Fix bbox crs for OAMaps (#1999)

* Fix bbox crs for wms_face

- project the bbox in the API code, not the provider
- add tests

* fix flake8 (#4)

* fix quote syntax for old python versions to pass flake8

* Small stylistic changes

---------

Co-authored-by: Benjamin Webb <benjamin.miller.webb@gmail.com>

Author: C-Loftus

pygeoapi/api/maps.py

@@ -48,7 +48,7 @@
 from pygeoapi.provider.base import ProviderGenericError
 from pygeoapi.util import (
     get_provider_by_type, to_json, filter_providers_by_type,
-    filter_dict_by_key_value
+    filter_dict_by_key_value, transform_bbox
 )
 
 from . import APIRequest, API, validate_datetime
@@ -60,6 +60,9 @@
 ]
 
 
+DEFAULT_CRS = 'http://www.opengis.net/def/crs/EPSG/0/4326'
+
+
 def get_collection_map(api: API, request: APIRequest,
                        dataset, style=None) -> Tuple[dict, int, str]:
     """
@@ -102,7 +105,10 @@ def get_collection_map(api: API, request: APIRequest,
 
     query_args['format_'] = request.params.get('f', 'png')
     query_args['style'] = style
-    query_args['crs'] = request.params.get('bbox-crs', 4326)
+    query_args['crs'] = collection_def.get('crs', DEFAULT_CRS)
+    query_args['bbox_crs'] = request.params.get(
+        'bbox-crs', DEFAULT_CRS
+    )
     query_args['transparent'] = request.params.get('transparent', True)
 
     try:
@@ -133,7 +139,7 @@ def get_collection_map(api: API, request: APIRequest,
     except AttributeError:
         bbox = api.config['resources'][dataset]['extents']['spatial']['bbox']  # noqa
     try:
-        query_args['bbox'] = [float(c) for c in bbox]
+        bbox = [float(c) for c in bbox]
     except ValueError:
         exception = {
             'code': 'InvalidParameterValue',
@@ -144,6 +150,12 @@ def get_collection_map(api: API, request: APIRequest,
         return headers, HTTPStatus.BAD_REQUEST, to_json(
             exception, api.pretty_print)
 
+    if query_args['bbox_crs'] != query_args['crs']:
+        LOGGER.debug(f'Reprojecting bbox CRS: {query_args["crs"]}')
+        bbox = transform_bbox(bbox, query_args['bbox_crs'], query_args['crs'])
+
+    query_args['bbox'] = bbox
+
     LOGGER.debug('Processing datetime parameter')
     datetime_ = request.params.get('datetime')
     try:

pygeoapi/provider/wms_facade.py

@@ -43,6 +43,7 @@
 
 CRS_CODES = {
     4326: 'EPSG:4326',
+    'http://www.opengis.net/def/crs/EPSG/0/4326': 'EPSG:4326',
     'http://www.opengis.net/def/crs/EPSG/0/3857': 'EPSG:3857'
 }
 
@@ -65,7 +66,7 @@ def __init__(self, provider_def):
 
     def query(self, style=None, bbox=[-180, -90, 180, 90], width=500,
               height=300, crs=4326, datetime_=None, transparent=True,
-              format_='png'):
+              bbox_crs=4326, format_='png'):
         """
         Generate map
 
@@ -86,28 +87,12 @@ def query(self, style=None, bbox=[-180, -90, 180, 90], width=500,
 
         version = self.options.get('version', '1.3.0')
 
-        if crs in [4326, 'CRS;84'] and version == '1.3.0':
-            LOGGER.debug('Swapping 4326 axis order to WMS 1.3 mode (yx)')
-            bbox2 = ','.join(str(c) for c in
-                             [bbox[1], bbox[0], bbox[3], bbox[2]])
-        else:
-            LOGGER.debug('Reprojecting coordinates')
-            LOGGER.debug(f'Output CRS: {CRS_CODES[crs]}')
-
-            src_crs = pyproj.CRS.from_string('epsg:4326')
-            dest_crs = pyproj.CRS.from_string(CRS_CODES[crs])
-
-            transformer = pyproj.Transformer.from_crs(src_crs, dest_crs,
-                                                      always_xy=True)
-
-            minx, miny = transformer.transform(bbox[0], bbox[1])
-            maxx, maxy = transformer.transform(bbox[2], bbox[3])
-
-            bbox2 = ','.join(str(c) for c in [minx, miny, maxx, maxy])
+        if version == '1.3.0' and CRS_CODES[bbox_crs] == 'EPSG:4326':
+            bbox = [bbox[1], bbox[0], bbox[3], bbox[2]]
+        bbox2 = ','.join(map(str, bbox))
 
         if not transparent:
             self._transparent = 'FALSE'
-
         crs_param = 'crs' if version == '1.3.0' else 'srs'
 
         params = {

tests/api/test_maps.py

@@ -50,3 +50,40 @@ def test_get_collection_map(config, api_):
     assert code == HTTPStatus.OK
     assert isinstance(response, bytes)
     assert response[1:4] == b'PNG'
+
+
+def test_map_crs_transform(config, api_):
+    # Florida in EPSG:4326
+    params = {
+        'bbox': '-88.374023,24.826625,-78.112793,31.015279',
+        # crs is 4326 by implicit since it is the default
+    }
+    req = mock_api_request(params)
+    _, code, floridaIn4326 = get_collection_map(
+        api_, req, 'mapserver_world_map')
+    assert code == HTTPStatus.OK
+
+    # Area that isn't florida in the ocean; used to make sure
+    # the same coords with different crs are not the same
+    params = {
+        'bbox': '-88.374023,24.826625,-78.112793,31.015279',
+        'bbox-crs': 'http://www.opengis.net/def/crs/EPSG/0/3857',
+    }
+
+    req = mock_api_request(params)
+    _, code, florida4326InWrongCRS = get_collection_map(
+        api_, req, 'mapserver_world_map')
+    assert code == HTTPStatus.OK
+
+    assert florida4326InWrongCRS != floridaIn4326
+
+    # Florida again, but this time in EPSG:3857
+    params = {
+        'bbox': '-9837751.2884,2854464.3843,-8695476.3377,3634733.5690',
+        'bbox-crs': 'http://www.opengis.net/def/crs/EPSG/0/3857'
+    }
+    req = mock_api_request(params)
+    _, code, floridaProjectedIn3857 = get_collection_map(
+        api_, req, 'mapserver_world_map')
+    assert code == HTTPStatus.OK
+    assert floridaIn4326 == floridaProjectedIn3857