/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.geometry.euclidean.threed;
  
  import java.util.List;
  
  import org.apache.commons.geometry.core.Transform;
  import org.apache.commons.geometry.core.partitioning.Hyperplane;
  import org.apache.commons.geometry.core.partitioning.Split;
  import org.apache.commons.geometry.euclidean.twod.AffineTransformMatrix2D;
  import org.apache.commons.geometry.euclidean.twod.ConvexArea;
  import org.apache.commons.geometry.euclidean.twod.Vector2D;
  
  /** Internal implementation of {@link PlaneConvexSubset} that uses an embedded
   * {@link ConvexArea} to represent the subspace region. This class is capable of
   * representing regions of infinite size.
   */
  final class EmbeddedAreaPlaneConvexSubset extends AbstractEmbeddedRegionPlaneSubset
      implements PlaneConvexSubset, PlaneConvexSubset.Embedded {
  
      /** The embedded 2D area. */
      private final ConvexArea area;
  
      /** Create a new instance from its component parts.
       * @param plane plane the the convex area is embedded in
       * @param area the embedded convex area
       */
      EmbeddedAreaPlaneConvexSubset(final EmbeddingPlane plane, final ConvexArea area) {
          super(plane);
  
          this.area = area;
      }
  
      /** {@inheritDoc} */
      @Override
      public PlaneConvexSubset.Embedded getEmbedded() {
          return this;
      }
  
      /** {@inheritDoc} */
      @Override
      public ConvexArea getSubspaceRegion() {
          return area;
      }
  
      /** {@inheritDoc} */
      @Override
      public List<Vector3D> getVertices() {
          return getPlane().toSpace(area.getVertices());
      }
  
      /** {@inheritDoc} */
      @Override
      public Bounds3D getBounds() {
          return getBoundsFromSubspace(area);
      }
  
      /** {@inheritDoc} */
      @Override
      public List<Triangle3D> toTriangles() {
          if (isInfinite()) {
              throw new IllegalStateException("Cannot convert infinite plane subset to triangles: " + this);
          }
  
          final EmbeddingPlane plane = getPlane();
          final List<Vector3D> vertices = plane.toSpace(area.getVertices());
  
          return Planes.convexPolygonToTriangleFan(plane, vertices);
      }
  
      /** {@inheritDoc} */
      @Override
      public EmbeddedAreaPlaneConvexSubset transform(final Transform<Vector3D> transform) {
          final EmbeddingPlane.SubspaceTransform st = getPlane().subspaceTransform(transform);
          final ConvexArea tArea = area.transform(st.getTransform());
  
          return new EmbeddedAreaPlaneConvexSubset(st.getPlane().getEmbedding(), tArea);
      }
  
      /** {@inheritDoc} */
      @Override
      public EmbeddedAreaPlaneConvexSubset reverse() {
          final EmbeddingPlane plane = getPlane();
          final EmbeddingPlane rPlane = plane.reverse();
  
         final Vector2D rU = rPlane.toSubspace(plane.toSpace(Vector2D.Unit.PLUS_X));
         final Vector2D rV = rPlane.toSubspace(plane.toSpace(Vector2D.Unit.PLUS_Y));
 
         final AffineTransformMatrix2D transform =
                 AffineTransformMatrix2D.fromColumnVectors(rU, rV);
 
         return new EmbeddedAreaPlaneConvexSubset(rPlane, area.transform(transform));
     }
 
     /** {@inheritDoc} */
     @Override
     public Split<PlaneConvexSubset> split(final Hyperplane<Vector3D> splitter) {
         // delegate back to the Planes factory method so that it has a chance to decide
         // on the best possible implementation for the given area
         return Planes.subspaceSplit((Plane) splitter, this,
             (p, r) -> Planes.subsetFromConvexArea(p, (ConvexArea) r));
     }
 }