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

#include "PocketLevelInstance.h"
#include "PocketLevel.h"
#include "Engine/LevelStreamingDynamic.h"
#include "Engine/Level.h"
#include "Engine/LocalPlayer.h"
#include "GameFramework/Actor.h"
#include "GameFramework/PlayerController.h"

UPocketLevelInstance::UPocketLevelInstance()
{

}

bool UPocketLevelInstance::Initialize(ULocalPlayer* InLocalPlayer, UPocketLevel* InPocketLevel, FVector InSpawnPoint)
{
	LocalPlayer = InLocalPlayer;
	World = LocalPlayer->GetWorld();
	PocketLevel = InPocketLevel;
	Bounds = FBoxSphereBounds(FSphere(InSpawnPoint, PocketLevel->Bounds.GetAbsMax()));

	if (ensure(StreamingPocketLevel == nullptr))
	{
		if (ensure(!PocketLevel->Level.IsNull()))
		{
			bool bSuccess = false;
			StreamingPocketLevel = ULevelStreamingDynamic::LoadLevelInstanceBySoftObjectPtr(LocalPlayer, PocketLevel->Level, Bounds.Origin, FRotator::ZeroRotator, bSuccess);

			if (ensure(bSuccess && StreamingPocketLevel))
			{
				StreamingPocketLevel->OnLevelLoaded.AddUniqueDynamic(this, &ThisClass::HandlePocketLevelLoaded);
				StreamingPocketLevel->OnLevelShown.AddUniqueDynamic(this, &ThisClass::HandlePocketLevelShown);
			}

			return bSuccess;
		}
	}

	return false;
}

void UPocketLevelInstance::StreamIn()
{
	if (StreamingPocketLevel)
	{
		StreamingPocketLevel->SetShouldBeVisible(true);
		StreamingPocketLevel->SetShouldBeLoaded(true);
	}
}

void UPocketLevelInstance::StreamOut()
{
	if (StreamingPocketLevel)
	{
		StreamingPocketLevel->SetShouldBeVisible(false);
		StreamingPocketLevel->SetShouldBeLoaded(false);
	}
}

FDelegateHandle UPocketLevelInstance::AddReadyCallback(FPocketLevelInstanceEvent::FDelegate Callback)
{
	if (StreamingPocketLevel->GetCurrentState() == ULevelStreaming::ECurrentState::LoadedVisible)
	{
		Callback.ExecuteIfBound(this);
	}
	
	return OnReadyEvent.Add(Callback);
}

void UPocketLevelInstance::RemoveReadyCallback(FDelegateHandle CallbackToRemove)
{
	OnReadyEvent.Remove(CallbackToRemove);
}

void UPocketLevelInstance::BeginDestroy()
{
	Super::BeginDestroy();

	if (StreamingPocketLevel)
	{
		StreamingPocketLevel->bShouldBlockOnUnload = false;
		StreamingPocketLevel->SetShouldBeLoaded(false);
		StreamingPocketLevel->OnLevelShown.RemoveAll(this);
		StreamingPocketLevel->OnLevelLoaded.RemoveAll(this);
		StreamingPocketLevel = nullptr;
	}
}

void UPocketLevelInstance::HandlePocketLevelLoaded()
{
	if (StreamingPocketLevel)
	{
		// Make everything in the level setup so that it's setup on the client, and we treat
		// everything as locally spawned, rather than bExchangedRoles = true, where it's spawned
		// on the client, but the expectation is the server said do it, and the server is going to 
		// be telling us about them later.
		if (ULevel* LoadedLevel = StreamingPocketLevel->GetLoadedLevel())
		{
			LoadedLevel->bClientOnlyVisible = true;

			for (AActor* Actor : LoadedLevel->Actors)
			{
				if (Actor)
				{
					Actor->bExchangedRoles = true;  // HACK, Remove when bClientOnlyVisible is all we need.
				}
			}

			// TODO: Don't put ownership over shared pocket spaces.
			if (LocalPlayer)
			{
				if (APlayerController* PC = LocalPlayer->GetPlayerController(GetWorld()))
				{
					for (AActor* Actor : LoadedLevel->Actors)
					{
						if (Actor)
						{
							Actor->SetOwner(PC);
						}
					}
				}
			}
		}
	}
}

void UPocketLevelInstance::HandlePocketLevelShown()
{
	OnReadyEvent.Broadcast(this);
}