From ef62b6f2aa5d42ae45865eed142ab1e69f6ae43f Mon Sep 17 00:00:00 2001
From: Mathieu Baudier <mbaudier@argeo.org>
Date: Fri, 6 Oct 2023 07:24:47 +0200
Subject: [PATCH] GeoShape to Geometry

---
 .../src/org/argeo/app/geo/GeoShapeUtils.java  | 49 +++++++++++++++++++
 .../src/org/argeo/app/geo/GpxUtils.java       | 10 ++--
 2 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/org.argeo.app.geo/src/org/argeo/app/geo/GeoShapeUtils.java b/org.argeo.app.geo/src/org/argeo/app/geo/GeoShapeUtils.java
index 1db099b..d35492a 100644
--- a/org.argeo.app.geo/src/org/argeo/app/geo/GeoShapeUtils.java
+++ b/org.argeo.app.geo/src/org/argeo/app/geo/GeoShapeUtils.java
@@ -1,14 +1,63 @@
 package org.argeo.app.geo;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.StringTokenizer;
+
 import org.locationtech.jts.geom.Coordinate;
 import org.locationtech.jts.geom.Geometry;
+import org.locationtech.jts.geom.GeometryFactory;
 import org.locationtech.jts.geom.LineString;
+import org.locationtech.jts.geom.MultiPoint;
 import org.locationtech.jts.geom.Point;
 import org.locationtech.jts.geom.Polygon;
 
 /** Utilities around ODK's GeoShape format */
 public class GeoShapeUtils {
 
+	@SuppressWarnings("unchecked")
+	public static <T> T geoShapeToGeometry(String geoShape, Class<T> clss) {
+		Objects.requireNonNull(geoShape);
+		GeometryFactory geometryFactory = JTS.GEOMETRY_FACTORY_WGS84;
+		List<Coordinate> coordinates = new ArrayList<>();
+		StringTokenizer stSeg = new StringTokenizer(geoShape.trim(), ";");
+		while (stSeg.hasMoreTokens()) {
+			StringTokenizer stPt = new StringTokenizer(stSeg.nextToken().trim(), " ");
+			String lat = stPt.nextToken();
+			String lng = stPt.nextToken();
+			String alt = stPt.nextToken();
+			// String precision = stPt.nextToken();
+			Coordinate coord;
+			if (!alt.equals("0.0")) {
+				coord = new Coordinate(Double.parseDouble(lat), Double.parseDouble(lng), Double.parseDouble(alt));
+			} else {
+				coord = new Coordinate(Double.parseDouble(lat), Double.parseDouble(lng));
+			}
+			coordinates.add(coord);
+		}
+		if (LineString.class.isAssignableFrom(clss)) {
+			LineString lineString = geometryFactory
+					.createLineString(coordinates.toArray(new Coordinate[coordinates.size()]));
+			return (T) lineString;
+		} else if (MultiPoint.class.isAssignableFrom(clss)) {
+			MultiPoint multiPoint = geometryFactory
+					.createMultiPointFromCoords(coordinates.toArray(new Coordinate[coordinates.size()]));
+			return (T) multiPoint;
+		} else if (Polygon.class.isAssignableFrom(clss)) {
+			Coordinate first = coordinates.get(0);
+			Coordinate last = coordinates.get(coordinates.size() - 1);
+			if (!(first.getX() == last.getX() && first.getY() == last.getY())) {
+				// close the line string
+				coordinates.add(first);
+			}
+			Polygon polygon = geometryFactory.createPolygon(coordinates.toArray(new Coordinate[coordinates.size()]));
+			return (T) polygon;
+		} else {
+			throw new IllegalArgumentException("Unsupported format " + clss);
+		}
+	}
+
 	/** Converts a {@link Geometry} with WGS84 coordinates to a GeoShape. */
 	public static String geometryToGeoShape(Geometry geometry) {
 		if (geometry instanceof Point point) {
diff --git a/org.argeo.app.geo/src/org/argeo/app/geo/GpxUtils.java b/org.argeo.app.geo/src/org/argeo/app/geo/GpxUtils.java
index 5b07d16..2a946f4 100644
--- a/org.argeo.app.geo/src/org/argeo/app/geo/GpxUtils.java
+++ b/org.argeo.app.geo/src/org/argeo/app/geo/GpxUtils.java
@@ -88,8 +88,12 @@ public class GpxUtils {
 			// multiPoint.normalize();
 			return (T) multiPoint;
 		} else if (Polygon.class.isAssignableFrom(clss)) {
-			// close the line string
-			coordinates.add(coordinates.get(0));
+			Coordinate first = coordinates.get(0);
+			Coordinate last = coordinates.get(coordinates.size() - 1);
+			if (!(first.getX() == last.getX() && first.getY() == last.getY())) {
+				// close the line string
+				coordinates.add(first);
+			}
 			Polygon polygon = geometryFactory.createPolygon(coordinates.toArray(new Coordinate[coordinates.size()]));
 			return (T) polygon;
 		} else if (SimpleFeature.class.isAssignableFrom(clss)) {
@@ -114,7 +118,7 @@ public class GpxUtils {
 		return area;
 	}
 
-	/** Write ODK GepShape as a GPX file. */
+	/** Write ODK GeoShape as a GPX file. */
 	public static void writeGeoShapeAsGpx(String geoShape, OutputStream out) throws IOException {
 		Objects.requireNonNull(geoShape);
 		Writer writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
-- 
2.30.2