ChatSocket.h

// Copyright 2022 Stream.IO, Inc. All Rights Reserved.
 
#pragma once
 
#include "ChatSocketEvents.h"
#include "Containers/Ticker.h"
#include "CoreMinimal.h"
#include "IChatSocket.h"
#include "Launch/Resources/Version.h"
 
class FTokenManager;
class IWebSocket;
struct FErrorResponseDto;
struct FHealthCheckEvent;
struct FOwnUserDto;
struct FUserObjectDto;
 
#if ENGINE_MAJOR_VERSION == 4 && ENGINE_MINOR_VERSION <= 27
using FTickHandle = FDelegateHandle;
using FTick = FTicker;
#else
using FTickHandle = FTSTicker::FDelegateHandle;
using FTick = FTSTicker;
#endif
 
class FChatSocket final : public IChatSocket
{
public:
    FChatSocket() = delete;
    explicit FChatSocket(const TSharedRef<FTokenManager>&, const FString& ApiKey, const FString& Host, const FUserObjectDto& User);
    virtual ~FChatSocket() override;
 
    virtual void Connect(TFunction<void(const FOwnUserDto&)> Callback) override;
    virtual void Disconnect() override;
    virtual bool IsConnected() const override;
    virtual const FString& GetConnectionId() const override;
 
    virtual FChatSocketEvents& Events() override;
 
private:
    enum class EConnectionState
    {
        NotConnected,
        Connecting,
        Connected,
        Disconnecting,
        Reconnecting,
    };
 
    void CreateUnderlyingWebSocket(bool bRefreshToken);
    void ConnectUnderlyingWebSocket();
    void CloseUnderlyingWebSocket();
 
    // WS event handlers
    void BindEventHandlers();
    void UnbindEventHandlers();
    void HandleWebSocketConnected();
    void HandleWebSocketConnectionError(const FString& Error);
    void HandleWebSocketConnectionClosed(int32 Status, const FString& Reason, bool bWasClean);
    void HandleWebSocketMessage(const FString& JsonString);
    void HandleChatError(const FErrorResponseDto& Error);
 
    void OnHealthCheckEvent(const FHealthCheckEvent&);
    void OnHealthyConnect(const FOwnUserDto&);
 
    void StartMonitoring();
    void StopMonitoring();
    bool KeepAlive(float DeltaTime) const;
    bool CheckNeedToReconnect(float DeltaTime);
    void Reconnect(bool bRefreshToken);
 
    void SetConnectionState(EConnectionState);
 
    FString BuildUrl(bool bRefreshToken) const;
 
    TUniquePtr<FChatSocketEvents> ChatSocketEvents;
    TSharedPtr<FTokenManager> TokenManager;
    FString ApiKey;
    FString Host;
    FString ConnectionRequestJson;
 
    FString ConnectionId;
 
    TSharedPtr<IWebSocket> WebSocket;
 
    DECLARE_DELEGATE_OneParam(FOnConnectDelegate, const FOwnUserDto&);
    FOnConnectDelegate PendingOnConnectCallback;
    EConnectionState ConnectionState = EConnectionState::NotConnected;
    FDelegateHandle HealthCheckEventDelegateHandle;
    FTickHandle KeepAliveTickerHandle;
    FTickHandle ReconnectTickerHandle;
    TOptional<FDateTime> LastEventTime;
    uint32 ReconnectAttempt = 0;
};