using System.Collections.Generic;
using UnityEngine;

[CreateAssetMenu(menuName = "Passer/Cluster")]
public class ClusterPrefab : ScriptableObject {

    //public virtual Cluster cluster {get;set;}

    // The ScriptableObject asset from which the runtime object has been created
    //public Cluster asset;

    [SerializeReference]
    public List<IReceptor> nuclei = new();

    // public List<Cluster> subClusters = new();
    // public void AddSubCluster(ClusterInstance subCluster) {
    //     this.nuclei.Add(subCluster);
    // }

    public virtual INucleus output => this.nuclei[0] as INucleus;

    public List<INucleus> _inputs = null;
    public virtual List<INucleus> inputs {
        get {
            if (this._inputs == null) {
                this._inputs = new();
                foreach (IReceptor receptor in this.nuclei) {
                    if (receptor is INucleus nucleus)
                        this._inputs.Add(nucleus);
                }
            }
            return this._inputs;
        }
    }

    // Call this function to ensure that there is at least one nucleus
    // This is an invariant and should be ensured before the nucleus is used
    // because output requires it.
    public void EnsureInitialization() {
        nuclei ??= new List<IReceptor>();
        if (nuclei.Count == 0)
            new Neuron(this, "Output"); // Every cluster should have at least 1 neuron
    }

    public void GarbageCollection() {
        HashSet<INucleus> visitedNuclei = new();
        MarkNuclei(visitedNuclei, this.output);
        //Debug.Log($"Garbage collection found {visitedNuclei.Count} Nuclei");
        this.nuclei.RemoveAll(nucleus => nucleus is INucleus n && visitedNuclei.Contains(n) == false);
    }

    public void MarkNuclei(HashSet<INucleus> visitedNuclei, INucleus nucleus) {
        if (nucleus is null)
            return;

        visitedNuclei.Add(nucleus);
        if (nucleus.synapses != null) {
            HashSet<Synapse> visitedSynapses = new();
            foreach (Synapse synapse in nucleus.synapses) {
                if (synapse != null && synapse.nucleus != null) {
                    visitedSynapses.Add(synapse);
                    if (synapse.nucleus is INucleus synapse_nucleus)
                        MarkNuclei(visitedNuclei, synapse_nucleus);
                }
            }
            nucleus.synapses.RemoveAll(synapse => visitedSynapses.Contains(synapse) == false);
        }
        if (nucleus.receivers != null) {
            HashSet<INucleus> visitedReceivers = new();
            foreach (INucleus receiver in nucleus.receivers) {
                if (receiver != null && receiver != null) {
                    visitedReceivers.Add(receiver);
                    visitedNuclei.Add(receiver);
                }
            }
            nucleus.receivers.RemoveAll(receiver => visitedReceivers.Contains(receiver) == false);
        }
    }

    public virtual void UpdateNuclei() {
        foreach (IReceptor nucleus in this.nuclei)
            nucleus.UpdateNuclei();
    }
}