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

public class WaterController : MonoBehaviour {


    public AnimationCurve RipplePower;

    private float waveOffset = 0;
    public float waveScale = 1;
    public float waterWidth = 1;
    public float waveSpeed = 1;
    public float maxWaveHeight = 2;


    #region Unity Functions
    // Use this for initialization
    void Start() {

    }

    // Update is called once per frame
    void Update() {

        waveOffset += 0.1f *waveSpeed * Time.deltaTime;

    }
    #endregion Unity Fucntions


    #region Interaction Functions

    /// <summary>
    /// Pushes any objects in water away from this point
    /// </summary>
    /// <param name="point"> point where water is createds</param>
    /// <param name="radius"> radius of effected object</param>
    /// <param name="power"> power with chich the objects are pushed</param>
    public void CreateWave(Vector3 point, float radius, float power){

        //find all colliders within the wave distance
        StartCoroutine(waveController(point, radius, power, 2));


    }
    #endregion Interaction Functions

    #region Helper Functions

    public IEnumerator waveController (Vector3 point, float radius, float power, float rippleTime) {


        float elapsedTime = 0.0f;

        while (elapsedTime < rippleTime) {

            float curRippleForce = RipplePower.Evaluate(elapsedTime / rippleTime);

            Collider[] colliders = Physics.OverlapSphere(point, radius);
            foreach (Collider hit in colliders) {

       

                Rigidbody rb = hit.GetComponent<Rigidbody>();

                Debug.DrawLine(point, hit.transform.position, Color.blue, 1);

                if (rb != null) {
                    Debug.DrawLine(point, hit.transform.position, Color.blue, 1);
                    Vector3 flatPoint = new Vector3(point.x, hit.transform.position.y, point.z);
                    rb.AddExplosionForce(power * curRippleForce, point, radius, 0.0f);
                }
            }

            yield return new WaitForEndOfFrame();
            elapsedTime += Time.deltaTime;
        }
    }




    #endregion Helper Functions


    #region Collision Functions
    void OnTriggerEnter(Collider other) {
        //calls appropriate function if the object should interact with the water on enter
        WaterObject waterInteraction = other.gameObject.GetComponent<WaterObject>();
        if (waterInteraction != null) {
            waterInteraction.OnWaterEnter(gameObject);
        }

    }

    void OnTriggerStay(Collider other) {

        //calls appropriate function if the object should interact with the water on stay
        WaterObject waterInteraction = other.gameObject.GetComponent<WaterObject>();
        if (waterInteraction != null) {

            Vector2 waveCoords = new Vector2(other.transform.position.x, other.transform.position.z);
            waveCoords = waveCoords / waterWidth * waveScale;
            float waveHeight = Mathf.PerlinNoise(waveCoords.x, waveCoords.y + waveOffset);


            waterInteraction.OnWaterStay(gameObject,waveHeight * maxWaveHeight);
        }

    }

    void OnTriggerExit(Collider other) {
        //calls appropriate function if the object should interact with the water on exit
        WaterObject waterInteraction = other.gameObject.GetComponent<WaterObject>();
        if (waterInteraction != null) {
            waterInteraction.OnWaterExit(gameObject);
        }

    }
    #endregion Collision Functions


}