feat(services): add rolling 48h window support to chart services

Add dynamic rolling window mode to get_chartdata and get_apexcharts_yaml
services that automatically adapts to data availability.

When 'day' parameter is omitted, services return 48-hour window:
- With tomorrow data (after ~13:00): today + tomorrow
- Without tomorrow data: yesterday + today

Changes:
- Implement rolling window logic in get_chartdata using has_tomorrow_data()
- Generate config-template-card wrapper in get_apexcharts_yaml for dynamic
  ApexCharts span.offset based on tomorrow_data_available binary sensor
- Update service descriptions in services.yaml
- Add rolling window descriptions to all translations (de, en, nb, nl, sv)
- Document rolling window mode in docs/user/services.md
- Add ApexCharts examples with prerequisites in docs/user/automation-examples.md

BREAKING CHANGE: get_apexcharts_yaml rolling window mode requires
config-template-card in addition to apexcharts-card for dynamic offset
calculation.

Impact: Users can create auto-adapting 48h price charts without manual day
selection. Fixed day views (day: today/yesterday/tomorrow) still work with
apexcharts-card only.

custom_components/tibber_prices/services.yaml

@@ -40,9 +40,9 @@ get_apexcharts_yaml:
           integration: tibber_prices
     day:
       name: Day
-      description: Which day to visualize (yesterday, today, or tomorrow).
+      description: >-
+        Which day to visualize (yesterday, today, or tomorrow). If not specified, returns a rolling 2-day window: today+tomorrow (when tomorrow data is available) or yesterday+today (when tomorrow data is not yet available).
       required: false
-      default: today
       example: today
       selector:
         select:
@@ -90,7 +90,8 @@ get_chartdata:
     # === DATA SELECTION ===
     day:
       name: Day
-      description: Which day(s) to fetch prices for. You can select multiple days. If not specified, returns all available data (today + tomorrow if available).
+      description: >-
+        Which day(s) to fetch prices for. You can select multiple days. If not specified, returns a rolling 2-day window: today+tomorrow (when tomorrow data is available) or yesterday+today (when tomorrow data is not yet available). This provides continuous chart display without gaps.
       required: false
       selector:
         select:

custom_components/tibber_prices/services/get_apexcharts_yaml.py

@@ -36,6 +36,7 @@ from custom_components.tibber_prices.const import (
     get_translation,
 )
 from homeassistant.exceptions import ServiceValidationError
+from homeassistant.helpers import config_validation as cv
 from homeassistant.helpers.entity_registry import (
     EntityRegistry,
 )
@@ -55,12 +56,12 @@ ATTR_DAY: Final = "day"
 ATTR_ENTRY_ID: Final = "entry_id"
 
 # Service schema
-APEXCHARTS_SERVICE_SCHEMA: Final = vol.Schema(
+APEXCHARTS_SERVICE_SCHEMA = vol.Schema(
     {
-        vol.Required(ATTR_ENTRY_ID): str,
+        vol.Required(ATTR_ENTRY_ID): cv.string,
-        vol.Optional("day", default="today"): vol.In(["yesterday", "today", "tomorrow"]),
+        vol.Optional("day"): vol.In(["yesterday", "today", "tomorrow"]),
         vol.Optional("level_type", default="rating_level"): vol.In(["rating_level", "level"]),
-        vol.Optional("highlight_best_price", default=True): bool,
+        vol.Optional("highlight_best_price", default=True): cv.boolean,
     }
 )
 
@@ -158,7 +159,7 @@ def _get_current_price_entity(entity_registry: EntityRegistry, entry_id: str) ->
     )
 
 
-async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:
+async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:  # noqa: PLR0912, PLR0915
     """
     Return YAML snippet for ApexCharts card.
 
@@ -186,7 +187,7 @@ async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:
         raise ServiceValidationError(translation_domain=DOMAIN, translation_key="missing_entry_id")
     entry_id: str = str(entry_id_raw)
 
-    day = call.data.get("day", "today")
+    day = call.data.get("day")  # Can be None (rolling window mode)
     level_type = call.data.get("level_type", "rating_level")
     highlight_best_price = call.data.get("highlight_best_price", True)
 
@@ -203,7 +204,8 @@ async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:
     entity_registry = async_get_entity_registry(hass)
 
     # Build entity mapping based on level_type and day for clickable states
-    entity_map = _build_entity_map(entity_registry, entry_id, level_type, day)
+    # When day is None, use "today" as fallback for entity mapping
+    entity_map = _build_entity_map(entity_registry, entry_id, level_type, day or "today")
 
     if level_type == "rating_level":
         series_levels = [
@@ -234,13 +236,16 @@ async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:
         else:
             filter_param = f"level_filter: ['{level_key}']"
 
+        # Conditionally include day parameter (omit for rolling window mode)
+        day_param = f"day: ['{day}'], " if day else ""
+
         data_generator = (
             f"const response = await hass.callWS({{ "
             f"type: 'call_service', "
             f"domain: 'tibber_prices', "
             f"service: 'get_chartdata', "
             f"return_response: true, "
-            f"service_data: {{ entry_id: '{entry_id}', day: ['{day}'], {filter_param}, "
+            f"service_data: {{ entry_id: '{entry_id}', {day_param}{filter_param}, "
             f"output_format: 'array_of_arrays', insert_nulls: 'segments', minor_currency: true, "
             f"connect_segments: true }} }}); "
             f"return response.response.data;"
@@ -276,13 +281,16 @@ async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:
     if highlight_best_price and entity_map:
         # Create vertical highlight bands using separate Y-axis (0-1 range)
         # This creates a semi-transparent overlay from bottom to top without affecting price scale
+        # Conditionally include day parameter (omit for rolling window mode)
+        day_param = f"day: ['{day}'], " if day else ""
+
         best_price_generator = (
             f"const response = await hass.callWS({{ "
             f"type: 'call_service', "
             f"domain: 'tibber_prices', "
             f"service: 'get_chartdata', "
             f"return_response: true, "
-            f"service_data: {{ entry_id: '{entry_id}', day: ['{day}'], "
+            f"service_data: {{ entry_id: '{entry_id}', {day_param}"
             f"period_filter: 'best_price', "
             f"output_format: 'array_of_arrays', minor_currency: true }} }}); "
             f"return response.response.data.map(point => [point[0], 1]);"
@@ -311,22 +319,34 @@ async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:
         "Price Phases Daily Progress" if level_type == "rating_level" else "Price Level"
     )
 
-    # Add translated day to title
+    # Add translated day to title (only if day parameter was provided)
+    if day:
         day_translated = get_translation(["selector", "day", "options", day], user_language) or day.capitalize()
         title = f"{title} - {day_translated}"
 
     # Configure span based on selected day
+    # For rolling window mode, use config-template-card for dynamic offset
     if day == "yesterday":
         span_config = {"start": "day", "offset": "-1d"}
+        graph_span_value = None
+        use_template = False
     elif day == "tomorrow":
         span_config = {"start": "day", "offset": "+1d"}
-    else:  # today
+        graph_span_value = None
+        use_template = False
+    elif day:  # today (explicit)
         span_config = {"start": "day"}
+        graph_span_value = None
+        use_template = False
+    else:  # Rolling window mode (None)
+        # Use config-template-card to dynamically set offset based on data availability
+        span_config = None  # Will be set in template
+        graph_span_value = "48h"
+        use_template = True
 
-    return {
+    result = {
         "type": "custom:apexcharts-card",
         "update_interval": "5m",
-        "span": span_config,
         "header": {
             "show": True,
             "title": title,
@@ -392,3 +412,55 @@ async def handle_apexcharts_yaml(call: ServiceCall) -> dict[str, Any]:
         },
         "series": series,
     }
+
+    # For rolling window mode, wrap in config-template-card for dynamic offset
+    if use_template:
+        # Add graph_span to base config (48h window)
+        result["graph_span"] = graph_span_value
+
+        # Find tomorrow_data_available binary sensor
+        tomorrow_data_sensor = next(
+            (
+                entity.entity_id
+                for entity in entity_registry.entities.values()
+                if entity.config_entry_id == entry_id
+                and entity.unique_id
+                and entity.unique_id.endswith("_tomorrow_data_available")
+            ),
+            None,
+        )
+
+        if tomorrow_data_sensor:
+            # Wrap in config-template-card with dynamic offset calculation
+            # Template checks if tomorrow data is available (binary sensor state)
+            # If 'on' (tomorrow data available) → offset +1d (show today+tomorrow)
+            # If 'off' (no tomorrow data) → offset +0d (show yesterday+today)
+            template_value = f"states['{tomorrow_data_sensor}'].state === 'on' ? '+1d' : '+0d'"
+            return {
+                "type": "custom:config-template-card",
+                "variables": {
+                    "v_offset": template_value,
+                },
+                "entities": [tomorrow_data_sensor],
+                "card": {
+                    **result,
+                    "span": {
+                        "end": "day",
+                        "offset": "${v_offset}",
+                    },
+                },
+            }
+
+        # Fallback if sensor not found: just use +1d offset
+        result["span"] = {"end": "day", "offset": "+1d"}
+        return result
+
+    # Add span for fixed-day views
+    if span_config:
+        result["span"] = span_config
+
+    # Add graph_span if needed
+    if graph_span_value:
+        result["graph_span"] = graph_span_value
+
+    return result

custom_components/tibber_prices/services/get_chartdata.py

@@ -48,7 +48,7 @@ from custom_components.tibber_prices.coordinator.helpers import (
 from homeassistant.exceptions import ServiceValidationError
 
 from .formatters import aggregate_hourly_exact, get_period_data, normalize_level_filter, normalize_rating_level_filter
-from .helpers import get_entry_and_data
+from .helpers import get_entry_and_data, has_tomorrow_data
 
 if TYPE_CHECKING:
     from homeassistant.core import ServiceCall
@@ -114,6 +114,11 @@ async def handle_chartdata(call: ServiceCall) -> dict[str, Any]:  # noqa: PLR091
     Supports both 15-minute intervals and hourly aggregation, with optional filtering by
     price level, rating level, or period (best_price/peak_price).
 
+    Default behavior (no day parameter):
+    - Returns rolling 2-day window for continuous chart display
+    - If tomorrow data available: today + tomorrow
+    - If tomorrow data NOT available: yesterday + today
+
     See services.yaml for detailed parameter documentation.
 
     Args:
@@ -132,10 +137,15 @@ async def handle_chartdata(call: ServiceCall) -> dict[str, Any]:  # noqa: PLR091
         raise ServiceValidationError(translation_domain=DOMAIN, translation_key="missing_entry_id")
     entry_id: str = str(entry_id_raw)
 
+    # Get coordinator to check data availability
+    _, coordinator, _ = get_entry_and_data(hass, entry_id)
+
     days_raw = call.data.get(ATTR_DAY)
-    # If no day specified, return all available data (today + tomorrow)
+    # If no day specified, use rolling 2-day window:
+    # - If tomorrow data available: today + tomorrow
+    # - If tomorrow data NOT available: yesterday + today
     if days_raw is None:
-        days = ["today", "tomorrow"]
+        days = ["today", "tomorrow"] if has_tomorrow_data(coordinator) else ["yesterday", "today"]
     # Convert single string to list for uniform processing
     elif isinstance(days_raw, str):
         days = [days_raw]
@@ -174,8 +184,6 @@ async def handle_chartdata(call: ServiceCall) -> dict[str, Any]:  # noqa: PLR091
         if average_field in array_fields_template:
             include_average = True
 
-    _, coordinator, _ = get_entry_and_data(hass, entry_id)
-
     # Get thresholds from config for rating aggregation
     threshold_low = coordinator.config_entry.options.get(
         CONF_PRICE_RATING_THRESHOLD_LOW, DEFAULT_PRICE_RATING_THRESHOLD_LOW

custom_components/tibber_prices/services/helpers.py

@@ -19,9 +19,11 @@ from __future__ import annotations
 from typing import TYPE_CHECKING, Any
 
 from custom_components.tibber_prices.const import DOMAIN
+from custom_components.tibber_prices.coordinator.helpers import get_intervals_for_day_offsets
 from homeassistant.exceptions import ServiceValidationError
 
 if TYPE_CHECKING:
+    from custom_components.tibber_prices.coordinator import TibberPricesDataUpdateCoordinator
     from homeassistant.core import HomeAssistant
 
 
@@ -51,3 +53,22 @@ def get_entry_and_data(hass: HomeAssistant, entry_id: str) -> tuple[Any, Any, di
     coordinator = entry.runtime_data.coordinator
     data = coordinator.data or {}
     return entry, coordinator, data
+
+
+def has_tomorrow_data(coordinator: TibberPricesDataUpdateCoordinator) -> bool:
+    """
+    Check if tomorrow's price data is available in coordinator.
+
+    Uses get_intervals_for_day_offsets() to automatically determine tomorrow
+    based on current date.
+
+    Args:
+        coordinator: TibberPricesDataUpdateCoordinator instance
+
+    Returns:
+        True if tomorrow's data exists (at least one interval), False otherwise
+
+    """
+    coordinator_data = coordinator.data or {}
+    tomorrow_intervals = get_intervals_for_day_offsets(coordinator_data, [1])
+    return len(tomorrow_intervals) > 0

custom_components/tibber_prices/translations/de.json

@@ -799,7 +799,7 @@
                 },
                 "day": {
                     "name": "Tag",
-                    "description": "Welcher Tag visualisiert werden soll (gestern, heute oder morgen)."
+                    "description": "Welcher Tag visualisiert werden soll (gestern, heute oder morgen). Falls nicht angegeben, wird ein rollierendes 2-Tage-Fenster zurückgegeben: heute+morgen (wenn Daten für morgen verfügbar sind) oder gestern+heute (wenn Daten für morgen noch nicht verfügbar sind)."
                 },
                 "level_type": {
                     "name": "Stufen-Typ",
@@ -817,7 +817,7 @@
                 },
                 "day": {
                     "name": "Tag",
-                    "description": "Für welche(n) Tag(e) sollen Preise abgerufen werden. Du kannst mehrere Tage auswählen. Falls nicht angegeben, werden alle verfügbaren Daten zurückgegeben (heute + morgen falls verfügbar)."
+                    "description": "Für welche(n) Tag(e) sollen Preise abgerufen werden. Du kannst mehrere Tage auswählen. Falls nicht angegeben, wird ein rollierendes 2-Tages-Fenster zurückgegeben: heute+morgen (wenn Morgendaten verfügbar) oder gestern+heute (wenn Morgendaten noch nicht verfügbar). Dies ermöglicht eine kontinuierliche Diagrammanzeige ohne Lücken."
                 },
                 "resolution": {
                     "name": "Auflösung",

custom_components/tibber_prices/translations/en.json

@@ -795,7 +795,7 @@
                 },
                 "day": {
                     "name": "Day",
-                    "description": "Which day to visualize (yesterday, today, or tomorrow)."
+                    "description": "Which day to visualize (yesterday, today, or tomorrow). If not specified, returns a rolling 2-day window: today+tomorrow (when tomorrow data is available) or yesterday+today (when tomorrow data is not yet available)."
                 },
                 "level_type": {
                     "name": "Level Type",
@@ -813,7 +813,7 @@
                 },
                 "day": {
                     "name": "Day",
-                    "description": "Which day(s) to fetch prices for. You can select multiple days. If not specified, returns all available data (today + tomorrow if available)."
+                    "description": "Which day(s) to fetch prices for. You can select multiple days. If not specified, returns a rolling 2-day window: today+tomorrow (when tomorrow data is available) or yesterday+today (when tomorrow data is not yet available). This provides continuous chart display without gaps."
                 },
                 "resolution": {
                     "name": "Resolution",

custom_components/tibber_prices/translations/nb.json

@@ -795,7 +795,7 @@
                 },
                 "day": {
                     "name": "Dag",
-                    "description": "Hvilken dag som skal visualiseres (i går, i dag eller i morgen)."
+                    "description": "Hvilken dag som skal visualiseres (i går, i dag eller i morgen). Hvis ikke angitt, returneres et rullende 2-dagers vindu: i dag+i morgen (når data for i morgen er tilgjengelig) eller i går+i dag (når data for i morgen ikke er tilgjengelig ennå)."
                 },
                 "level_type": {
                     "name": "Nivåtype",
@@ -813,7 +813,7 @@
                 },
                 "day": {
                     "name": "Dag",
-                    "description": "Hvilken dag(er) skal det hentes priser for. Du kan velge flere dager. Hvis ikke angitt, returneres alle tilgjengelige data (i dag + i morgen hvis tilgjengelig)."
+                    "description": "Hvilken dag(er) skal det hentes priser for. Du kan velge flere dager. Hvis ikke angitt, returneres et rullerende 2-dagers vindu: i dag+i morgen (når morgendagens data er tilgjengelig) eller i går+i dag (når morgendagens data ikke er tilgjengelig ennå). Dette gir kontinuerlig diagramvisning uten hull."
                 },
                 "resolution": {
                     "name": "Oppløsning",

custom_components/tibber_prices/translations/nl.json

@@ -795,7 +795,7 @@
                 },
                 "day": {
                     "name": "Dag",
-                    "description": "Welke dag gevisualiseerd moet worden (gisteren, vandaag of morgen)."
+                    "description": "Welke dag gevisualiseerd moet worden (gisteren, vandaag of morgen). Indien niet opgegeven, wordt een rollend 2-dagen venster geretourneerd: vandaag+morgen (wanneer gegevens voor morgen beschikbaar zijn) of gisteren+vandaag (wanneer gegevens voor morgen nog niet beschikbaar zijn)."
                 },
                 "level_type": {
                     "name": "Niveautype",
@@ -813,7 +813,7 @@
                 },
                 "day": {
                     "name": "Dag",
-                    "description": "Voor welke dag(en) moeten prijzen worden opgehaald. Je kunt meerdere dagen selecteren. Als niet opgegeven, worden alle beschikbare gegevens geretourneerd (vandaag + morgen indien beschikbaar)."
+                    "description": "Voor welke dag(en) moeten prijzen worden opgehaald. Je kunt meerdere dagen selecteren. Als niet opgegeven, wordt een rollend 2-daags venster geretourneerd: vandaag+morgen (wanneer morgengegevens beschikbaar zijn) of gisteren+vandaag (wanneer morgengegevens nog niet beschikbaar zijn). Dit zorgt voor een continue grafiekweergave zonder hiaten."
                 },
                 "resolution": {
                     "name": "Resolutie",

custom_components/tibber_prices/translations/sv.json

@@ -795,7 +795,7 @@
                 },
                 "day": {
                     "name": "Dag",
-                    "description": "Vilken dag som ska visualiseras (igår, idag eller imorgon)."
+                    "description": "Vilken dag som ska visualiseras (igår, idag eller imorgon). Om inte angivet returneras ett rullande 2-dagarsfönster: idag+imorgon (när data för imorgon är tillgänglig) eller igår+idag (när data för imorgon inte är tillgänglig ännu)."
                 },
                 "level_type": {
                     "name": "Nivåtyp",
@@ -813,7 +813,7 @@
                 },
                 "day": {
                     "name": "Dag",
-                    "description": "Vilken dag(ar) ska priser hämtas för. Du kan välja flera dagar. Om inte angivet, returneras alla tillgängliga data (idag + imorgon om tillgängligt)."
+                    "description": "Vilken dag(ar) ska priser hämtas för. Du kan välja flera dagar. Om inte angivet, returneras ett rullande 2-dagars fönster: idag+imorgon (när morgondagens data är tillgänglig) eller igår+idag (när morgondagens data inte är tillgänglig ännu). Detta ger kontinuerlig diagramvisning utan luckor."
                 },
                 "resolution": {
                     "name": "Upplösning",

docs/user/automation-examples.md

@@ -241,4 +241,60 @@ Coming soon...
 
 ## ApexCharts Cards
 
-Coming soon...
+The `tibber_prices.get_apexcharts_yaml` service generates complete ApexCharts card configurations for visualizing electricity prices.
+
+### Prerequisites
+
+**Required:**
+- [ApexCharts Card](https://github.com/RomRider/apexcharts-card) - Install via HACS
+
+**Optional (for rolling window mode):**
+- [Config Template Card](https://github.com/iantrich/config-template-card) - Install via HACS
+
+### Installation
+
+1. Open HACS → Frontend
+2. Search for "ApexCharts Card" and install
+3. (Optional) Search for "Config Template Card" and install if you want rolling window mode
+
+### Example: Fixed Day View
+
+```yaml
+# Generate configuration via automation/script
+service: tibber_prices.get_apexcharts_yaml
+data:
+    entry_id: YOUR_ENTRY_ID
+    day: today  # or "yesterday", "tomorrow"
+    level_type: rating_level  # or "level" for 5-level view
+response_variable: apexcharts_config
+```
+
+Then copy the generated YAML into your Lovelace dashboard.
+
+### Example: Rolling 48h Window
+
+For a dynamic chart that automatically adapts to data availability:
+
+```yaml
+service: tibber_prices.get_apexcharts_yaml
+data:
+    entry_id: YOUR_ENTRY_ID
+    # Omit 'day' parameter for rolling window
+    level_type: rating_level
+response_variable: apexcharts_config
+```
+
+**Behavior:**
+- **When tomorrow data available** (typically after ~13:00): Shows today + tomorrow
+- **When tomorrow data not available**: Shows yesterday + today
+
+**Note:** Rolling window mode requires Config Template Card to dynamically adjust the time range.
+
+### Features
+
+- Color-coded price levels/ratings (green = cheap, yellow = normal, red = expensive)
+- Best price period highlighting (semi-transparent green overlay)
+- Automatic NULL insertion for clean gaps
+- Translated labels based on your Home Assistant language
+- Interactive zoom and pan
+- Live marker showing current time

docs/user/services.md

@@ -57,6 +57,25 @@ response_variable: chart_data
 | `minor_currency` | Return prices in ct/øre instead of EUR/NOK  | `false`                 |
 | `round_decimals` | Decimal places (0-10)                       | 4 (major) or 2 (minor)  |
 
+**Rolling Window Mode:**
+
+Omit the `day` parameter to get a dynamic 48-hour rolling window that automatically adapts to data availability:
+
+```yaml
+service: tibber_prices.get_chartdata
+data:
+    entry_id: YOUR_ENTRY_ID
+    # Omit 'day' for rolling window
+    output_format: array_of_objects
+response_variable: chart_data
+```
+
+**Behavior:**
+- **When tomorrow data available** (typically after ~13:00): Returns today + tomorrow
+- **When tomorrow data not available**: Returns yesterday + today
+
+This is useful for charts that should always show a 48-hour window without manual day selection.
+
 **Period Filter Example:**
 
 Get best price periods as summaries instead of intervals:
@@ -93,15 +112,26 @@ For detailed parameter descriptions, see the service definition in **Developer T
 
 **Purpose:** Generates complete ApexCharts card YAML configuration for visualizing electricity prices.
 
+**Prerequisites:**
+- [ApexCharts Card](https://github.com/RomRider/apexcharts-card) (required for all configurations)
+- [Config Template Card](https://github.com/iantrich/config-template-card) (required only for rolling window mode without `day` parameter)
+
 **Quick Example:**
 
 ```yaml
 service: tibber_prices.get_apexcharts_yaml
 data:
     entry_id: YOUR_ENTRY_ID
+    day: today  # Optional: omit for rolling 48h window (requires config-template-card)
 response_variable: apexcharts_config
 ```
 
+**Rolling Window Mode:** When omitting the `day` parameter, the service generates a dynamic 48-hour rolling window that automatically shows:
+- Today + Tomorrow (when tomorrow data is available)
+- Yesterday + Today (when tomorrow data is not yet available)
+
+This mode requires the Config Template Card to dynamically adjust the time window based on data availability.
+
 Use the response in Lovelace dashboards by copying the generated YAML.
 
 **Documentation:** See Developer Tools → Services for parameter details.