using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using UnityEngine;
using VRTK;

public class CoriolisDisplay : MonoBehaviour
{

    [Header("References")]
    [SerializeField]
    private RotationController m_ship;

    [SerializeField]
    private GameObject m_segmentPrefab;

    [SerializeField]
    private Transform m_tip;


    [Header("settings")]
    [SerializeField]
    private int m_segmentCount = 20;
    [SerializeField]
    private float m_segmentSpacing = 0.5f;
    [SerializeField]
    private float m_coriolisMultiplier = 1;



    private VRTK_InteractableObject m_interactable;
    private List<GameObject> m_segments = new List<GameObject>();


    private void Awake()
    {
        if (m_ship == null)
            m_ship = FindObjectOfType<RotationController>();

        m_interactable = GetComponent<VRTK_InteractableObject>();
    }

    private void OnEnable()
    {
        RegisterEvents(true);
    }

    private void OnDisable()
    {
        RegisterEvents(false);
        DestroySegments();
    }

    private void Update()
    {
        UpdateSegments();
    }




    private void GenerateSegments()
    {      
        for (int i = 0; i < m_segmentCount; i++)
        {
            GameObject segment = Instantiate(m_segmentPrefab);
            segment.transform.position = transform.position;
            m_segments.Add(segment);
        }
    }

    private void DestroySegments()
    {
        foreach (GameObject segment in m_segments)
        {
            Destroy(segment);
        }

        m_segments.Clear();
    }

    private void UpdateSegments()
    {

        if (m_segments == null || m_segments.Count == 0)
            return;


        Vector3 position = m_tip.position;
        Vector3 direction = m_tip.forward;
        Vector3 shipDirection = m_ship.RotationAxis;

        foreach(GameObject segment in m_segments)
        {

            Vector3 force = 2 * Vector3.Cross(direction, m_ship.RotationAxis) * (2 * Mathf.PI / m_ship.RotationPeriod);
            direction = (direction + force * m_coriolisMultiplier).normalized * m_segmentSpacing;
            position = position + direction;

            segment.transform.position = position;
            segment.transform.forward = direction;
        }
    }




    private void OnGrab(object sender, InteractableObjectEventArgs args)
    {
        GenerateSegments();
    }


    private void OnDrop(object sender, InteractableObjectEventArgs args)
    {
        DestroySegments();
    }


    private void RegisterEvents(bool value)
    {
        if (value)
        {
            m_interactable.InteractableObjectGrabbed += OnGrab;
            m_interactable.InteractableObjectUngrabbed += OnDrop;
        }
        else
        {
            m_interactable.InteractableObjectGrabbed -= OnGrab;
            m_interactable.InteractableObjectUngrabbed -= OnDrop;
        }
    }

}