From ab71728f74dd06575e1d5647cdb6de67a29bddb1 Mon Sep 17 00:00:00 2001
From: Henri Kynsilehto <henri.kynsilehto@gmail.com>
Date: Wed, 26 Nov 2025 15:40:05 +0200
Subject: [PATCH] Add CRS parameter support to EDR API

---
 pygeoapi/api/environmental_data_retrieval.py  | 27 ++++++++++++++++---
 .../api/test_environmental_data_retrieval.py  | 20 ++++++++++++++
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/pygeoapi/api/environmental_data_retrieval.py b/pygeoapi/api/environmental_data_retrieval.py
index 1c2550740..a601a9919 100644
--- a/pygeoapi/api/environmental_data_retrieval.py
+++ b/pygeoapi/api/environmental_data_retrieval.py
@@ -43,11 +43,13 @@
 from typing import Tuple
 import urllib
 
+from pyproj.exceptions import CRSError
 from shapely.errors import ShapelyError
 from shapely.wkt import loads as shapely_loads
 
 from pygeoapi import l10n
 from pygeoapi.api import evaluate_limit
+from pygeoapi.crs import (create_crs_transform_spec, set_content_crs_header)
 from pygeoapi.plugin import load_plugin, PLUGINS
 from pygeoapi.provider.base import (
     ProviderGenericError, ProviderItemNotFoundError)
@@ -265,8 +267,9 @@ def get_collection_edr_query(api: API, request: APIRequest,
 
     LOGGER.debug('Loading provider')
     try:
-        p = load_plugin('provider', get_provider_by_type(
-            collections[dataset]['providers'], 'edr'))
+        provider_def = get_provider_by_type(
+            collections[dataset]['providers'], 'edr')
+        p = load_plugin('provider', provider_def)
     except ProviderGenericError as err:
         return api.get_exception(
             err.http_status_code, headers, request.format,
@@ -284,6 +287,21 @@ def get_collection_edr_query(api: API, request: APIRequest,
             HTTPStatus.BAD_REQUEST, headers, request.format,
             'InvalidParameterValue', msg)
 
+    crs_transform_spec = None
+    query_crs_uri = request.params.get('crs')
+    if query_crs_uri is not None:
+        LOGGER.debug('Processing crs parameter')
+        try:
+            crs_transform_spec = create_crs_transform_spec(
+                provider_def, query_crs_uri
+            )
+        except (ValueError, CRSError) as err:
+            msg = str(err)
+            return api.get_exception(
+                HTTPStatus.BAD_REQUEST, headers, request.format,
+                'InvalidParameterValue', msg)
+        set_content_crs_header(headers, provider_def, query_crs_uri)
+
     LOGGER.debug('Processing query parameters')
 
     LOGGER.debug('Processing datetime parameter')
@@ -377,7 +395,8 @@ def get_collection_edr_query(api: API, request: APIRequest,
         within=within,
         within_units=within_units,
         limit=limit,
-        location_id=location_id
+        location_id=location_id,
+        crs_transform_spec=crs_transform_spec
     )
 
     try:
@@ -507,6 +526,7 @@ def get_oas_30(cfg: dict, locale: str) -> tuple[list[dict[str, str]], dict[str,
                             {'$ref': f"{OPENAPI_YAML['oapif-1']}#/components/parameters/datetime"},  # noqa
                             {'$ref': f"{OPENAPI_YAML['oaedr']}/parameters/parameter-name.yaml"},  # noqa
                             {'$ref': f"{OPENAPI_YAML['oaedr']}/parameters/z.yaml"},  # noqa
+                            {'$ref': '#/components/parameters/crs'},
                             {'$ref': '#/components/parameters/f'}
                         ],
                         'responses': {
@@ -590,6 +610,7 @@ def get_oas_30(cfg: dict, locale: str) -> tuple[list[dict[str, str]], dict[str,
                             {'$ref': f"{OPENAPI_YAML['oaedr']}/parameters/locationId.yaml"},  # noqa
                             {'$ref': f"{OPENAPI_YAML['oapif-1']}#/components/parameters/datetime"},  # noqa
                             {'$ref': f"{OPENAPI_YAML['oaedr']}/parameters/parameter-name.yaml"},  # noqa
+                            {'$ref': '#/components/parameters/crs'},
                             {'$ref': '#/components/parameters/f'}
                         ],
                         'responses': {
diff --git a/tests/api/test_environmental_data_retrieval.py b/tests/api/test_environmental_data_retrieval.py
index 230218499..8b7d665e1 100644
--- a/tests/api/test_environmental_data_retrieval.py
+++ b/tests/api/test_environmental_data_retrieval.py
@@ -252,3 +252,23 @@ def test_get_collection_edr_query(config, api_):
     rsp_headers, code, response = get_collection_edr_query(
         api_, req, 'usgs-prism', None, 'cube')
     assert code == HTTPStatus.OK
+
+
+def test_get_collection_edr_query_crs(config, api_):
+    # Invalid CRS query parameter (not a URI)
+    req = mock_api_request({'coords': 'POINT(11 11)', 'crs': '4326'})
+    rsp_headers, code, response = get_collection_edr_query(
+        api_, req, 'icoads-sst', None, 'position')
+    assert code == HTTPStatus.BAD_REQUEST
+
+    # Valid CRS parameter (default CRS)
+    req = mock_api_request({
+        'coords': 'POINT(11 11)',
+        'crs': 'http://www.opengis.net/def/crs/OGC/1.3/CRS84'
+    })
+    rsp_headers, code, response = get_collection_edr_query(
+        api_, req, 'icoads-sst', None, 'position')
+    assert code == HTTPStatus.OK
+    assert 'Content-Crs' in rsp_headers
+    expected_crs = '<http://www.opengis.net/def/crs/OGC/1.3/CRS84>'
+    assert rsp_headers['Content-Crs'] == expected_crs