Resolve "Add height from GHSL characteristics"

Closes #18 (closed)

\approve @ds @pdlmora

building/01_select/ghsl_characteristics_information/ghsl_characteristics_information.py

+#!/usr/bin/env python3
+
+# Copyright (c) 2024:
+#   Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or (at
+# your option) any later version.
+#
+# This program 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 Affero
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see http://www.gnu.org/licenses/.
+
+
+class GHSLCharacteristicsInformation:
+    def __call__(self, database, geometry_wkt, *args, **kwargs):
+        """
+        Intersect the building geometry with the GHSL characteristics layer and return the type
+        with the largest overlap.
+
+        Args:
+            database (PostGISDatabase):
+                GHSL source database.
+            geometry_wkt (string):
+                The WKT representation of the geometry of the building.
+
+        Returns:
+            A dictionary with the GHSL characteristics type exhibiting the largest overlap with
+            the building.
+        """
+
+        # Get the total area of the intersection between a GHSL type and the building.
+        get_area_function = f"""
+            SUM(
+                ST_Area(
+                    ST_Intersection(geom, ST_Buffer(ST_GeomFromText('{geometry_wkt}', 4326),0)
+                ), True)
+            ) AS area
+            """
+
+        # Select the type with the largest overlap with the building.
+        sql_statement = f"""
+            SELECT type
+            FROM (
+                SELECT type, {get_area_function}
+                FROM ghsl_characteristics
+                WHERE geom && ST_GeomFromText('{geometry_wkt}', 4326)
+                GROUP BY type
+            ) AS ghsl_area
+            ORDER BY area DESC
+            LIMIT 1
+            """
+
+        database.cursor.execute(sql_statement)
+        result = database.cursor.fetchone()
+
+        if result:
+            return {"ghsl_characteristics_type": result[0]}
+        else:
+            return {"ghsl_characteristics_type": None}