// Copyright Patrick Werner 2019

#pragma once

#include "CoreMinimal.h"
#include "Components/ActorComponent.h"
#include "PhysicsEngine/PhysicsHandleComponent.h"
#include "Components/InputComponent.h"
#include "Grabber.generated.h"

struct PlayerViewportTransform
{
	FVector Location;
	FRotator Rotation;
};

UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )
class UE4CPP_SECTION_03_API UGrabber : public UActorComponent
{
	GENERATED_BODY()

public:	
	// Sets default values for this component's properties
	UGrabber();

protected:
	// Called when the game starts
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) override;

private:
	// how far ahead of the player can we reach in cm
	float Reach = 150.f;
		
	UPhysicsHandleComponent* PhysicsHandle = nullptr;
	UInputComponent* InputComponent = nullptr;

	// gets relevant player viewport transform data
	PlayerViewportTransform GetPlayerViewportTransformData() const;

	// returns current start of reach line
	FVector GetLineTraceStart() const;

	// returns current end of reach line
	FVector GetLineTraceEnd() const;

	// ray cast and grab what's in reach
	void Grab();

	// called when greb is released
	void Release();

	// find PhysicsHandle
	void FindPhysicsHandleComponent();

	// find InputComponent
	void FindInputComponent();

	// bind user inputs to methods
	void BindInputs() const;

	// Return hit for first physics body in reach
	FHitResult GetFirstPhysicsBodyInReach() const;
};