tm geometries as bounding box, 7 digits #333

Author: Hagellach37

mapswipe_workers/mapswipe_workers/utils/geojson_functions.py

@@ -27,7 +27,7 @@ def csv_to_geojson(filename: str, geometry_field: str = "geom"):
             outfile,
             filename,
             "-sql",
-            f'SELECT *, CAST({geometry_field} as geometry) FROM "{filename_without_path}"',
+            f'SELECT *, CAST({geometry_field} as geometry) FROM "{filename_without_path}"',  # noqa E501
         ],
         check=True,
     )
@@ -101,28 +101,59 @@ def add_metadata_to_geojson(filename: str, geometry_field: str = "geom"):
     logger.info(f"added metadata to {filename}.")
 
 
-def create_group_geom(group_data):
+def create_group_geom(group_data, shape="bounding_box"):
+    """Create bounding box or convex hull of input task geometries."""
+
     result_geom_collection = ogr.Geometry(ogr.wkbMultiPolygon)
     for result, data in group_data.items():
         result_geom = ogr.CreateGeometryFromWkt(data["wkt"])
         result_geom_collection.AddGeometry(result_geom)
 
-    group_geom = result_geom_collection.ConvexHull()
+    if shape == "convex_hull":
+        group_geom = result_geom_collection.ConvexHull()
+    elif shape == "bounding_box":
+        # Get Envelope
+        lon_left, lon_right, lat_top, lat_bottom = result_geom_collection.GetEnvelope()
+
+        # Create Geometry
+        ring = ogr.Geometry(ogr.wkbLinearRing)
+        ring.AddPoint(lon_left, lat_top)
+        ring.AddPoint(lon_right, lat_top)
+        ring.AddPoint(lon_right, lat_bottom)
+        ring.AddPoint(lon_left, lat_bottom)
+        ring.AddPoint(lon_left, lat_top)
+        group_geom = ogr.Geometry(ogr.wkbPolygon)
+        group_geom.AddGeometry(ring)
+
     return group_geom
 
 
 def create_geojson_file_from_dict(final_groups_dict, outfile):
-    # TODO: adapt input name
+    """Take output from generate stats and create TM geometries.
+
+    In order to create a GeoJSON file with a coordinate precision of 7
+    we take a small detour.
+    First, we create a GeoJSONSeq file.
+    This contains only the features.
+    Then we add these features to the final GeoJSON file.
+    The current shape of the output geometries is set to 'bounding_box'.
+    """
 
-    driver = ogr.GetDriverByName("GeoJSON")
+    driver = ogr.GetDriverByName("GeoJSONSeq")
     # define spatial Reference
     srs = osr.SpatialReference()
     srs.ImportFromEPSG(4326)
+    outfile_temp = outfile.replace(".geojson", "_temp.geojson")
+
+    if os.path.exists(outfile_temp):
+        driver.DeleteDataSource(outfile_temp)
+
     if os.path.exists(outfile):
         driver.DeleteDataSource(outfile)
-    dataSource = driver.CreateDataSource(outfile)
+
+    dataSource = driver.CreateDataSource(outfile_temp)
     # create layer
-    layer = dataSource.CreateLayer(outfile, srs, geom_type=ogr.wkbPolygon)
+    layer = dataSource.CreateLayer(outfile_temp, srs, geom_type=ogr.wkbPolygon,)
 
     # create fields
     field_id = ogr.FieldDefn("group_id", ogr.OFTInteger)
@@ -133,7 +164,8 @@ def create_geojson_file_from_dict(final_groups_dict, outfile):
     else:
         for group_id in final_groups_dict.keys():
             group_data = final_groups_dict[group_id]
-            group_geom = create_group_geom(group_data)
+            # create the final group geometry
+            group_geom = create_group_geom(group_data, "bounding_box")
             final_groups_dict[group_id]["group_geom"] = group_geom
             # init feature
 
@@ -163,8 +195,35 @@ def create_geojson_file_from_dict(final_groups_dict, outfile):
                 print(group_geom)
                 continue
 
+    # make sure to close layer and data source
     layer = None
-    logger.info("created outfile: %s." % outfile)
+    dataSource = None
+
+    # load the features from temp file
+    feature_collection = []
+    with open(outfile_temp, "r") as f:
+        for cnt, line in enumerate(f):
+            feature_collection.append(json.loads(line))
+
+    # create final geojson structure
+    geojson_structure = {
+        "type": "FeatureCollection",
+        "name": outfile,
+        "crs": {
+            "type": "name",
+            "properties": {"name": "urn:ogc:def:crs:OGC:1.3:CRS84"},
+        },
+        "features": feature_collection,
+    }
+
+    # save to geojson
+    with open(outfile, "w") as json_file:
+        json.dump(geojson_structure, json_file)
+        logger.info("created outfile: %s." % outfile)
+
+    # remove temp file
+    if os.path.exists(outfile_temp):
+        driver.DeleteDataSource(outfile_temp)
 
 
 def create_geojson_file(geometries, outfile):