cirnogodot/Scripts/InventoryManager.cs

using Godot;
using System;
using System.Collections.Generic;
using System.Linq;
using Cirno.Scripts;
using Cirno.Scripts.Resources;

public partial class InventoryManager : Node2D
{
	public static InventoryManager Instance { get; private set; }
	public bool RedKeycard { get; set; }

	private Dictionary<string, ItemContainer> _itemsDict = new Dictionary<string, ItemContainer>();

	public List<ItemContainer> Items => _itemsDict.Where(x => x.Value.Count > 0).Select(x => x.Value).ToList();

	[Signal]
	public delegate void ItemAddedEventHandler(LootItem item, int currentAmount);

	[Signal]
	public delegate void ItemRemovedEventHandler(string itemKey, int currentAmount);

	[Signal]
	public delegate void WeaponEquipEventHandler(string itemKey);

	[Signal]
	public delegate void ItemUsedEventHandler(LootItem itemKey, int totalCount);

	[Signal]
	public delegate void TotalAmmoChangedEventHandler(StringName ammoKey, int count);
	
	[Signal]
	public delegate void LoadedAmmoChangedEventHandler(StringName weaponKey, int count);
	
	public override void _Ready()
	{
		Instance = this;
	}

	// Called every frame. 'delta' is the elapsed time since the previous frame.
	public override void _Process(double delta)
	{
	}

	public bool TryGetItem(string key, out ItemContainer item)
	{
		return _itemsDict.TryGetValue(key, out item);
	}

	public bool HasItems(List<string> itemKeys)
	{
		return itemKeys.Aggregate(false, (current, item) => current || GetItemCount(item) > 0);
	}

	public int GetItemCount(string itemKey)
	{
		return _itemsDict.TryGetValue(itemKey, out var itm) ? itm.Count : 0;
	}

	public int RemoveItem(string itemKey, int amount)
	{
		if (!_itemsDict.TryGetValue(itemKey, out var itm)) return 0;

		int removed = Math.Min(itm.Count, amount);

		itm.Count -= amount;

		if (itm.Count < 0)
		{
			itm.Count = 0;
			//_itemsDict.Remove(itemKey);
		}

		EmitSignal(SignalName.ItemRemoved, itemKey, itm.Count);

		if (itm.Item.Item is ItemTypes.Ammo)
		{
			EmitSignal(SignalName.TotalAmmoChanged, itemKey, itm.Count);
		}
		
		return removed;

	}

	public bool AddItem(LootItem item)
	{
		//var item = new LootItem() { Item = type, Amount = amount };

		if (!_itemsDict.TryGetValue(item.ItemKey, out var itm))
		{
			_itemsDict.Add(item.ItemKey, new ItemContainer()
			{
				Item = item,
				Count = item.Amount,
			});
			GD.Print($"Added new ({item.ItemKey}) {item.Item} x{item.Amount}");

			EmitSignal(SignalName.ItemAdded, item, item.Amount);
		}
		else
		{
			if (itm.Count < item.Max)
			{
				itm.Count += item.Amount;
			}
			else
			{
				if (item.PickupIfMaxed)
				{
					itm.Count = item.Max;
				}
				else
				{
					return false;
				}
			}
			EmitSignal(SignalName.ItemAdded, item, itm.Count);
		}

		return true;
	}
	
	public bool UseItem(string itemKey)
	{
		if (!_itemsDict.TryGetValue(itemKey, out var itm)) return false;

		if (itm.Count == 0) return false;
		GD.Print($"Used item in manager {itemKey}");

		switch (itm.Item.Item)
		{
			case ItemTypes.Medkit:
			// Heal
			case ItemTypes.FrogBomb:
			// Use Bomb
			case ItemTypes.Bomb:
			// Bomb
			case ItemTypes.Mine:
			case ItemTypes.Battery:
				EmitSignal(SignalName.ItemUsed, itm.Item, itm.Count);
				break;
			case ItemTypes.Weapon:
				// Equip weapon
				EmitSignal(SignalName.WeaponEquip, itm.Item.ItemKey);
				break;

		}

		return true;
	}

	public void NotifyLoadedAmmoChange(string weaponDataItemKey, int loadedAmmo)
	{
		EmitSignal(SignalName.LoadedAmmoChanged, weaponDataItemKey, loadedAmmo);
	}
}

public class ItemContainer
{
	public LootItem Item { get; set; }
	public int Count { get; set; }
}