/* Synchronet MQTT (publish/subscribe messaging protocol) functions */

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#include <string.h>

#include "mqtt.h"

int mqtt_init(struct mqtt* mqtt, scfg_t* cfg, const char* host, const char* server)
{
	if(mqtt == NULL || cfg == NULL)
		return MQTT_FAILURE;
	if(!cfg->mqtt.enabled)
		return MQTT_SUCCESS;
	if(mqtt != NULL) {
		memset(mqtt, 0, sizeof(*mqtt));
		mqtt->cfg = cfg;
		mqtt->host = host;
		mqtt->server = server;
#ifdef USE_MOSQUITTO
		return mosquitto_lib_init();
#endif
	}
	return MQTT_FAILURE;
}

static char* format_topic(struct mqtt* mqtt, enum topic_depth depth, char* str, size_t size, const char* sbuf)
{
	switch(depth) {
		case TOPIC_ROOT:
			safe_snprintf(str, size, "sbbs/%s", sbuf);
			break;
		case TOPIC_BBS:
			safe_snprintf(str, size, "sbbs/%s/%s", mqtt->cfg->sys_id, sbuf);
			break;
		case TOPIC_HOST:
			safe_snprintf(str, size, "sbbs/%s/%s/%s", mqtt->cfg->sys_id, mqtt->host, sbuf);
			break;
		case TOPIC_SERVER:
			safe_snprintf(str, size, "sbbs/%s/%s/%s/%s", mqtt->cfg->sys_id, mqtt->host, mqtt->server, sbuf);
			break;
		case TOPIC_EVENT:
			safe_snprintf(str, size, "sbbs/%s/%s/event/%s", mqtt->cfg->sys_id, mqtt->host, sbuf);
			break;
		default:
			safe_snprintf(str, size, "%s", sbuf);
			break;
	}
	return str;
}

char* mqtt_topic(struct mqtt* mqtt, enum topic_depth depth, char* str, size_t size, const char* fmt, ...)
{
	va_list argptr;
	char sbuf[1024];

    va_start(argptr, fmt);
    vsnprintf(sbuf, sizeof(sbuf), fmt, argptr);
	sbuf[sizeof(sbuf) - 1]=0;
    va_end(argptr);

	return format_topic(mqtt, depth, str, size, sbuf);
}

static int mqtt_sub(struct mqtt* mqtt, const char* topic)
{
	if(mqtt == NULL || mqtt->cfg == NULL)
		return MQTT_FAILURE;
	if(!mqtt->cfg->mqtt.enabled)
		return MQTT_SUCCESS;
#ifdef USE_MOSQUITTO
	if(mqtt->handle != NULL && topic != NULL) {
		return mosquitto_subscribe(mqtt->handle, /* mid: */NULL, topic, mqtt->cfg->mqtt.subscribe_qos);
	}
#endif
	return MQTT_FAILURE;
}

int mqtt_subscribe(struct mqtt* mqtt, enum topic_depth depth, char* str, size_t size, const char* fmt, ...)
{
	va_list argptr;
	char sbuf[1024];

    va_start(argptr, fmt);
    vsnprintf(sbuf, sizeof(sbuf), fmt, argptr);
	sbuf[sizeof(sbuf) - 1]=0;
    va_end(argptr);

	format_topic(mqtt, depth, str, size, sbuf);

	return mqtt_sub(mqtt, str);
}

int mqtt_lputs(struct mqtt* mqtt, enum topic_depth depth, int level, const char* str)
{
	if(mqtt == NULL || mqtt->cfg == NULL)
		return MQTT_FAILURE;
	if(!mqtt->cfg->mqtt.enabled)
		return MQTT_SUCCESS;
	if(level > mqtt->cfg->mqtt.log_level)
		return MQTT_SUCCESS;
#ifdef USE_MOSQUITTO
	if(mqtt->handle != NULL && str != NULL) {
		char sub[128];
		mqtt_topic(mqtt, depth, sub, sizeof(sub), "log/%d", level);
		char lvl[32];
		sprintf(lvl, "%d", level);
		mosquitto_publish_v5(mqtt->handle,
			/* mid: */NULL,
			/* topic: */sub,
			/* payloadlen */strlen(str),
			/* payload */str,
			/* qos */mqtt->cfg->mqtt.publish_qos,
			/* retain */false,
			/* properties */NULL);
		mqtt_topic(mqtt, depth, sub, sizeof(sub), "log");
		mosquitto_property* props = NULL;
		mosquitto_property_add_string_pair(&props, MQTT_PROP_USER_PROPERTY, "level", lvl);
		int result = mosquitto_publish_v5(mqtt->handle,
			/* mid: */NULL,
			/* topic: */sub,
			/* payloadlen */strlen(str),
			/* payload */str,
			/* qos */mqtt->cfg->mqtt.publish_qos,
			/* retain */false,
			/* properties */props);
		mosquitto_property_free_all(&props);
		return result;
	}
#endif
	return MQTT_FAILURE;
}

int mqtt_pub_noval(struct mqtt* mqtt, enum topic_depth depth, const char* key)
{
	if(mqtt == NULL || mqtt->cfg == NULL)
		return MQTT_FAILURE;
	if(!mqtt->cfg->mqtt.enabled)
		return MQTT_SUCCESS;
#ifdef USE_MOSQUITTO
	if(mqtt != NULL && mqtt->handle != NULL) {
		char sub[128];
		mqtt_topic(mqtt, depth, sub, sizeof(sub), "%s", key);
		return mosquitto_publish_v5(mqtt->handle,
			/* mid: */NULL,
			/* topic: */sub,
			/* payloadlen */0,
			/* payload */NULL,
			/* qos */mqtt->cfg->mqtt.publish_qos,
			/* retain */true,
			/* properties */NULL);
	}
#endif
	return MQTT_FAILURE;
}


int mqtt_pub_strval(struct mqtt* mqtt, enum topic_depth depth, const char* key, const char* str)
{
	if(mqtt == NULL || mqtt->cfg == NULL)
		return MQTT_FAILURE;
	if(!mqtt->cfg->mqtt.enabled)
		return MQTT_SUCCESS;
#ifdef USE_MOSQUITTO
	if(mqtt != NULL && mqtt->handle != NULL) {
		char sub[128];
		mqtt_topic(mqtt, depth, sub, sizeof(sub), "%s", key);
		return mosquitto_publish_v5(mqtt->handle,
			/* mid: */NULL,
			/* topic: */sub,
			/* payloadlen */strlen(str),
			/* payload */str,
			/* qos */mqtt->cfg->mqtt.publish_qos,
			/* retain */true,
			/* properties */NULL);
	}
#endif
	return MQTT_FAILURE;
}

int mqtt_pub_uintval(struct mqtt* mqtt, enum topic_depth depth, const char* key, ulong value)
{
	if(mqtt == NULL || mqtt->cfg == NULL)
		return MQTT_FAILURE;
	if(!mqtt->cfg->mqtt.enabled)
		return MQTT_SUCCESS;
#ifdef USE_MOSQUITTO
	if(mqtt != NULL && mqtt->handle != NULL) {
		char str[128];
		sprintf(str, "%lu", value);
		char sub[128];
		mqtt_topic(mqtt, depth, sub, sizeof(sub), "%s", key);
		return mosquitto_publish_v5(mqtt->handle,
			/* mid: */NULL,
			/* topic: */sub,
			/* payloadlen */strlen(str),
			/* payload */str,
			/* qos */mqtt->cfg->mqtt.publish_qos,
			/* retain */true,
			/* properties */NULL);
	}
#endif
	return MQTT_FAILURE;
}

int mqtt_pub_message(struct mqtt* mqtt, enum topic_depth depth, const char* key, const void* buf, size_t len)
{
	if(mqtt == NULL || mqtt->cfg == NULL)
		return MQTT_FAILURE;
	if(!mqtt->cfg->mqtt.enabled)
		return MQTT_SUCCESS;
#ifdef USE_MOSQUITTO
	if(mqtt != NULL && mqtt->handle != NULL) {
		char sub[128];
		mqtt_topic(mqtt, depth, sub, sizeof(sub), "%s", key);
		return mosquitto_publish_v5(mqtt->handle,
			/* mid: */NULL,
			/* topic: */sub,
			/* payloadlen */len,
			/* payload */buf,
			/* qos */mqtt->cfg->mqtt.publish_qos,
			/* retain */false,
			/* properties */NULL);
	}
#endif
	return MQTT_FAILURE;
}

char* mqtt_libver(char* str, size_t size)
{
#ifdef USE_MOSQUITTO
		int major, minor, revision;
		mosquitto_lib_version(&major, &minor, &revision);
		safe_snprintf(str, size, "mosquitto %d.%d.%d", major, minor, revision);
		return str;
#else
		return NULL;
#endif
}

int mqtt_open(struct mqtt* mqtt)
{
	char client_id[256];
	if(mqtt == NULL)
		return MQTT_FAILURE;
	if(mqtt->handle != NULL) // already open
		return MQTT_FAILURE;
	SAFEPRINTF(client_id, "sbbs-%s", mqtt->host);
#ifdef USE_MOSQUITTO
	mqtt->handle = mosquitto_new(client_id, /* clean_session: */true, /* userdata: */mqtt);
	return mqtt->handle == NULL ? MQTT_FAILURE : MQTT_SUCCESS;
#else
	return MQTT_FAILURE;
#endif
}

void mqtt_close(struct mqtt* mqtt)
{
#ifdef USE_MOSQUITTO
	if(mqtt->handle != NULL) {
		mosquitto_destroy(mqtt->handle);
		mqtt->handle = NULL;
	}
#endif
}

static int pw_callback(char* buf, int size, int rwflag, void* userdata)
{
	struct mqtt* mqtt = (struct mqtt*)userdata;

	strncpy(buf, mqtt->cfg->mqtt.tls.keypass, size);
	return strlen(mqtt->cfg->mqtt.tls.keypass);
}

int mqtt_connect(struct mqtt* mqtt, const char* bind_address)
{
	if(mqtt == NULL || mqtt->handle == NULL || mqtt->cfg == NULL)
		return MQTT_FAILURE;

#ifdef USE_MOSQUITTO
	char topic[128];
	char* username = mqtt->cfg->mqtt.username;
	char* password = mqtt->cfg->mqtt.password;
	if(*username == '\0')
		username = NULL;
	if(*password == '\0')
		password = NULL;
	mosquitto_int_option(mqtt->handle, MOSQ_OPT_PROTOCOL_VERSION, mqtt->cfg->mqtt.protocol_version);
	mosquitto_username_pw_set(mqtt->handle, username, password);
	const char* value = "disconnected";
	mosquitto_will_set(mqtt->handle
		,mqtt_topic(mqtt, TOPIC_HOST, topic, sizeof(topic), "status")
		,strlen(value), value, /* QOS: */2, /* retain: */true);
	if(mqtt->cfg->mqtt.tls.mode == MQTT_TLS_CERT) {
		char* certfile = NULL;
		char* keyfile = NULL;
		if(mqtt->cfg->mqtt.tls.certfile[0] && mqtt->cfg->mqtt.tls.keyfile[0]) {
			certfile = mqtt->cfg->mqtt.tls.certfile;
			keyfile = mqtt->cfg->mqtt.tls.keyfile;
		}
		int result = mosquitto_tls_set(mqtt->handle,
			mqtt->cfg->mqtt.tls.cafile,
			NULL, // capath
			certfile,
			keyfile,
			pw_callback);
		if(result != MOSQ_ERR_SUCCESS)
			return result;
	}
	else if(mqtt->cfg->mqtt.tls.mode == MQTT_TLS_PSK) {
		int result = mosquitto_tls_psk_set(mqtt->handle,
			mqtt->cfg->mqtt.tls.psk,
			mqtt->cfg->mqtt.tls.identity,
			NULL // ciphers (default)
			);
		if(result != MOSQ_ERR_SUCCESS)
			return result;
	}
	return mosquitto_connect_bind(mqtt->handle,
		mqtt->cfg->mqtt.broker_addr,
		mqtt->cfg->mqtt.broker_port,
		mqtt->cfg->mqtt.keepalive,
		bind_address);
#else
	return MQTT_FAILURE;
#endif
}

int mqtt_disconnect(struct mqtt* mqtt)
{
	if(mqtt == NULL || mqtt->handle == NULL)
		return MQTT_FAILURE;

#ifdef USE_MOSQUITTO
	return mosquitto_disconnect(mqtt->handle);
#else
	return MQTT_FAILURE;
#endif
}

int mqtt_thread_start(struct mqtt* mqtt)
{
	if(mqtt == NULL || mqtt->handle == NULL)
		return MQTT_FAILURE;

#ifdef USE_MOSQUITTO
	return mosquitto_loop_start(mqtt->handle);
#else
	return MQTT_FAILURE;
#endif
}

int mqtt_thread_stop(struct mqtt* mqtt)
{
	if(mqtt == NULL || mqtt->handle == NULL)
		return MQTT_FAILURE;

#ifdef USE_MOSQUITTO
	return mosquitto_loop_stop(mqtt->handle, /* force: */false);
#else
	return MQTT_FAILURE;
#endif
}