/*
Copyright (c) 2009-2020 Roger Light <roger@atchoo.org>

All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
and Eclipse Distribution License v1.0 which accompany this distribution.

The Eclipse Public License is available at
   http://www.eclipse.org/legal/epl-v10.html
and the Eclipse Distribution License is available at
  http://www.eclipse.org/org/documents/edl-v10.php.

Contributors:
   Roger Light - initial implementation and documentation.
*/

#include "config.h"

#include <stdio.h>
#include <string.h>

#include "mosquitto_broker_internal.h"
#include "memory_mosq.h"
#include "mqtt_protocol.h"
#include "packet_mosq.h"
#include "send_mosq.h"

int handle__unsubscribe(struct mosquitto_db *db, struct mosquitto *context)
{
	uint16_t mid;
	char *sub;
	int slen;
	int rc;
	uint8_t reason;
	int reason_code_count = 0;
	int reason_code_max;
	uint8_t *reason_codes = NULL, *reason_tmp;
	mosquitto_property *properties = NULL;

	if(!context) return MOSQ_ERR_INVAL;

	if(context->state != mosq_cs_active){
		return MOSQ_ERR_PROTOCOL;
	}
	log__printf(NULL, MOSQ_LOG_DEBUG, "Received UNSUBSCRIBE from %s", context->id);

	if(context->protocol != mosq_p_mqtt31){
		if((context->in_packet.command&0x0F) != 0x02){
			return MOSQ_ERR_PROTOCOL;
		}
	}
	if(packet__read_uint16(&context->in_packet, &mid)) return 1;
	if(mid == 0) return MOSQ_ERR_PROTOCOL;

	if(context->protocol == mosq_p_mqtt5){
		rc = property__read_all(CMD_UNSUBSCRIBE, &context->in_packet, &properties);
		if(rc) return rc;
		/* Immediately free, we don't do anything with User Property at the moment */
		mosquitto_property_free_all(&properties);
	}

	if(context->protocol == mosq_p_mqtt311 || context->protocol == mosq_p_mqtt5){
		if(context->in_packet.pos == context->in_packet.remaining_length){
			/* No topic specified, protocol error. */
			return MOSQ_ERR_PROTOCOL;
		}
	}

	reason_code_max = 10;
	reason_codes = mosquitto__malloc(reason_code_max);
	if(!reason_codes){
		return MOSQ_ERR_NOMEM;
	}

	while(context->in_packet.pos < context->in_packet.remaining_length){
		sub = NULL;
		if(packet__read_string(&context->in_packet, &sub, &slen)){
			mosquitto__free(reason_codes);
			return 1;
		}

		if(!slen){
			log__printf(NULL, MOSQ_LOG_INFO,
					"Empty unsubscription string from %s, disconnecting.",
					context->id);
			mosquitto__free(sub);
			mosquitto__free(reason_codes);
			return 1;
		}
		if(mosquitto_sub_topic_check(sub)){
			log__printf(NULL, MOSQ_LOG_INFO,
					"Invalid unsubscription string from %s, disconnecting.",
					context->id);
			mosquitto__free(sub);
			mosquitto__free(reason_codes);
			return 1;
		}

		log__printf(NULL, MOSQ_LOG_DEBUG, "\t%s", sub);
		rc = sub__remove(db, context, sub, db->subs, &reason);
		log__printf(NULL, MOSQ_LOG_UNSUBSCRIBE, "%s %s", context->id, sub);
		mosquitto__free(sub);
		if(rc){
			mosquitto__free(reason_codes);
			return rc;
		}

		reason_codes[reason_code_count] = reason;
		reason_code_count++;
		if(reason_code_count == reason_code_max){
			reason_tmp = mosquitto__realloc(reason_codes, reason_code_max*2);
			if(!reason_tmp){
				mosquitto__free(reason_codes);
				return MOSQ_ERR_NOMEM;
			}
			reason_codes = reason_tmp;
			reason_code_max *= 2;
		}
	}
#ifdef WITH_PERSISTENCE
	db->persistence_changes++;
#endif

	log__printf(NULL, MOSQ_LOG_DEBUG, "Sending UNSUBACK to %s", context->id);

	/* We don't use Reason String or User Property yet. */
	rc = send__unsuback(context, mid, reason_code_count, reason_codes, NULL);
	mosquitto__free(reason_codes);
	return rc;
}