using System.Collections;
using SWS;
using UnityEngine;
using UnityEngine.AI;

public class Enemy : MonoBehaviour 
{
	[SerializeField] private splineMove spline;
	[SerializeField] private NavMeshAgent agent;
	[SerializeField] private Detector detector;
	[SerializeField] private Animator anim;
	[SerializeField] private float jumpAttackDistance;
	[SerializeField] private float speed = 5;
	[SerializeField] private float attackDelay = .5f;
	
	public bool IsAngry { get; private set; }
	
    private Transform _playerTransform;
	private NavMeshPath _navigationPath;
	private WaitForSeconds _delay;
	
	private static readonly int State = Animator.StringToHash("State");
	
	private GameManager _manager;
	private GameManager Manager
	{
		get
		{
			if (_manager == null) _manager = GameManager.Instance;
			return _manager;
		}
	}

	private void Start()
	{
		detector.OnDetectPlayer += DetectPlayer;
        _navigationPath = new NavMeshPath();
        _delay = new WaitForSeconds(attackDelay);
        IsAngry = false;
    }
	
	private IEnumerator StartChase()
	{
		while (IsAngry)
		{
			if (_playerTransform != null)
			{
				var playerPosition = _playerTransform.position;
	        
				agent.CalculatePath(playerPosition, _navigationPath);
				agent.destination = playerPosition;

				// Extract to call only once
				if (anim.GetInteger(State) != 2)
				{
					anim.SetInteger(State, 2);
					agent.speed = speed;
					agent.stoppingDistance = jumpAttackDistance;
				}

				if (Vector3.Distance(transform.position, playerPosition) < agent.stoppingDistance + 0.1f)
				{
					agent.isStopped = true;
					transform.LookAt(_playerTransform.position);
					anim.SetInteger(State, 3);
					detector.HideDetector();
					StartCoroutine(Attack());
					yield break;
				}
			}
			
			if (_playerTransform == null)
			{
				IsAngry = false;
				anim.SetInteger(State, 3); // Wrong state
				// Reset detector as well.
			}
			
			yield return null;
		}
	}
	
	// Integrate into chase coroutine.
	private IEnumerator Attack() 
	{
        Manager.GameOver(_playerTransform);
        yield return _delay;
		if (Vector3.Distance(transform.position, _playerTransform.position) > agent.stoppingDistance + 0.1f) 
		{
			agent.isStopped = false;
			anim.SetInteger(State, 2);
		}
	}

	private void DetectPlayer(Transform inPlayerTransform)
	{
		Manager.SoundWhistle();
		_playerTransform = inPlayerTransform;
		IsAngry = true;
		// TODO: Notify player controller instead
		_playerTransform.GetComponent<PlayerController>().ActivateChaseState(); // (not the best implementation.)
		agent.enabled = true;
		spline.Pause();
		StartCoroutine(StartChase());
	}
	
}