// Standard C
#include <stdio.h>

// System
#include <unistd.h>

// Project
#include "config.h"
#include "mqtt.h"

struct mosquitto *
mqtt_connect(const char *clientid, // NOLINT
             const char *username, // NOLINT
             const char *password, // NOLINT
             const char *hostname, // NOLINT
             int         port,
             void        callback(struct mosquitto *, void *, const struct mosquitto_message *),
             void       *userdata)
{
	struct mosquitto *client = mosquitto_new(clientid, true, userdata);
	if ( client == NULL ) {
		(void) fprintf(stderr, "error on new client...\n");
		return NULL;
	}

	int err = mosquitto_username_pw_set(client, username, password);
	if ( err != MOSQ_ERR_SUCCESS ) {
		(void) fprintf(stderr, "error: %s\n", mosquitto_strerror(err));
		mosquitto_destroy(client);
		return NULL;
	}

	if ( callback ) {
		mosquitto_message_callback_set(client, callback);
	}

	err = mosquitto_connect(client, hostname, port, KEEPALIVE);
	if ( err != MOSQ_ERR_SUCCESS ) {
		(void) fprintf(stderr, "error: %s\n", mosquitto_strerror(err));
		mosquitto_destroy(client);
		return NULL;
	}

	return client;
}

void
mqtt_run(struct mosquitto *client, const char *topics[], const volatile bool *quit)
{
	int *mid = NULL;

	for ( size_t idx = 0; topics[idx] != NULL; ++idx ) {
		mosquitto_subscribe(client, mid, topics[idx], 0);
	}

	while ( !*quit ) {
		static const int defaultTimeout = -1; // 1000ms

		int err = mosquitto_loop(client, defaultTimeout, 1);
		if ( !*quit && err ) {
			(void) fprintf(stderr, "connection error: %s\n", mosquitto_strerror(err));
			sleep(WAIT_UNTIL_RECONNECT); // NOLINT
			mosquitto_reconnect(client);
		}
	}

	for ( size_t idx = 0; topics[idx] != NULL; ++idx ) {
		mosquitto_unsubscribe(client, mid, topics[idx]);
	}
}

void
mqtt_shutdown(struct mosquitto *client)
{
	mosquitto_disconnect(client);
	mosquitto_destroy(client);
}