using UnityEngine;

public enum ArcOrientation
{
    HORIZONTAL,
    VERTICAL,
}

[RequireComponent(typeof(LineRenderer))]
public class EditableArc : MonoBehaviour
{
    [SerializeField] private ArcOrientation orientation = ArcOrientation.HORIZONTAL;
    [SerializeField, Range(5, 50)] private int samples = 15;
    [SerializeField] private float visualRadius = 1f;

    [SerializeField] private Vector2 rotationMinMax = new Vector2(-30f, 30f);
    private LineRenderer lineRenderer;

    public Observer<float> Value { get; private set; } = new(0);
    public Vector2 RotationMinMax => rotationMinMax;

    private void Awake()
    {
        lineRenderer = GetComponent<LineRenderer>();

        Value.AddListener(UpdateArc);

        Value.Value = (rotationMinMax.x + rotationMinMax.y) / 2f;
    }

    private void Update()
    {
        UpdateArc(Value.Value);
    }

    private void UpdateArc(float rotation)
    {
        Vector3 normal;
        Vector3 tangent;

        if (orientation == ArcOrientation.HORIZONTAL)
        {
            normal = transform.up;
            tangent = transform.right;
        }
        else if (orientation == ArcOrientation.VERTICAL)
        {
            normal = transform.right;
            tangent = transform.up;
        }
        else
        {
            throw new System.Exception("WTFFFFF HAVE YOU DONE YOU MF!!?");
        }

        float angle = rotationMinMax.y - rotationMinMax.x;
        float v = (Mathf.PI - Value * Mathf.Deg2Rad) / 2f;
        Vector3 start = Quaternion.AngleAxis(rotationMinMax.x, normal) * tangent;
        Vector3 end = Quaternion.AngleAxis(rotationMinMax.y, normal) * tangent;

        // Sample LineRenderer points
        lineRenderer.positionCount = samples + 1;
        Vector3[] positions = new Vector3[samples + 1];
        float stepSize = 1f / samples;
        float t = 0;
        for (int i = 0; i <= samples; i++)
        {
            positions[i] = SamplePointOnArc(start, end, visualRadius, t);
            // Debug.Log($"t: = {t}, pos: {positions[i]}");
            t += stepSize;
        }

        lineRenderer.SetPositions(positions);
    }

    public Vector3 SamplePointOnArc(Vector3 startPoint, Vector3 endPoint, float radius, float t)
    {
        // Calculate the angle between start and end points
        float angle = Vector3.Angle(startPoint, endPoint) * t;

        // Calculate the perpendicular vector from start to end
        Vector3 axis = Vector3.Cross(startPoint, endPoint).normalized;

        // Calculate the position of the point on the arc
        Vector3 pointOnArc = Quaternion.AngleAxis(angle, axis) * startPoint;

        // Scale the point by the radius
        pointOnArc *= radius;

        return pointOnArc;
    }
}