using System;
using Godot;

public class Entity : KinematicBody {
    [Flags]
    public enum EntityMaskEnum {
        Obstacle = 1 << 1,
        Ground = 1 << 2,
        Water = 1 << 3
    }

    [Export(PropertyHint.Flags, "Obstacle,Ground,Water")]
    public int EntityMask { get; set; }

    public Vector3 Velocity { get; set; } = Vector3.Zero;
    public float RotationalVelocity { get; set; } = 0;

    /**
     * Defines the angle in plane coordinates, 0 => pointing to the right/east, pi/2 pointing up/north, range [-pi,pi].
     */
    public float PlaneAngle {
        get => Globals.CalcPlaneAngle(GlobalTransform);
        set => GlobalTransform = new Transform(new Basis(Vector3.Up, value + Mathf.Pi * 0.5f), GlobalTranslation);
    }

    public float CalcShortestPlaneRotationToTargetDirection(Vector3 globalTargetDirection) {
        float angleToTarget = Vector3.Right.SignedAngleTo(globalTargetDirection, Vector3.Up);
        float currentAngle = PlaneAngle;

        float delta = angleToTarget - currentAngle;

        delta += delta > Mathf.Pi ? -Mathf.Pi * 2 : delta < -Mathf.Pi ? Mathf.Pi * 2 : 0;
        return delta;
    }
}