using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;
using Opsive.UltimateCharacterController.Traits;

public class ArtificialIntelligence : MonoBehaviour {

    private EnemySpawner enemySpawner;
    private CharacterHealth hp;
    private Animator anim;
    private NavMeshAgent agent;
    private FieldOfView fov;

    [SerializeField]
    private GameObject[] players;
    public List<Transform> playersList = new List<Transform>();
    public Transform closestPlayer;

    public bool seeingPlayer;


    public Waypoints waypoints;
    [SerializeField]
    private Transform nextWaypoint;
    //public bool movingToWaypoint = false;
    //public float distanceToPlayer;

    //private float timeToAttack = 0f;
    //public GameObject impactPoint;

    // Use this for initialization
    void Start () {
        fov = GetComponent<FieldOfView>();
        waypoints = GameObject.Find("Waypoints").GetComponent<Waypoints>();
        enemySpawner = GameObject.Find("WaveSpawner").GetComponent<EnemySpawner>();

        players = GameObject.FindGameObjectsWithTag("Player");

        for (int i = 0; i < players.Length; i++)
        {
            playersList.Add(players[i].transform);
        }

        hp = GetComponent<CharacterHealth>();
        agent = GetComponent<NavMeshAgent>();
        anim = GetComponent<Animator>();

        StartCoroutine("GoToNextWaypoint");
    }

    // Update is called once per frame
    void Update ()
    {
        if(seeingPlayer)
        {
            closestPlayer = fov.GetClosestEnemy(playersList.ToArray());
        }
        else
        {
            closestPlayer = null;
        }

        if (closestPlayer != null)
        {
            ChaseTarget();
        }

        if (hp.HealthValue <= 0)
        {
            RemoveEnemyFromList();
        }
    }

    void ChaseTarget()
    {
        agent.SetDestination(closestPlayer.position);
        float playerDistance = Vector3.Distance(transform.position, closestPlayer.position);

        if(playerDistance > 30f)
        {
            seeingPlayer = false;
            StartCoroutine("GoToNextWaypoint");
        }
    }
    public IEnumerator GoToNextWaypoint()
    {
        anim.SetBool("Following", false);
        anim.SetBool("Run", false);
        yield return new WaitForSeconds(2.5f);
        nextWaypoint = waypoints.waypoints[Random.Range(0, waypoints.waypoints.Length)].transform;
        agent.SetDestination(nextWaypoint.position);

        if (agent.velocity.magnitude > 3f)
        {
            anim.SetBool("Following", true);
            anim.SetBool("Run", true);
            anim.SetBool("Attack", false);
        }
        else
        {
            anim.SetBool("Following", true);
            anim.SetBool("Run", false);
            anim.SetBool("Attack", false);
        }
    }

    private void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.tag == "Waypoint")
        {
            StartCoroutine("GoToNextWaypoint");
        }
    }

    public void RemoveEnemyFromList()
    {
        enemySpawner.SendMessage("RemoveEnemy", this.gameObject);
        Destroy(gameObject);
    }
}