VoiceConnection.hpp

/*
	MIT License

	DiscordCoreAPI, A bot library for Discord, written in C++, and featuring explicit multithreading through the usage of custom, asynchronous C++ CoRoutines.

	Copyright 2022, 2023 Chris M. (RealTimeChris)

	Permission is hereby granted, free of charge, to any person obtaining a copy
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	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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*/
/// VoiceConnection.hpp - Header for the voice connection class.
/// Jul 15, 2021
/// https://discordcoreapi.com
/// \file VoiceConnection.hpp
#pragma once

#include <discordcoreapi/Utilities/UDPConnection.hpp>
#include <discordcoreapi/Utilities/AudioEncoder.hpp>
#include <discordcoreapi/Utilities/AudioDecoder.hpp>
#include <discordcoreapi/Utilities/RingBuffer.hpp>
#include <discordcoreapi/FoundationEntities.hpp>
#include <discordcoreapi/Utilities/WebSocketClient.hpp>
#include <discordcoreapi/CoRoutine.hpp>
#include <sodium.h>

namespace discord_core_api {

	/// @brief Voice websocket close codes.
	class voice_websocket_close {
	  public:
		/// @brief Voice websocket close codes.
		enum class voice_websocket_close_code : uint16_t {
			Unset					= 1 << 0,///< Unset.
			Normal_Close			= 1 << 1,///< Normal close.
			Unknown_Opcode			= 1 << 2,///< You sent an invalid opcode.
			Failed_To_Decode		= 1 << 3,///< You sent an invalid payload in your identifying to the gateway.
			Not_Authenticated		= 1 << 4,///< You sent a payload before identifying with the gateway.
			Authentication_Failed	= 1 << 5,///<	the token you sent in your identify payload is incorrect.
			Already_Authenticated	= 1 << 6,///<	you sent more than one identify payload. stahp.
			Session_No_Longer_Valid = 1 << 7,///< Your session is no longer valid.
			Session_Timeout			= 1 << 8,///< Your session has timed out.
			Server_Not_Found		= 1 << 9,///< We can't find the server you're trying to connect to.
			Unknown_Protocol		= 1 << 10,///< We didn't recognize the protocol you sent.
			disconnected			= 1 << 11,///< channel_data was deleted, you were kicked, voice server changed, or the main gateway session was dropped. should not reconnect.
			Voice_Server_Crashed	= 1 << 12,///< The server crashed. our bad! try resuming.
			Unknown_Encryption_Mode = 1 << 13///< We didn't recognize your encryption.
		};

		DCA_INLINE static unordered_map<int32_t, voice_websocket_close_code> mappingValues{ { 0, voice_websocket_close_code::Unset },
			{ 1000, voice_websocket_close_code::Normal_Close }, { 4001, voice_websocket_close_code::Unknown_Opcode }, { 4002, voice_websocket_close_code::Failed_To_Decode },
			{ 4003, voice_websocket_close_code::Not_Authenticated }, { 4004, voice_websocket_close_code::Authentication_Failed },
			{ 4005, voice_websocket_close_code::Already_Authenticated }, { 4006, voice_websocket_close_code::Session_No_Longer_Valid },
			{ 4009, voice_websocket_close_code::Session_Timeout }, { 4011, voice_websocket_close_code::Server_Not_Found }, { 4012, voice_websocket_close_code::Unknown_Protocol },
			{ 4014, voice_websocket_close_code::disconnected }, { 4015, voice_websocket_close_code::Voice_Server_Crashed },
			{ 4016, voice_websocket_close_code::Unknown_Encryption_Mode } };

		DCA_INLINE static unordered_map<voice_websocket_close_code, jsonifier::string> outputErrorValues{ { voice_websocket_close_code::Unset, "Unset." },
			{ voice_websocket_close_code::Normal_Close, "normal close." }, { voice_websocket_close_code::Unknown_Opcode, "you sent an invalid opcode." },
			{ voice_websocket_close_code::Failed_To_Decode, "you sent an invalid payload in your identifying to the gateway." },
			{ voice_websocket_close_code::Not_Authenticated, "you sent a payload before identifying with the gateway." },
			{ voice_websocket_close_code::Authentication_Failed, "the token you sent in your identify payload is incorrect." },
			{ voice_websocket_close_code::Already_Authenticated, "you sent more than one identify payload. stahp." },
			{ voice_websocket_close_code::Session_No_Longer_Valid, "your session is no longer valid." },
			{ voice_websocket_close_code::Session_Timeout, "your session has timed out." },
			{ voice_websocket_close_code::Server_Not_Found, "we can't find the server you're trying to connect to." },
			{ voice_websocket_close_code::Unknown_Protocol, "we didn't recognize the protocol you sent." },
			{ voice_websocket_close_code::disconnected,
				"channel_data was deleted, you were kicked, voice server changed, or the main gateway session was dropped. should not "
				"reconnect." },
			{ voice_websocket_close_code::Voice_Server_Crashed, "the server crashed. our bad! try resuming." },
			{ voice_websocket_close_code::Unknown_Encryption_Mode, "we didn't recognize your encryption." } };
		voice_websocket_close_code value{};

		DCA_INLINE voice_websocket_close& operator=(uint16_t valueNew) {
			value = static_cast<voice_websocket_close_code>(valueNew);
			return *this;
		};

		DCA_INLINE voice_websocket_close(uint16_t value) {
			*this = value;
		};

		DCA_INLINE operator jsonifier::string_view() {
			return voice_websocket_close::outputErrorValues[mappingValues[static_cast<uint16_t>(value)]];
		}

		DCA_INLINE operator bool() {
			return true;
		}
	};

	struct voice_socket_ready_data {
		jsonifier::vector<jsonifier::string> modes{};
		jsonifier::string ip{};
		uint16_t port{};
		uint32_t ssrc{};
	};

	struct voice_session_description_data {
		jsonifier::vector<uint8_t> secretKey{};
	};

	struct speaking_data {
		snowflake userId{};
		uint32_t ssrc{};
	};

	struct voice_connection_hello_data {
		uint32_t heartBeatInterval{};
	};

	struct voice_user_disconnect_data {
		snowflake userId{};
	};

	/// @brief The voice data for a given user, as raw PCM data, along with their Id.
	struct voice_user_payload {
		jsonifier::string_view_base<uint8_t> voiceData{};
		snowflake userId{};
	};

	struct DiscordCoreAPI_Dll voice_user {
		voice_user() = default;

		voice_user(snowflake userId);

		voice_user& operator=(voice_user&& data) noexcept;

		voice_user& operator=(const voice_user&) = delete;

		voice_user(const voice_user&) = delete;

		discord_core_internal::opus_decoder_wrapper& getDecoder();

		jsonifier::string_view_base<uint8_t> extractPayload();

		void insertPayload(jsonifier::string_view_base<uint8_t>);

		snowflake getUserId();

	  protected:
		discord_core_internal::ring_buffer<uint8_t, 10> payloads{};
		discord_core_internal::opus_decoder_wrapper decoder{};
		snowflake userId{};
	};

	struct DiscordCoreAPI_Dll rtp_packet_encrypter {
		rtp_packet_encrypter() = default;

		rtp_packet_encrypter(uint32_t ssrcNew, const jsonifier::string_base<uint8_t>& keysNew);

		jsonifier::string_view_base<uint8_t> encryptPacket(discord_core_internal::encoder_return_data& audioData);

	  protected:
		jsonifier::string_base<uint8_t> data{};
		jsonifier::string_base<uint8_t> keys{};
		uint32_t timeStamp{};
		uint16_t sequence{};
		uint32_t ssrc{};
	};

	struct DiscordCoreAPI_Dll moving_averager {
		moving_averager(uint64_t collectionCountNew);

		moving_averager operator+=(int64_t value);

		operator float();

	  protected:
		std::deque<int64_t> values{};
		uint64_t collectionCount{};
	};

	/// @brief The various opcodes that could be sent/received by the voice-websocket.
	enum class voice_socket_op_codes {
		identify			= 0,///< Begin a voice websocket connection.
		Select_Protocol		= 1,///< Select the voice protocol.
		Ready_Server		= 2,///< complete the websocket handshake.
		heartbeat			= 3,///< Keep the websocket connection alive.
		Session_Description = 4,///< Describe the session.
		speaking			= 5,///< Indicate which users are speaking.
		Heartbeat_ACK		= 6,///< Sent to acknowledge a received client heartbeat.
		resume				= 7,///< Resume a connection.
		hello				= 8,///< Time to wait between sending heartbeats in milliseconds.
		resumed				= 9,///< Acknowledge a successful session resume.
		Client_Disconnect	= 13,///< A client has disconnected from the voice channel.
	};

	/// @brief For the various connection states of the voice_connection class.
	enum class voice_connection_state : uint8_t {
		Collecting_Init_Data		   = 0,///< collecting initialization data.
		Initializing_WebSocket		   = 1,///< Initializing the websocket.
		Collecting_Hello			   = 2,///< collecting the client hello.
		Sending_Identify			   = 3,///< Sending the identify payload.
		Collecting_Ready			   = 4,///< collecting the client ready.
		Initializing_DatagramSocket	   = 5,///< Initializing the datagram udp SOCKET.
		Sending_Select_Protocol		   = 6,///< Sending the select-protocol payload.
		Collecting_Session_Description = 7///< collecting the session-description payload.
	};

	/// @brief For the various active states of the voice_connection class.
	enum class voice_active_state : int8_t {
		connecting = 0,///< connecting.
		playing	   = 1,///< Playing.
		stopped	   = 2,///< Stopped.
		paused	   = 3,///< Paused.
		exiting	   = 4//< exiting.
	};

	class DiscordCoreAPI_Dll voice_connection_bridge : public discord_core_internal::udp_connection {
	  public:
		friend class voice_connection;

		voice_connection_bridge(unordered_map<uint64_t, unique_ptr<voice_user>>* voiceUsersPtrNew, jsonifier::string_base<uint8_t>& encryptionKeyNew, stream_type streamType,
			const jsonifier::string& baseUrlNew, const uint16_t portNew, snowflake guildIdNew,
			std::coroutine_handle<discord_core_api::co_routine<void, false>::promise_type>* tokenNew);

		DCA_INLINE void applyGainRamp(int64_t sampleCount);

		void parseOutgoingVoiceData();

		void handleAudioBuffer() override;

		void mixAudio();

		void disconnect() override;

	  protected:
		std::coroutine_handle<discord_core_api::co_routine<void, false>::promise_type>* token{};
		unordered_map<uint64_t, unique_ptr<voice_user>>* voiceUsersPtr{};
		jsonifier::string_base<uint8_t> decryptedDataString{};
		std::array<opus_int16, 23040> downSampledVector{};
		jsonifier::string_base<uint8_t> encryptionKey{};
		std::array<opus_int32, 23040> upSampledVector{};
		jsonifier::vector<uint8_t> resampleVector{};
		moving_averager voiceUserCountAverage{ 25 };
		bool doWeKeepAudioData{ false };
		snowflake guildId{};
		float currentGain{};
		float increment{};
		float endGain{};
	};

	class DiscordCoreAPI_Dll voice_udpconnection : public discord_core_internal::udp_connection {
	  public:
		voice_udpconnection() = default;

		voice_udpconnection(const jsonifier::string& baseUrlNew, uint16_t portNew, stream_type streamType, voice_connection* ptrNew,
			std::coroutine_handle<discord_core_api::co_routine<void, false>::promise_type>* stopToken);

		void handleAudioBuffer() override;

		void disconnect() override;

	  protected:
		voice_connection* voiceConnection{};
	};

	/**
	 * \addtogroup voice_connection
	 * @{
	 */
	/// @brief voice_connection class - represents the connection to a given voice channel_data.
	class DiscordCoreAPI_Dll voice_connection : public discord_core_internal::websocket_core {
	  public:
		friend class discord_core_internal::base_socket_agent;
		friend class discord_core_internal::sound_cloud_api;
		friend class discord_core_internal::you_tube_api;
		friend class voice_connection_bridge;
		friend class voice_udpconnection;
		friend class discord_core_client;
		friend class guild_cache_data;
		friend class guild_data;
		friend class song_api;

		/// the constructor.
		/// @param baseShardNew a pointer to the base shard that this voice connection belongs to.
		/// @param doWeQuitNew a pointer to the global signalling boolean for exiting the application.
		voice_connection(discord_core_internal::websocket_client* baseShardNew, std::atomic_bool* doWeQuitNew);

		bool areWeConnected();

		/// @brief Collects the currently connected-to voice channel_data's id.
		/// @return snowflake a snowflake containing the channel_data's id.
		snowflake getChannelId();

		/// @brief Collects some voice data for a given user.
		/// @return voice_user_payload The raw PCM audio data, along with that user's id.
		voice_user_payload extractVoicePayload();

		/// @brief Connects to a currently held voice channel.
		/// @param initData a discord_coer_api::voice_connect_init_dat structure.
		void connect(const voice_connect_init_data& initData);

		~voice_connection() = default;

	  protected:
		std::atomic<voice_connection_state> connectionState{ voice_connection_state::Collecting_Init_Data };
		unbounded_message_block<discord_core_internal::voice_connection_data> voiceConnectionDataBuffer{};
		std::coroutine_handle<discord_core_api::co_routine<void, false>::promise_type> token{};
		nanoseconds intervalCount{ static_cast<int64_t>(960.0l / 48000.0l * 1000000000.0l) };
		std::atomic<voice_active_state> prevActiveState{ voice_active_state::stopped };
		std::atomic<voice_active_state> activeState{ voice_active_state::connecting };
		discord_core_internal::voice_connection_data voiceConnectionData{};
		unordered_map<uint64_t, unique_ptr<voice_user>> voiceUsers{};
		discord_core_internal::opus_encoder_wrapper encoder{};
		discord_core_internal::websocket_client* baseShard{};
		unique_ptr<voice_connection_bridge> streamSocket{};
		jsonifier::string_base<uint8_t> encryptionKey{};
		voice_connect_init_data voiceConnectInitData{};
		jsonifier::string audioEncryptionMode{};
		rtp_packet_encrypter packetEncrypter{};
		int64_t sampleRatePerSecond{ 48000 };
		co_routine<void, false> taskThread{};
		voice_udpconnection udpConnection{};
		int64_t nsPerSecond{ 1000000000 };
		audio_frame_data xferAudioData{};
		jsonifier::string externalIp{};
		std::atomic_bool wasItAFail{};
		std::atomic_bool* doWeQuit{};
		std::atomic_bool doWeSkip{};
		jsonifier::string voiceIp{};
		jsonifier::string baseUrl{};
		int64_t samplesPerPacket{};
		snowflake currentUserId{};
		int64_t msPerPacket{};
		uint32_t audioSSRC{};
		uint16_t port{};

		void parseIncomingVoiceData(jsonifier::string_view_base<uint8_t> rawDataBufferNew);

		bool onMessageReceived(jsonifier::string_view_base<uint8_t> data);

		unbounded_message_block<audio_frame_data>& getAudioBuffer();

		void skipInternal(uint32_t currentRecursionDepth = 0);

		void checkForAndSendHeartBeat(const bool isImmedate);

		void sendSpeakingMessage(const bool isSpeaking);

		co_routine<void, false> runVoice();

		void sendVoiceConnectionData();

		bool areWeCurrentlyPlaying();

		bool skip(bool wasItAFail);

		void connectInternal();

		bool voiceConnect();

		void sendSilence();

		bool pauseToggle();

		void disconnect();

		void reconnect();

		void onClosed();

		bool stop();

		bool play();
	};
	/**@}*/

};