using UnityEngine;
using UnityEngine.Events;
using Arena.Characters;

namespace Arena.Interactions
{
	/// <summary>
	/// Zone that raises OnPlayer when the player enters it, or when the player interacts inside it.
	/// It never acts on the player itself: the actions are set up in the Inspector.
	/// </summary>
	[RequireComponent(typeof(Collider))]
	public class PlayerEvent : MonoBehaviour
	{
		public enum Trigger
		{
			OnPlayerEnter,
			OnPlayerInteract
		}

		[System.Serializable]
		public class Settings
		{
			[Tooltip("OnPlayerEnter: as soon as the player enters. OnPlayerInteract: when the player interacts inside the zone.")]
			public Trigger Trigger;
		}

		#region Fields

		[SerializeField] private Settings _settings;

		[Tooltip("Actions raised for the player: heal, ammo, sound, hide this object...")]
		[SerializeField] private UnityEvent _onPlayer;

		private bool _isListening;

		#endregion

		#region Unity Lifecycle

		private void OnDisable()
		{
			// The object can be hidden while the player is inside
			StopListening();
		}

		private void OnTriggerEnter(Collider other)
		{
			if (!IsPlayer(other))
				return;

			if (_settings.Trigger == Trigger.OnPlayerEnter)
				_onPlayer.Invoke();
			else
				StartListening();
		}

		private void OnTriggerExit(Collider other)
		{
			if (IsPlayer(other))
				StopListening();
		}

		#endregion

		#region Private Methods

		private bool IsPlayer(Collider other)
		{
			return Player.Instance != null && other.gameObject == Player.Instance.gameObject;
		}

		private void StartListening()
		{
			Player.Instance.OnInteract += HandleInteract;
			_isListening = true;
		}

		private void StopListening()
		{
			if (!_isListening)
				return;

			if (Player.Instance != null)
				Player.Instance.OnInteract -= HandleInteract;

			_isListening = false;
		}

		private void HandleInteract()
		{
			_onPlayer.Invoke();
		}

		#endregion
	}
}