using UnityEngine;

namespace Obi
{
    [RequireComponent(typeof(Camera))]
    public class LookAroundCamera : MonoBehaviour
    {
        public struct CameraShot
        {
            public Vector3 position;
            public Quaternion rotation;
            public Vector3 up;
            public float fieldOfView;

            public CameraShot(Vector3 position, Quaternion rotation, Vector3 up, float fieldOfView)
            {
                this.position = position;
                this.rotation = rotation;
                this.up = up;
                this.fieldOfView = fieldOfView;
            }
        }

        private Camera cam;
        private CameraShot currentShot;

        public float movementSpeed = 5;
        public float rotationSpeed = 8;
        public float translationResponse = 10;
        public float rotationResponse = 10;
        public float fovResponse = 10;

        private void Awake()
        {
            cam = GetComponent<Camera>();
            currentShot = new CameraShot(transform.position, transform.rotation, transform.up, cam.fieldOfView);
        }

        private void LookAt(Vector3 position, Vector3 up)
        {
            currentShot.up = up;
            currentShot.rotation = Quaternion.LookRotation(position - currentShot.position, currentShot.up);
        }

        private void UpdateShot()
        {
            transform.position = Vector3.Lerp(transform.position, currentShot.position, translationResponse * Time.deltaTime);
            transform.rotation = Quaternion.Slerp(transform.rotation, currentShot.rotation, rotationResponse * Time.deltaTime);
            cam.fieldOfView = Mathf.Lerp(cam.fieldOfView, currentShot.fieldOfView, fovResponse * Time.deltaTime);
        }

        private void LateUpdate()
        {
            Vector3 delta = Vector3.zero;

            if (Input.GetKey(KeyCode.W))
                delta += cam.transform.forward;
            if (Input.GetKey(KeyCode.A))
                delta -= cam.transform.right;
            if (Input.GetKey(KeyCode.S))
                delta -= cam.transform.forward;
            if (Input.GetKey(KeyCode.D))
                delta += cam.transform.right;

            currentShot.position += delta * Time.deltaTime * movementSpeed;

            var system = UnityEngine.EventSystems.EventSystem.current;
            bool focusUI = system != null && system.IsPointerOverGameObject();

            if (Input.GetKey(KeyCode.Mouse0) && !focusUI)
            {
                float deltaX = Input.GetAxis("Mouse X") * rotationSpeed;
                float deltaY = Input.GetAxis("Mouse Y") * rotationSpeed;
                Quaternion fwd = currentShot.rotation * Quaternion.AngleAxis(deltaX, Vector3.up) * Quaternion.AngleAxis(deltaY, -Vector3.right);
                LookAt(currentShot.position + fwd * Vector3.forward, Vector3.up);
            }

            UpdateShot();
        }
    }
}