using System;
using StereoKit;

// build this out tentatively
public abstract class SpatialCursor {
  public Vec3 pos;
  public Quat rot;

  public static Model model = Model.FromFile("cursor.glb", Shader.Default);
}

// : SpatialCursor
public class ReachCursor {
  static Material unlitMat = Default.MaterialUnlit.Copy();
  static Model modelCursor = Model.FromFile("cursor.glb", Shader.Default);
  static Model modelSphere = new Model(Default.MeshSphere, unlitMat);

  static Vec3[] pullPoints = new Vec3[2];

  public void Step() {
    for (int h = 0; h < (int)Handed.Max; h++) {
      // Get the pose for the index fingertip
      Hand hand = Input.Hand((Handed)h);
      Vec3 indexTip = hand[FingerId.Index, JointId.Tip].Pose.position;
      Vec3 thumbTip = hand[FingerId.Thumb, JointId.Tip].Pose.position;
      Vec3 pinchPos = Vec3.Lerp(indexTip, thumbTip, 0.5f);
      if (hand.IsPinched) {
        pullPoints[h] = pinchPos;
      }

      float stretch = (pullPoints[h] - pinchPos).Length;
      Vec3 dir = (pinchPos - pullPoints[h]).Normalized;
      Vec3 pos = pinchPos + dir * stretch * 3;
      modelCursor.Draw(Matrix.TS(pos, 0.06f));
      Lines.Add(pullPoints[h], pos, Color.White, 0.01f);
      modelSphere.Draw(Matrix.TS(pullPoints[h], 0.04f));
    }
  }
}

public class TwistCursor : SpatialCursor {
  public void Step() {
    Quat rel = Quat.LookAt(Vec3.Zero, Mono.mainHand.aim.orientation * Vec3.Forward);
    float twist = Vec3.Dot(rel * Vec3.Up, Mono.mainHand.aim.orientation * Vec3.Up);
    twist = MathF.Max(twist - 0.05f, 0);
    pos = Mono.mainHand.aim.position + Mono.mainHand.aim.orientation * Vec3.Forward * twist;

    model.Draw(Matrix.TS(pos, 0.06f));
  }
}

public class SupineCursor : SpatialCursor {
  float calibStr;
  Quat calibQuat;

  public void Step() {
    // calibration
    if (Mono.mainHand.IsStickClicked) {
      Vec3 target = Input.Head.position + Input.Head.Forward;
      calibStr = Vec3.Distance(Mono.mainHand.aim.position, target) * 2;

      Quat calibAlign = Quat.LookAt(Mono.mainHand.aim.position, target);
      calibQuat = Mono.mainHand.aim.orientation.Inverse * calibAlign;
    }

    Quat rel = Quat.LookAt(Vec3.Zero, Mono.offHand.aim.orientation * Vec3.Forward);
    float twist = (Vec3.Dot(rel * -Vec3.Right, Mono.offHand.aim.orientation * Vec3.Up) + 1) / 2;
    
    pos = Mono.mainHand.aim.position + Mono.mainHand.aim.orientation * calibQuat * Vec3.Forward * calibStr * twist;

    model.Draw(Matrix.TS(pos, 0.06f));
  }
}

public class TankCursor : SpatialCursor {
  public void Step() {
    pos = Vec3.Zero;
    rot = Quat.Identity;

    model.Draw(Matrix.TS(pos, 0.06f));
  }
}