using UnityEngine;

public class Boomerang : MonoBehaviour {
    
    private bool _initialized;
    private Transform _target;

    private NeuralNetwork _network;
    private Rigidbody2D _rigidbody;

    public void Initialize(NeuralNetwork network, Transform target) {
        _network = network;
        _target = target;
        _initialized = true;
    }

    private void Start() {
        _rigidbody = GetComponent<Rigidbody2D>();
    }

    private void FixedUpdate() {
        if (!_initialized) return;

        var input = CalculateInputs();
        var output = _network.FeedForward(input);

        _rigidbody.velocity = 2.5f * transform.up;
        _rigidbody.angularVelocity = 500.0f * output[0];

        _network.Fitness += 1.0f - Mathf.Abs(input[0]);
    }

    private float[] CalculateInputs() {
        var inputs = new float[1];
        
        var angle = transform.eulerAngles.z % 360.0f;
        if (angle < 0.0f) angle += 360.0f;

        var delta = (_target.position - transform.position).normalized;
        var rad = Mathf.Atan2(delta.y, delta.x) * Mathf.Rad2Deg;

        rad = rad % 360.0f;
        if (rad < 0.0f) rad = 360.0f + rad;

        rad = 90.0f - rad;
        if (rad < 0.0f) rad += 360.0f;

        rad = 360.0f - rad - angle;
        
        if (rad < 0.0f) rad = 360.0f + rad;
        if (rad >= 180.0f) rad = -(360.0f - rad);
        rad *= Mathf.Deg2Rad;

        inputs[0] = rad / Mathf.PI;

        return inputs;
    }
    
}