using UnityEngine;
using System.Collections;

public class EnemyMovement : MonoBehaviour
    {
    public float movSpeed, rotSpeed;
    public Transform[] waypoints;
    public int curWaypoint, nextWaypoint;
    Quaternion targetRotation;
    public float y;
    bool choosing, goingStraight;
    public float curveSpeed, curve;
    public float attackRange;
    public float chaseRange;
    Vector3 targetPosition, playerPosition;
    PlayerHealth player;


    NavMeshAgent agent;
    Animator anim;

    public enum EnemyState { idle, patroling, chasing, attacking, escaping, dying };
    public EnemyState eState= 0;
    public int animVariable = 0;
    public float fieldOfView = 90;





    void Start() {
        animVariable = 0;
        player = FindObjectOfType<PlayerHealth>();
        //     goingStraight = true;
        /*    transform.position = waypoints[0].position + Vector3.up * y;
            StartCoroutine(Turning());
            StartCoroutine(CheckPlayerPosition());*/
        agent = GetComponent<NavMeshAgent>();
        anim = GetComponent<Animator>();
        eState = EnemyState.idle;
    }


    void Update()
        {
        Sight(transform, player.transform,fieldOfView, "Player");
        SetAnimVariable();
        switch (eState)
            {
            case EnemyState.idle:
                Idling();
                break;
            case EnemyState.patroling:
                Patroling();
                break;
            case EnemyState.chasing:
                Chasing();
                break;
            case EnemyState.attacking:
                Attacking();
                break;
            case EnemyState.escaping:
                break;
            case EnemyState.dying:
                break;
            default:
                break;
            }


    }

    void SetAnimVariable() {
        switch (eState) {
            case EnemyState.idle:
                animVariable = 0;
                break;
            case EnemyState.chasing:
                lol();
                break;
            case EnemyState.attacking:
                animVariable = 2;
                break;
            default:
                break;
        }
    }

    void lol() {
        animVariable = 1;
    }

    void Idling()
        {
        //animVariable = 0;
       /* transform.position += transform.forward * movSpeed * Time.deltaTime;
        transform.Rotate(0, curve, 0);
        //if (goingStraight)
            curve = (Mathf.PingPong(Time.time, curveSpeed) - curveSpeed / 2);*/
        }

    void Patroling()
        {
        targetPosition = waypoints[nextWaypoint].position;
        transform.position = Vector3.MoveTowards(transform.position, targetPosition + Vector3.up * y, movSpeed * Time.deltaTime);
        targetRotation = Quaternion.LookRotation(targetPosition + Vector3.up * y - transform.position);
        transform.eulerAngles = Vector3.up * Mathf.MoveTowardsAngle(transform.eulerAngles.y, targetRotation.eulerAngles.y, rotSpeed * Time.deltaTime);
        if ((targetPosition + Vector3.up * y - transform.position).magnitude < 1f)
            {
            StartCoroutine(ChooseNextWaypoint());
            }
        }

    void Chasing(){
   //     animVariable = 1;
        LookAtPlayer();
        if (attackRange > PlayerEnemyDistance) {
            eState = EnemyState.attacking;
        }
        else if(PlayerEnemyDistance > chaseRange) {
            eState = EnemyState.idle;
        }

        /*     targetPosition = playerPosition;
             transform.position = Vector3.MoveTowards(transform.position, targetPosition + Vector3.up * y, movSpeed * Time.deltaTime);
             targetRotation = Quaternion.LookRotation(targetPosition + Vector3.up * y - transform.position);
             transform.eulerAngles = Vector3.up * Mathf.MoveTowardsAngle(transform.eulerAngles.y, targetRotation.eulerAngles.y, rotSpeed * Time.deltaTime);
             if ((targetPosition + Vector3.up * y - transform.position).magnitude < 1f)
                 {
                 StartCoroutine(ChooseNextWaypoint());
                 }*/
    }

    void Attacking()
        {
      //  animVariable = 2;
        agent.Stop();
        if (PlayerEnemyDistance > attackRange)
            eState = EnemyState.chasing;

    }

    IEnumerator ChooseNextWaypoint()
        {
        if (!choosing)
            {
            choosing = true;
            yield return new WaitForSeconds(1f);
            nextWaypoint++;
            if (nextWaypoint == waypoints.Length) nextWaypoint = 0;
            choosing = false;
            StopCoroutine(ChooseNextWaypoint());
            }
        }



    IEnumerator Turning()
        {
        while (eState == EnemyState.idle)
            {
            float orCurve = curve;
            goingStraight = false;
            curve = (Random.Range(0, 6) > 3) ? 3f : -3f;
            yield return new WaitForSeconds(Random.Range(.1f, 1f));
            curve = orCurve;
            yield return new WaitForSeconds(Random.Range(1f, 5f));
            goingStraight = true;
            }

        }

    IEnumerator CheckPlayerPosition()
        {
        if (eState == EnemyState.chasing)
            {
            // playerPosition = player.transform.position;
            yield return new WaitForSeconds(2f);
            }
        }

    void Sight(Transform me, Transform target, float angleRange, string targetTag) {
        Vector3 direction = target.position - me.position;
        float angle = Mathf.Atan2(direction.z, direction.x) * Mathf.Rad2Deg;
        if (IsTargerWithinAngleRange(me, angle, angleRange)) {
            Ray ray = new Ray(me.GetChild(0).position, direction);
            RaycastHit hit;
            if (Physics.Raycast(ray, out hit)) {
                if (hit.collider.gameObject.tag == "Player") {
                    eState = EnemyState.chasing;
                }

            }
        }
    }


    void LookAtPlayer() {
        Vector3 v = player.transform.position - transform.position;
        float angle = -Mathf.Rad2Deg * Mathf.Atan2(v.z, v.x);
        transform.eulerAngles = new Vector3(0, angle, 0);
    }

    float PlayerEnemyDistance {
        get {
            return Vector3.Magnitude(player.transform.position - transform.position);
        }
    }

    bool IsTargerWithinAngleRange(Transform me, float angle, float angleField) {
        return SomeFunctions.Is_C_Between_A_and_B(angle, -me.eulerAngles.y - angleField / 2, -me.eulerAngles.y + angleField / 2);
    }

}