/*-
 *  Copyright 2020 Beuth Hochschule für Technik Berlin, Hochschule für Technik Stuttgart
 * 
 *  This file is part of CityDoctor2.
 *
 *  CityDoctor2 is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  CityDoctor2 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
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with CityDoctor2.  If not, see <https://www.gnu.org/licenses/>.
 */
package de.hft.stuttgart.citydoctor2.mapper.citygml3;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.locationtech.proj4j.BasicCoordinateTransform;
import org.locationtech.proj4j.ProjCoordinate;
import org.xmlobjects.gml.model.geometry.primitives.AbstractRing;
import org.xmlobjects.gml.model.geometry.primitives.AbstractRingProperty;
import org.xmlobjects.gml.model.geometry.primitives.Polygon;
import org.xmlobjects.gml.model.geometry.primitives.Ring;
import org.xmlobjects.gml.visitor.GeometryWalker;

import de.hft.stuttgart.citydoctor2.datastructure.ConcretePolygon;
import de.hft.stuttgart.citydoctor2.datastructure.GmlId;
import de.hft.stuttgart.citydoctor2.datastructure.LinearRing;
import de.hft.stuttgart.citydoctor2.datastructure.LinearRing.LinearRingType;
import de.hft.stuttgart.citydoctor2.datastructure.Vertex;
import de.hft.stuttgart.citydoctor2.parser.ParserConfiguration;
import de.hft.stuttgart.citydoctor2.utils.Localization;

public class Citygml3GeometryMapper extends GeometryWalker {
	
	private static final Logger logger = LogManager.getLogger(Citygml3GeometryMapper.class);
	
	private List<ConcretePolygon> polygons = new ArrayList<>();
	private LinearRing currentRing = null;
	private ParserConfiguration config;
	private ProjCoordinate p1 = new ProjCoordinate();
	private ProjCoordinate p2 = new ProjCoordinate();
	private Map<Vertex, Vertex> vertexMap;
	
	public Citygml3GeometryMapper(ParserConfiguration config, Map<Vertex, Vertex> vertices) {
		this.config = config;
		this.vertexMap = vertices;
	}
	
	@Override
	public void visit(Polygon polygon) {
		parsePolygon(polygon.getId(), polygon.getExterior(), polygon.getInterior());
		if (polygon.getExterior() == null) {
			System.out.println("No exterior: " + polygon.getId());
		}
	}
	
	private void parsePolygon(String id, AbstractRingProperty exterior, List<AbstractRingProperty> interior) {
		if (exterior == null || exterior.getObject() == null) {
			if (logger.isWarnEnabled()) {
				logger.warn(Localization.getText("GeometryMapper.emptyPolygon"));
			}
			return;
		}
		ConcretePolygon cdPoly = new ConcretePolygon();
		polygons.add(cdPoly);
		
		if (id != null) {
			cdPoly.setGmlId(new GmlId(id));
		}
		
		currentRing = new LinearRing(LinearRingType.EXTERIOR);
		exterior.getObject().accept(this);
		cdPoly.setExteriorRing(currentRing);
		
		for (AbstractRingProperty interiorGmlRing : interior) {
			AbstractRing gmlRing = interiorGmlRing.getObject();
			if (gmlRing == null) {
				continue;
			}
			currentRing = new LinearRing(LinearRingType.INTERIOR);
			gmlRing.accept(this);
			cdPoly.addInteriorRing(currentRing);
		}
	}
	
	@Override
	public void visit(org.xmlobjects.gml.model.geometry.primitives.LinearRing gmlRing) {
		if (gmlRing.getSrsDimension() != null && gmlRing.getSrsDimension() != 3) {
			logger.warn("Cannot handle geometry with srsDimension not 3");
			return;
		}
		if (gmlRing.getId() != null) {
			currentRing.setGmlId(new GmlId(gmlRing.getId()));
		}
		List<Double> coordinates = gmlRing.toCoordinateList3D();
		handleCoordinateList(coordinates);
	}
	
	@Override
	public void visit(Ring ring) {
		if (ring.getSrsDimension() != null && ring.getSrsDimension() != 3) {
			logger.warn("Cannot handle geometry with srsDimension not 3");
			return;
		}
		if (ring.getId() != null) {
			currentRing.setGmlId(new GmlId(ring.getId()));
		}
		List<Double> coordinates = ring.toCoordinateList3D();
		handleCoordinateList(coordinates);
	}
	
	private void handleCoordinateList(List<Double> coordinates) {
		if (coordinates.size() % 3 != 0) {
			String id;
			if (currentRing.hasExistingGmlId()) {
				id = currentRing.getGmlId().getGmlString();
			} else {
				id = "";
			}
			logger.warn("The number of coordinates for linear ring {} do not result in fully 3D points", id);
		}
		for (int i = 0; i < coordinates.size(); i = i + 3) {
			double x = coordinates.get(i + 0);
			double y = coordinates.get(i + 1);
			double z = coordinates.get(i + 2);
			createVertex(x, y, z);
		}
	}
	
	private void createVertex(double x, double y, double z) {
		// transform into utm, if available
		BasicCoordinateTransform trans = config.getTargetTransform();
		if (trans != null) {
			p1.setValue(x, y);
			trans.transform(p1, p2);
			x = p2.x;
			y = p2.y;
			z = z / config.getFromMetres();
		}
		x = round(x, config.getNumberOfRoundingPlaces());
		y = round(y, config.getNumberOfRoundingPlaces());
		z = round(z, config.getNumberOfRoundingPlaces());
		Vertex v = new Vertex(x, y, z);
		Vertex duplicate = vertexMap.get(v);
		if (duplicate == null) {
			vertexMap.put(v, v);
		} else {
			v = duplicate;
		}

		currentRing.addVertex(v);
	}
	
	private double round(double value, int places) {
		if (places < 0) {
			throw new IllegalArgumentException();
		}

		BigDecimal bd = BigDecimal.valueOf(value);
		bd = bd.setScale(places, RoundingMode.HALF_UP);
		return bd.doubleValue();
	}
	
	public List<ConcretePolygon> getPolygons() {
		return polygons;
	}

}