/*-
 * Copyright 2016 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.
 */
#include "config.h"
#include "rspamd.h"
#include "ottery.h"
#include "contrib/libev/ev.h"

#include <math.h>

const char *test_upstream_list = "microsoft.com:443:1,google.com:80:2,kernel.org:443:3";
const char *new_upstream_list = "freebsd.org:80";
char test_key[32];
extern struct ev_loop *event_loop;

static void
rspamd_upstream_test_method(struct upstream_list *ls,
							enum rspamd_upstream_rotation rot, const gchar *expected)
{
	struct upstream *up;

	if (rot != RSPAMD_UPSTREAM_HASHED) {
		up = rspamd_upstream_get(ls, rot, NULL, 0);
		g_assert(up != NULL);
		g_assert(strcmp(rspamd_upstream_name(up), expected) == 0);
	}
	else {
		up = rspamd_upstream_get(ls, RSPAMD_UPSTREAM_HASHED, test_key,
								 sizeof(test_key));
		g_assert(up != NULL);
		g_assert(strcmp(rspamd_upstream_name(up), expected) == 0);
	}
}

static void
rspamd_upstream_timeout_handler(EV_P_ ev_timer *w, int revents)
{
	struct rspamd_dns_resolver *resolver = (struct rspamd_dns_resolver *) w->data;

	rdns_resolver_release(resolver->r);
}

void rspamd_upstream_test_func(void)
{
	struct upstream_list *ls, *nls;
	struct upstream *up, *upn;
	struct rspamd_dns_resolver *resolver;
	struct rspamd_config *cfg;
	gint i, success = 0;
	const gint assumptions = 100500;
	gdouble p;
	static ev_timer ev;
	rspamd_inet_addr_t *addr, *next_addr, *paddr;

	cfg = rspamd_config_new(RSPAMD_CONFIG_INIT_SKIP_LUA);
	cfg->dns_retransmits = 2;
	cfg->dns_timeout = 0.5;
	cfg->upstream_max_errors = 1;
	cfg->upstream_revive_time = 0.5;
	cfg->upstream_error_time = 2;

	resolver = rspamd_dns_resolver_init(NULL, event_loop, cfg);
	rspamd_upstreams_library_config(cfg, cfg->ups_ctx, event_loop, resolver->r);

	/*
	 * Test v4/v6 priorities
	 */
	nls = rspamd_upstreams_create(cfg->ups_ctx);
	g_assert(rspamd_upstreams_add_upstream(nls, "127.0.0.1", 0,
										   RSPAMD_UPSTREAM_PARSE_DEFAULT,
										   NULL));
	up = rspamd_upstream_get(nls, RSPAMD_UPSTREAM_RANDOM, NULL, 0);
	rspamd_parse_inet_address(&paddr, "127.0.0.2", strlen("127.0.0.2"),
							  RSPAMD_INET_ADDRESS_PARSE_DEFAULT);
	g_assert(rspamd_upstream_add_addr(up, paddr));
	rspamd_parse_inet_address(&paddr, "::1", strlen("::1"),
							  RSPAMD_INET_ADDRESS_PARSE_DEFAULT);
	g_assert(rspamd_upstream_add_addr(up, paddr));
	/* Rewind to start */
	addr = rspamd_upstream_addr_next(up);
	addr = rspamd_upstream_addr_next(up);
	/* cur should be zero here */
	addr = rspamd_upstream_addr_next(up);
	next_addr = rspamd_upstream_addr_next(up);
	g_assert(rspamd_inet_address_get_af(addr) == AF_INET);
	g_assert(rspamd_inet_address_get_af(next_addr) == AF_INET);
	next_addr = rspamd_upstream_addr_next(up);
	g_assert(rspamd_inet_address_get_af(next_addr) == AF_INET6);
	next_addr = rspamd_upstream_addr_next(up);
	g_assert(rspamd_inet_address_get_af(next_addr) == AF_INET);
	next_addr = rspamd_upstream_addr_next(up);
	g_assert(rspamd_inet_address_get_af(next_addr) == AF_INET);
	next_addr = rspamd_upstream_addr_next(up);
	g_assert(rspamd_inet_address_get_af(next_addr) == AF_INET6);
	/* Test errors with IPv6 */
	rspamd_upstream_fail(up, TRUE, NULL);
	/* Now we should have merely IPv4 addresses in rotation */
	addr = rspamd_upstream_addr_next(up);
	for (i = 0; i < 256; i++) {
		next_addr = rspamd_upstream_addr_next(up);
		g_assert(rspamd_inet_address_get_af(addr) == AF_INET);
		g_assert(rspamd_inet_address_get_af(next_addr) == AF_INET);
		g_assert(rspamd_inet_address_compare(addr, next_addr, FALSE) != 0);
		addr = next_addr;
	}
	rspamd_upstreams_destroy(nls);

	ls = rspamd_upstreams_create(cfg->ups_ctx);
	g_assert(rspamd_upstreams_parse_line(ls, test_upstream_list, 443, NULL));
	g_assert(rspamd_upstreams_count(ls) == 3);

	/* Test master-slave rotation */
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_MASTER_SLAVE, "kernel.org");
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_MASTER_SLAVE, "kernel.org");

	/* Test round-robin rotation */
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_ROUND_ROBIN, "kernel.org");
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_ROUND_ROBIN, "kernel.org");
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_ROUND_ROBIN, "google.com");
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_ROUND_ROBIN, "kernel.org");
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_ROUND_ROBIN, "google.com");
	rspamd_upstream_test_method(ls, RSPAMD_UPSTREAM_ROUND_ROBIN, "microsoft.com");

	/* Test stable hashing */
	nls = rspamd_upstreams_create(cfg->ups_ctx);
	g_assert(rspamd_upstreams_parse_line(nls, test_upstream_list, 443, NULL));
	g_assert(rspamd_upstreams_parse_line(nls, new_upstream_list, 443, NULL));
	for (i = 0; i < assumptions; i++) {
		ottery_rand_bytes(test_key, sizeof(test_key));
		up = rspamd_upstream_get(ls, RSPAMD_UPSTREAM_HASHED, test_key,
								 sizeof(test_key));
		upn = rspamd_upstream_get(nls, RSPAMD_UPSTREAM_HASHED, test_key,
								  sizeof(test_key));

		if (strcmp(rspamd_upstream_name(up), rspamd_upstream_name(upn)) == 0) {
			success++;
		}
	}

	p = 1.0 - fabs(3.0 / 4.0 - (gdouble) success / (gdouble) assumptions);
	/*
	 * P value is calculated as following:
	 * when we add/remove M upstreams from the list, the probability of hash
	 * miss should be close to the relation N / (N + M), where N is the size of
	 * the previous upstreams list.
	 */
	msg_debug("p value for hash consistency: %.6f", p);
	g_assert(p > 0.9);

	rspamd_upstreams_destroy(nls);


	/* Upstream fail test */
	ev.data = resolver;
	ev_timer_init(&ev, rspamd_upstream_timeout_handler, 2.0, 0.0);

	up = rspamd_upstream_get(ls, RSPAMD_UPSTREAM_MASTER_SLAVE, NULL, 0);
	for (i = 0; i < 100; i++) {
		rspamd_upstream_fail(up, TRUE, NULL);
	}
	g_assert(rspamd_upstreams_alive(ls) == 2);

	ev_timer_start(event_loop, &ev);

	ev_run(event_loop, 0);
	g_assert(rspamd_upstreams_alive(ls) == 3);

	rspamd_upstreams_destroy(ls);
	REF_RELEASE(cfg);
}
