#include "Core/DescentGameMode.h"
#include "Core/DescentGameClasses.h"
#include "Debug/DescentDebugSubsystem.h"
#include "TheDescent.h"

#include "Engine/World.h"
#include "GameFramework/GameStateBase.h"
#include "GameFramework/HUD.h"
#include "GameFramework/PlayerController.h"
#include "GameFramework/PlayerState.h"
#include "GameFramework/Pawn.h"

namespace
{
	/** The registered class for a slot if it derives from Base, otherwise the engine default already in Current. */
	template <typename TBase>
	TSubclassOf<TBase> ResolveSlot(EDescentGameClassSlot Slot, TSubclassOf<TBase> Current)
	{
		UClass* Registered = FDescentGameClassRegistry::Get().Resolve(Slot);
		if (!Registered)
		{
			return Current;
		}
		if (!Registered->IsChildOf(TBase::StaticClass()))
		{
			UE_LOG(LogDescent, Error, TEXT("GameClasses: %s registered for slot %d does not derive from %s; ignored"),
				*Registered->GetName(), static_cast<int32>(Slot), *TBase::StaticClass()->GetName());
			return Current;
		}
		return Registered;
	}
}

ADescentGameMode::ADescentGameMode()
{
	// Which pawn, controller, HUD, game state and player state the game uses is decided by registration
	// (Core/DescentGameClasses.h), so adding the real character or controller never edits this file.
	DefaultPawnClass = ResolveSlot<APawn>(EDescentGameClassSlot::Pawn, DefaultPawnClass);
	PlayerControllerClass = ResolveSlot<APlayerController>(EDescentGameClassSlot::PlayerController, PlayerControllerClass);
	HUDClass = ResolveSlot<AHUD>(EDescentGameClassSlot::HUD, HUDClass);
	GameStateClass = ResolveSlot<AGameStateBase>(EDescentGameClassSlot::GameState, GameStateClass);
	PlayerStateClass = ResolveSlot<APlayerState>(EDescentGameClassSlot::PlayerState, PlayerStateClass);
}

void ADescentGameMode::StartPlay()
{
	// Super first: the world is marked as begun and existing actors get BeginPlay, so every actor a boot step
	// spawns afterwards is begun at once and the next step can rely on it.
	Super::StartPlay();

	FDescentBootContext Context;
	Context.World = GetWorld();
	Context.GameMode = this;
	const UDescentDebugSubsystem* Debug = UDescentDebugSubsystem::Get(Context.World);
	const FDescentScenarioRunner* Runner = Debug ? Debug->GetRunner() : nullptr;
	Context.bScenarioRunning = Runner && !Runner->IsFinished();

	BootReport = FDescentBootRegistry::Get().Run(Context);
	UE_LOG(LogDescent, Display, TEXT("Boot: %d step(s) ran, %s"), BootReport.Ran.Num(), BootReport.bOk ? TEXT("all ok") : TEXT("AT LEAST ONE FAILED"));
}