#ifndef MS_RTC_ICE_ICE_SERVER_HPP
#define MS_RTC_ICE_ICE_SERVER_HPP

#include "common.hpp"
#include "FBS/webRtcTransport.h"
#include "RTC/ICE/StunPacket.hpp"
#include "RTC/TransportTuple.hpp"
#include "handles/TimerHandle.hpp"
#include <list>
#include <string>
#include <unordered_map>

namespace RTC
{
	namespace ICE
	{
		class IceServer : public TimerHandle::Listener
		{
		public:
			enum class IceState : uint8_t
			{
				NEW = 1,
				CONNECTED,
				COMPLETED,
				DISCONNECTED,
			};

		public:
			class Listener
			{
			public:
				virtual ~Listener() = default;

			public:
				/**
				 * These callbacks are guaranteed to be called before ProcessStunPacket()
				 * returns, so the given pointers are still usable.
				 */
				virtual void OnIceServerSendStunPacket(
				  const RTC::ICE::IceServer* iceServer,
				  const RTC::ICE::StunPacket* packet,
				  RTC::TransportTuple* tuple) = 0;
				virtual void OnIceServerLocalUsernameFragmentAdded(
				  const RTC::ICE::IceServer* iceServer, const std::string& usernameFragment) = 0;
				virtual void OnIceServerLocalUsernameFragmentRemoved(
				  const RTC::ICE::IceServer* iceServer, const std::string& usernameFragment) = 0;
				virtual void OnIceServerTupleAdded(
				  const RTC::ICE::IceServer* iceServer, RTC::TransportTuple* tuple) = 0;
				virtual void OnIceServerTupleRemoved(
				  const RTC::ICE::IceServer* iceServer, RTC::TransportTuple* tuple) = 0;
				virtual void OnIceServerSelectedTuple(
				  const RTC::ICE::IceServer* iceServer, RTC::TransportTuple* tuple)        = 0;
				virtual void OnIceServerConnected(const RTC::ICE::IceServer* iceServer)    = 0;
				virtual void OnIceServerCompleted(const RTC::ICE::IceServer* iceServer)    = 0;
				virtual void OnIceServerDisconnected(const RTC::ICE::IceServer* iceServer) = 0;
			};

		public:
			static const std::string& IceStateToString(IceState iceState);
			static FBS::WebRtcTransport::IceState IceStateToFbs(IceState state);

		private:
			static std::unordered_map<IceState, std::string> iceStateToString;

		public:
			IceServer(
			  Listener* listener,
			  const std::string& usernameFragment,
			  const std::string& password,
			  uint8_t consentTimeoutSec);
			~IceServer() override;

		public:
			void Dump(int indentation = 0) const;
			void ProcessStunPacket(const RTC::ICE::StunPacket* packet, RTC::TransportTuple* tuple);
			const std::string& GetUsernameFragment() const
			{
				return this->usernameFragment;
			}
			const std::string& GetPassword() const
			{
				return this->password;
			}
			IceState GetState() const
			{
				return this->state;
			}
			RTC::TransportTuple* GetSelectedTuple() const
			{
				return this->selectedTuple;
			}
			void RestartIce(const std::string& usernameFragment, const std::string& password);
			bool IsValidTuple(const RTC::TransportTuple* tuple) const;
			void RemoveTuple(RTC::TransportTuple* tuple);
			/**
			 * This should be just called in 'connected' or 'completed' state and the
			 * given tuple must be an already valid tuple.
			 */
			void MayForceSelectedTuple(const RTC::TransportTuple* tuple);

		private:
			void ProcessStunRequest(const RTC::ICE::StunPacket* request, RTC::TransportTuple* tuple);
			void ProcessStunIndication(const RTC::ICE::StunPacket* indication);
			void ProcessStunResponse(const RTC::ICE::StunPacket* response);
			void HandleTuple(
			  RTC::TransportTuple* tuple, bool hasUseCandidate, bool hasNomination, uint32_t nomination);
			/**
			 * Store the given tuple and return its stored address.
			 */
			RTC::TransportTuple* AddTuple(RTC::TransportTuple* tuple);
			/**
			 * If the given tuple exists return its stored address, nullptr otherwise.
			 */
			RTC::TransportTuple* HasTuple(const RTC::TransportTuple* tuple) const;
			/**
			 * Set the given tuple as the selected tuple.
			 * NOTE: The given tuple MUST be already stored within the list.
			 */
			void SetSelectedTuple(RTC::TransportTuple* storedTuple);
			bool IsConsentCheckSupported() const
			{
				return this->consentTimeoutMs != 0u;
			}
			bool IsConsentCheckRunning() const
			{
				return (this->consentCheckTimer && this->consentCheckTimer->IsActive());
			}
			void StartConsentCheck();
			void RestartConsentCheck();
			void StopConsentCheck();

			/* Pure virtual methods inherited from TimerHandle::Listener. */
		public:
			void OnTimer(TimerHandle* timer) override;

		private:
			// Passed by argument.
			Listener* listener{ nullptr };
			std::string usernameFragment;
			std::string password;
			uint16_t consentTimeoutMs{ 30000u };
			// Others.
			std::string oldUsernameFragment;
			std::string oldPassword;
			IceState state{ IceState::NEW };
			uint32_t remoteNomination{ 0u };
			std::list<RTC::TransportTuple> tuples;
			RTC::TransportTuple* selectedTuple{ nullptr };
			TimerHandle* consentCheckTimer{ nullptr };
			bool isRemovingTuples{ false };
		};
	} // namespace ICE
} // namespace RTC

#endif