/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * (c) ZeroTier, Inc.
 * https://www.zerotier.com/
 */

#ifndef ZT_WINDOWSETHERNETTAP_HPP
#define ZT_WINDOWSETHERNETTAP_HPP

#include "../node/Constants.hpp"
#include "../node/InetAddress.hpp"
#include "../node/MulticastGroup.hpp"
#include "../node/Mutex.hpp"
#include "../osdep/Thread.hpp"
#include "EthernetTap.hpp"

#include <ifdef.h>
#include <queue>
#include <stdexcept>
#include <stdio.h>
#include <stdlib.h>
#include <string>

namespace ZeroTier {

class WindowsEthernetTap : public EthernetTap {
  public:
	/**
	 * Installs a new instance of the ZT tap driver
	 *
	 * @param pathToInf Path to zttap driver .inf file
	 * @param deviceInstanceId Buffer to fill with device instance ID on success (and if SetupDiGetDeviceInstanceIdA succeeds, which it should)
	 * @return Empty string on success, otherwise an error message
	 */
	static std::string addNewPersistentTapDevice(const char* pathToInf, std::string& deviceInstanceId);

	/**
	 * Uninstalls all persistent tap devices that have legacy drivers
	 *
	 * @return Empty string on success, otherwise an error message
	 */
	static std::string destroyAllLegacyPersistentTapDevices();

	/**
	 * Uninstalls all persistent tap devices on the system
	 *
	 * @return Empty string on success, otherwise an error message
	 */
	static std::string destroyAllPersistentTapDevices();

	/**
	 * Uninstalls a specific persistent tap device by instance ID
	 *
	 * @param instanceId Device instance ID
	 * @return Empty string on success, otherwise an error message
	 */
	static std::string deletePersistentTapDevice(const char* instanceId);

	/**
	 * Disable a persistent tap device by instance ID
	 *
	 * @param instanceId Device instance ID
	 * @param enabled Enable device?
	 * @return True if device was found and disabled
	 */
	static bool setPersistentTapDeviceState(const char* instanceId, bool enabled);

	WindowsEthernetTap(
		const char* hp,
		const MAC& mac,
		unsigned int mtu,
		unsigned int metric,
		uint64_t nwid,
		const char* friendlyName,
		void (*handler)(void*, void*, uint64_t, const MAC&, const MAC&, unsigned int, unsigned int, const void*, unsigned int),
		void* arg);

	virtual ~WindowsEthernetTap();

	virtual void setEnabled(bool en);
	virtual bool enabled() const;
	virtual bool addIp(const InetAddress& ip);
	virtual bool removeIp(const InetAddress& ip);
	virtual std::vector<InetAddress> ips() const;
	virtual void put(const MAC& from, const MAC& to, unsigned int etherType, const void* data, unsigned int len);
	virtual std::string deviceName() const;
	virtual void setFriendlyName(const char* friendlyName);
	virtual std::string friendlyName() const;
	virtual void scanMulticastGroups(std::vector<MulticastGroup>& added, std::vector<MulticastGroup>& removed);
	virtual void setMtu(unsigned int mtu);
	virtual void setDns(const char* domain, const std::vector<InetAddress>& servers);

	inline const NET_LUID& luid() const
	{
		return _deviceLuid;
	}
	inline const GUID& guid() const
	{
		return _deviceGuid;
	}
	inline const std::string& instanceId() const
	{
		return _deviceInstanceId;
	}
	NET_IFINDEX interfaceIndex() const;

	void threadMain() throw();

	bool isInitialized() const
	{
		return _initialized;
	};

  private:
	NET_IFINDEX _getDeviceIndex();	 // throws on failure
	std::vector<std::string> _getRegistryIPv4Value(const char* regKey);
	void _setRegistryIPv4Value(const char* regKey, const std::vector<std::string>& value);
	void _syncIps();

	void (*_handler)(void*, void*, uint64_t, const MAC&, const MAC&, unsigned int, unsigned int, const void*, unsigned int);
	void* _arg;
	MAC _mac;
	uint64_t _nwid;
	volatile unsigned int _mtu;
	Thread _thread;

	volatile HANDLE _tap;
	HANDLE _injectSemaphore;

	GUID _deviceGuid;
	NET_LUID _deviceLuid;
	std::string _netCfgInstanceId;
	std::string _deviceInstanceId;
	std::string _mySubkeyName;
	std::string _friendlyName;
	Mutex _friendlyName_m;

	std::vector<InetAddress> _assignedIps;	 // IPs assigned with addIp
	Mutex _assignedIps_m;

	std::vector<MulticastGroup> _multicastGroups;

	struct _InjectPending {
		unsigned int len;
		char data[ZT_MAX_MTU + 32];
	};
	std::queue<_InjectPending> _injectPending;
	Mutex _injectPending_m;

	std::string _pathToHelpers;

	volatile bool _run;
	volatile bool _initialized;
	volatile bool _enabled;

	mutable std::vector<InetAddress> _ifaddrs;
	mutable uint64_t _lastIfAddrsUpdate;
};

}	// namespace ZeroTier

#endif
