// Copyright Epic Games, Inc. All Rights Reserved.

#include "CoreMinimal.h"

#include "Modules/ModuleManager.h"
#include "RHI.h"

#include "ElectraPlayerMisc.h"
#include "IElectraPlayerPluginModule.h"
#include "IElectraPlayerRuntimeModule.h"
#include "ElectraPlayerPlugin.h"
#include "ParameterDictionary.h"
#include "SimpleElectraAudioPlayer.h"
#include "IElectraDecoderResourceDelegateBase.h"
#include "IElectraPlayerDecoderResourceManager.h"

#define LOCTEXT_NAMESPACE "ElectraPlayerPluginModule"

DEFINE_LOG_CATEGORY(LogElectraPlayerPlugin);

DECLARE_CYCLE_STAT(TEXT("Electra AsyncJob"), STAT_ElectraAsyncJob, STATGROUP_Media);

// -----------------------------------------------------------------------------------------------------------------------------------

class FElectraPlayerPluginModule : public IElectraPlayerPluginModule
{
public:
	// IElectraPlayerPluginModule interface

	bool IsInitialized() const override
	{
		return bInitialized;
	}

	TSharedPtr<IMediaPlayer, ESPMode::ThreadSafe> CreatePlayer(IMediaEventSink& EventSink) override
	{
		if (bInitialized)
		{
			TSharedPtr<FElectraPlayerPlugin, ESPMode::ThreadSafe> NewPlayer = MakeShared<FElectraPlayerPlugin, ESPMode::ThreadSafe>();
			check(NewPlayer.IsValid());
			if (NewPlayer->Initialize(EventSink, SendAnalyticMetricsDelegate, SendAnalyticMetricsPerMinuteDelegate, ReportVideoStreamingErrorDelegate, ReportSubtitlesMetricsDelegate))
			{
				return NewPlayer;
			}
		}
		return nullptr;
	}

	void SendAnalyticMetrics(const TSharedPtr<IAnalyticsProviderET>& AnalyticsProvider, const FGuid& PlayerGuid) override
	{
		SendAnalyticMetricsDelegate.Broadcast(AnalyticsProvider, PlayerGuid);
	}

	void SendAnalyticMetricsPerMinute(const TSharedPtr<IAnalyticsProviderET>& AnalyticsProvider) override
	{
		SendAnalyticMetricsPerMinuteDelegate.Broadcast(AnalyticsProvider);
		ISimpleElectraAudioPlayer::SendAnalyticMetrics(AnalyticsProvider);
	}

	void ReportVideoStreamingError(const FGuid& PlayerGuid, const FString& LastError) override
	{
		ReportVideoStreamingErrorDelegate.Broadcast(PlayerGuid, LastError);
	}

	void ReportSubtitlesMetrics(const FGuid& PlayerGuid, const FString& URL, double ResponseTime, const FString& LastError) override
	{
		ReportSubtitlesMetricsDelegate.Broadcast(PlayerGuid, URL, ResponseTime, LastError);
	}

	// Create a suitable video decoder resource delegate for and via the Electra Player runtime to be used with it by external means.
	TSharedPtr<Electra::IVideoDecoderResourceDelegate, ESPMode::ThreadSafe> CreatePlatformVideoDecoderResourceDelegate() override
	{
	#if PLATFORM_WINDOWS
		// This is a bit of a convoluted process due to this whole plugin/adapter/delegate nature.
		class FDummyAdapter : public IElectraPlayerAdapterDelegate
		{
		public:
			FDummyAdapter(TSharedPtr<IElectraPlayerResourceDelegate, ESPMode::ThreadSafe> InPlayerResourceDlg) : PlayerResourceDlg(MoveTemp(InPlayerResourceDlg)) { }
			virtual ~FDummyAdapter() { }
			Electra::FVariantValue QueryOptions(EOptionType Type, const Electra::FVariantValue& Param = Electra::FVariantValue()) override { return Electra::FVariantValue(); }
			void BlobReceived(const TSharedPtr<TArray<uint8>, ESPMode::ThreadSafe>& InBlobData, EBlobResultType InResultType, int32 InResultCode, const Electra::FParamDict* InExtraInfo) override { }
			void SendMediaEvent(EPlayerEvent Event) override { }
			void OnVideoFlush() override { }
			void OnAudioFlush() override { }
			void OnSubtitleFlush() override { }
			void PresentVideoFrame(const FVideoDecoderOutputPtr& InVideoFrame) override { }
			void PresentAudioFrame(const IAudioDecoderOutputPtr& InAudioFrame) override { }
			void PresentSubtitleSample(const ISubtitleDecoderOutputPtr& InSubtitleSample) override { }
			void PresentMetadataSample(const IMetaDataDecoderOutputPtr& InMetadataSample) override { }
			bool CanReceiveVideoSamples(int32 NumFrames) override { return false; }
			bool CanReceiveAudioSamples(int32 NumFrames) override { return false; }
			FString GetVideoAdapterName() const override { return FString(); }
			TSharedPtr<IElectraPlayerResourceDelegate, ESPMode::ThreadSafe> GetResourceDelegate() const override { return PlayerResourceDlg; }
		private:
			TSharedPtr<IElectraPlayerResourceDelegate, ESPMode::ThreadSafe> PlayerResourceDlg;
		};
		return FElectraPlayerDecoderResourceManager::CreatePlatformVideoDecoderResourceDelegate(MakeShareable(new FDummyAdapter(MakeShareable(FElectraPlayerPlugin::PlatformCreateStaticPlayerResourceDelegate()))));
	#else
		return nullptr;
	#endif
	}

public:
	// IModuleInterface interface
	static void GetDynamicRHIInfo(void** OutGDynamicRHI, int64* OutGDynamicRHIType)
	{
		if (OutGDynamicRHI)
		{
			*OutGDynamicRHI = GDynamicRHI ? GDynamicRHI->RHIGetNativeDevice() : nullptr;
		}
		if (OutGDynamicRHIType)
		{
			*OutGDynamicRHIType = (int64)RHIGetInterfaceType();
		}
	}

	class FAsyncConsecutiveTaskSync : public IElectraDecoderResourceDelegateBase::IAsyncConsecutiveTaskSync
	{
	public:
		FAsyncConsecutiveTaskSync() {}
		virtual ~FAsyncConsecutiveTaskSync() {}

		FGraphEventRef	GraphEvent;
	};

	static TSharedPtr<IElectraDecoderResourceDelegateBase::IAsyncConsecutiveTaskSync, ESPMode::ThreadSafe> CreateAsyncConsecutiveTaskSync()
	{
		return MakeShared<FAsyncConsecutiveTaskSync, ESPMode::ThreadSafe>();
	}

	static void RunCodeAsync(TFunction<void()>&& CodeToRun, IElectraDecoderResourceDelegateBase::IAsyncConsecutiveTaskSync* TaskSync)
	{
		FScopeLock Lock(&AsyncJobAccessCS);

		// Execute code async
		// (We assume this to be code copying buffer data around. Hence we allow only ONE at any time to not clog up
		//  the buses even more and delay the copy process further)
		FGraphEventArray Events;
		auto& Event = TaskSync ? static_cast<FAsyncConsecutiveTaskSync*>(TaskSync)->GraphEvent : RunCodeAsyncEvent;
		if (Event.IsValid())
		{
			Events.Add(Event);
		}
		Event = FFunctionGraphTask::CreateAndDispatchWhenReady(MoveTemp(CodeToRun), GET_STATID(STAT_ElectraAsyncJob), &Events);
	}

	void StartupModule() override
	{
		// Check that we have the player module and that it has initialized successfully.
		if (FModuleManager::Get().GetModule("ElectraPlayerRuntime"))
		{
			IElectraPlayerRuntimeModule* ElectraPlayer = &FModuleManager::Get().GetModuleChecked<IElectraPlayerRuntimeModule>("ElectraPlayerRuntime");
			if (!ElectraPlayer || !ElectraPlayer->IsInitialized())
			{
				return;
			}
		}
		else
		{
			return;
		}

		if (!bInitialized)
		{
//WE COULD ALSO CHECK FOR SINGLE THREADING ISSUES HERE!? -- kinda piggy back on this?
			// to detect cooking and other commandlets that run with NullRHI
			if (GDynamicRHI == nullptr || RHIGetInterfaceType() == ERHIInterfaceType::Null)
			{
				UE_LOG(LogElectraPlayerPlugin, Log, TEXT("Dummy Dynamic RHI detected. Electra Player plugin is not initialised."));
				return;
			}

			Electra::FParamDict Params;
			Params.Set(FName(TEXT("GetDeviceTypeCallback")), Electra::FVariantValue((void*)&FElectraPlayerPluginModule::GetDynamicRHIInfo));
			Params.Set(FName(TEXT("CreateAsyncConsecutiveTaskSync")), Electra::FVariantValue((void*)&FElectraPlayerPluginModule::CreateAsyncConsecutiveTaskSync));
			Params.Set(FName(TEXT("RunCodeAsyncCallback")), Electra::FVariantValue((void*)&FElectraPlayerPluginModule::RunCodeAsync));
			if (!FElectraPlayerPlatform::StartupPlatformResources(Params))
			{
				UE_LOG(LogElectraPlayerPlugin, Log, TEXT("Platform resource setup failed! Electra Player plugin is not initialised."));
				return;
			}

			bInitialized = true;
		}
	}

	void ShutdownModule() override
	{
		bInitialized = false;
	}

private:
	bool bInitialized = false;

	FElectraPlayerSendAnalyticMetricsDelegate			SendAnalyticMetricsDelegate;
	FElectraPlayerSendAnalyticMetricsPerMinuteDelegate	SendAnalyticMetricsPerMinuteDelegate;
	FElectraPlayerReportVideoStreamingErrorDelegate		ReportVideoStreamingErrorDelegate;
	FElectraPlayerReportSubtitlesMetricsDelegate		ReportSubtitlesMetricsDelegate;

	static FCriticalSection AsyncJobAccessCS;
	static FGraphEventRef RunCodeAsyncEvent;
};

FCriticalSection FElectraPlayerPluginModule::AsyncJobAccessCS;
FGraphEventRef FElectraPlayerPluginModule::RunCodeAsyncEvent;

IMPLEMENT_MODULE(FElectraPlayerPluginModule, ElectraPlayerPlugin);

#undef LOCTEXT_NAMESPACE