using UnityEngine;
using UnityEngine.EventSystems;

public class MoveCamera : MonoBehaviour
{
    private Camera cam;
    
    // Rotation variables
    [SerializeField]
    private float rotationSpeed = 5f; //How sensitive it with mouse
    [SerializeField]
    private float maxVerticalRotation = 45.0f;
    private float rotationX = 0.0f;
    private float rotationY = 0.0f;

    // Zoom variables
    //[SerializeField]
    //private float zoomSpeed = 20f; //How sensitive it with mousewheel
    //private float minFov = 10f;
    //private float maxFov = 90f;

    // Scroll variables (Go up, down in World coordinates)
    [SerializeField]
    private float scrollSpeed = 20f;

    // Move variables
    [SerializeField]
    private float mainSpeed = 7.0f; //regular speed
    private float shiftAdd = 5.0f; //multiplied by how long shift is held.  Basically running
    private float maxShift = 27.0f; //Maximum speed when holding shift
    private float totalRun = 1.0f;

    // Reset variables
    private Vector3 startPos;
    private Quaternion startRot;

    private void Start()
    {
        cam = GameObject.Find("MoveCamera").GetComponent<Camera>();
        startPos = cam.transform.position;
        startRot = cam.transform.rotation;

        rotationX = transform.eulerAngles.x;
        rotationY = transform.eulerAngles.y;
    }

    void Update()
    {
        if (Input.GetKey(KeyCode.R) || Input.GetKey(KeyCode.Escape))
        {
            cam.transform.position = startPos;
            cam.transform.rotation = startRot;
        }

        // Mouse camera angle
        if (Input.GetMouseButton(0))
        {
            // Blocks rotating camera if the playback is used
            if (EventSystem.current.currentSelectedGameObject != null)
                return;

            // Clamps the vertical rotation to maxVrticalRotation
            rotationY += rotationSpeed * Input.GetAxis("Mouse X");
            rotationX -= rotationSpeed * Input.GetAxis("Mouse Y");
            rotationX = Mathf.Clamp(rotationX, -maxVerticalRotation, maxVerticalRotation);
            transform.eulerAngles = new Vector3(rotationX, rotationY, 0);
        }

        // MouseWheel Zoom In Out
        //float fov = cam.fieldOfView;
        //fov -= Input.GetAxis("Mouse ScrollWheel") * zoomSpeed;
        //fov = Mathf.Clamp(fov, minFov, maxFov);
        //cam.fieldOfView = fov;

        // MouseWheel up and down
        float scroll = Input.GetAxis("Mouse ScrollWheel") * scrollSpeed;
        transform.Translate(new Vector3(0, scroll, 0), Space.World);

        // Keyboard commands camera movement
        Vector3 p = GetBaseInput();
        if (p.sqrMagnitude > 0)
        {
            // only move while a direction key is pressed
            if (Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift))
            {
                totalRun += Time.deltaTime;
                p = p * totalRun * shiftAdd;
                p.x = Mathf.Clamp(p.x, -maxShift, maxShift);
                p.y = Mathf.Clamp(p.y, -maxShift, maxShift);
                p.z = Mathf.Clamp(p.z, -maxShift, maxShift);
            }
            else
            {
                totalRun = Mathf.Clamp(totalRun * 0.5f, 1f, 1000f);
                p = p * mainSpeed;
            }

            p = p * Time.deltaTime;
            Vector3 newPosition = transform.position;
            if (Input.GetKey(KeyCode.Space))
            { 
                transform.Translate(p);
            }
            else
            {
                //If player wants to move on X and Z axis only
                transform.Translate(p);
                newPosition.x = transform.position.x;
                newPosition.z = transform.position.z;
                transform.position = newPosition;
            }
        }
    }

    private Vector3 GetBaseInput()
    { //returns the basic values, if it's 0 than it's not active.
        Vector3 p_Velocity = new Vector3();
        if (Input.GetKey(KeyCode.W) || Input.GetKey(KeyCode.UpArrow))
        {
            p_Velocity += new Vector3(0, 0, 1);
        }
        if (Input.GetKey(KeyCode.S) || Input.GetKey(KeyCode.DownArrow))
        {
            p_Velocity += new Vector3(0, 0, -1);
        }
        if (Input.GetKey(KeyCode.A) || Input.GetKey(KeyCode.LeftArrow))
        {
            p_Velocity += new Vector3(-1, 0, 0);
        }
        if (Input.GetKey(KeyCode.D) || Input.GetKey(KeyCode.RightArrow))
        {
            p_Velocity += new Vector3(1, 0, 0);
        }
        return p_Velocity;
    }
}