/*
 * Copyright (c)2019 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2025-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */
/****/

#include "DB.hpp"

#ifdef ZT_CONTROLLER_USE_LIBPQ

#ifndef ZT_CONTROLLER_LIBPQ_HPP
#define ZT_CONTROLLER_LIBPQ_HPP

#define ZT_CENTRAL_CONTROLLER_COMMIT_THREADS 4

#include "ConnectionPool.hpp"
#include <pqxx/pqxx>

#include <memory>
#include <redis++/redis++.h>

extern "C" {
typedef struct pg_conn PGconn;
}

namespace ZeroTier {

struct RedisConfig;


class PostgresConnection : public Connection {
public:
	virtual ~PostgresConnection() {
	}

	std::shared_ptr<pqxx::connection> c;
	int a;
};


class PostgresConnFactory : public ConnectionFactory {
public:
	PostgresConnFactory(std::string &connString) 
		: m_connString(connString)
	{
	}

	virtual std::shared_ptr<Connection> create() {
		auto c = std::shared_ptr<PostgresConnection>(new PostgresConnection());
		c->c = std::make_shared<pqxx::connection>(m_connString);
		return std::static_pointer_cast<Connection>(c);
	}
private:
	std::string m_connString;
};

class PostgreSQL;

class MemberNotificationReceiver : public pqxx::notification_receiver {
public: 
	MemberNotificationReceiver(PostgreSQL *p, pqxx::connection &c, const std::string &channel);
	virtual ~MemberNotificationReceiver() {
		fprintf(stderr, "MemberNotificationReceiver destroyed\n");
	}

	virtual void operator() (const std::string &payload, int backendPid);
private:
	PostgreSQL *_psql;
};

class NetworkNotificationReceiver : public pqxx::notification_receiver {
public:
	NetworkNotificationReceiver(PostgreSQL *p, pqxx::connection &c, const std::string &channel);
	virtual ~NetworkNotificationReceiver() {
		fprintf(stderr, "NetworkNotificationReceiver destroyed\n");
	};

	virtual void operator() (const std::string &payload, int packend_pid);
private:
	PostgreSQL *_psql;
};

/**
 * A controller database driver that talks to PostgreSQL
 *
 * This is for use with ZeroTier Central.  Others are free to build and use it
 * but be aware that we might change it at any time.
 */
class PostgreSQL : public DB
{
	friend class MemberNotificationReceiver;
	friend class NetworkNotificationReceiver;
public:
	PostgreSQL(const Identity &myId, const char *path, int listenPort, RedisConfig *rc);
	virtual ~PostgreSQL();

	virtual bool waitForReady();
	virtual bool isReady();
	virtual bool save(nlohmann::json &record,bool notifyListeners);
	virtual void eraseNetwork(const uint64_t networkId);
	virtual void eraseMember(const uint64_t networkId, const uint64_t memberId);
	virtual void nodeIsOnline(const uint64_t networkId, const uint64_t memberId, const InetAddress &physicalAddress);
	virtual std::string getSSOAuthURL(const nlohmann::json &member, const std::string &redirectURL);

protected:
	struct _PairHasher
	{
		inline std::size_t operator()(const std::pair<uint64_t,uint64_t> &p) const { return (std::size_t)(p.first ^ p.second); }
	};
	virtual void _memberChanged(nlohmann::json &old,nlohmann::json &memberConfig,bool notifyListeners) {
		DB::_memberChanged(old, memberConfig, notifyListeners);
	}

	virtual void _networkChanged(nlohmann::json &old,nlohmann::json &networkConfig,bool notifyListeners) {
		DB::_networkChanged(old, networkConfig, notifyListeners);
	}

private:
	void initializeNetworks();
	void initializeMembers();
	void heartbeat();
	void membersDbWatcher();
	void _membersWatcher_Postgres();
	void networksDbWatcher();
	void _networksWatcher_Postgres();

	void _membersWatcher_Redis();
	void _networksWatcher_Redis();

	void commitThread();
	void onlineNotificationThread();
	void onlineNotification_Postgres();
	void onlineNotification_Redis();
	void _doRedisUpdate(sw::redis::Transaction &tx, std::string &controllerId, 
		std::unordered_map< std::pair<uint64_t,uint64_t>,std::pair<int64_t,InetAddress>,_PairHasher > &lastOnline);

	enum OverrideMode {
		ALLOW_PGBOUNCER_OVERRIDE = 0,
		NO_OVERRIDE = 1
	};

	std::shared_ptr<ConnectionPool<PostgresConnection> > _pool;

	const Identity _myId;
	const Address _myAddress;
	std::string _myAddressStr;
	std::string _connString;

	BlockingQueue< std::pair<nlohmann::json,bool> > _commitQueue;

	std::thread _heartbeatThread;
	std::thread _membersDbWatcher;
	std::thread _networksDbWatcher;
	std::thread _commitThread[ZT_CENTRAL_CONTROLLER_COMMIT_THREADS];
	std::thread _onlineNotificationThread;

	std::unordered_map< std::pair<uint64_t,uint64_t>,std::pair<int64_t,InetAddress>,_PairHasher > _lastOnline;

	mutable std::mutex _lastOnline_l;
	mutable std::mutex _readyLock;
	std::atomic<int> _ready, _connected, _run;
	mutable volatile bool _waitNoticePrinted;

	int _listenPort;
	uint8_t _ssoPsk[48];

	RedisConfig *_rc;
	std::shared_ptr<sw::redis::Redis> _redis;
	std::shared_ptr<sw::redis::RedisCluster> _cluster;
};

} // namespace ZeroTier

#endif // ZT_CONTROLLER_LIBPQ_HPP

#endif // ZT_CONTROLLER_USE_LIBPQ
