using System;
using System.Collections.Generic;
using UnityEngine;
using Unity.Mathematics;
using static Unity.Mathematics.math;

[System.Serializable]
public class Cluster : INucleus {
    // The ScriptableObject asset from which the runtime object has been created
    public readonly ClusterPrefab prefab;

    public ClusterPrefab cluster { get; set; }

    [SerializeField]
    protected string _name;
    public virtual string name {
        get => _name;
        set => _name = value;
    }

    // Hmm, a cluster instance can never be part of a scriptable object...(Cluster)
    public Cluster(ClusterPrefab parent, ClusterPrefab prefab) {
        this.prefab = prefab;
        this.cluster = parent;
        if (this.cluster != null)
            this.cluster.nuclei.Add(this);

        // foreach (IReceptor nucleus in this.prefab.nuclei) {
        //     IReceptor clone = nucleus.CloneTo(null);
        //     this.dynamicNuclei.Add(clone);
        // }
    }

    public virtual IReceptor Clone() {
        Neuron clone = new(this.cluster, this.name) {
            array = this.array,
        };

        foreach (Synapse synapse in this.synapses) {
            Synapse clonedSynapse = clone.AddSynapse(synapse.nucleus);
            clonedSynapse.weight = synapse.weight;
        }
        foreach (INucleus receiver in this.receivers) {
            clone.AddReceiver(receiver);
        }
        return clone;
    }

    // Not sure if this belongs here...
    [SerializeReference]
    private NucleusArray _array;
    public NucleusArray array {
        get { return _array; }
        set { _array = value; }
    }

    #region Synapses

    // class ClusterSynapse : Synapse {
    //     public IReceptor receptor;
    //     public ClusterSynapse(IReceptor nucleus, INucleus receptor, float weight = 1.0f) : base(nucleus, weight) {
    //         this.receptor = receptor;
    //     }
    // }
    [SerializeField]
    private List<Synapse> _synapses = new();
    public List<Synapse> synapses => _synapses;

    public Synapse AddSynapse(IReceptor sendingNucleus) {
        Synapse synapse = new(sendingNucleus); //, this.prefab.inputs[0]);
        this._synapses.Add(synapse);
        return synapse;
        // else {
        //     INucleus receptor = (INucleus)this.prefab.nuclei.Find(nucleus => nucleus is INucleus n && nucleus.name == nucleusName);
        //     ClusterSynapse synapse = new(sendingNucleus, receptor);
        //     receptor.AddSynapse(sendingNucleus);
        // }
        // // Add synapse to which neuron?
        // return null;
    }

    // Does this even exist already?
    public void RemoveSynapse() {

    }

    #endregion Synapses

    #region Receivers

    [SerializeReference]
    private List<INucleus> _receivers = new();
    public List<INucleus> receivers {
        get { return _receivers; }
        set { _receivers = value; }
    }

    public virtual void AddReceiver(INucleus receivingNucleus) {
        this._receivers.Add(receivingNucleus);
        receivingNucleus.AddSynapse(this);
    }

    public void RemoveReceiver(INucleus receiverNucleus) {
        this._receivers.RemoveAll(receiver => receiver == receiverNucleus);
        receiverNucleus.synapses.RemoveAll(synapse => synapse.nucleus == this);
    }

    // public void AddReceiver(INucleus receivingNucleus) {
    //     int newLength = this._receivers.Count + 1;
    //     INucleus[] newReceivers = new INucleus[newLength];

    //     // Copy the existing receivers
    //     for (int ix = 0; ix < this._receivers.Count; ix++)
    //         newReceivers[ix] = this._receivers[ix];
    //     // Add the new receivers
    //     newReceivers[this._receivers.Count] = receivingNucleus;
    //     // Replace the receivers with the new receivers
    //     this._receivers = new(newReceivers);

    //     receivingNucleus.AddSynapse(this);
    // }

    // public void RemoveReceiver(INucleus receivingNucleus) {
    //     Debug.Log("Clusterinstance. remote receiver");
    //     int newLength = this._receivers.Count - 1;
    //     if (newLength < 0)
    //         //  Array was empty, so we cannot remove anything
    //         return;

    //     INucleus[] newReceivers = new INucleus[newLength];

    //     int newIx = 0;
    //     // Copy all receivers except receivingNucleus
    //     for (int ix = 0; ix < this._receivers.Count; ix++) {
    //         if (this._receivers[ix] == receivingNucleus)
    //             // skip the receiver we want to remote
    //             continue;

    //         if (newIx >= newLength)
    //             // We want to copy more elements than expected
    //             // the receivingNucleus is not found
    //             // and the original array is returned
    //             return;
    //         newReceivers[newIx] = this._receivers[ix];
    //         newIx++;
    //     }
    //     this._receivers = new(newReceivers);
    // }

    #endregion Receivers

    #region Runtime

    [NonSerialized]
    private int stale = 1000;
    public bool isSleeping => lengthsq(this.outputValue) == 0;

    [NonSerialized]
    protected float3 _outputValue;
    public virtual float3 outputValue {
        get { return _outputValue; }
        set {
            this.stale = 0;
            _outputValue = value;
        }
    }

    #region Update

    public virtual void UpdateState() {
        UpdateState(new float3(0, 0, 0));
    }

    public void UpdateState(float3 inputValue) {
        float3 sum = inputValue; // new(0, 0, 0);

        //Applying the weight factgors
        foreach (Synapse synapse in this.synapses) {
            sum += synapse.weight * synapse.nucleus.outputValue;
        }
        
        // This does not work because the prefab nucleus does not have a state
        this.prefab.inputs[0].UpdateState(sum);
    }

    public void UpdateNuclei() {
        this.stale++;
        if (this.stale >  2)
            _outputValue = Vector3.zero;

        foreach (IReceptor nucleus in this.prefab.nuclei)
            nucleus.UpdateNuclei();
    }

    #endregion Update

    #endregion Runtime    

    /*
        [SerializeField]
        private List<IReceptor> _dynamicNuclei;
        public List<IReceptor> dynamicNuclei {// = new();
            get {
                if (_dynamicNuclei == null) {
                    this._dynamicNuclei = new();
                    foreach (IReceptor nucleus in this.prefab.nuclei) {
                        IReceptor clone = nucleus.CloneTo(null);
                        this._dynamicNuclei.Add(clone);
                    }
                }
                return this._dynamicNuclei;
            }
        }

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

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

        public float3 outputValue => this.output.outputValue;


        public IReceptor CloneTo(ClusterPrefab parent) {
            Cluster clone = new(parent, this.prefab);
            return clone;
        }
        public IReceptor Clone() {
            Cluster clone = new(this.cluster, this.prefab);
            return clone;
        }

        #region Properties

        public string name {
            get { return prefab.name; }
            set { prefab.name = value; }
        }

        public bool isSleeping => lengthsq(this.outputValue) == 0;

        public NucleusArray array { get; set; }

        #endregion Properties


    */

}