using Godot;

public partial class PhysicsSpike : Node3D
{
    private RigidBody3D _ball;
    private RigidBody3D _chaser;
    private Node3D _chaseTarget;
    private float _elapsed;
    private bool _ballTouched;

    public override void _Ready()
    {
        StaticBody3D floor = new() { Position = new Vector3(0, -0.5f, 0) };
        floor.AddChild(new CollisionShape3D { Shape = new BoxShape3D { Size = new Vector3(20, 1, 20) } });
        AddChild(floor);

        _ball = new RigidBody3D { Position = new Vector3(0, 2, 0), ContactMonitor = true, MaxContactsReported = 4 };
        _ball.AddChild(new CollisionShape3D { Shape = new SphereShape3D { Radius = 0.25f } });
        _ball.BodyEntered += _ => _ballTouched = true;
        AddChild(_ball);

        StaticBody3D wall = new() { Position = new Vector3(5, 2, 0) };
        wall.AddChild(new CollisionShape3D { Shape = new BoxShape3D { Size = new Vector3(0.5f, 4, 4) } });
        AddChild(wall);

        _chaser = new RigidBody3D { Position = new Vector3(0, 1, 0), GravityScale = 0f };
        _chaser.AddChild(new CollisionShape3D { Shape = new SphereShape3D { Radius = 0.25f } });
        AddChild(_chaser);

        _chaseTarget = new Node3D();
        AddChild(_chaseTarget);
        GD.Print("SPIKE: physics spike scene ready");
    }

    public override void _PhysicsProcess(double delta)
    {
        _elapsed += (float)delta;

        _chaseTarget.GlobalPosition = new Vector3(Mathf.Min(8f, _elapsed * 2f), 1, 0);
        Vector3 to = _chaseTarget.GlobalPosition - _chaser.GlobalPosition;
        Vector3 desired = to / (float)delta;
        if (desired.Length() > 3f)
            desired = desired.Normalized() * 3f;
        _chaser.LinearVelocity = desired;

        if (_elapsed < 2.5f)
            return;

        bool dropOk = _ballTouched && _ball.GlobalPosition.Y > 0.2f && _ball.GlobalPosition.Y < 0.35f;
        bool chaseOk = _chaser.GlobalPosition.X > 4.4f && _chaser.GlobalPosition.X < 5.05f;
        GD.Print($"SPIKE: drop test — ball y={_ball.GlobalPosition.Y:F3} (expected ~0.25), contact={_ballTouched} → {(dropOk ? "PASS" : "FAIL")}");
        GD.Print($"SPIKE: chase test — chaser x={_chaser.GlobalPosition.X:F3} (wall face 4.75, body radius 0.25), vel={_chaser.LinearVelocity.Length():F2} → {(chaseOk ? "PASS" : "FAIL")}");
        GD.Print($"SPIKE: overall {(dropOk && chaseOk ? "PASS — Box3D functional from C#" : "CHECK — behavior differs, inspect above")}");
        GetTree().Quit();
    }
}