/*
 * Copyright (c) 2018 Nordic Semiconductor ASA
 * Copyright (c) 2024 Conexio Technologies, Inc
 *
 * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
 */

#include <stdio.h>
#include <ncs_version.h>
#include <zephyr/kernel.h>
#include <zephyr/net/socket.h>

#include <zephyr/logging/log.h>
#include <dk_buttons_and_leds.h>
#include <modem/nrf_modem_lib.h>
#include <modem/lte_lc.h>
/* Header file for the MQTT Library*/
#include <zephyr/net/mqtt.h>
#include <nrf_modem_gnss.h>
#include "mqtt_connection.h"

/* The mqtt client struct */
static struct mqtt_client client;
/* File descriptor */
static struct pollfd fds;

/* Define the PVT data frame variable */
static struct nrf_modem_gnss_pvt_data_frame pvt_data;

/* Declare helper variables to find the TTFF */
static int64_t gnss_start_time;
static bool first_fix = false;

static void gnss_event_handler(int event);
static void print_fix_data(struct nrf_modem_gnss_pvt_data_frame *pvt_data);

static K_SEM_DEFINE(lte_connected, 0, 1);

LOG_MODULE_REGISTER(mqtt_app, LOG_LEVEL_INF);

static void lte_handler(const struct lte_lc_evt *const evt)
{
	LOG_INF("LTE handler");
     switch (evt->type) {
     case LTE_LC_EVT_NW_REG_STATUS:
        if ((evt->nw_reg_status != LTE_LC_NW_REG_REGISTERED_HOME) &&
            (evt->nw_reg_status != LTE_LC_NW_REG_REGISTERED_ROAMING)) {
            break;
        }
		LOG_INF("Network registration status: %s",
				evt->nw_reg_status == LTE_LC_NW_REG_REGISTERED_HOME ?
				"Connected - home network" : "Connected - roaming");
		k_sem_give(&lte_connected);
        break;
	case LTE_LC_EVT_RRC_UPDATE:
		LOG_INF("RRC mode: %s", evt->rrc_mode == LTE_LC_RRC_MODE_CONNECTED ?
				"Connected" : "Idle");
		break;
     default:
			break;
     }
}

static int modem_configure(void)
{
	int err;

	LOG_INF("Initializing modem library");
	err = nrf_modem_lib_init();
	if (err) {
		LOG_ERR("Failed to initialize the modem library, error: %d", err);
		return err;
	}

	/* lte_lc_init deprecated in >= v2.6.0 */
	#if NCS_VERSION_NUMBER < 0x20600
	err = lte_lc_init();
	if (err) {
		LOG_ERR("Failed to initialize LTE link control library, error: %d", err);
		return err;
	}
	#endif
	
	LOG_INF("Connecting to LTE network");
	err = lte_lc_connect_async(lte_handler);
	if (err) {
		LOG_ERR("Error in lte_lc_connect_async, error: %d", err);
		return err;
	}

	k_sem_take(&lte_connected, K_FOREVER);
	LOG_INF("Connected to LTE network");

	#if 1

	/* Activate only the GNSS stack * 	/
	if (lte_lc_func_mode_set(LTE_LC_FUNC_MODE_ACTIVATE_GNSS) != 0) {
		LOG_ERR("Failed to activate GNSS functional mode");
		return 0;
	} */

	/* Register the GNSS event handler */
	if (nrf_modem_gnss_event_handler_set(gnss_event_handler) != 0) {
		LOG_ERR("Failed to set GNSS event handler");
		return 0;
	}

	/* Set the GNSS fix interval and GNSS fix retry period */
	//if (nrf_modem_gnss_fix_interval_set(CONFIG_GNSS_PERIODIC_INTERVAL) != 0) {
	//	LOG_ERR("Failed to set GNSS fix interval");
	//	return 0;
	//}

	//if (nrf_modem_gnss_fix_retry_set(CONFIG_GNSS_PERIODIC_TIMEOUT) != 0) {
	//	LOG_ERR("Failed to set GNSS fix retry");
	//	return 0;
	//}

	/* Start the GNSS receiver */
	LOG_INF("Starting GNSS");
	if (nrf_modem_gnss_start() != 0) {
		LOG_ERR("Failed to start GNSS");
		return 0;
	}
	#endif
	

	// Blink LED to indicate we connected to MQTT broker
	dk_set_led_on(DK_LED1);
	k_msleep(2000);
	dk_set_led_off(DK_LED1);

	return 0;
}

static void button_handler(uint32_t button_state, uint32_t has_changed)
{
	switch (has_changed) {
	case DK_BTN1_MSK:
		/* When button 1/Mode is pressed, call data_publish() to publish a message */
		if (button_state & DK_BTN1_MSK){
			int err = data_publish(&client, MQTT_QOS_1_AT_LEAST_ONCE,
				   CONFIG_BUTTON_EVENT_PUBLISH_MSG, sizeof(CONFIG_BUTTON_EVENT_PUBLISH_MSG)-1);
			if (err) {
				LOG_INF("Failed to send message, %d", err);
				return;
			}
		}
		break;
	}
}

#if 1
/* Define a function to log fix data in a readable format */
static void print_fix_data(struct nrf_modem_gnss_pvt_data_frame *pvt_data)
{
	LOG_INF("Latitude:       %.06f", pvt_data->latitude);
	LOG_INF("Longitude:      %.06f", pvt_data->longitude);
	LOG_INF("Altitude:       %.01f m", pvt_data->altitude);
	LOG_INF("Time (UTC):     %02u:%02u:%02u.%03u",
	       pvt_data->datetime.hour,
	       pvt_data->datetime.minute,
	       pvt_data->datetime.seconds,
	       pvt_data->datetime.ms);
}


static void gnss_event_handler(int event)
{
	int err;

	switch (event) {
	/* On a PVT event, confirm if PVT data is a valid fix */
	case NRF_MODEM_GNSS_EVT_PVT:
		LOG_INF("Searching...");
		/* Print satellite information */
		int num_satellites = 0;
		for (int i = 0; i < 12 ; i++) {
			if (pvt_data.sv[i].signal != 0) {
				LOG_INF("sv: %d, cn0: %d", pvt_data.sv[i].sv, pvt_data.sv[i].cn0);
				num_satellites++;
			}
		}
		LOG_INF("Number of current satellites: %d", num_satellites);
		err = nrf_modem_gnss_read(&pvt_data, sizeof(pvt_data), NRF_MODEM_GNSS_DATA_PVT);
		if (err) {
			LOG_ERR("nrf_modem_gnss_read failed, err %d", err);
			return;
		}
		if (pvt_data.flags & NRF_MODEM_GNSS_PVT_FLAG_FIX_VALID) {
			dk_set_led_on(DK_LED1);
			print_fix_data(&pvt_data);
			/* Print the time to first fix */
			if (!first_fix) {
				LOG_INF("Time to first fix: %2.1lld s", (k_uptime_get() - gnss_start_time)/1000);
				first_fix = true;
			}
			return;
		}
		break;
	/* Log when the GNSS sleeps and wakes up */
	case NRF_MODEM_GNSS_EVT_PERIODIC_WAKEUP:
		LOG_INF("GNSS has woken up");
		break;
	case NRF_MODEM_GNSS_EVT_SLEEP_AFTER_FIX:
		LOG_INF("GNSS enter sleep after fix");
		break;
	default:
		break;
	}
}
#endif

int main(void)
{
	int err;
	uint32_t connect_attempt = 0;

	LOG_INF("Starting MQTT sample on %s\n", CONFIG_BOARD);

	if (dk_leds_init() != 0) {
		LOG_ERR("Failed to initialize the LED library");
	}

	err = modem_configure();
	if (err) {
		LOG_ERR("Failed to configure the modem");
		return 0;
	}

	if (dk_buttons_init(button_handler) != 0) {
		LOG_ERR("Failed to initialize the buttons library");
	}

	err = client_init(&client);
	if (err) {
		LOG_ERR("Failed to initialize MQTT client: %d", err);
		return 0;
	}

do_connect:
	if (connect_attempt++ > 0) {
		LOG_INF("Reconnecting in %d seconds...",
			CONFIG_MQTT_RECONNECT_DELAY_S);
		k_sleep(K_SECONDS(CONFIG_MQTT_RECONNECT_DELAY_S));
	}

	LOG_INF("Connection to broker using mqtt_connect");
	err = mqtt_connect(&client);
	if (err) {
		LOG_ERR("Error in mqtt_connect: %d", err);
		goto do_connect;
	}

	err = fds_init(&client,&fds);
	if (err) {
		LOG_ERR("Error in fds_init: %d", err);
		return 0;
	}

	while (1) {
		err = poll(&fds, 1, mqtt_keepalive_time_left(&client));
		if (err < 0) {
			LOG_ERR("Error in poll(): %d", errno);
			break;
		}

		err = mqtt_live(&client);
		if ((err != 0) && (err != -EAGAIN)) {
			LOG_ERR("Error in mqtt_live: %d", err);
			break;
		}

		if ((fds.revents & POLLIN) == POLLIN) {
			err = mqtt_input(&client);
			if (err != 0) {
				LOG_ERR("Error in mqtt_input: %d", err);
				break;
			}
		}

		if ((fds.revents & POLLERR) == POLLERR) {
			LOG_ERR("POLLERR");
			break;
		}

		if ((fds.revents & POLLNVAL) == POLLNVAL) {
			LOG_ERR("POLLNVAL");
			break;
		}
	}

	LOG_INF("Disconnecting MQTT client");

	err = mqtt_disconnect(&client);
	if (err) {
		LOG_ERR("Could not disconnect MQTT client: %d", err);
	}
	goto do_connect;

	/* This is never reached */
	return 0;
}