/*

Copyright (c) 2008, Arvid Norberg
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

*/

#ifndef TORRENT_DISABLE_DHT

#include "libtorrent/session.hpp"
#include "libtorrent/kademlia/node.hpp" // for verify_message
#include "libtorrent/bencode.hpp"
#include "libtorrent/socket_io.hpp" // for hash_address
#include "libtorrent/broadcast_socket.hpp" // for supports_ipv6
#include "libtorrent/alert_dispatcher.hpp"
#include <iostream>

#include "../ed25519/src/ed25519.h"

#include "test.hpp"
#include "setup_transfer.hpp"

using namespace libtorrent;
using namespace libtorrent::dht;

std::list<std::pair<udp::endpoint, entry> > g_responses;

struct mock_socket : udp_socket_interface
{
	bool send_packet(entry& msg, udp::endpoint const& ep, int flags)
	{
		g_responses.push_back(std::make_pair(ep, msg));
		return true;
	}
};

address rand_v4()
{
	return address_v4((rand() << 16 | rand()) & 0xffffffff);
}

udp::endpoint rand_ep()
{
	return udp::endpoint(rand_v4(), rand());
}

sha1_hash generate_next()
{
	sha1_hash ret;
	for (int i = 0; i < 20; ++i) ret[i] = rand();
	return ret;
}

node_id random_id()
{
	node_id ret;
	for (int i = 0; i < 20; ++i)
		ret[i] = rand();
	return ret;
}

boost::array<char, 64> generate_key()
{
	boost::array<char, 64> ret;
	for (int i = 0; i < 64; ++i) ret[i] = rand();
	return ret;
}

static const std::string no;

void send_dht_msg(node_impl& node, char const* msg, udp::endpoint const& ep
	, lazy_entry* reply, char const* t = "10", char const* info_hash = 0
	, char const* name = 0, std::string const token = std::string(), int port = 0
	, char const* target = 0, entry const* value = 0
	, bool scrape = false, bool seed = false
	, std::string const key = std::string(), std::string const sig = std::string()
	, int seq = -1)
{
	// we're about to clear out the backing buffer
	// for this lazy_entry, so we better clear it now
	reply->clear();
	entry e;
	e["q"] = msg;
	e["t"] = t;
	e["y"] = "q";
	entry::dictionary_type& a = e["a"].dict();
	a["id"] = generate_next().to_string();
	if (info_hash) a["info_hash"] = std::string(info_hash, 20);
	if (name) a["n"] = name;
	if (!token.empty()) a["token"] = token;
	if (port) a["port"] = port;
	if (target) a["target"] = std::string(target, 20);
	if (value) a["v"] = *value;
	if (!sig.empty()) a["sig"] = sig;
	if (!key.empty()) a["k"] = key;
	if (scrape) a["scrape"] = 1;
	if (seed) a["seed"] = 1;
	if (seq >= 0) a["seq"] = seq;
	char msg_buf[1500];
	int size = bencode(msg_buf, e);
#if defined TORRENT_DEBUG && TORRENT_USE_IOSTREAM
// this yields a lot of output. too much
//	std::cerr << "sending: " <<  e << "\n";
#endif

	lazy_entry decoded;
	error_code ec;
	lazy_bdecode(msg_buf, msg_buf + size, decoded, ec);
	if (ec) fprintf(stderr, "lazy_bdecode failed: %s\n", ec.message().c_str());

	dht::msg m(decoded, ep);
	node.incoming(m);

	// by now the node should have invoked the send function and put the
	// response in g_responses

	std::list<std::pair<udp::endpoint, entry> >::iterator i
		= std::find_if(g_responses.begin(), g_responses.end()
			, boost::bind(&std::pair<udp::endpoint, entry>::first, _1) == ep);
	if (i == g_responses.end())
	{
		TEST_ERROR("not response from DHT node");
		return;
	}

	static char inbuf[1500];
	int len = bencode(inbuf, i->second);
	g_responses.erase(i);
	int ret = lazy_bdecode(inbuf, inbuf + len, *reply, ec);
	TEST_CHECK(ret == 0);
}

struct announce_item
{
	sha1_hash next;
	int num_peers;
	entry ent;
	sha1_hash target;
	void gen()
	{
		num_peers = (rand() % 5) + 1;
		ent["next"] = next.to_string();
		ent["A"] = "a";
		ent["B"] = "b";
		ent["num_peers"] = num_peers;

		char buf[512];
		char* ptr = buf;
		int len = bencode(ptr, ent);
		target = hasher(buf, len).final();
	}
};

void announce_immutable_items(node_impl& node, udp::endpoint const* eps
	, announce_item const* items, int num_items)
{
	std::string token;
	for (int i = 0; i < 1000; ++i)
	{
		for (int j = 0; j < num_items; ++j)
		{
			if ((i % items[j].num_peers) == 0) continue;
			lazy_entry response;
			send_dht_msg(node, "get", eps[i], &response, "10", 0
				, 0, no, 0, (char const*)&items[j].target[0]);
			
			key_desc_t desc[] =
			{
				{ "r", lazy_entry::dict_t, 0, key_desc_t::parse_children },
					{ "id", lazy_entry::string_t, 20, 0},
					{ "token", lazy_entry::string_t, 0, 0},
					{ "ip", lazy_entry::string_t, 0, key_desc_t::optional | key_desc_t::last_child},
				{ "y", lazy_entry::string_t, 1, 0},
			};

			lazy_entry const* parsed[5];
			char error_string[200];

//			fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
			int ret = verify_message(&response, desc, parsed, 5, error_string, sizeof(error_string));
			if (ret)
			{
				TEST_EQUAL(parsed[4]->string_value(), "r");
				token = parsed[2]->string_value();
//				fprintf(stderr, "got token: %s\n", token.c_str());
			}
			else
			{
				fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
				fprintf(stderr, "   invalid get response: %s\n", error_string);
				TEST_ERROR(error_string);
			}

			if (parsed[3])
			{
				address_v4::bytes_type b;
				memcpy(&b[0], parsed[3]->string_ptr(), b.size());
				address_v4 addr(b);
				TEST_EQUAL(addr, eps[i].address());
			}

			send_dht_msg(node, "put", eps[i], &response, "10", 0
				, 0, token, 0, (char const*)&items[j].target[0], &items[j].ent);

			key_desc_t desc2[] =
			{
				{ "y", lazy_entry::string_t, 1, 0 }
			};

			ret = verify_message(&response, desc2, parsed, 1, error_string, sizeof(error_string));
			if (ret)
			{
				if (parsed[0]->string_value() != "r")
					fprintf(stderr, "msg: %s\n", print_entry(response).c_str());

				TEST_EQUAL(parsed[0]->string_value(), "r");
			}
			else
			{
				fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
				fprintf(stderr, "   invalid put response: %s\n", error_string);
				TEST_ERROR(error_string);
			}
		}
	}

	std::set<int> items_num;
	for (int j = 0; j < num_items; ++j)
	{
		lazy_entry response;
		send_dht_msg(node, "get", eps[j], &response, "10", 0
			, 0, no, 0, (char const*)&items[j].target[0]);
		
		key_desc_t desc[] =
		{
			{ "r", lazy_entry::dict_t, 0, key_desc_t::parse_children },
				{ "v", lazy_entry::dict_t, 0, 0},
				{ "id", lazy_entry::string_t, 20, key_desc_t::last_child},
			{ "y", lazy_entry::string_t, 1, 0},
		};

		lazy_entry const* parsed[4];
		char error_string[200];

		int ret = verify_message(&response, desc, parsed, 4, error_string, sizeof(error_string));
		if (ret)
		{
			items_num.insert(items_num.begin(), j);
		}
	}

	TEST_EQUAL(items_num.size(), 4);

	// items_num should contain 1,2 and 3
	// #error this doesn't quite hold
//	TEST_CHECK(items_num.find(1) != items_num.end());
//	TEST_CHECK(items_num.find(2) != items_num.end());
//	TEST_CHECK(items_num.find(3) != items_num.end());
}

struct print_alert : alert_dispatcher
{
	virtual bool post_alert(alert* a)
	{
		fprintf(stderr, "ALERT: %s\n", a->message().c_str());
		delete a;
		return true;
	}
};

int test_main()
{
	dht_settings sett;
	sett.max_torrents = 4;
	sett.max_dht_items = 4;
	address ext = address::from_string("236.0.0.1");
	mock_socket s;
	print_alert ad;
	dht::node_impl node(&ad, &s, sett, node_id(0), ext, 0);

	// DHT should be running on port 48199 now
	lazy_entry response;
	lazy_entry const* parsed[5];
	char error_string[200];
	bool ret;

	// ====== ping ======
	udp::endpoint source(address::from_string("10.0.0.1"), 20);
	send_dht_msg(node, "ping", source, &response, "10");

	dht::key_desc_t pong_desc[] = {
		{"y", lazy_entry::string_t, 1, 0},
		{"t", lazy_entry::string_t, 2, 0},
		{"r", lazy_entry::dict_t, 0, key_desc_t::parse_children},
			{"id", lazy_entry::string_t, 20, key_desc_t::last_child},
	};

	fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
	ret = dht::verify_message(&response, pong_desc, parsed, 4, error_string, sizeof(error_string));
	TEST_CHECK(ret);
	if (ret)
	{
		TEST_CHECK(parsed[0]->string_value() == "r");
		TEST_CHECK(parsed[1]->string_value() == "10");
	}
	else
	{
		fprintf(stderr, "   invalid ping response: %s\n", error_string);
	}

	// ====== invalid message ======

	send_dht_msg(node, "find_node", source, &response, "10");

	dht::key_desc_t err_desc[] = {
		{"y", lazy_entry::string_t, 1, 0},
		{"e", lazy_entry::list_t, 2, 0},
		{"r", lazy_entry::dict_t, 0, key_desc_t::parse_children},
			{"id", lazy_entry::string_t, 20, key_desc_t::last_child},
	};

	fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
	ret = dht::verify_message(&response, err_desc, parsed, 4, error_string, sizeof(error_string));
	TEST_CHECK(ret);
	if (ret)
	{
		TEST_CHECK(parsed[0]->string_value() == "e");
		if (parsed[1]->list_at(0)->type() == lazy_entry::int_t
			&& parsed[1]->list_at(1)->type() == lazy_entry::string_t)
		{
			TEST_CHECK(parsed[1]->list_at(1)->string_value() == "missing 'target' key");
		}
		else
		{
			TEST_ERROR("invalid error response");
		}
	}
	else
	{
		fprintf(stderr, "   invalid error response: %s\n", error_string);
	}

	// ====== get_peers ======

	send_dht_msg(node, "get_peers", source, &response, "10", "01010101010101010101");

	dht::key_desc_t peer1_desc[] = {
		{"y", lazy_entry::string_t, 1, 0},
		{"r", lazy_entry::dict_t, 0, key_desc_t::parse_children},
			{"token", lazy_entry::string_t, 0, 0},
			{"id", lazy_entry::string_t, 20, key_desc_t::last_child},
	};

	std::string token;
	fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
	ret = dht::verify_message(&response, peer1_desc, parsed, 4, error_string, sizeof(error_string));
	TEST_CHECK(ret);
	if (ret)
	{
		TEST_CHECK(parsed[0]->string_value() == "r");
		token = parsed[2]->string_value();
//		fprintf(stderr, "got token: %s\n", token.c_str());
	}
	else
	{
		fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
		fprintf(stderr, "   invalid get_peers response: %s\n", error_string);
	}

	// ====== announce ======

	send_dht_msg(node, "announce_peer", source, &response, "10", "01010101010101010101", "test", token, 8080);

	dht::key_desc_t ann_desc[] = {
		{"y", lazy_entry::string_t, 1, 0},
		{"r", lazy_entry::dict_t, 0, key_desc_t::parse_children},
			{"id", lazy_entry::string_t, 20, key_desc_t::last_child},
	};

	fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
	ret = dht::verify_message(&response, ann_desc, parsed, 3, error_string, sizeof(error_string));
	TEST_CHECK(ret);
	if (ret)
	{
		TEST_CHECK(parsed[0]->string_value() == "r");
	}
	else
	{
		fprintf(stderr, "   invalid announce response: %s\n", error_string);
	}

	// announce from 100 random IPs and make sure scrape works
	// 50 downloaders and 50 seeds
	for (int i = 0; i < 100; ++i)
	{
		source = udp::endpoint(rand_v4(), 6000);
		send_dht_msg(node, "get_peers", source, &response, "10", "01010101010101010101");
		ret = dht::verify_message(&response, peer1_desc, parsed, 4, error_string, sizeof(error_string));

		if (ret)
		{
			TEST_CHECK(parsed[0]->string_value() == "r");
			token = parsed[2]->string_value();
//			fprintf(stderr, "got token: %s\n", token.c_str());
		}
		else
		{
			fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
			fprintf(stderr, "   invalid get_peers response: %s\n", error_string);
		}
		response.clear();
		send_dht_msg(node, "announce_peer", source, &response, "10", "01010101010101010101"
			, "test", token, 8080, 0, 0, false, i >= 50);
		response.clear();
	}

	// ====== get_peers ======

	send_dht_msg(node, "get_peers", source, &response, "10", "01010101010101010101"
		, 0, no, 0, 0, 0, true);

	dht::key_desc_t peer2_desc[] = {
		{"y", lazy_entry::string_t, 1, 0},
		{"r", lazy_entry::dict_t, 0, key_desc_t::parse_children},
			{"BFpe", lazy_entry::string_t, 256, 0},
			{"BFse", lazy_entry::string_t, 256, 0},
			{"id", lazy_entry::string_t, 20, key_desc_t::last_child},
	};

	fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
	ret = dht::verify_message(&response, peer2_desc, parsed, 5, error_string, sizeof(error_string));
	TEST_CHECK(ret);
	if (ret)
	{
		TEST_CHECK(parsed[0]->string_value() == "r");
		TEST_EQUAL(parsed[1]->dict_find_string_value("n"), "test");

		bloom_filter<256> downloaders;
		bloom_filter<256> seeds;
		downloaders.from_string(parsed[2]->string_ptr());
		seeds.from_string(parsed[3]->string_ptr());

		fprintf(stderr, "seeds: %f\n", seeds.size());
		fprintf(stderr, "downloaders: %f\n", downloaders.size());

		TEST_CHECK(fabs(seeds.size() - 50.f) <= 3.f);
		TEST_CHECK(fabs(downloaders.size() - 50.f) <= 3.f);
	}
	else
	{
		fprintf(stderr, "   invalid get_peers response: %s\n", error_string);
	}

	bloom_filter<256> test;
	for (int i = 0; i < 256; ++i)
	{
		char adr[50];
		snprintf(adr, 50, "192.0.2.%d", i);
		address a = address::from_string(adr);
		sha1_hash iphash;
		hash_address(a, iphash);
		test.set(iphash);
	}

	if (supports_ipv6())
	{
		for (int i = 0; i < 0x3E8; ++i)
		{
			char adr[50];
			snprintf(adr, 50, "2001:db8::%x", i);
			address a = address::from_string(adr);
			sha1_hash iphash;
			hash_address(a, iphash);
			test.set(iphash);
		}
	}

	// these are test vectors from BEP 33
	// http://www.bittorrent.org/beps/bep_0033.html
	fprintf(stderr, "test.size: %f\n", test.size());
	fprintf(stderr, "%s\n", to_hex(test.to_string()).c_str());
	if (supports_ipv6())
	{
		TEST_CHECK(fabs(test.size() - 1224.93f) < 0.001);
		TEST_CHECK(to_hex(test.to_string()) == "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");
	}
	else
	{
		TEST_CHECK(fabs(test.size() - 257.854f) < 0.001);
		TEST_CHECK(to_hex(test.to_string()) == "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");
	}

	response.clear();

	// ====== put ======

	udp::endpoint eps[1000];

 	for (int i = 0; i < 1000; ++i)
		eps[i] = udp::endpoint(rand_v4(), (rand() % 16534) + 1);

	announce_item items[] =
	{
		{ generate_next(), 1 },
		{ generate_next(), 2 },
		{ generate_next(), 3 },
		{ generate_next(), 4 },
		{ generate_next(), 5 },
		{ generate_next(), 6 },
		{ generate_next(), 7 },
		{ generate_next(), 8 }
	};

	for (int i = 0; i < sizeof(items)/sizeof(items[0]); ++i)
		items[i].gen();

	announce_immutable_items(node, eps, items, sizeof(items)/sizeof(items[0]));

	// ==== get / put mutable items ===

	fprintf(stderr, "generating ed25519 keys\n");
	unsigned char seed[32];
	ed25519_create_seed(seed);
	unsigned char private_key[64];
	unsigned char public_key[32];

	ed25519_create_keypair(public_key, private_key, seed);
	fprintf(stderr, "pub: %s priv: %s\n"
		, to_hex(std::string((char*)public_key, 32)).c_str()
		, to_hex(std::string((char*)private_key, 64)).c_str());

	TEST_CHECK(ret);

	send_dht_msg(node, "get", source, &response, "10", 0
		, 0, no, 0, (char*)&hasher((char*)public_key, 32).final()[0]
		, 0, false, false, std::string(), std::string(), 64);
			
	key_desc_t desc[] =
	{
		{ "r", lazy_entry::dict_t, 0, key_desc_t::parse_children },
			{ "id", lazy_entry::string_t, 20, 0},
			{ "token", lazy_entry::string_t, 0, 0},
			{ "ip", lazy_entry::string_t, 0, key_desc_t::optional | key_desc_t::last_child},
		{ "y", lazy_entry::string_t, 1, 0},
	};

	ret = verify_message(&response, desc, parsed, 5, error_string, sizeof(error_string));
	if (ret)
	{
		TEST_EQUAL(parsed[4]->string_value(), "r");
		token = parsed[2]->string_value();
		fprintf(stderr, "got token: %s\n", token.c_str());
	}
	else
	{
		fprintf(stderr, "msg: %s\n", print_entry(response).c_str());
		fprintf(stderr, "   invalid get response: %s\n%s\n"
			, error_string, print_entry(response).c_str());
		TEST_ERROR(error_string);
	}

	unsigned char signature[64];
	char buffer[1200];
	int seq = 4;
	int pos = snprintf(buffer, sizeof(buffer), "3:seqi%de1:v", seq);
	char* ptr = buffer + pos;
	pos += bencode(ptr, items[0].ent);
	ed25519_sign(signature, (unsigned char*)buffer, pos, private_key, public_key);

	send_dht_msg(node, "put", source, &response, "10", 0
		, 0, token, 0, 0, &items[0].ent, false, false
		, std::string((char*)public_key, 32)
		, std::string((char*)signature, 64), seq);

	key_desc_t desc2[] =
	{
		{ "y", lazy_entry::string_t, 1, 0 }
	};

	ret = verify_message(&response, desc2, parsed, 1, error_string, sizeof(error_string));
	if (ret)
	{
		fprintf(stderr, "put response: %s\n"
			, print_entry(response).c_str());
		TEST_EQUAL(parsed[0]->string_value(), "r");
	}
	else
	{
		fprintf(stderr, "   invalid put response: %s\n%s\n"
			, error_string, print_entry(response).c_str());
		TEST_ERROR(error_string);
	}

// test routing table

	{
		sett.extended_routing_table = false;
		routing_table tbl(random_id(), 8, sett);
   
		// insert 256 nodes evenly distributed across the ID space.
		// we expect to fill the top 5 buckets
		for (int i = 0; i < 256; ++i)
		{
			node_id id = random_id();
			id[0] = i;
			tbl.node_seen(id, rand_ep(), 50);
		}
		TEST_EQUAL(tbl.num_active_buckets(), 6);
   
#if defined TORRENT_DHT_VERBOSE_LOGGING || defined TORRENT_DEBUG
		tbl.print_state(std::cerr);
#endif
	}

	{
		sett.extended_routing_table = true;
		routing_table tbl(random_id(), 8, sett);
		for (int i = 0; i < 256; ++i)
		{
			node_id id = random_id();
			id[0] = i;
			tbl.node_seen(id, rand_ep(), 50);
		}
		TEST_EQUAL(tbl.num_active_buckets(), 6);

#if defined TORRENT_DHT_VERBOSE_LOGGING || defined TORRENT_DEBUG
		tbl.print_state(std::cerr);
#endif
	}

	return 0;
}

#else

int test_main()
{
	return 0;
}

#endif