using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;
using System;

public class Enemy : MonoBehaviour
{
    [SerializeField]
    private GameObject bullet;

    [SerializeField]
    private Transform gun;

    [SerializeField]
    private float shootPower = 20000f;

    [SerializeField]
    private float targetEnemyMaxDistance = 50f;

    [SerializeField]
    private float shootDelay = 2.5f;

    [SerializeField]
    private int bulletDamage = 2;

    [SerializeField]
    private Transform[] wayPoints;

    private Transform target;

    private NavMeshAgent agent;

    private Transform player;

    private bool seeTarget;

    private Vector3 targetDirection;

    private int currentWayPoint = 0;


    public Transform Target

    {
        get
        {
            return target;
        }

        set
        {
            target = value;
        }
    }

    void Awake()
    {
        agent = GetComponent<NavMeshAgent>();

    }

    private void Start()
    {
        InvokeRepeating("Shoot", 0.0f, shootDelay);
    }

    // Update is called once per frame
    void Update()
    {
        /* if(target!= null)
         {
             agent.SetDestination(target.position);
             CheckTargetVisibility();

         }
         */
        GoByWayPoints();
        GoToPlayer();


    }

    private void Shoot()
    {
        if (seeTarget)
        {
            GameObject newBullet = Instantiate(bullet, gun.position, gun.rotation);

            if (targetDirection != null)
            {
                targetDirection.Normalize();
                newBullet.GetComponent<Rigidbody>().AddForce(targetDirection * shootPower);
            }


            newBullet.GetComponent<Damager>().Damage = bulletDamage;
            Destroy(newBullet, 5);
        }
    }

    private void CheckTargetVisibility()
    {
        RaycastHit hit;
        targetDirection = target.position - gun.position;
        Ray ray = new Ray(gun.position, targetDirection);

        if (Physics.Raycast(ray, out hit) && hit.transform == target)
        {
            seeTarget = true;
            return;
        }


        seeTarget = false;
    }

    private void GoByWayPoints()
    {

        float minDistance = 50f;

        if (wayPoints.Length > 0 )
        {
            try
            {
                 player = GameObject.FindGameObjectWithTag("Player").transform;
            }
            catch(NullReferenceException e)
            {

                return;
            }

            if (player != null )
            {
                if((player.position - transform.position).magnitude < targetEnemyMaxDistance)
                {
                    target = player;
                    agent.SetDestination(target.position);
                    CheckTargetVisibility();
                    Debug.Log("GoToPlayer()");
                    target = null;

                }

                else
                {
                    if (target == null || (transform.position - target.position).magnitude <= minDistance)
                    {
                        seeTarget = false;
                        target = wayPoints[currentWayPoint];
                        agent.SetDestination(target.position);
                        currentWayPoint++;
                        Debug.Log(currentWayPoint);
                        if (currentWayPoint >= wayPoints.Length)
                            currentWayPoint = 0;
                        Debug.Log("GoWayPoints()");
                    }

                }

            }
        }
    }

    private void GoToPlayer()
    {
        try
        {
           player = GameObject.FindGameObjectWithTag("Player").transform;
        }
        catch (NullReferenceException e)
        {
            Debug.Log("null");
            return;
        }
        if (target != null && target == player)
          {
            agent.SetDestination(target.position);
            CheckTargetVisibility();
            Debug.Log("GoToPlayer()");
          }


    }


    }