[Fixes #11171] Fix calculation of wkt for regions crossing the dateli…

…ne (#11172)

* Fix region wkt calculation when crossing dateline

* simplification

* fix PEP8

* fix failing test

* fixed wrong local path for fixtures

* restore test

* Keep WKT for regions not across IDL return Polygon

geonode/base/fixtures/regions.json

@@ -4334,6 +4334,23 @@
       "bbox_y1": 27.454559
     }
   },
+  {
+    "pk": 256,
+    "model": "base.region",
+    "fields": {
+      "rght": 515,
+      "code": "PAC",
+      "name": "Pacific",
+      "parent": null,
+      "level": 1,
+      "lft": 464,
+      "tree_id": 90,
+      "bbox_x0": 112.921112,
+      "bbox_x1": -108.87291,
+      "bbox_y0": -54.640301,
+      "bbox_y1": 20.41712
+    }
+  },
   {
     "pk": 257,
     "model": "base.region",

geonode/tests/test_utils.py

@@ -28,7 +28,7 @@
 from unittest.mock import patch
 from datetime import datetime, timedelta
 
-from django.contrib.gis.geos import Polygon
+from django.contrib.gis.geos import GEOSGeometry, Polygon
 from django.contrib.auth import get_user_model
 from django.core.management import call_command
 
@@ -37,7 +37,7 @@
 from geonode.geoserver.helpers import set_attributes
 from geonode.tests.base import GeoNodeBaseTestSupport
 from geonode.br.management.commands.utils.utils import ignore_time
-from geonode.utils import copy_tree, fixup_shp_columnnames, get_supported_datasets_file_types, unzip_file
+from geonode.utils import copy_tree, fixup_shp_columnnames, get_supported_datasets_file_types, unzip_file, bbox_to_wkt
 from geonode import settings
 
 
@@ -286,3 +286,68 @@ def test_should_replace_the_type_id_if_already_exists(self):
         self.assertEqual(len(supported_keys), prev_count)
         shp_type = [t for t in supported_types if t["id"] == "shp"][0]
         self.assertEqual(shp_type["label"], "Replaced type")
+
+
+class TestRegionsCrossingDateLine(TestCase):
+    def setUp(self):
+        self.test_region_coords = [
+            [112.921111999999994, -108.872910000000005, -54.640301000000001, 20.417120000000001],  # Pacific
+            [174.866196000000002, -178.203156000000007, -21.017119999999998, -12.466220000000000],  # Fiji
+            [158.418335000000013, -150.208359000000002, -11.437030000000000, 4.719560000000000],  # Kiribati
+            [165.883803999999998, -175.987198000000006, -52.618591000000002, -29.209969999999998],  # New Zeland
+        ]
+
+        self.region_across_idl = [
+            112.921111999999994,
+            -108.872910000000005,
+            -54.640301000000001,
+            20.417120000000001,
+        ]  # Pacific
+        self.region_not_across_idl = [
+            -31.266000999999999,
+            39.869301000000000,
+            27.636310999999999,
+            81.008797000000001,
+        ]  # Europe
+
+        self.dataset_crossing = GEOSGeometry(
+            "POLYGON ((-179.30100799101168718 -17.31310259828852693, -170.41740336774466869 -9.63481116511300328, -164.30155495876181249 -19.7237289784715415, \
+            -177.91712988386967709 -30.43762400150689018, -179.30100799101168718 -17.31310259828852693))",
+            srid=4326,
+        )
+        self.dataset_not_crossing = GEOSGeometry(
+            "POLYGON ((-41.86461347546176626 5.43160371103088835, 34.20404118809119609 4.3602142087273279, 9.56208263510924894 -48.8521310723496498,  \
+            -42.22174330956295307 -32.42415870369499942, -41.86461347546176626 5.43160371103088835))",
+            srid=4326,
+        )
+
+    def test_region_across_dateline_do_not_intersect_areas_outside(self):
+        for i, region_coords in enumerate(self.test_region_coords):
+            geographic_bounding_box = bbox_to_wkt(
+                region_coords[0], region_coords[1], region_coords[2], region_coords[3]
+            )
+            _, wkt = geographic_bounding_box.split(";")
+            poly = GEOSGeometry(wkt, srid=4326)
+
+            self.assertFalse(
+                poly.intersection(self.dataset_crossing).empty, f"True intersection not detected for region {i}"
+            )
+            self.assertTrue(poly.intersection(self.dataset_not_crossing).empty, "False intersection detected")
+
+    def test_region_wkt_multipolygon_if_across_idl(self):
+        bbox_across_idl = bbox_to_wkt(
+            self.region_not_across_idl[0],
+            self.region_not_across_idl[1],
+            self.region_not_across_idl[2],
+            self.region_not_across_idl[3],
+        )
+        _, wkt = bbox_across_idl.split(";")
+        poly = GEOSGeometry(wkt, srid=4326)
+        self.assertEqual(poly.geom_type, "Polygon", f"Expexted 'Polygon' type but received {poly.geom_type}")
+
+        bbox_across_idl = bbox_to_wkt(
+            self.region_across_idl[0], self.region_across_idl[1], self.region_across_idl[2], self.region_across_idl[3]
+        )
+        _, wkt = bbox_across_idl.split(";")
+        poly = GEOSGeometry(wkt, srid=4326)
+        self.assertEqual(poly.geom_type, "MultiPolygon", f"Expexted 'MultiPolygon' type but received {poly.geom_type}")

geonode/utils.py

@@ -496,9 +496,44 @@ def bbox_to_wkt(x0, x1, y0, y1, srid="4326", include_srid=True):
     if srid and str(srid).startswith("EPSG:"):
         srid = srid[5:]
     if None not in {x0, x1, y0, y1}:
-        wkt = "POLYGON(({:f} {:f},{:f} {:f},{:f} {:f},{:f} {:f},{:f} {:f}))".format(
-            float(x0), float(y0), float(x0), float(y1), float(x1), float(y1), float(x1), float(y0), float(x0), float(y0)
+        polys = []
+
+        # We assume that if x1 is smaller then x0 we're crossing the date line
+        crossing_idl = x1 < x0
+        if crossing_idl:
+            polys.append(
+                [
+                    (float(x0), float(y0)),
+                    (float(x0), float(y1)),
+                    (180.0, float(y1)),
+                    (180.0, float(y0)),
+                    (float(x0), float(y0)),
+                ]
+            )
+            polys.append(
+                [
+                    (-180.0, float(y0)),
+                    (-180.0, float(y1)),
+                    (float(x1), float(y1)),
+                    (float(x1), float(y0)),
+                    (-180.0, float(y0)),
+                ]
+            )
+        else:
+            polys.append(
+                [
+                    (float(x0), float(y0)),
+                    (float(x0), float(y1)),
+                    (float(x1), float(y1)),
+                    (float(x1), float(y0)),
+                    (float(x0), float(y0)),
+                ]
+            )
+
+        poly_wkts = ",".join(
+            ["(({}))".format(",".join(["{:f} {:f}".format(coords[0], coords[1]) for coords in poly])) for poly in polys]
         )
+        wkt = f"MULTIPOLYGON({poly_wkts})" if len(polys) > 1 else f"POLYGON{poly_wkts}"
         if include_srid:
             wkt = f"SRID={srid};{wkt}"
     else: