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

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/GameModeBase.h"
#include "lpx-enginewrapper.hpp"
#include "StringDecoder.h"
#include "TangibleManager.h"
#include "AssetLookup.h"
#include "LuprexSockets.h"
#include "TriggeredTask.h"
#include "BlueprintErrors.h"
#include "Blueprint/UserWidget.h"
#include "Widgets/CommonActivatableWidgetContainer.h"
#include "CommonActivatableWidget.h"
#include "LuprexGameModeBase.generated.h"

class UlxLuaValues;

UCLASS(BlueprintType)
class INTEGRATION_API UlxLuaWidget : public UCommonActivatableWidget
{
	GENERATED_BODY()

public:
	UFUNCTION(BlueprintImplementableEvent, BlueprintCallable, Category = "Luprex|Miscellaneous")
	void ReadLuaConfiguration(UlxLuaValues *Config);
};

/**
 * 
 */
UCLASS(BlueprintType)
class INTEGRATION_API ALuprexGameModeBase : public AGameModeBase, public FRunnable
{
	GENERATED_BODY()
	
public:
	ALuprexGameModeBase();
	~ALuprexGameModeBase();
	virtual void BeginPlay() override;
	virtual void EndPlay(const EEndPlayReason::Type EndPlayReason);

	// Delete all the state created in BeginPlay.  That
	// includes: the Luprex engine, the thread, and the socket state.
	void ResetToInitialState();

	// Initialize the Luprex DLL, and do other global initialization.
	void InitializeGlobalState();
	
	// Send prints into Unreal, for display on the virtual console.
	UFUNCTION(BlueprintImplementableEvent, Category = "Luprex|Miscellaneous")
	void ConsoleAddOutput(const FString& text);

	UFUNCTION(BlueprintCallable, Category = "Luprex|Miscellaneous")
	int64 GetPlayerId();

	UFUNCTION(BlueprintCallable, meta = (WorldContext = "Context"), Category = "Luprex|Look-At Detection")
    static void SetLookAt(const UObject *Context, const FHitResult &HitResult);
	
	UFUNCTION(BlueprintPure, meta = (WorldContext = "Context"),Category = "Luprex|Look-At Detection")
	static const FHitResult &GetLookAt(const UObject *Context) { return FromContext(Context)->CurrentLookAt; }

	UFUNCTION(BlueprintPure, meta = (WorldContext = "Context"),Category = "Luprex|Look-At Detection")
	static const AActor *GetLookAtActor(const UObject *Context) { return FromContext(Context)->CurrentLookAt.GetActor(); }
	
	UFUNCTION(BlueprintPure, meta = (WorldContext = "Context"),Category = "Luprex|Look-At Detection")
	static FVector2D GetLookAtPixel(const UObject *Context);

	UFUNCTION(BlueprintCallable, meta = (WorldContext = "Context"), Category = "Luprex|Look-At Detection")
	static void SetLookAtChanged(const UObject* Context);
	
	//
	// Look-At Related Events
	//

	UFUNCTION(BlueprintImplementableEvent, Category = "Luprex|Look-At Detection")
	void CalculateLookAt(APlayerController *PlayerController);

	UFUNCTION(BlueprintImplementableEvent, Category = "Luprex|Look-At Detection")
	void LookAtChanged();


	// Assemble a lua call. Note that this is the lowest-level interface.
	// These functions are wrapped by the functions in UlxLuaCallLibrary,
	// and those in turn are wrapped by the K2Node "LuaInvoke" and "LuaProbe".
	//
	// At this level, the process of calling Lua is:
	//
	// * Use LuaCallBegin
	// * Get the lua call buffer:
	//	  - add a class name
	//    - add a function name
	//    - add function parameters
	// * Use LuaCallEnd.
	// * Process any return values in the UlxLuaValues array.
	//
	FlxStreamBuffer &LuaCallBegin() { LuaCallBuffer.clear(); return LuaCallBuffer; }
	FlxStreamBuffer &LuaCallGetBuffer() { return LuaCallBuffer; }
	UlxLuaValues *LuaCallEnd(AccessKind kind);
	UlxLuaValues *LuaCallEnd(AccessKind kind, int64 place_id);
	UlxLuaValues *LuaCallEnd(AccessKind kind, AActor *place);
	void LuaCallClear() { LuaCallBuffer.clear(); }
	
	// Validate some lua code.  Returns an error message.
	// If the lua is well-formed, the error message is the
	// empty string.  The syntax of the code is checked using
	// an otherwise empty lua interpreter, so this is purely
	// a syntax check.
	//
	FString ValidateLuaExpr(const FString &Code);

	// Invoke some lua code.
	//
	void InvokeLuaExpr(const FString &Code);

	// Get the Asset Lookup table.
	const UlxAssetLookup *GetAssetLookup() const { return AssetLookup; }

	// Transfer console output from the Luprex engine to unreal.
	void UpdateConsoleOutput();

	// Update the tangibles according to what Luprex tells us.
	// This also includes calling 'AnimationQueueChanged' on all
	// tangibles that have been changed.
	void UpdateTangibles();

	// Look for a tangible whose ID is equal to the current actor ID.
	// Tell the player controller to possess that tangible.
	void UpdatePossessedTangible();

	// Call 'CalculateLookAt', but only if everything is valid.
	// It is up to the blueprint code to actually determine what we're looking at.
	void UpdateLookAt();

	// Pre-tick and post-tick functions.
	void OnWorldPreActorTick(UWorld* InWorld, ELevelTick InLevelTick, float InDeltaSeconds);
	void OnWorldPostActorTick(UWorld* InWorld, ELevelTick InLevelTick, float InDeltaSeconds);

	// The run function is called by a background thread
	// to update luprex sockets and update luprex itself.
	virtual uint32 Run() override;

	// Get the current Luprex Game Mode Base, given a Context object.
	static ALuprexGameModeBase *FromContext(const UObject *Context);
	
	// Asset Lookup by Name.
	UPROPERTY()
	UlxAssetLookup *AssetLookup;

	UPROPERTY()
	UlxTangibleManager *TangibleManager;

	// The actor that the player is looking at, current frame.
	UPROPERTY()
	FHitResult CurrentLookAt;

	bool MustCallLookAtChanged;

	// The sensitivity level at which a log message triggers a debugger breakpoint.
	UPROPERTY(EditAnywhere, Category="Debugging Tools")
	ElxLogVerbosity BreakToDebuggerLogVerbosity;

	// The Luprex EngineWrapper, with a Mutex to protect it.
	// To access it, construct a FlxLockedWrapper.
	FlxLockableWrapper LockableWrapper;

	// The Lua Call Assembly Buffer.
	FlxStreamBuffer LuaCallBuffer;

	// This utility runs the luprex update and socket update in a thread.
	FTriggeredTask LuprexUpdateTask;
	
	// Luprex socket system.  Aside from construction, only touched by Luprex thread.
	TUniquePtr<FlxSockets> Sockets;

	// True if 'BeginPlay' has been successfully completed.
	bool Playing;

	// This is always true unless you use the debugger to set it to false.
	bool TickEnabled;

	// Current Player ID
	int64 PlayerId;

	// Amount of elapsed time since BeginPlay.
	float EngineSeconds;

	// When do we next rotate the cube.
	float NextRotateCube;

	// These allow us to pre-tick and post-tick.
	FDelegateHandle OnWorldPreActorTickHandle;
	FDelegateHandle OnWorldPostActorTickHandle;

	// The device that implements BreakToDebuggerLogVerbosity, above.
	TUniquePtr<FlxDebugBlueprintErrorsOutputDevice> BreakToDebuggerLogVerbosityDevice;
};