using System;
using UnityEngine;

namespace NanoBrain.Unity {

    /// <summary>
    /// A NanoBrain which can be used to control a gameobject
    /// </summary>
    /// A NanoBrain is a small neural network which can be used to implement functional behaviour.
    /// The network consists of neurons which are connected together with synapses.
    /// The output values of the neurons are of type Vector3 to support spatial computing.
    /// 
    /// This component is basically a Unity representation of a nanobrain cluster.
    /// \sa
    /// - \ref NanoBrain::Cluster "Cluster"
    /// - \ref NanoBrain::Neuron "Neuron"
    [HelpURL("https://passer.life/documentation/nanobrain/Documentation/html/class_nano_brain_1_1_unity_1_1_brain.html")] 
    public class Brain : MonoBehaviour {
        /// <summary>
        /// The Cluster prefab from which the cluster is created
        /// </summary>
        public ClusterPrefab brainPrefab;

        [NonSerialized]
        private Cluster brainInstance;
        /// <summary>
        /// The cluster isntance
        /// </summary>
        public Cluster brain {
            get {
                if (brainInstance == null && brainPrefab != null) {
                    brainInstance = new Cluster(brainPrefab) {
                        name = brainPrefab.name
                    };
                } else if (brainInstance != null && brainPrefab == null) {
                    brainInstance = null;
                }
                return brainInstance;
            }
        }

        // public Cluster InitializeBrain() {
        //     brainInstance = new Cluster(brainPrefab) {
        //         name = brainPrefab.name
        //     };
        //     return brainInstance;
        // }

        /// <summary>
        /// Update the weight for all Synapses coming from the Neuron with the given name
        /// </summary>
        /// <param name="brain">The cluster in which the synapses are updated</param>
        /// <param name="name">The name of the Neuron for which the weights are updated</param>
        /// <param name="weight">The new Synapse weight</param>
        public static void UpdateWeight(Cluster brain, string name, float weight) {
            Neuron root = brain.defaultOutput;
            foreach (Synapse synapse in root.synapses) {
                if (synapse.neuron.name == name) {
                    if (synapse.weight != weight) {
                        synapse.weight = weight;
                        // Debug.Log($"Updated weight for {name}");
                    }
                }
            }
        }
    }

}