *path,
				   s8_t value)
{
	return out->writer->put_s8(out, path, value);
}

static inline size_t engine_put_s16(struct lwm2m_output_context *out,
				    struct lwm2m_obj_path *path,
				    s16_t value)
{
	return out->writer->put_s16(out, path, value);
}

static inline size_t engine_put_s32(struct lwm2m_output_context *out,
				    struct lwm2m_obj_path *path,
				    s32_t value)
{
	return out->writer->put_s32(out, path, value);
}

static inline size_t engine_put_s64(struct lwm2m_output_context *out,
				    struct lwm2m_obj_path *path,
				    s64_t value)
{
	return out->writer->put_s64(out, path, value);
}

static inline size_t engine_put_string(struct lwm2m_output_context *out,
				       struct lwm2m_obj_path *path,
				       char *buf, size_t buflen)
{
	return out->writer->put_string(out, path, buf, buflen);
}

static inline size_t engine_put_float32fix(struct lwm2m_output_context *out,
					   struct lwm2m_obj_path *path,
					   float32_value_t *value)
{
	return out->writer->put_float32fix(out, path, value);
}

static inline size_t engine_put_float64fix(struct lwm2m_output_context *out,
					   struct lwm2m_obj_path *path,
					   float64_value_t *value)
{
	return out->writer->put_float64fix(out, path, value);
}

static inline size_t engine_put_bool(struct lwm2m_output_context *out,
				     struct lwm2m_obj_path *path,
				     bool value)
{
	return out->writer->put_bool(out, path, value);
}

static inline size_t engine_put_opaque(struct lwm2m_output_context *out,
				       struct lwm2m_obj_path *path,
				       char *buf, size_t buflen)
{
	if (out->writer->put_opaque) {
		return out->writer->put_opaque(out, path, buf, buflen);
	}

	return 0;
}

static inline size_t engine_get_s32(struct lwm2m_input_context *in,
				    s32_t *value)
{
	return in->reader->get_s32(in, value);
}

static inline size_t engine_get_s64(struct lwm2m_input_context *in,
				    s64_t *value)
{
	return in->reader->get_s64(in, value);
}

static inline size_t engine_get_string(struct lwm2m_input_context *in,
				       u8_t *buf, size_t buflen)
{
	return in->reader->get_string(in, buf, buflen);
}

static inline size_t engine_get_float32fix(struct lwm2m_input_context *in,
					   float32_value_t *value)
{
	return in->reader->get_float32fix(in, value);
}

static inline size_t engine_get_float64fix(struct lwm2m_input_context *in,
					   float64_value_t *value)
{
	return in->reader->get_float64fix(in, value);
}

static inline size_t engine_get_bool(struct lwm2m_input_context *in,
				     bool *value)
{
	return in->reader->get_bool(in, value);
}

static inline size_t engine_get_opaque(struct lwm2m_input_context *in,
				       u8_t *buf, size_t buflen,
				       bool *last_block)
{
	if (in->reader->get_opaque) {
		return in->reader->get_opaque(in, buf, buflen, last_block);
	}

	return 0;
}

#endif /* LWM2M_OBJECT_H_ */