/*
MIT License

Copyright (c) 2014-2022 Eron Gjoni
Copyright (c) 2019-2022 K. S. Ernest (iFire) Lee
Copyright (c) 2021 Rafael Martinez Gordillo.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

int current_bone_index = 0;
Vector<int> bones_to_process = skeleton->get_parentless_bones();
for (int32_t child_i = 0; child_i < label_mesh_origin->get_child_count(); child_i++) {
  Label3D *label = cast_to<Label3D>(label_mesh_origin->get_child(child_i));
  if (label) {
    label->queue_delete();
  }
}
Vector3 current_bone;
while (bones_to_process.size() > current_bone_index) {
  int current_bone_idx = bones_to_process[current_bone_index];
  current_bone_index++;
  Vector<int> child_bones_vector;
  child_bones_vector = skeleton->get_bone_children(current_bone_idx);
  int child_bones_size = child_bones_vector.size();
  int child_bone_idx = -1;
  for (int i = 0; i < child_bones_size; i++) {
    if (child_bones_vector[i] < 0) {
      // Something wrong.
      continue;
    }
    child_bone_idx = child_bones_vector[i];
    Label3D *label_mesh = memnew(Label3D);
    float snap = 0.1;
    float x_angle = 0.0f;
    {
      Vector3 current_bone = skeleton->get_bone_global_pose(current_bone_idx).basis[Vector3::AXIS_X];
      Vector3 child_bone = skeleton->get_bone_global_pose(child_bone_idx).basis[Vector3::AXIS_X];
      Quaternion rot = IKKusudama::quaternion_unnormalized(child_bone, current_bone);
      Vector3 x_axis = Vector3(1.0, 0.0, 0.0);
      Vector<Quaternion> decomposed = IKKusudama::get_swing_twist(rot, x_axis);
      x_angle = decomposed[1].get_angle();
      x_angle = Math::rad2deg(x_angle) + snap * 0.5; // else it won't reach +180
      x_angle -= Math::fmod(x_angle, snap);
    }
    float z_angle = 0.0f;
    {
      Vector3 current_bone = skeleton->get_bone_global_pose(current_bone_idx).basis[Vector3::AXIS_Z];
      Vector3 child_bone = skeleton->get_bone_global_pose(child_bone_idx).basis[Vector3::AXIS_Z];
      Quaternion rot = IKKusudama::quaternion_unnormalized(child_bone, current_bone);
      Vector3 z_axis = Vector3(0.0, 0.0, 1.0);
      Vector<Quaternion> decomposed = IKKusudama::get_swing_twist(rot, z_axis);
      z_angle = decomposed[1].get_angle();
      z_angle = Math::rad2deg(z_angle) + snap * 0.5; // else it won't reach +180
      z_angle -= Math::fmod(z_angle, snap);
    }
    float y_angle = 0.0f;
    {
      Vector3 current_bone = skeleton->get_bone_global_pose(current_bone_idx).basis[Vector3::AXIS_Y];
      Vector3 child_bone = skeleton->get_bone_global_pose(child_bone_idx).basis[Vector3::AXIS_Y];
      Quaternion rot = IKKusudama::quaternion_unnormalized(child_bone, current_bone);
      Vector3 y_axis = Vector3(0.0, 1.0, 0.0);
      Vector<Quaternion> decomposed = IKKusudama::get_swing_twist(rot, y_axis);
      y_angle = decomposed[1].get_angle();
      y_angle = Math::rad2deg(y_angle) + snap * 0.5; // else it won't reach +180
      y_angle -= Math::fmod(y_angle, snap);
    }
    label_mesh->set_text(
        vformat(String("Rotating %s\nX %s degrees\nY %s degrees\nTwist %s degrees"),
            skeleton->get_bone_name(current_bone_idx),
            String::num(x_angle, Math::range_step_decimals(snap)),
            String::num(y_angle, Math::range_step_decimals(snap)),
            String::num(z_angle, Math::range_step_decimals(snap))));
    label_mesh->set_font_size(8);
    label_mesh_origin->add_child(label_mesh);
    Transform3D xform = skeleton->get_bone_global_pose(current_bone_idx);
    xform.basis = Basis();
    label_mesh_origin->set_transform(xform);
    // Add the bone's children to the list of bones to be processed.
    bones_to_process.push_back(child_bones_vector[i]);
  }
}