/*
 * Copyright 2023 Vsevolod Stakhov
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef RSPAMD_DNS_H
#define RSPAMD_DNS_H

#include "config.h"
#include "mem_pool.h"
#include "async_session.h"
#include "logger.h"
#include "rdns.h"
#include "upstream.h"
#include "libutil/hash.h"

#ifdef __cplusplus
extern "C" {
#endif

struct rspamd_config;
struct rspamd_task;
struct event_loop;

struct rspamd_dns_resolver {
	struct rdns_resolver *r;
	struct ev_loop *event_loop;
	rspamd_lru_hash_t *fails_cache;
	void *uidna;
	double fails_cache_time;
	struct upstream_list *ups;
	struct rspamd_config *cfg;
	double request_timeout;
	unsigned int max_retransmits;
};

/* Rspamd DNS API */

/**
 * Init DNS resolver, params are obtained from a config file or system file /etc/resolv.conf
 */
struct rspamd_dns_resolver *rspamd_dns_resolver_init(rspamd_logger_t *logger,
													 struct ev_loop *ev_base,
													 struct rspamd_config *cfg);

void rspamd_dns_resolver_deinit(struct rspamd_dns_resolver *resolver);

struct rspamd_dns_request_ud;

/**
 * Make a DNS request
 * @param resolver resolver object
 * @param session async session to register event
 * @param pool memory pool for storage
 * @param cb callback to call on resolve completing
 * @param ud user data for callback
 * @param type request type
 * @param ... string or ip address based on a request type
 * @return TRUE if request was sent.
 */
struct rspamd_dns_request_ud *rspamd_dns_resolver_request(struct rspamd_dns_resolver *resolver,
														  struct rspamd_async_session *session,
														  rspamd_mempool_t *pool,
														  dns_callback_type cb,
														  gpointer ud,
														  enum rdns_request_type type,
														  const char *name);

gboolean rspamd_dns_resolver_request_task(struct rspamd_task *task,
										  dns_callback_type cb,
										  gpointer ud,
										  enum rdns_request_type type,
										  const char *name);

gboolean rspamd_dns_resolver_request_task_forced(struct rspamd_task *task,
												 dns_callback_type cb,
												 gpointer ud,
												 enum rdns_request_type type,
												 const char *name);

/**
 * Converts a name into idna from UTF8
 * @param resolver resolver (must be initialised)
 * @param pool optional memory pool (can be NULL, then you need to g_free) the result
 * @param name input name
 * @param namelen length of input (-1 for zero terminated)
 * @return encoded string
 */
char *rspamd_dns_resolver_idna_convert_utf8(struct rspamd_dns_resolver *resolver,
											rspamd_mempool_t *pool,
											const char *name,
											int namelen,
											unsigned int *outlen);

#ifdef __cplusplus
}
#endif

#endif