/*
 * Copyright (c) 2017 Linaro Limited
 * Copyright (c) 2018-2019 Foundries.io
 * Copyright (c) 2020 Laird Connectivity
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/*
 * Generic sensor is based off temperature sensor.
 * It is a template used to create other sensors.
 */

#define LOG_MODULE_NAME net_ipso_generic_sensor
#define LOG_LEVEL CONFIG_LWM2M_LOG_LEVEL

#include <logging/log.h>
LOG_MODULE_REGISTER(LOG_MODULE_NAME);

#include <stdint.h>
#include <init.h>

#include "lwm2m_object.h"
#include "lwm2m_engine.h"
#include "lwm2m_resource_ids.h"

#ifdef CONFIG_LWM2M_IPSO_GENERIC_SENSOR_TIMESTAMP
#define ADD_TIMESTAMPS 1
#define NUMBER_OF_OBJ_FIELDS 10
#else
#define ADD_TIMESTAMPS 0
#define NUMBER_OF_OBJ_FIELDS 9
#endif

#define MAX_INSTANCE_COUNT CONFIG_LWM2M_IPSO_GENERIC_SENSOR_INSTANCE_COUNT

#define IPSO_OBJECT_ID IPSO_OBJECT_GENERIC_SENSOR_ID

#define SENSOR_NAME CONFIG_LWM2M_IPSO_GENERIC_SENSOR_NAME

#define UNIT_STR_MAX_SIZE 8
#define APP_TYPE_STR_MAX_SIZE 32
#define SENSOR_TYPE_STR_MAX_SIZE 32

BUILD_ASSERT(SENSOR_TYPE_STR_MAX_SIZE >=
	     sizeof(CONFIG_LWM2M_IPSO_GENERIC_SENSOR_TYPE),
	     "CONFIG_LWM2M_IPSO_GENERIC_SENSOR_TYPE is too long.");

/*
 * Calculate resource instances as follows:
 * start with NUMBER_OF_OBJ_FIELDS
 * subtract EXEC resources (1)
 */
#define RESOURCE_INSTANCE_COUNT (NUMBER_OF_OBJ_FIELDS - 1)

/* resource state variables */
static float32_value_t sensor_value[MAX_INSTANCE_COUNT];
static char units[MAX_INSTANCE_COUNT][UNIT_STR_MAX_SIZE];
static float32_value_t min_measured_value[MAX_INSTANCE_COUNT];
static float32_value_t max_measured_value[MAX_INSTANCE_COUNT];
static float32_value_t min_range_value[MAX_INSTANCE_COUNT];
static float32_value_t max_range_value[MAX_INSTANCE_COUNT];
static char app_type[MAX_INSTANCE_COUNT][APP_TYPE_STR_MAX_SIZE];
static char sensor_type[MAX_INSTANCE_COUNT][SENSOR_TYPE_STR_MAX_SIZE];

static struct lwm2m_engine_obj sensor;
static struct lwm2m_engine_obj_field fields[] = {
	OBJ_FIELD_DATA(SENSOR_VALUE_RID, R, FLOAT32),
	OBJ_FIELD_DATA(SENSOR_UNITS_RID, R_OPT, STRING),
	OBJ_FIELD_DATA(MIN_MEASURED_VALUE_RID, R_OPT, FLOAT32),
	OBJ_FIELD_DATA(MAX_MEASURED_VALUE_RID, R_OPT, FLOAT32),
	OBJ_FIELD_DATA(MIN_RANGE_VALUE_RID, R_OPT, FLOAT32),
	OBJ_FIELD_DATA(MAX_RANGE_VALUE_RID, R_OPT, FLOAT32),
	OBJ_FIELD_EXECUTE_OPT(RESET_MIN_MAX_MEASURED_VALUES_RID),
	OBJ_FIELD_DATA(APPLICATION_TYPE_RID, RW_OPT, STRING),
	OBJ_FIELD_DATA(SENSOR_TYPE_RID, R_OPT, STRING),
#if ADD_TIMESTAMPS
	OBJ_FIELD_DATA(TIMESTAMP_RID, RW_OPT, TIME),
#endif
};

static struct lwm2m_engine_obj_inst inst[MAX_INSTANCE_COUNT];
static struct lwm2m_engine_res res[MAX_INSTANCE_COUNT][NUMBER_OF_OBJ_FIELDS];
static struct lwm2m_engine_res_inst res_inst[MAX_INSTANCE_COUNT]
					    [RESOURCE_INSTANCE_COUNT];

static void update_min_measured(uint16_t obj_inst_id, int index)
{
	min_measured_value[index].val1 = sensor_value[index].val1;
	min_measured_value[index].val2 = sensor_value[index].val2;
	NOTIFY_OBSERVER(IPSO_OBJECT_ID, obj_inst_id, MIN_MEASURED_VALUE_RID);
}

static void update_max_measured(uint16_t obj_inst_id, int index)
{
	max_measured_value[index].val1 = sensor_value[index].val1;
	max_measured_value[index].val2 = sensor_value[index].val2;
	NOTIFY_OBSERVER(IPSO_OBJECT_ID, obj_inst_id, MAX_MEASURED_VALUE_RID);
}

static int reset_min_max_measured_values_cb(uint16_t obj_inst_id)
{
	int i;

	LOG_DBG("RESET MIN/MAX %d", obj_inst_id);
	for (i = 0; i < MAX_INSTANCE_COUNT; i++) {
		if (inst[i].obj && inst[i].obj_inst_id == obj_inst_id) {
			update_min_measured(obj_inst_id, i);
			update_max_measured(obj_inst_id, i);
			return 0;
		}
	}

	return -ENOENT;
}

static int sensor_value_write_cb(uint16_t obj_inst_id, uint16_t res_id,
				 uint16_t res_inst_id, uint8_t *data,
				 uint16_t data_len, bool last_block,
				 size_t total_size)
{
	int i;
	bool update_min = false;
	bool update_max = false;

	for (i = 0; i < MAX_INSTANCE_COUNT; i++) {
		if (inst[i].obj && inst[i].obj_inst_id == obj_inst_id) {
			/* update min / max */
			if (sensor_value[i].val1 < min_measured_value[i].val1) {
				update_min = true;
			} else if (sensor_value[i].val1 ==
					   min_measured_value[i].val1 &&
				   sensor_value[i].val2 <
					   min_measured_value[i].val2) {
				update_min = true;
			}

			if (sensor_value[i].val1 > max_measured_value[i].val1) {
				update_max = true;
			} else if (sensor_value[i].val1 ==
					   max_measured_value[i].val1 &&
				   sensor_value[i].val2 >
					   max_measured_value[i].val2) {
				update_max = true;
			}

			if (update_min) {
				update_min_measured(obj_inst_id, i);
			}

			if (update_max) {
				update_max_measured(obj_inst_id, i);
			}
		}
	}

	return 0;
}

static struct lwm2m_engine_obj_inst *generic_sensor_create(uint16_t obj_inst_id)
{
	int index, i = 0, j = 0;

	/* Check that there is no other instance with this ID */
	for (index = 0; index < MAX_INSTANCE_COUNT; index++) {
		if (inst[index].obj && inst[index].obj_inst_id == obj_inst_id) {
			LOG_ERR("Can not create instance - "
				"already existing: %u",
				obj_inst_id);
			return NULL;
		}
	}

	for (index = 0; index < MAX_INSTANCE_COUNT; index++) {
		if (!inst[index].obj) {
			break;
		}
	}

	if (index >= MAX_INSTANCE_COUNT) {
		LOG_ERR("Can not create instance - no more room: %u",
			obj_inst_id);
		return NULL;
	}

	/* Set default values */
	sensor_value[index].val1 = 0;
	sensor_value[index].val2 = 0;
	units[index][0] = '\0';
	min_measured_value[index].val1 = INT32_MAX;
	min_measured_value[index].val2 = 0;
	max_measured_value[index].val1 = -INT32_MAX;
	max_measured_value[index].val2 = 0;
	min_range_value[index].val1 = 0;
	min_range_value[index].val2 = 0;
	max_range_value[index].val1 = 0;
	max_range_value[index].val2 = 0;
	app_type[index][0] = '\0';
	strncpy(sensor_type[index], CONFIG_LWM2M_IPSO_GENERIC_SENSOR_TYPE,
		SENSOR_TYPE_STR_MAX_SIZE);

	(void)memset(res[index], 0,
		     sizeof(res[index][0]) * ARRAY_SIZE(res[index]));
	init_res_instance(res_inst[index], ARRAY_SIZE(res_inst[index]));

	/* initialize instance resource data */
	INIT_OBJ_RES(SENSOR_VALUE_RID, res[index], i, res_inst[index], j, 1,
		     true, &sensor_value[index], sizeof(*sensor_value), NULL,
		     NULL, sensor_value_write_cb, NULL);
	INIT_OBJ_RES_DATA(SENSOR_UNITS_RID, res[index], i, res_inst[index], j,
			  units[index], UNIT_STR_MAX_SIZE);
	INIT_OBJ_RES_DATA(MIN_MEASURED_VALUE_RID, res[index], i,
			  res_inst[index], j, &min_measured_value[index],
			  sizeof(*min_measured_value));
	INIT_OBJ_RES_DATA(MAX_MEASURED_VALUE_RID, res[index], i,
			  res_inst[index], j, &max_measured_value[index],
			  sizeof(*max_measured_value));
	INIT_OBJ_RES_DATA(MIN_RANGE_VALUE_RID, res[index], i, res_inst[index],
			  j, &min_range_value[index], sizeof(*min_range_value));
	INIT_OBJ_RES_DATA(MAX_RANGE_VALUE_RID, res[index], i, res_inst[index],
			  j, &max_range_value[index], sizeof(*max_range_value));
	INIT_OBJ_RES_EXECUTE(RESET_MIN_MAX_MEASURED_VALUES_RID, res[index], i,
			     reset_min_max_measured_values_cb);
	INIT_OBJ_RES_DATA(APPLICATION_TYPE_RID, res[index], i, res_inst[index],
			  j, app_type[index], APP_TYPE_STR_MAX_SIZE);
	INIT_OBJ_RES_DATA(SENSOR_TYPE_RID, res[index], i, res_inst[index], j,
			  sensor_type[index], SENSOR_TYPE_STR_MAX_SIZE);

#if ADD_TIMESTAMPS
	INIT_OBJ_RES_OPTDATA(TIMESTAMP_RID, res[index], i, res_inst[index], j);
#endif

	inst[index].resources = res[index];
	inst[index].resource_count = i;
	LOG_DBG("Created IPSO %s Sensor instance: %d", SENSOR_NAME,
		obj_inst_id);
	return &inst[index];
}

static int ipso_generic_sensor_init(const struct device *dev)
{
	sensor.obj_id = IPSO_OBJECT_ID;
	sensor.fields = fields;
	sensor.field_count = ARRAY_SIZE(fields);
	sensor.max_instance_count = MAX_INSTANCE_COUNT;
	sensor.create_cb = generic_sensor_create;
	lwm2m_register_obj(&sensor);

	return 0;
}

SYS_INIT(ipso_generic_sensor_init, APPLICATION,
	 CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);