/********************************************************************************
 *                                                                              *
 * This file is part of IfcOpenShell.                                           *
 *                                                                              *
 * IfcOpenShell is free software: you can redistribute it and/or modify         *
 * it under the terms of the Lesser GNU General Public License as published by  *
 * the Free Software Foundation, either version 3.0 of the License, or          *
 * (at your option) any later version.                                          *
 *                                                                              *
 * IfcOpenShell is distributed in the hope that it will be useful,              *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
 * Lesser GNU General Public License for more details.                          *
 *                                                                              *
 * You should have received a copy of the Lesser GNU General Public License     *
 * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
 *                                                                              *
 ********************************************************************************/

#include "mapping.h"
#define mapping POSTFIX_SCHEMA(mapping)
using namespace ifcopenshell::geometry;

#if defined SCHEMA_HAS_IfcAxis2PlacementLinear

taxonomy::ptr mapping::map_impl(const IfcSchema::IfcAxis2PlacementLinear* inst) {

	if (!inst->Location()->as<IfcSchema::IfcPointByDistanceExpression>())
         Logger::Error(std::runtime_error("Location must be IfcPointByDistanceExpression for IfcAxis2PlacementLinear"));

	Eigen::Vector3d o, axis(0, 0, 1), refDirection;

   taxonomy::matrix4::ptr m = taxonomy::cast<taxonomy::matrix4>(map(inst->Location()));
   o = m->components().col(3).head<3>();

	// From 8.9.3.4 IfcAxis2PlacementLinear there are 4 cases that need to be considered
	// 1) Axis is given but not RefDirection
	// 2) RefDirection is given but not Axis
   // 3) Neither Axis or RefDirection are provided
   // 4) Both Axis and RefDirection are provided

	const bool hasAxis = inst->Axis() != nullptr;
   const bool hasRef = inst->RefDirection() != nullptr;

	if (hasAxis != hasRef) {
		Logger::Warning("Axis and RefDirection should be specified together", inst);
	}

	if (hasAxis && !hasRef) 
	{
      taxonomy::direction3::ptr a = taxonomy::cast<taxonomy::direction3>(map(inst->Axis()));
      axis = *a->components_;

	   refDirection = m->components().col(0).head<3>(); // RefDirection is the curve tangent when omitted
      // refDirection is not necessarily orthogonal to axis.
      // axis.cross(refDirection) gives y. y.cross(axis) gives x=refDirection
      refDirection = axis.cross(refDirection).cross(axis);
   } 
	else if (!hasAxis && hasRef) 
	{
      taxonomy::direction3::ptr r = taxonomy::cast<taxonomy::direction3>(map(inst->RefDirection()));
      refDirection = *r->components_;
      Eigen::Vector3d up(0, 0, 1);
      axis = refDirection.cross(up.cross(refDirection));
   } 
	else if (!hasAxis && !hasRef) 
	{
       refDirection = m->components().col(0).head<3>(); // RefDirection is the curve tangent when omitted
       Eigen::Vector3d up(0, 0, 1);
       axis = refDirection.cross(up.cross(refDirection));
   }
	else 
	{
       taxonomy::direction3::ptr a = taxonomy::cast<taxonomy::direction3>(map(inst->Axis()));
       axis = *a->components_;

       taxonomy::direction3::ptr r = taxonomy::cast<taxonomy::direction3>(map(inst->RefDirection()));
       refDirection = *r->components_;
       refDirection = axis.cross(refDirection).cross(axis); // refDirection needs to be orthogonal to axis
   }

   // axis and refDirection need to be orthogonal
	return taxonomy::make<taxonomy::matrix4>(o, axis, refDirection);
}

#endif