using System.Collections.Generic;
using Cirno.Scripts.Interactables;
using Godot;

namespace Cirno.Scripts.Components.FSM._3DPlayer;

public partial class SelectorController : Node
{
    [Signal]
    public delegate void ShowSelectorEventHandler();

    [Signal]
    public delegate void HideSelectorEventHandler();

    [Signal]
    public delegate void ChangePositionEventHandler(Vector2 position);

    [Signal]
    public delegate void ChangeParent3DEventHandler(Node3D node);

    private bool _canSelect = true;

    public bool CanSelect => _canSelect;

    private bool _autoSelect = false;

    private double _cooldownTimer = 0f;

    private Interactable _lastInteractable;

    private List<IInteractable> _interactables = [];

    private int _selectedInteractable;

    private int SelectedInteractableIndex
    {
        get => _selectedInteractable;
        set
        {
            if (value >= _interactables.Count)
            {
                _selectedInteractable = 0;
                return;
            }

            if (value < 0)
            {
                _selectedInteractable = _interactables.Count - 1;
                // if (_selectedInteractable < 0)
                // {
                //     _selectedInteractable = 0;
                // }
                return;
            }

            _selectedInteractable = value;
        }
    }

    public IInteractable GetSelectedInteractable()
    {
        return SelectedInteractableIndex < 0
            ? null
            : _interactables.Count > 0
                ? SelectedInteractableIndex >= _interactables.Count
                    ? _interactables[^1]
                    : _interactables[SelectedInteractableIndex]
                : null;
    }

    public IInteractable SelectedInteractable
    {
        // The problem here is that if it's deselected the index is -1
        // get =>
        //     SelectedInteractableIndex < 0
        //         ? null
        //         : _interactables.Count > 0
        //             ? SelectedInteractableIndex >= _interactables.Count
        //                 ? _interactables[^1]
        //                 : _interactables[SelectedInteractableIndex]
        //             : null;
        set
        {
            // Passing null deselects the interactable
            if (value == null)
            {
                _selectedInteractable = -1;
                NotifyChanged(null);
                return;
            }

            // If it's already in the list, set the current one to it, otherwise add it
            if (!_interactables.Contains(value))
            {
                AddInteractable(value);
            }

            SelectedInteractableIndex = _interactables.IndexOf(value);
            NotifyChanged(value);
        }
    }

    public void SelectNext()
    {
        SelectedInteractableIndex += 1;
        // _selectedInteractable += 1;
        // if (_selectedInteractable >= _interactables.Count)
        // {
        //     _selectedInteractable = 0;
        // }

        if (_interactables.Count <= 0)
        {
            SelectedInteractable = null;
            //SelectedInteractableIndex = -1;
        }

        // No need to set it because the selection is already handled when reading
        // else
        // {
        //     SelectedInteractable = _interactables[_selectedInteractable];
        // }

        UpdatePosition();
    }

    public void SelectNextDelayed()
    {
        if (!_canSelect)
        {
            _autoSelect = true;
        }
        else
        {
            SelectNext();
        }
        //CallDeferred(MethodName.SelectNext);
    }

    public void AddInteractable(IInteractable interactable)
    {
        if (!_interactables.Contains(interactable))
        {
            _interactables.Add(interactable);


            // if (_interactables.Count == 1)
            // {
            //     SelectedInteractable = interactable;
            //     //_selectedInteractable = 0;
            // }
        }

        // Always set the current one to the newest
        SelectedInteractable = interactable;

        UpdatePosition();
    }

    public void RemoveInteractable(IInteractable interactable)
    {
        _interactables.Remove(interactable);

        UpdatePosition();
    }

    public void Deselect()
    {
        SelectedInteractable = null;
        //SelectedInteractableIndex = -1;
        EmitSignalHideSelector();
    }

    public void DeselectWithCooldown()
    {
        Deselect();
        _canSelect = false;
        _cooldownTimer = 0d;
    }

    public void UpdatePosition()
    {
        var selected = GetSelectedInteractable();
        if (selected != null)
        {
            EmitSignalChangePosition(selected.GetScreenPosition());
            //EmitSignalChangePosition3D();
            EmitSignalChangeParent3D(selected as Node3D);
            EmitSignalShowSelector();
        }
        else
        {
            EmitSignalHideSelector();
        }
    }

    private void NotifyChanged(IInteractable interactable)
    {
        //EmitSignal(nameof(SelectedItemInteractableChanged), interactable);
    }

    public void Hide()
    {
        EmitSignalHideSelector();
    }

    public void PhysicsProcess(double delta)
    {
        if (_canSelect is true) return;
        _cooldownTimer += delta;

        if (!(_cooldownTimer >= 0.2d)) return;
        _canSelect = true;
        _cooldownTimer = 0;
        if (!_autoSelect) return;
        _autoSelect = false;
        SelectNext();
        //if (SelectedInteractable is null) return;
        //EmitSignalChangePosition(SelectedInteractable.GetScreenPosition());
    }
}