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

public class GameManager : MonoBehaviour
{
    public Rigidbody2D ball;
    public Transform cam;
    public Vector3 camTargetPos;    
    public float cameraSmoothness = 0.1f;
    public float inputSensitivity = 100f;
    public float BallFriction = 0.1f;
    public float StopVelocity = 0.01f;
    public float StopTime = 0.1f;

    public float curVelocity;
    public float forceMultiplier;
    public Transform ballProjection;
    public float ballProjectionScaleMin, ballProjectionScaleMax;

    void Start()
    {
        camTargetPos = ball.transform.position;
    }
    float stopCooldown = 0;
    
    void FixedUpdate(){
        curVelocity = ball.velocity.magnitude;
        ball.velocity = Vector2.Lerp(ball.velocity, new Vector2(0, ball.velocity.y), BallFriction);
        if(Mathf.Abs(ball.velocity.magnitude) <  StopVelocity){
            if(stopCooldown > StopTime){
                ball.simulated=false;
            }else{
                stopCooldown+=Time.deltaTime;
            }
        }else{
            stopCooldown=0;
        }
    }

    void Update(){
        camTargetPos = ball.transform.position;
    }
    
    void LateUpdate()
    {
        cam.position = Vector3.Lerp(cam.position, new Vector3(camTargetPos.x, cam.position.y,cam.position.z), cameraSmoothness);
    }


    bool dragging = false;
    Vector2 startPos;
    public void OnMouseDown(BaseEventData e){
        if(ball.simulated){return;}
        PointerEventData ped = (PointerEventData) e as PointerEventData;

        startPos = ped.position;
        dragging = true;
    }

    public void OnMouseUp(BaseEventData e){

        PointerEventData ped = (PointerEventData) e as PointerEventData;
        if(dragging){
            Vector2 v = ((ped.position-startPos)/inputSensitivity);
            if(v.magnitude > 1){v = v.normalized;}
            stopCooldown=0;

            ball.simulated=true;
            ball.AddForce(-v * forceMultiplier);
        }
        dragging = false;
        ballProjection.position = Vector3.zero;
    }

    public void OnMouseDrag(BaseEventData e){
        if(ball.simulated){return;}

        ballProjection.position = ball.position;
        PointerEventData ped = (PointerEventData) e as PointerEventData;
        Vector2 v = ((ped.position-startPos)/inputSensitivity);
        Debug.Log(v.magnitude);

        if(v.magnitude > 1){v = v.normalized;}

        Vector3 direction = (ped.position - startPos).normalized;
        float rot_z = Mathf.Atan2(direction.y,direction.x) * Mathf.Rad2Deg;
        ballProjection.rotation = Quaternion.Euler(0,0,rot_z+180);

        float scaleDiff = ballProjectionScaleMax - ballProjectionScaleMin;
        ballProjection.GetChild(0).localScale = new Vector3(ballProjection.GetChild(0).localScale.x,ballProjectionScaleMin + (scaleDiff*v.magnitude));
    }
}