fix(sensor): best price calculation on v-shaped days

custom_components/tibber_prices/binary_sensor/attributes.py

@@ -445,7 +445,7 @@ async def build_async_extra_state_attributes(  # noqa: PLR0913
         position="end",
     )
 
-    return attributes if attributes else None
+    return attributes or None
 
 
 def build_sync_extra_state_attributes(  # noqa: PLR0913
@@ -508,4 +508,4 @@ def build_sync_extra_state_attributes(  # noqa: PLR0913
         position="end",
     )
 
-    return attributes if attributes else None
+    return attributes or None

custom_components/tibber_prices/coordinator/period_handlers/level_filtering.py

@@ -133,20 +133,30 @@ def check_interval_criteria(
     # - Peak price (reverse_sort=True): daily MAXIMUM
     # - Best price (reverse_sort=False): daily MINIMUM
     #
-    # Flex band calculation (using absolute values):
-    # - Peak price: [max - max*flex, max] → accept prices near the maximum
-    # - Best price: [min, min + min*flex] → accept prices near the minimum
+    # Flex base = max(price_span, abs(ref_price)):
+    # - On V-shape days (tiny minimum, large span): span wins → meaningful flex band
+    # - On flat days (large minimum, small span): ref_price wins → same as before
     #
-    # Examples with flex=20%:
-    # - Peak: max=30 ct → accept [24, 30] ct (prices ≥ 24 ct)
-    # - Best: min=10 ct → accept [10, 12] ct (prices ≤ 12 ct)
+    # WHY NOT plain ref_price * flex: When daily_min is a single low outlier
+    # (e.g., min=1 ct, avg=19 ct), the flex band collapses to near-zero
+    # (1 ct * 15% = 0.15 ct) and no period of sufficient length can be found.
+    #
+    # WHY NOT plain span * flex: On flat days (e.g., min=30 ct, span=3 ct),
+    # this makes the band much narrower than before, breaking existing behaviour.
+    #
+    # Examples with flex=15%:
+    # - V-shape: min=1 ct, avg=19 ct → span=18 ct → flex_base=18 → threshold=1+2.7=3.7 ct  (spans fixed)
+    # - Flat:    min=30 ct, avg=33 ct → span=3 ct  → flex_base=30 → threshold=30+4.5=34.5 ct (unchanged)
+    # - Normal:  min=10 ct, avg=20 ct → span=10 ct → flex_base=10 → threshold=10+1.5=11.5 ct (unchanged)
 
-    if criteria.ref_price == 0:
-        # Zero reference: flex has no effect, use strict equality
+    price_span = abs(criteria.avg_price - criteria.ref_price)
+    flex_base = max(price_span, abs(criteria.ref_price))
+
+    if flex_base == 0:
+        # Degenerate case: all prices are zero → only exact zero qualifies
         in_flex = price == 0
     else:
-        # Calculate flex amount using absolute value
-        flex_amount = abs(criteria.ref_price) * flex_abs
+        flex_amount = flex_base * flex_abs
 
         if criteria.reverse_sort:
             # Peak price: accept prices >= (ref_price - flex_amount)

custom_components/tibber_prices/entity.py

@@ -40,7 +40,7 @@ class TibberPricesEntity(CoordinatorEntity[TibberPricesDataUpdateCoordinator]):
             name=home_name,
             manufacturer="Tibber",
             model=translated_model,
-            serial_number=home_id if home_id else None,
+            serial_number=home_id or None,
             configuration_url="https://developer.tibber.com/explorer",
         )
 

custom_components/tibber_prices/entity_utils/attributes.py

@@ -95,7 +95,7 @@ def add_description_attributes(  # noqa: PLR0913, PLR0912
         get_entity_description,
     )
 
-    language = hass.config.language if hass.config.language else "en"
+    language = hass.config.language or "en"
 
     # Build description dict
     desc_attrs: dict[str, str] = {}
@@ -186,7 +186,7 @@ async def async_add_description_attributes(  # noqa: PLR0913, PLR0912
         async_get_entity_description,
     )
 
-    language = hass.config.language if hass.config.language else "en"
+    language = hass.config.language or "en"
 
     # Build description dict
     desc_attrs: dict[str, str] = {}

custom_components/tibber_prices/number/core.py

@@ -97,7 +97,7 @@ class TibberPricesConfigNumber(RestoreNumber, NumberEntity):
             name=home_name,
             manufacturer="Tibber",
             model=translated_model,
-            serial_number=home_id if home_id else None,
+            serial_number=home_id or None,
             configuration_url="https://developer.tibber.com/explorer",
         )
 
@@ -233,7 +233,7 @@ class TibberPricesConfigNumber(RestoreNumber, NumberEntity):
         if description:
             attrs["description"] = description
 
-        return attrs if attrs else None
+        return attrs or None
 
     @callback
     def async_registry_entry_updated(self) -> None:

custom_components/tibber_prices/sensor/attributes/__init__.py

@@ -214,7 +214,7 @@ def build_sensor_attributes(
         )
         return None
     else:
-        return attributes if attributes else None
+        return attributes or None
 
 
 def build_extra_state_attributes(  # noqa: PLR0913
@@ -287,7 +287,7 @@ def build_extra_state_attributes(  # noqa: PLR0913
         if sensor_attrs:
             attributes.update({k: v for k, v in sensor_attrs.items() if k not in ("timestamp", "error")})
 
-        return attributes if attributes else None
+        return attributes or None
 
     # For all other sensors: standard behavior
     # Start with default timestamp (datetime object - HA serializes automatically)
@@ -322,4 +322,4 @@ def build_extra_state_attributes(  # noqa: PLR0913
         position="end",
     )
 
-    return attributes if attributes else None
+    return attributes or None

custom_components/tibber_prices/sensor/attributes/future.py

@@ -43,7 +43,7 @@ def add_next_avg_attributes(  # noqa: PLR0913
     """
     # Extract hours from sensor key (e.g., "next_avg_3h" -> 3)
     try:
-        hours = int(key.split("_")[-1].replace("h", ""))
+        hours = int(key.rsplit("_", maxsplit=1)[-1].replace("h", ""))
     except (ValueError, AttributeError):
         return
 

custom_components/tibber_prices/sensor/calculators/timing.py

@@ -104,9 +104,9 @@ class TibberPricesTimingCalculator(TibberPricesBaseCalculator):
             ),
             "period_duration": lambda: self._calc_period_duration(current_period, next_period),
             "next_start_time": lambda: next_period.get("start") if next_period else None,
-            "remaining_minutes": lambda: (self._calc_remaining_minutes(current_period) if current_period else 0),
+            "remaining_minutes": lambda: self._calc_remaining_minutes(current_period) if current_period else 0,
             "progress": lambda: self._calc_progress_with_grace_period(current_period, previous_period, now),
-            "next_in_minutes": lambda: (self._calc_next_in_minutes(next_period) if next_period else None),
+            "next_in_minutes": lambda: self._calc_next_in_minutes(next_period) if next_period else None,
         }
 
         calculator = calculators.get(value_type)

custom_components/tibber_prices/services/get_chartdata.py

@@ -616,7 +616,7 @@ async def handle_chartdata(call: ServiceCall) -> dict[str, Any]:  # noqa: PLR091
             # Mode 'segments': Add NULL points at segment boundaries for clean gaps
             # Process ALL intervals as one continuous list - no special midnight handling needed
             filter_field = "rating_level" if rating_level_filter else "level"
-            filter_values = rating_level_filter if rating_level_filter else level_filter
+            filter_values = rating_level_filter or level_filter
             use_rating = rating_level_filter is not None
 
             for i in range(len(all_prices) - 1):

custom_components/tibber_prices/switch/core.py

@@ -93,7 +93,7 @@ class TibberPricesConfigSwitch(RestoreEntity, SwitchEntity):
             name=home_name,
             manufacturer="Tibber",
             model=translated_model,
-            serial_number=home_id if home_id else None,
+            serial_number=home_id or None,
             configuration_url="https://developer.tibber.com/explorer",
         )
 
@@ -236,7 +236,7 @@ class TibberPricesConfigSwitch(RestoreEntity, SwitchEntity):
         if description:
             attrs["description"] = description
 
-        return attrs if attrs else None
+        return attrs or None
 
     @callback
     def async_registry_entry_updated(self) -> None: