TeaSpeak-Client/native/serverconnection/src/connection/audio/VoiceClient.h

#pragma once

#include <array>
#include <nan.h>
#include <include/NanEventCallback.h>
#include <functional>
#include <pipes/buffer.h>
#include "../../audio/AudioResampler.h"
#include "../../audio/codec/Converter.h"
#include "../../audio/AudioOutput.h"
#include "../../EventLoop.h"

namespace tc::connection {
    class ServerConnection;
    class VoiceConnection;
    class VoiceClient;

    namespace codec {
        enum value {
            MIN = 0,

            SPEEX_NARROWBAND = 0,
            SPEEX_WIDEBAND = 1,
            SPEEX_ULTRA_WIDEBAND = 2,

            CELT_MONO = 3,

            OPUS_VOICE = 4,
            OPUS_MUSIC = 5,

            MAX = 5,
        };

        struct condec_info {
            bool supported;
            std::string name;
            std::function<std::shared_ptr<audio::codec::Converter>(std::string&)> new_converter;
        };

        extern const condec_info info[6];
        inline const condec_info* get_info(value codec) {
            if(codec > value::MAX || codec < value::MIN)
                return nullptr;
            return &info[codec];
        }
    }

    class VoiceClient : private event::EventEntry {
            friend class VoiceConnection;

#ifdef WIN32
            template<typename _Tp, typename _Up>
            friend _NODISCARD std::shared_ptr<_Tp> std::static_pointer_cast(std::shared_ptr<_Up>&& _Other) noexcept;
#else
            template<typename _Tp, typename _Up>
            friend inline std::shared_ptr<_Tp> std::static_pointer_cast(const std::shared_ptr<_Up>& __r) noexcept;
#endif
        public:
            struct state {
                enum value {
                    buffering, /* this state is never active */
                    playing,
                    stopping,
                    stopped
                };
            };
            VoiceClient(const std::shared_ptr<VoiceConnection>& /* connection */, uint16_t /* client id */);
            virtual ~VoiceClient();

            void initialize();

            inline uint16_t client_id() const { return this->client_id_; }

            void initialize_js_object();
            void finalize_js_object();

            v8::Local<v8::Object> js_handle() {
                assert(v8::Isolate::GetCurrent());
                return this->js_handle_.Get(Nan::GetCurrentContext()->GetIsolate());
            }

            inline std::shared_ptr<VoiceClient> ref() { return this->ref_.lock(); }

            void process_packet(uint16_t packet_id, const pipes::buffer_view& /* buffer */, codec::value /* codec */, bool /* head */);
            void execute_tick();

            inline float get_volume() const { return this->volume_; }
            inline void set_volume(float value) { this->volume_ = value; }

            inline state::value state() { return this->state_; }

            void cancel_replay();

            std::function<void()> on_state_changed;

            inline std::shared_ptr<audio::AudioOutputSource> output_stream() { return this->output_source; }
        private:
            struct EncodedBuffer {
                bool head{false};
                bool reset_decoder{false};

                std::chrono::system_clock::time_point receive_timestamp;

                pipes::buffer buffer;
                codec::value codec{codec::MIN};

                uint16_t packet_id{0};
                EncodedBuffer* next{nullptr};
            };

            struct AudioCodec {
                enum struct State {
                    UNINITIALIZED,
                    INITIALIZED_SUCCESSFULLY,
                    INITIALIZED_FAIL,
                    UNSUPPORTED,
                };

                codec::value codec{};

                uint16_t last_packet_id{0xFFFF}; /* the first packet id is 0 so one packet before is 0xFFFF */
                std::chrono::system_clock::time_point last_packet_timestamp;

                inline std::chrono::system_clock::time_point stream_timeout() const {
                    return this->last_packet_timestamp + std::chrono::milliseconds{1000};
                }

                State state{State::UNINITIALIZED};
                std::shared_ptr<audio::codec::Converter> converter{nullptr};
                std::shared_ptr<audio::AudioResampler> resampler{nullptr};

                std::mutex pending_lock{};
                EncodedBuffer* pending_buffers{nullptr};

                /* forces all packets which are within the next chain to replay until (inclusive) force_replay is reached */
                EncodedBuffer* force_replay{nullptr};

                bool process_pending{false};
            };

            std::array<AudioCodec, codec::MAX + 1> codec{};
            void initialize_code(const codec::value& /* codec */);

            /* might be null (if audio hasn't been initialized) */
            std::shared_ptr<audio::AudioOutputSource> output_source;

            std::weak_ptr<VoiceClient> ref_;
            v8::Persistent<v8::Object> js_handle_;

            uint16_t client_id_{0};
            float volume_{1.f};

            std::chrono::system_clock::time_point _last_received_packet;
            state::value state_ = state::stopped;
            inline void set_state(state::value value) {
                if(value == this->state_) {
                    return;
                }

                this->state_ = value;
                if(this->on_state_changed) {
                    this->on_state_changed();
                }
            }

            std::atomic_bool audio_decode_event_dropped{false};
            void event_execute(const std::chrono::system_clock::time_point &point) override;
            void event_execute_dropped(const std::chrono::system_clock::time_point &point) override;

            /* its recommend to call this in correct packet oder */
            std::shared_ptr<audio::SampleBuffer> decode_buffer(const codec::value& /* codec */,const pipes::buffer_view& /* buffer */, bool /* fec */);
    };


    class VoiceClientWrap : public Nan::ObjectWrap {
        public:
            static NAN_MODULE_INIT(Init);
            static NAN_METHOD(NewInstance);
            static inline Nan::Persistent<v8::Function> & constructor() {
                static Nan::Persistent<v8::Function> my_constructor;
                return my_constructor;
            }

            explicit VoiceClientWrap(const std::shared_ptr<VoiceClient>&);
            ~VoiceClientWrap() override;

            void do_wrap(const v8::Local<v8::Object>&);
        private:
            static NAN_METHOD(_get_state);
            static NAN_METHOD(_get_volume);
            static NAN_METHOD(_set_volume);
            static NAN_METHOD(_abort_replay);
            static NAN_METHOD(_get_stream);

            std::weak_ptr<VoiceClient> _handle;

            bool currently_playing_{false};
            Nan::callback_t<> call_state_changed;
            void call_state_changed_();
    };
}