using System.Collections.Generic;
using UnityEngine;

public class OrbitalPosition : MonoBehaviour
{
    public float DistanceFromCentre = 0;
    public float RadiusDistance = 0;

    public Vector3 TranslateToVec3() => new
    (
        x: DistanceFromCentre * Mathf.Cos(RadiusDistance),
        y: DistanceFromCentre * Mathf.Sin(RadiusDistance)
    );
}

public class GlobalOrbitalPositionManager : MonoBehaviour
{
    static GlobalOrbitalPositionManager s_Instance = null;

    List<OrbitalPosition> m_ObjectInstances = new();

    [SerializeField, Range(0f, Mathf.PI * 2)] float m_RadiusSpeed = 2f;
    [SerializeField, Range(0f, 2f)] float m_DistanceSpeed = 2f;

    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
    private static void OnApplicationStart()
    {
        GameObject manager = new("GLOBAL ORBITAL MANAGER");
        DontDestroyOnLoad(manager);

        s_Instance = manager.AddComponent<GlobalOrbitalPositionManager>();
    }

    public void Update()
    {
        foreach (OrbitalPosition orbitalPosition in m_ObjectInstances)
        {
            orbitalPosition.DistanceFromCentre = Mathf.Clamp(orbitalPosition.DistanceFromCentre - (m_DistanceSpeed * Time.deltaTime * m_DistanceSpeed), 0f, float.PositiveInfinity);
            orbitalPosition.RadiusDistance = (orbitalPosition.RadiusDistance + (m_RadiusSpeed * Time.deltaTime * m_RadiusSpeed)) % (Mathf.PI * 2);

            orbitalPosition.gameObject.transform.position = orbitalPosition.TranslateToVec3();
        }
    }

    public static void RegisterOrbitalPositionInstance(OrbitalPosition newInstance) =>
        s_Instance.m_ObjectInstances.Add(newInstance);

    public static void UnregisterOrbitalPositionInstance(OrbitalPosition removedInstance) =>
        s_Instance.m_ObjectInstances.Remove(removedInstance);
}

[RequireComponent(typeof(OrbitalPosition))]
public abstract class OrbitalPositionBehaviour : MonoBehaviour
{
    protected OrbitalPosition m_OrbitalPosition = null;

    private void Start()
    {
        m_OrbitalPosition = GetComponent<OrbitalPosition>();
        GlobalOrbitalPositionManager.RegisterOrbitalPositionInstance(m_OrbitalPosition);

        OnStart();
    }

    private void OnDestroy() =>
        GlobalOrbitalPositionManager.UnregisterOrbitalPositionInstance(m_OrbitalPosition);

    public abstract void OnStart();
}