Added next slot sensor

custom_components/ohme/sensor.py

@@ -11,7 +11,7 @@
 from homeassistant.helpers.entity import generate_entity_id
 from .const import DOMAIN, DATA_CLIENT, DATA_COORDINATOR, DATA_STATISTICS_COORDINATOR
 from .coordinator import OhmeUpdateCoordinator, OhmeStatisticsUpdateCoordinator
-
+from .utils import charge_graph_next_slot
 
 async def async_setup_entry(
     hass: core.HomeAssistant,
@@ -24,7 +24,7 @@ async def async_setup_entry(
     stats_coordinator = hass.data[DOMAIN][DATA_STATISTICS_COORDINATOR]
 
     sensors = [PowerDrawSensor(coordinator, hass, client), EnergyUsageSensor(
-        stats_coordinator, hass, client)]
+        stats_coordinator, hass, client), NextSlotSensor(coordinator, hass, client)]
 
     async_add_entities(sensors, update_before_add=True)
 
@@ -112,3 +112,44 @@ def native_value(self):
             return self.coordinator.data['energyChargedTotalWh'] / 1000
 
         return None
+
+class NextSlotSensor(CoordinatorEntity[OhmeStatisticsUpdateCoordinator], SensorEntity):
+    """Sensor for next smart charge slot."""
+    _attr_name = "Ohme Next Smart Charge Slot"
+    _attr_device_class = SensorDeviceClass.TIMESTAMP
+
+    def __init__(
+            self,
+            coordinator: OhmeUpdateCoordinator,
+            hass: HomeAssistant,
+            client):
+        super().__init__(coordinator=coordinator)
+
+        self._state = None
+        self._attributes = {}
+        self._last_updated = None
+        self._client = client
+
+        self.entity_id = generate_entity_id(
+            "sensor.{}", "ohme_next_slot", hass=hass)
+
+        self._attr_device_info = hass.data[DOMAIN][DATA_CLIENT].get_device_info(
+        )
+
+    @property
+    def unique_id(self) -> str:
+        """Return the unique ID of the sensor."""
+        return self._client.get_unique_id("next_slot")
+
+    @property
+    def icon(self):
+        """Icon of the sensor."""
+        return "mdi:clock-star-four-points-outline"
+
+    @property
+    def native_value(self):
+        """Get value from data returned from API by coordinator"""
+        if self.coordinator.data and self.coordinator.data['mode'] != "DISCONNECTED":
+            return charge_graph_next_slot(self.coordinator.data['startTime'], self.coordinator.data['chargeGraph']['points'])
+
+        return None

custom_components/ohme/utils.py

@@ -0,0 +1,36 @@
+from time import time
+from datetime import datetime
+import pytz
+
+def charge_graph_next_slot(charge_start, points):
+    """Get the next charge slot from a list of graph points."""
+    # Get start and current timestamp in seconds
+    charge_start = round(charge_start / 1000)
+    now = int(time())
+
+    # Replace relative timestamp (seconds) with real timestamp
+    data = [{"t": x["x"] + charge_start, "y": x["y"]} for x in points]
+
+    # Filter to points from now onwards
+    data = [x for x in data if x["t"] > now]
+
+    # Give up if we have less than 3 points
+    if len(data) < 3:
+        return False
+
+    next_ts = None
+
+    # Loop through every remaining value, skipping the last
+    for idx in range(0, len(data) - 1):
+        # Calculate the delta between this element and the next
+        delta = data[idx + 1]["y"] - data[idx]["y"]
+
+        # If the next point has a Y delta of 10+, consider this the start of a slot
+        # This should be 0+ but I had some strange results in testing... revisit
+        if delta > 10:
+            next_ts = data[idx]["t"]
+            break
+
+    # This needs to be presented with tzinfo or Home Assistant will reject it
+    return None if next_ts is None else datetime.utcfromtimestamp(next_ts).replace(tzinfo=pytz.utc)
+