#include <DB/Interpreters/Cluster.h>
#include <DB/Common/escapeForFileName.h>
#include <DB/Common/isLocalAddress.h>
#include <Poco/Util/AbstractConfiguration.h>
#include <Poco/Util/Application.h>

namespace DB
{


Cluster::Address::Address(const String & config_prefix)
{
	auto & config = Poco::Util::Application::instance().config();

	host_name = config.getString(config_prefix + ".host");
	port = config.getInt(config_prefix + ".port");
	resolved_address = Poco::Net::SocketAddress(host_name, port);
	user = config.getString(config_prefix + ".user", "default");
	password = config.getString(config_prefix + ".password", "");
}

Cluster::Address::Address(const String & host_port_, const String & user_, const String & password_)
	: user(user_), password(password_)
{
	UInt16 default_port = Poco::Util::Application::instance().config().getInt("tcp_port", 0);

	/// Похоже на то, что строка host_port_ содержит порт. Если условие срабатывает - не обязательно значит, что порт есть (пример: [::]).
	if (nullptr != strchr(host_port_.c_str(), ':') || !default_port)
	{
		resolved_address = Poco::Net::SocketAddress(host_port_);
		host_name = host_port_.substr(0, host_port_.find(':'));
		port = resolved_address.port();
	}
	else
	{
		resolved_address = Poco::Net::SocketAddress(host_port_, default_port);
		host_name = host_port_;
		port = default_port;
	}
}

namespace
{
	inline std::string addressToDirName(const Cluster::Address & address)
	{
		return
			escapeForFileName(address.user) +
			(address.password.empty() ? "" : (':' + escapeForFileName(address.password))) + '@' +
			escapeForFileName(address.resolved_address.host().toString()) + ':' +
			std::to_string(address.resolved_address.port());
	}
}


Clusters::Clusters(const Settings & settings, const String & config_name)
{
	Poco::Util::AbstractConfiguration & config = Poco::Util::Application::instance().config();
	Poco::Util::AbstractConfiguration::Keys config_keys;
	config.keys(config_name, config_keys);

	for (Poco::Util::AbstractConfiguration::Keys::const_iterator it = config_keys.begin(); it != config_keys.end(); ++it)
		impl.emplace(std::piecewise_construct,
			std::forward_as_tuple(*it),
			std::forward_as_tuple(settings, config_name + "." + *it));
}


Cluster::Cluster(const Settings & settings, const String & cluster_name)
{
	/// Создать кластер.

	Poco::Util::AbstractConfiguration & config = Poco::Util::Application::instance().config();
	Poco::Util::AbstractConfiguration::Keys config_keys;
	config.keys(cluster_name, config_keys);

	const auto & config_prefix = cluster_name + ".";

	UInt32 current_shard_num = 1;

	for (auto it = config_keys.begin(); it != config_keys.end(); ++it)
	{
		if (0 == strncmp(it->c_str(), "node", strlen("node")))
		{
			const auto & prefix = config_prefix + *it;
			const auto weight = config.getInt(prefix + ".weight", 1);
			if (weight == 0)
				continue;

			addresses.emplace_back(prefix);
			addresses.back().replica_num = 1;

			slot_to_shard.insert(std::end(slot_to_shard), weight, shard_info_vec.size());
			if (const auto is_local = isLocal(addresses.back()))
				shard_info_vec.push_back({{}, current_shard_num, weight, is_local});
			else
				shard_info_vec.push_back({{addressToDirName(addresses.back())}, current_shard_num, weight, is_local});
		}
		else if (0 == strncmp(it->c_str(), "shard", strlen("shard")))
		{
			Poco::Util::AbstractConfiguration::Keys replica_keys;
			config.keys(config_prefix + *it, replica_keys);

			addresses_with_failover.emplace_back();
			Addresses & replica_addresses = addresses_with_failover.back();
			UInt32 current_replica_num = 1;

			const auto & partial_prefix = config_prefix + *it + ".";
			const auto weight = config.getInt(partial_prefix + ".weight", 1);
			if (weight == 0)
				continue;

			const auto internal_replication = config.getBool(partial_prefix + ".internal_replication", false);

			/** in case of internal_replication we will be appending names to
			 *  the first element of vector; otherwise we will just .emplace_back
			 */
			std::vector<std::string> dir_names{};
			size_t num_local_nodes = 0;

			auto first = true;
			for (auto jt = replica_keys.begin(); jt != replica_keys.end(); ++jt)
			{
				if (0 == strncmp(jt->data(), "weight", strlen("weight")) ||
					0 == strncmp(jt->data(), "internal_replication", strlen("internal_replication")))
					continue;

				if (0 == strncmp(jt->c_str(), "replica", strlen("replica")))
				{
					replica_addresses.emplace_back(partial_prefix + *jt);
					replica_addresses.back().replica_num = current_replica_num;
					++current_replica_num;

					if (isLocal(replica_addresses.back()))
					{
						++num_local_nodes;
					}
					else
					{
						if (internal_replication)
						{
							auto dir_name = addressToDirName(replica_addresses.back());
							if (first)
								dir_names.emplace_back(std::move(dir_name));
							else
								dir_names.front() += "," + dir_name;
						}
						else
							dir_names.emplace_back(addressToDirName(replica_addresses.back()));

						if (first) first = false;
					}
				}
				else
					throw Exception("Unknown element in config: " + *jt, ErrorCodes::UNKNOWN_ELEMENT_IN_CONFIG);
			}

			slot_to_shard.insert(std::end(slot_to_shard), weight, shard_info_vec.size());
			shard_info_vec.push_back({std::move(dir_names), current_shard_num, weight, num_local_nodes});
		}
		else
			throw Exception("Unknown element in config: " + *it, ErrorCodes::UNKNOWN_ELEMENT_IN_CONFIG);

		++current_shard_num;
	}

	/// Создать соответствующие пулы соединений.

	if (!addresses_with_failover.empty() && !addresses.empty())
		throw Exception("There must be either 'node' or 'shard' elements in config", ErrorCodes::EXCESSIVE_ELEMENT_IN_CONFIG);

	if (!addresses_with_failover.empty())
	{
		for (const auto & shard : addresses_with_failover)
		{
			ConnectionPools replicas;
			replicas.reserve(shard.size());

			bool has_local_replica = false;

			for (const auto & replica : shard)
			{
				if (isLocal(replica))
				{
					has_local_replica = true;
					local_addresses.push_back(replica);
					break;
				}
				else
				{
					replicas.emplace_back(new ConnectionPool(
						settings.distributed_connections_pool_size,
						replica.host_name, replica.port, replica.resolved_address,
						"", replica.user, replica.password,
						"server", Protocol::Compression::Enable,
						saturate(settings.connect_timeout_with_failover_ms, settings.limits.max_execution_time),
						saturate(settings.receive_timeout, settings.limits.max_execution_time),
						saturate(settings.send_timeout, settings.limits.max_execution_time)));
				}
			}

			if (has_local_replica)
				++local_nodes_num;
			else
				pools.emplace_back(new ConnectionPoolWithFailover(replicas, settings.load_balancing, settings.connections_with_failover_max_tries));
		}
	}
	else if (!addresses.empty())
	{
		for (const auto & address : addresses)
		{
			if (isLocal(address))
			{
				local_addresses.push_back(address);
				++local_nodes_num;
			}
			else
			{
				pools.emplace_back(new ConnectionPool(
					settings.distributed_connections_pool_size,
					address.host_name, address.port, address.resolved_address,
					"", address.user, address.password,
					"server", Protocol::Compression::Enable,
					saturate(settings.connect_timeout, settings.limits.max_execution_time),
					saturate(settings.receive_timeout, settings.limits.max_execution_time),
					saturate(settings.send_timeout, settings.limits.max_execution_time)));
			}
		}
	}
	else
		throw Exception("No addresses listed in config", ErrorCodes::NO_ELEMENTS_IN_CONFIG);
}


Cluster::Cluster(const Settings & settings, std::vector<std::vector<String>> names,
				 const String & username, const String & password)
{
	for (const auto & shard : names)
	{
		Addresses current;
		for (auto & replica : shard)
			current.emplace_back(replica, username, password);
		addresses_with_failover.emplace_back(current);
	}

	for (const auto & shard : addresses_with_failover)
	{
		ConnectionPools replicas;
		replicas.reserve(shard.size());

		for (const auto & replica : shard)
		{
			replicas.emplace_back(new ConnectionPool(
				settings.distributed_connections_pool_size,
				replica.host_name, replica.port, replica.resolved_address,
				"", replica.user, replica.password,
				"server", Protocol::Compression::Enable,
				saturate(settings.connect_timeout_with_failover_ms, settings.limits.max_execution_time),
				saturate(settings.receive_timeout, settings.limits.max_execution_time),
				saturate(settings.send_timeout, settings.limits.max_execution_time)));
		}

		pools.emplace_back(new ConnectionPoolWithFailover(replicas, settings.load_balancing, settings.connections_with_failover_max_tries));
	}
}


Poco::Timespan Cluster::saturate(const Poco::Timespan & v, const Poco::Timespan & limit)
{
	if (limit.totalMicroseconds() == 0)
		return v;
	else
		return v > limit ? limit : v;
}


bool Cluster::isLocal(const Address & address)
{
	///	Если среди реплик существует такая, что:
	/// - её порт совпадает с портом, который слушает сервер;
	/// - её хост резолвится в набор адресов, один из которых совпадает с одним из адресов сетевых интерфейсов сервера
	/// то нужно всегда ходить на этот шард без межпроцессного взаимодействия
	return isLocalAddress(address.resolved_address);
}

}