MechDefence/Private/MGameMode.cpp

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


#include "MGameMode.h"
#include "Kismet/GameplayStatics.h"
#include "MPlayerController.h"
#include "EngineUtils.h"
#include "GameFramework/Character.h"
#include "MAICharacterBase.h"
#include "GameplayTagsManager.h"
#include "MHealthComponent.h"

AMGameMode::AMGameMode()
{
	PrimaryActorTick.bCanEverTick = true;
	PrimaryActorTick.TickInterval = 1.f;
	WaveCount = 0;
	LevelEndViewTargetBlendTime = 2.f;
	TimeBetweenWaves = 60.f;
	NumEnemiesKilled = 0;
	MaxEnemiesInWave = 10;
	MinEnemiesInWave = 3;
}

void AMGameMode::StartPlay()
{
	Super::StartPlay();
	PrepareForNextWave();
}

void AMGameMode::HandlePlayerKilled()
{
	GameOver();
}

void AMGameMode::HandlePlayerVehicleDestroyed(AActor* Vehicle)
{
	GameOver();
}

void AMGameMode::GameOver()
{
	if(SpectatingViewPointClass)
	{
		TArray<AActor*> ReturnedActors;
		UGameplayStatics::GetAllActorsOfClass(this, SpectatingViewPointClass, ReturnedActors);

		AActor* NewViewTarget = nullptr;
		if(ReturnedActors.Num() > 0)
		{
			NewViewTarget = ReturnedActors[0];
			for(FConstPlayerControllerIterator It = GetWorld()->GetPlayerControllerIterator(); It; It++)
			{
				AMPlayerController* PC = Cast<AMPlayerController>(It->Get());
				if(PC)
				{
					PC->SetViewTargetWithBlend(NewViewTarget, LevelEndViewTargetBlendTime, EViewTargetBlendFunction::VTBlend_Cubic);
					PC->OnGameOver();
					SetWaveState(EWaveState::GameOver);
				}
			}
		}
	}
}

void AMGameMode::LevelCompleted()
{
	if(SpectatingViewPointClass)
	{
		TArray<AActor*> ReturnedActors;
		UGameplayStatics::GetAllActorsOfClass(this, SpectatingViewPointClass, ReturnedActors);

		AActor* NewViewTarget = nullptr;
		if(ReturnedActors.Num() > 0)
		{
			NewViewTarget = ReturnedActors[0];
			for(FConstPlayerControllerIterator It = GetWorld()->GetPlayerControllerIterator(); It; It++)
			{
				AMPlayerController* PC = Cast<AMPlayerController>(It->Get());
				if(PC)
				{
					PC->SetViewTargetWithBlend(NewViewTarget, LevelEndViewTargetBlendTime, EViewTargetBlendFunction::VTBlend_Cubic);
					PC->OnLevelComplete();
					SetWaveState(EWaveState::LevelComplete);
				}
			}
		}
	}
}

void AMGameMode::PrepareForNextWave()
{
	GetWorldTimerManager().SetTimer(TimerHandle_NextWaveStart, this, &AMGameMode::StartWave, TimeBetweenWaves, false);
	SetWaveState(EWaveState::WaitingToStart);
}

void AMGameMode::StartWave()
{
	FTimerManager& TimerManager = GetWorldTimerManager();

	// Cancel Timer if it is still active. This needs to be done if
	// the wave is triggered manually by a console command to make sure wave isn't
	// triggered twice
	if(TimerManager.IsTimerActive(TimerHandle_NextWaveStart))
		TimerManager.ClearTimer(TimerHandle_NextWaveStart);
	
	WaveCount++;
	NumEnemiesToSpawn = FMath::RandRange(MinEnemiesInWave, MaxEnemiesInWave);
	NumEnemiesToSpawn = WaveCount * NumEnemiesToSpawn;
	TimerManager.SetTimer(TimerHandle_EnemySpawn, this, &AMGameMode::SpawnEnemyTimerElapsed, 1.f, true, 0.f);
	SetWaveState(EWaveState::WaveInProgress);
	UE_LOG(LogTemp, Log, TEXT("Enemies to spawn %d"), NumEnemiesToSpawn);
}

void AMGameMode::EndWave()
{
	GetWorldTimerManager().ClearTimer(TimerHandle_EnemySpawn);
	SetWaveState(EWaveState::WaitingToComplete);
}

void AMGameMode::CheckWaveState()
{
	bool IsPreparingForNextWave = GetWorldTimerManager().IsTimerActive(TimerHandle_NextWaveStart);
	if(NumEnemiesToSpawn > 0 || IsPreparingForNextWave)
		return;

	bool IsAnyEnemyAlive = false;
	for(TActorIterator<AMAICharacterBase> It(GetWorld()); It; ++It)
	{
		AMAICharacterBase* EnemyChar = *It;
		if(EnemyChar->HasAllMatchingGameplayTags(SpawnedEnemyTags))
		{
			UMHealthComponent* HealthComponent = Cast<UMHealthComponent>(EnemyChar->GetComponentByClass(UMHealthComponent::StaticClass()));
			if(HealthComponent && HealthComponent->GetHealth() > 0.f)
			{
				IsAnyEnemyAlive = true;
				break;
			}
		}
	}

	if(!IsAnyEnemyAlive)
	{
		SetWaveState(EWaveState::WaveComplete);
		PrepareForNextWave();
	}
}

void AMGameMode::SetWaveState(EWaveState NewWaveState)
{
	WaveStateChanged(NewWaveState, WaveState);
	WaveState = NewWaveState;
}

void AMGameMode::SpawnEnemyTimerElapsed()
{
	SpawnNewEnemy();
	NumEnemiesToSpawn--;

	if(NumEnemiesToSpawn <= 0)
	{
		EndWave();
	}
}

void AMGameMode::Tick(float DeltaSeconds)
{
	Super::Tick(DeltaSeconds);
	CheckWaveState();
}