using UnityEngine;

public class PlayerCameraController : MonoBehaviour
{
    public Transform target;
    public float distance = 50.0f;
    public float xSpeed = 1.0f;
    public float ySpeed = 20.0f;
    public float yMinLimit = 5;
    public float yMaxLimit = 130f;
    public float zoomSpeedDesktop = 20f;
    public float zoomSpeedMobile = 20f;
    public float distanceMin = 10f;
    public float distanceMax = 150f;
    public float smoothTime = 2f;
    float rotationYAxis = 0.0f;
    float rotationXAxis = 0.0f;
    float velocityX = 0.0f;
    float velocityY = 0.0f;
    
    // Use this for initialization
    void Start()
    {
        Vector3 angles = transform.eulerAngles;
        rotationYAxis = angles.y;
        rotationXAxis = angles.x;
        // Make the rigid body not change rotation
        if (GetComponent<Rigidbody>())
        {
            GetComponent<Rigidbody>().freezeRotation = true;
        }
    }
    void LateUpdate()
    {
        if (target)
        {
            Vector2 movementInputDelta = Vector2.zero;
            if (SystemInfo.deviceType == DeviceType.Handheld)
            {
                if (Input.touchCount == 1)
                {
                    movementInputDelta = Input.touches[0].deltaPosition * 0.02f;
                }
            }
            else
            {
                if (Input.GetMouseButton(0))
                {
                    movementInputDelta = new Vector2(Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y"));
                }
            }

            movementInputDelta *= 0.2f;
            velocityX = xSpeed * movementInputDelta.x * distance;
            velocityY = ySpeed * movementInputDelta.y;

            rotationYAxis += velocityX;
            rotationXAxis -= velocityY;
            rotationXAxis = ClampAngle(rotationXAxis, yMinLimit, yMaxLimit);
            //Quaternion fromRotation = Quaternion.Euler(transform.rotation.eulerAngles.x, transform.rotation.eulerAngles.y, 0);
            Quaternion toRotation = Quaternion.Euler(rotationXAxis, rotationYAxis, 0);
            Quaternion rotation = toRotation;

            distance = Mathf.Clamp(distance - GetZoomAmount(), distanceMin, distanceMax);
//            RaycastHit hit;
//            if (Physics.Linecast(target.position, transform.position, out hit))
//            {
//                distance -= hit.distance;
//            }
            Vector3 negDistance = new Vector3(0.0f, 0.0f, -distance);
            Vector3 position = rotation * negDistance + target.position;

            transform.rotation = rotation;
            transform.position = position;
            
            velocityX = Mathf.Lerp(velocityX, 0, Time.deltaTime * smoothTime);
            velocityY = Mathf.Lerp(velocityY, 0, Time.deltaTime * smoothTime);
        }
    }

    private float GetZoomAmount()
    {
        // If this is a handheld, use pinch to zoom
        if (SystemInfo.deviceType == DeviceType.Handheld)
        {
            // If there are two touches on the device...
            if (Input.touchCount == 2)
            {
                // Store both touches.
                Touch touchZero = Input.GetTouch(0);
                Touch touchOne = Input.GetTouch(1);

                // Find the position in the previous frame of each touch.
                Vector2 touchZeroPrevPos = touchZero.position - touchZero.deltaPosition;
                Vector2 touchOnePrevPos = touchOne.position - touchOne.deltaPosition;

                // Find the magnitude of the vector (the distance) between the touches in each frame.
                float prevTouchDeltaMag = (touchZeroPrevPos - touchOnePrevPos).magnitude;
                float touchDeltaMag = (touchZero.position - touchOne.position).magnitude;

                // Find the difference in the distances between each frame.
                return - (prevTouchDeltaMag - touchDeltaMag) * zoomSpeedMobile;
            }
            else
            {
                return 0;
            }
        }
        else
        {
            // Otherwise, we use the scrollwheel for zooming
            return Input.GetAxis("Mouse ScrollWheel") * zoomSpeedDesktop;
        }

    }
    
    public static float ClampAngle(float angle, float min, float max)
    {
        if (angle < -360F)
            angle += 360F;
        if (angle > 360F)
            angle -= 360F;
        return Mathf.Clamp(angle, min, max);
    }
}