using UnityEngine;
using System.Collections;

public class EnemyMovementController : MonoBehaviour {

    public float enemySpeed;

    Animator enemyAnimator;

    // Direction enemy is facing
    public GameObject enemyGraphic;
    bool canFlip = true;
    bool facingRight = false;
    float flipTime = 5f;
    float nextFlipChance = 0f;

    // When enemy is attacking
    public float chargeTime;
    float startChargeTime;
    bool charging;
    Rigidbody2D enemyRB;

    // Use this for initialization
    void Start() {
        enemyAnimator = GetComponentInChildren<Animator>();
        enemyRB = GetComponent<Rigidbody2D>();
    }

    // Update is called once per frame
    void Update() {
        if (Time.time > nextFlipChance)
        {
            if (Random.Range(0, 10) >= 5) flipFacing();
            nextFlipChance = Time.time + flipTime;
        }
    }

    void OnTriggerEnter2D(Collider2D other)
    {
        if (other.tag == "Player")
        {
            if (facingRight && other.transform.position.x < transform.position.x)
            {
                flipFacing();

            }
            else if (!facingRight && other.transform.position.x > transform.position.x)
            {
                flipFacing();
            }
            canFlip = false;
            charging = true;
            startChargeTime = Time.time + chargeTime;

        }
        }

    void OnTriggerStay2D(Collider2D other)
    {
        if(other.tag == "Player")
        {
            if(startChargeTime < Time.time)
            {
                if (!facingRight) enemyRB.AddForce(new Vector2(-1, 0) * enemySpeed);
                else enemyRB.AddForce(new Vector2(1, 0) * enemySpeed);
                enemyAnimator.SetBool("isCharging", charging);
            }
        }
    }

    void OnTriggerExit2D(Collider2D other)
    {
        if (other.tag == "Player")
        {
            canFlip = true;
            charging = false;
            enemyRB.velocity = new Vector2(0f, 0f);
            enemyAnimator.SetBool("isCharging", charging);
        }
    }


    void flipFacing()
    {
        if (!canFlip) return;
        float facingX = enemyGraphic.transform.localScale.x;
        facingX *= -1f;
        facingRight = !facingRight;

    }

}