Add debug log to resampler when no samples are found

Signed-off-by: Mathias L. Baumann <[email protected]>

Author: Marenz

src/frequenz/sdk/timeseries/_resampling.py

@@ -747,6 +747,16 @@ def resample(self, timestamp: datetime) -> Sample[Quantity]:
         relevant_samples = list(itertools.islice(self._buffer, min_index, max_index))
         if not relevant_samples:
             _logger.warning("No relevant samples found for: %s", self._name)
+            _logger.debug("Requested: %s - %s", minimum_relevant_timestamp, timestamp)
+            if self._buffer:
+                _logger.debug(
+                    "Buffer:    %s - %s",
+                    self._buffer[0].timestamp,
+                    self._buffer[-1].timestamp,
+                )
+            else:
+                _logger.debug("Buffer is empty")
+
         value = (
             conf.resampling_function(relevant_samples, conf, props)
             if relevant_samples