feat: set up logging of http requests (#250)

Fixes: #156

src/oaipmh_scythe/client.py

@@ -23,7 +23,7 @@
 from oaipmh_scythe.iterator import BaseOAIIterator, OAIItemIterator
 from oaipmh_scythe.models import Header, Identify, MetadataFormat, OAIItem, Record, Set
 from oaipmh_scythe.response import OAIResponse
-from oaipmh_scythe.utils import filter_dict_except_resumption_token, remove_none_values
+from oaipmh_scythe.utils import filter_dict_except_resumption_token, log_response, remove_none_values
 
 if TYPE_CHECKING:
     from collections.abc import Iterable, Iterator
@@ -113,7 +113,7 @@ def client(self) -> httpx.Client:
         """
         if self._client is None or self._client.is_closed:
             headers = {"Accept": "text/xml; charset=utf-8", "user-agent": USER_AGENT}
-            self._client = httpx.Client(headers=headers, timeout=self.timeout)
+            self._client = httpx.Client(headers=headers, timeout=self.timeout, event_hooks={"response": [log_response]})
         return self._client
 
     def close(self) -> None:

src/oaipmh_scythe/utils.py

@@ -10,6 +10,7 @@
 more accessible data structures.
 
 Functions:
+    log_response: Log the details of an HTTP response.
     remove_none_values: Remove keys from the dictionary where the value is `None`.
     filter_dict_except_resumption_token: Filter keys from the dictionary, if resumption token is not `None`.
     get_namespace: Extracts the namespace from an XML element.
@@ -26,11 +27,29 @@
 if TYPE_CHECKING:
     from typing import Any
 
+    import httpx
     from lxml import etree
 
 logger = logging.getLogger(__name__)
 
 
+def log_response(response: httpx.Response) -> None:
+    """Log the details of an HTTP response.
+
+    This function logs the HTTP method, URL, and status code of the response for debugging purposes.
+    It uses the 'debug' logging level to provide detailed diagnostic information.
+
+    Args:
+        response: The response object received from an HTTP request.
+
+    Returns:
+        None
+    """
+    logger.debug(
+        "[http] Response: %s %s - Status %s", response.request.method, response.request.url, response.status_code
+    )
+
+
 def remove_none_values(d: dict[str, Any | None]) -> dict[str, Any]:
     """Remove keys from the dictionary where the value is `None`.