#pragma once

#include "CoreMinimal.h"
#include "Core/DescentHandle.h"
#include "Core/DescentWorldSubsystem.h"
#include "DescentCraft.generated.h"

/** Fabricator recipes (M7, DESIGN_UE.md section 6.7) as plain data. */
namespace Descent::Craft
{
	enum ERes : int32 { Ingot = 0, Wafer, Lattice, Ferrite, Cobalt, NumRes };
	THEDESCENT_API FString ResName(int32 Res);

	struct FRecipe
	{
		FName Id, Cat;
		FString Name, Desc;
		int32 Cost[NumRes] = { 0, 0, 0, 0, 0 };
		FName Needs;               // another recipe that must be built first
		bool bRepeatable = false;
		bool bLocked = false;      // the weapon row
		FName Kit;                 // BUILD category: the kit it gives
		FName Item;                // the inventory item it gives ...
		int32 ItemCount = 0;       // ... and how many
	};
	THEDESCENT_API const TArray<FRecipe>& Recipes();
	THEDESCENT_API const FRecipe* Find(FName Id);
	/** Takes exactly the cost from Have, or nothing (returns false) when something is short. */
	THEDESCENT_API bool Pay(const FRecipe& R, int32 Have[NumRes]);
	THEDESCENT_API FString ItemName(FName Item);
}

struct FDescentItemStack
{
	FName Item;
	int32 Count = 0;
};

/** Crafting, upgrades, the suit inventory and the hotbar (V8, V11). Fills the fabricator, PDA inventory and storage windows. */
UCLASS()
class THEDESCENT_API UDescentCraftSubsystem : public UDescentWorldSubsystem
{
	GENERATED_BODY()

public:
	static UDescentCraftSubsystem* Get(const UWorld* World);
	virtual void OnWorldBeginPlay(UWorld& InWorld) override;
	virtual void Deinitialize() override;

	// ---- crafting ----
	bool CanCraft(FName Id, FString* OutWhyNot = nullptr) const;
	bool Craft(FName Id, FString* OutWhyNot = nullptr);
	bool IsBuilding() const { return BuildTimer > 0.0; }
	bool Has(FName Recipe) const { return Done.Contains(Recipe); }
	/** Applies one finished recipe to the game (Tender upgrades, tanks, kits, items). */
	void ApplyOne(FName Id, bool bFromLoad = false);
	TSet<FName> Done;
	int32 Crafted = 0;

	// ---- the suit inventory (24 cells) and the hotbar (9 slots) ----
	TArray<FDescentItemStack> Slots;
	int32 Count(FName Item) const;
	bool AddItem(FName Item, int32 N);
	bool RemoveItem(FName Item, int32 N);
	FName Hotbar[9];
	int32 HotbarSelected = 0;
	int32 PdaSelected = -1;
	bool AssignHotbar(int32 Slot1to9, FName Item);
	void SelectHotbar(int32 Slot1to9) { HotbarSelected = FMath::Clamp(Slot1to9 - 1, 0, 8); }
	FName SelectedItem() const { return Hotbar[HotbarSelected]; }
	void ResetAll();

	void OpenFabricator();
	void FillWindows();

private:
	void Step(double Dt);
	void GatherHave(int32 Have[Descent::Craft::NumRes]) const;
	double BuildTimer = 0.0, WindowTimer = 0.0;
	FDescentHandle StepHandle;
};