// Fill out your copyright notice in the Description page of Project Settings.


#include "EnemySpawner.h"

// Sets default values
AEnemySpawner::AEnemySpawner()
{
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;

	spawn_delay_s = 5.0f;
}

// Called when the game starts or when spawned
void AEnemySpawner::BeginPlay()
{
	Super::BeginPlay();
	
	/*
	 * Initialize random stream.
	 */
	random.Initialize(FMath::Rand());
}

// Called every frame
void AEnemySpawner::Tick(float delta_s)
{
	Super::Tick(delta_s);

	spawn_wait_s += delta_s;
	if (next_spawn_threshold_s == 0)
	{
		next_spawn_threshold_s = spawn_delay_s + random.GetFraction();
	}
	else if (spawn_wait_s > next_spawn_threshold_s)
	{
		FActorSpawnParameters spawnParameters;
		spawnParameters.SpawnCollisionHandlingOverride = ESpawnActorCollisionHandlingMethod::AlwaysSpawn;
		spawnParameters.Owner = this;
		AAIController* controller = GetWorld()->SpawnActor<AAIController>(
			controller_class,
			GetActorLocation(),
			FRotator(0,0,0),
			spawnParameters
		);

		ABasePawn* enemy = GetWorld()->SpawnActor<ABasePawn>(
			pawn_class,
			GetActorLocation(),
			FRotator(0,0,0),
			spawnParameters
		);
		controller->Possess(enemy);
		spawn_wait_s = 0;
		next_spawn_threshold_s = spawn_delay_s + random.GetFraction();
	}
}