/*
 * 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: 2023-01-01
 *
 * 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 <memory>
#include <redis++/redis++.h>

extern "C" {
typedef struct pg_conn PGconn;
}

namespace ZeroTier {

struct RedisConfig;

/**
 * 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 taht we might change it at any time.
 */
class PostgreSQL : public DB
{
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);

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); }
	};

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

	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
	};

	PGconn * getPgConn( OverrideMode m = ALLOW_PGBOUNCER_OVERRIDE );

	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;

	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