Fix dataset prefix matching in STAC server

README.md

@@ -72,6 +72,32 @@ async def main():
             },
         )
 
+# ERA5 land datasets
+#
+# ERA5 and ERA5-Land datasets are separate dataset IDs within the ECMWF ERA5
+# collection. Use list_datasets() or list_available_datasets() to inspect the
+# exact names before loading.
+async def main_era5_land():
+    async with dClimateClient() as dclimate:
+        # Non-land ERA5 total precipitation
+        precip, precip_metadata = await dclimate.load_dataset(
+            dataset="precipitation_total",
+            collection="era5",
+            organization="ecmwf",
+            variant="finalized",
+        )
+
+        # ERA5-Land total precipitation
+        land_precip, land_metadata = await dclimate.load_dataset(
+            dataset="precipitation_total_land",
+            collection="era5",
+            organization="ecmwf",
+            variant="finalized",
+        )
+
+        # ERA5-Land wind datasets follow the same pattern:
+        # dataset="wind_u_10m_land" or dataset="wind_v_10m_land"
+
 # Custom IPFS endpoints (optional)
 async def main_custom_ipfs():
     async with dClimateClient(

dclimate_client_py/stac_server.py

@@ -13,6 +13,33 @@
 STAC_SERVER_URL = "https://api.stac.dclimate.net"
 
 
+def _dataset_id_from_item_id(feature_id: str, collection: str) -> Optional[str]:
+    prefix = f"{collection}-"
+    remainder = (
+        feature_id[len(prefix) :] if feature_id.startswith(prefix) else feature_id
+    )
+    dataset, _, _ = remainder.partition("-")
+    return dataset or None
+
+
+def _feature_matches_dataset(
+    feature: Dict[str, Any], collection: str, dataset: str
+) -> bool:
+    feature_collection = feature.get("collection")
+    if feature_collection and feature_collection != collection:
+        return False
+
+    props = feature.get("properties") or {}
+    dataset_id = props.get("dclimate:dataset_id")
+    if dataset_id:
+        return dataset_id == dataset
+
+    feature_id = feature.get("id")
+    if not isinstance(feature_id, str):
+        return False
+    return _dataset_id_from_item_id(feature_id, collection) == dataset
+
+
 def resolve_cid_from_stac_server(
     collection: str,
     dataset: str,
@@ -48,9 +75,9 @@ def resolve_cid_from_stac_server(
 
     features = response.json().get("features", [])
 
-    # Filter to matching dataset (item ID pattern: {collection}-{dataset}-{variant})
-    prefix = f"{collection}-{dataset}"
-    matches = [f for f in features if f["id"].startswith(prefix)]
+    # Filter to the exact dataset. A prefix match would conflate datasets such
+    # as precipitation_total and precipitation_total_land.
+    matches = [f for f in features if _feature_matches_dataset(f, collection, dataset)]
     if not matches:
         raise ValueError(f"No items found for {collection}/{dataset}")
 

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "pdm.backend"
 
 [project]
 name = "dclimate-client-py"
-version = "0.5.8" # Set a static version or handle it in versioning strategy
+version = "0.5.9" # Set a static version or handle it in versioning strategy
 description = "Python client library for accessing dClimate weather and climate data"
 readme = "README.md"
 license = {text = "MIT"}

tests/test_stac_server_listing.py

@@ -16,6 +16,7 @@
 
 from dclimate_client_py.stac_server import (
     list_available_datasets_from_stac_server,
+    resolve_cid_from_stac_server,
 )
 
 
@@ -240,6 +241,111 @@ def test_groups_multiple_variants_under_same_dataset(monkeypatch):
     assert result["ecmwf_era5"]["types"] == ["temperature_2m"]
 
 
+def test_resolve_cid_uses_exact_dataset_id_for_prefix_collisions(monkeypatch):
+    """Base ERA5 datasets must not resolve to similarly named *_land datasets."""
+    _install_mocks(
+        monkeypatch,
+        collections_body=SAMPLE_COLLECTIONS,
+        search_body={
+            "features": [
+                {
+                    "id": "ecmwf_era5-precipitation_total_land-finalized",
+                    "collection": "ecmwf_era5",
+                    "properties": {
+                        "dclimate:dataset_id": "precipitation_total_land",
+                        "dclimate:variant": "finalized",
+                    },
+                    "assets": {
+                        "data": {"href": "ipfs://bafy-era5-land-precip-finalized"}
+                    },
+                },
+                {
+                    "id": "ecmwf_era5-precipitation_total-finalized",
+                    "collection": "ecmwf_era5",
+                    "properties": {
+                        "dclimate:dataset_id": "precipitation_total",
+                        "dclimate:variant": "finalized",
+                    },
+                    "assets": {"data": {"href": "ipfs://bafy-era5-precip-finalized"}},
+                },
+            ]
+        },
+    )
+
+    cid = resolve_cid_from_stac_server(
+        "ecmwf_era5",
+        "precipitation_total",
+        "finalized",
+        "https://example.test",
+    )
+
+    assert cid == "bafy-era5-precip-finalized"
+
+
+def test_resolve_cid_rejects_only_prefix_dataset_match(monkeypatch):
+    _install_mocks(
+        monkeypatch,
+        collections_body=SAMPLE_COLLECTIONS,
+        search_body={
+            "features": [
+                {
+                    "id": "ecmwf_era5-wind_u_10m_land-finalized",
+                    "collection": "ecmwf_era5",
+                    "properties": {
+                        "dclimate:dataset_id": "wind_u_10m_land",
+                        "dclimate:variant": "finalized",
+                    },
+                    "assets": {"data": {"href": "ipfs://bafy-era5-land-wind-u"}},
+                }
+            ]
+        },
+    )
+
+    with pytest.raises(ValueError, match="No items found"):
+        resolve_cid_from_stac_server(
+            "ecmwf_era5",
+            "wind_u_10m",
+            "finalized",
+            "https://example.test",
+        )
+
+
+def test_resolve_cid_legacy_id_fallback_is_exact(monkeypatch):
+    _install_mocks(
+        monkeypatch,
+        collections_body=SAMPLE_COLLECTIONS,
+        search_body={
+            "features": [
+                {
+                    "id": "ecmwf_era5-temperature_2m_land-finalized",
+                    "collection": "ecmwf_era5",
+                    "properties": {
+                        "dclimate:variant": "finalized",
+                    },
+                    "assets": {"data": {"href": "ipfs://bafy-era5-land-t2m"}},
+                },
+                {
+                    "id": "ecmwf_era5-temperature_2m-finalized",
+                    "collection": "ecmwf_era5",
+                    "properties": {
+                        "dclimate:variant": "finalized",
+                    },
+                    "assets": {"data": {"href": "ipfs://bafy-era5-t2m"}},
+                },
+            ]
+        },
+    )
+
+    cid = resolve_cid_from_stac_server(
+        "ecmwf_era5",
+        "temperature_2m",
+        "finalized",
+        "https://example.test",
+    )
+
+    assert cid == "bafy-era5-t2m"
+
+
 def test_collections_endpoint_error_propagates(monkeypatch):
     def failing_get(url, *args, **kwargs):
         return _mock_response({}, status=500)