@using Sandbox;
@using Sandbox.UI;
@inherits PanelComponent
@implements ILocalPlayerEvent

<root>
	@for (int i = 0; i < 5; i++)
	{
        @if ( ItemsInSlot(i).Count() < 1 )
        {
            continue;
        }

        <InventorySlot Index=@i Inventory=@inventory Hovered=@hovered Active=@active></InventorySlot>
	}
</root>

@code
{
    [Property] public SoundEvent SwitchSound { get; set; }
    [Property] public SoundEvent SelectSound { get; set; }
    [Property] public SoundEvent CancelSound { get; set; }

    PlayerInventory inventory => Player.Local.IsValid() ? Player.Local.Inventory : null;
    Carryable hovered;
    Carryable active;
    Carryable prev;

    protected override int BuildHash() => HashCode.Combine(inventory, hovered, active);

    IEnumerable<Carryable> ItemsInSlot( int slot )
    {
        return inventory.IsValid() ? inventory.Carryables.Where(x => x.InventorySlot == slot) : [];
    }

    void ILocalPlayerEvent.OnPickup( Item weapon )
    {
        StateHasChanged();
    }

    protected override void OnUpdate()
    {
        DoInventoryInput();
	}

	RealTimeSince timeSinceInteraction;

	void DoInventoryInput()
	{
		if (inventory is null)
			return;

		if (GameManager.Current.CurrentGameStage != GameManager.GameStage.Game)
		{
			if (hovered is not null)
			{
				hovered = null;
				active = null;
				prev = null;
			}

			return;
		}

		MoveSlot(-(int)Input.MouseWheel.y);

		if ( Input.Pressed( "Menu" ) && prev.IsValid() )
		{
			var weapon = prev;
            prev = inventory.Current;
			inventory.SwitchWeapon( weapon );
		}

		if (Input.Pressed("SlotNext")) MoveSlot(1);
		if (Input.Pressed("SlotPrev")) MoveSlot(-1);

		if (Input.Pressed("Slot1")) IterateSlot(0);
		if (Input.Pressed("Slot2")) IterateSlot(1);
		if (Input.Pressed("Slot3")) IterateSlot(2);
		if (Input.Pressed("Slot4")) IterateSlot(3);
		if (Input.Pressed("Slot5")) IterateSlot(4);

		if (hovered is null)
			return;

		if (Input.Pressed("Attack1"))
		{
			Input.ReleaseAction("Attack1");
			Input.SetAction("Attack1", false);

			prev = inventory.Current;
			inventory.SwitchWeapon(hovered);
			active = hovered;
			hovered = null;
			Sound.Play(SelectSound);
		}

		if (Input.Pressed("Attack2") || timeSinceInteraction > 2f)
		{
			Input.ReleaseAction("Attack2");
			Input.SetAction("Attack2", false);
			active = null;
			hovered = null;
			Sound.Play(CancelSound);
		}
	}

	public void MoveSlot( int delta )
	{
		if ( delta == 0 )
			return;

		var weapons = inventory.Carryables.Where( x => x.CanSwitch() ).ToList();

		if ( weapons.Count == 0 )
			return;

        var currentHover = hovered ?? active ?? inventory.Current ?? weapons.FirstOrDefault();

		int currentIndex = weapons.IndexOf( currentHover );

		currentIndex += delta;
		currentIndex %= weapons.Count;
		if ( currentIndex < 0 )
			currentIndex = weapons.Count + currentIndex;

		active = null;
		if ( GamePreferences.FastSwitch )
		{
			inventory.SwitchWeapon( weapons[currentIndex] );
		}
		else
		{
			hovered = weapons[currentIndex];
			timeSinceInteraction = 0;
		}

		Sound.Play( SwitchSound );
	}

	public void IterateSlot( int slot )
	{
		var slotWeapons = inventory.Carryables.Where( x => x.InventorySlot == slot ).Where( x => x.CanSwitch() ).OrderBy( x => x.InventoryOrder ).ToList();
		if ( slotWeapons.Count == 0 )
			return;

		// if inventory wasn't open, and current weapon is in a different slot, currentIndex will be -1 (incremented to 0), and first weapon in target slot will be selected
        var currentHover = hovered ?? active ?? inventory.Current ?? slotWeapons.FirstOrDefault();

		int currentIndex = slotWeapons.IndexOf( currentHover );

		currentIndex += 1;
		currentIndex %= slotWeapons.Count;

		if ( currentIndex < 0 )
			currentIndex = slotWeapons.Count + currentIndex;

		active = null;
		if ( GamePreferences.FastSwitch )
		{
			inventory.SwitchWeapon( slotWeapons[currentIndex] );
		}
		else
		{
			hovered = slotWeapons[currentIndex];
			timeSinceInteraction = 0;
		}

		Sound.Play( SwitchSound );
    }
}