using System;
using UnityEngine;

namespace Lean.Common
{
	/// <summary>
	///     This is the base class for all components that need to implement some kind of special logic when selected. You can
	///     do this manually without this class, but this makes it much easier.
	///     NOTE: This component will register and unregister the associated LeanSelectable in OnEnable and OnDisable.
	/// </summary>
	public abstract class LeanSelectableBehaviour : MonoBehaviour
    {
        [NonSerialized] private LeanSelectable selectable;

        /// <summary>This tells you which LeanSelectable is currently associated with this component.</summary>
        public LeanSelectable Selectable
        {
            get
            {
                if (selectable == null) Register();

                return selectable;
            }
        }

        protected virtual void Start()
        {
            if (selectable == null) Register();
        }

        protected virtual void OnEnable()
        {
            Register();
        }

        protected virtual void OnDisable()
        {
            Unregister();
        }

        /// <summary>
        ///     This method allows you to manually register the LeanSelectable this component is associated with. This is
        ///     useful if you're manually spawning and attaching children from code.
        /// </summary>
        [ContextMenu("Register")]
        public void Register()
        {
            Register(GetComponentInParent<LeanSelectable>());
        }

        /// <summary>This method allows you to manually register the LeanSelectable this component is associated with.</summary>
        public void Register(LeanSelectable newSelectable)
        {
            if (newSelectable != selectable)
            {
                // Unregister existing
                Unregister();

                // Register a new one?
                if (newSelectable != null)
                {
                    selectable = newSelectable;

                    selectable.OnSelected.AddListener(OnSelected);
                    selectable.OnDeselected.AddListener(OnDeselected);
                }
            }
        }

        /// <summary>
        ///     This method allows you to manually register the LeanSelectable this component is associated with. This is
        ///     useful if you're changing the associated LeanSelectable.
        /// </summary>
        [ContextMenu("Unregister")]
        public void Unregister()
        {
            if (selectable != null)
            {
                selectable.OnSelected.RemoveListener(OnSelected);
                selectable.OnDeselected.RemoveListener(OnDeselected);

                selectable = null;
            }
        }

        /// <summary>Called when selection begins.</summary>
        protected virtual void OnSelected(LeanSelect select)
        {
        }

        /// <summary>Called when this is deselected.</summary>
        protected virtual void OnDeselected(LeanSelect select)
        {
        }
    }
}