Cost chip: follow the scrub + draw the ring for multi-tariff

The cost chip now reads the cost at the hovered instant while scrubbing (like the
other chips) instead of staying on the live value; and its around-house day curve
now samples HA's cost statistics per slot, so it draws for a multi-tariff grid,
not only a fixed price.

Rolls 2026.9.0-a5.

Author: ReikanYsora

CHANGELOG.md

@@ -11,7 +11,7 @@ and the project follows a date-based versioning scheme (`YEAR.MONTH.PATCH`).
 
 The weather release, "Your real sky": the scene now reflects the weather over
 your home, and the outdoor temperature and humidity join the card. Currently in
-alpha (`2026.9.0-a4`).
+alpha (`2026.9.0-a5`).
 
 ### Added: a cost chip
 
@@ -32,7 +32,9 @@ statistic still works, computed as energy times price. **Multi-tariff grids
 price per tariff and never an explicit cost sensor: Helios finds Home Assistant's
 own per-tariff cost statistics and sums them. And the chip is **fully in the
 editor** now, show or hide it, and pick its colour and icon, like every other
-chip.
+chip. The chip **follows the timeline** as you scrub (the cost at the hovered
+moment, like the other chips), and its **day curve around the house** now draws
+for multi-tariff grids too, not just a fixed price.
 
 ### Added: the real weather, painted over the scene
 

dist/helios.js

@@ -1,6 +1,6 @@
 {
   "name": "helios",
-  "version": "2026.9.0-a4",
+  "version": "2026.9.0-a5",
   "description": "HELIOS - real-time solar exposure, cloud cover and PV production card for Home Assistant",
   "license": "GPL-3.0-or-later",
   "type": "module",

package.json

@@ -24,7 +24,7 @@ import { TIMELINE_MODES } from '../../timeline/timeline-modes';
 import { buildPeriodData, binSlotSum, type PeriodHost, type PeriodLayer } from './period-totals';
 import { changeSeriesToWatts } from '../sources/energy-stats';
 import { groupDevices } from '../sources/device-consumption';
-import { staticPrice } from '../sources/cost';
+import { staticPrice, costRateAt } from '../sources/cost';
 import type { PeriodWindow } from './slot-walk';
 
 //One drawn line of the day, unit-agnostic. `colour` is a descriptor the card resolves; everything else is the data
@@ -467,22 +467,37 @@ export function buildDayProfile(host: PeriodHost, target: ChartTarget, dayMs: nu
 
     if (target === 'cost')
     {
-        const store = host._unifiedStore;
-        if (!store) { return []; }
-        //Static price only for now (cost = energy x constant price, exact across the whole history). The ring shows
-        //the SPENDING magnitude per slot (currency/hour, floored at 0); earning hours read as no ring, since the
-        //around-house ring is a positive-magnitude shape. store powers are watts, hence /1000.
-        const impP = staticPrice(host._energyDefaults.gridImportPriceNumbers);
-        if (impP === null) { return []; }
-        const expP = staticPrice(host._energyDefaults.gridExportPriceNumbers) ?? 0;
-        const imp = binSlotAvg(store, store.gridImport, slots, win);
-        const exp = binSlotAvg(store, store.gridExport, slots, win);
-        const values = imp.map((iv, i) =>
+        //The ring shows the SPENDING magnitude per slot (currency/hour, floored at 0); earning hours read as no
+        //ring, since the around-house ring is a positive-magnitude shape. Preferred source: HA's cost statistics
+        //(any tariff), sampled at each slot's midpoint. Fallback: a single static price x grid energy (store
+        //powers are watts, hence /1000).
+        const hasStats = !!(host._costImportSeries || host._costExportSeries);
+        let values: (number | null)[];
+        if (hasStats)
         {
-            const ev = exp[i];
-            if ((iv === null || !isFinite(iv)) && (ev === null || !isFinite(ev))) { return null; }
-            return Math.max(0, ((iv ?? 0) * impP - (ev ?? 0) * expP) / 1000);
-        });
+            const slotLen = DAY_MS / slots;
+            values = Array.from({ length: slots }, (_v, s) =>
+            {
+                const r = costRateAt(host, win.fromMs + (s + 0.5) * slotLen);
+                return r === null ? null : Math.max(0, r);
+            });
+        }
+        else
+        {
+            const store = host._unifiedStore;
+            if (!store) { return []; }
+            const impP = staticPrice(host._energyDefaults.gridImportPriceNumbers);
+            if (impP === null) { return []; }
+            const expP = staticPrice(host._energyDefaults.gridExportPriceNumbers) ?? 0;
+            const imp = binSlotAvg(store, store.gridImport, slots, win);
+            const exp = binSlotAvg(store, store.gridExport, slots, win);
+            values = imp.map((iv, i) =>
+            {
+                const ev = exp[i];
+                if ((iv === null || !isFinite(iv)) && (ev === null || !isFinite(ev))) { return null; }
+                return Math.max(0, ((iv ?? 0) * impP - (ev ?? 0) * expP) / 1000);
+            });
+        }
         dropShortRuns(values);
         const peak = peakOf(values);
         if (peak <= 0) { return []; }

src/data/period-totals/day-profile.ts

@@ -29,6 +29,9 @@ export interface CostHost
     //Rolling past-window days + recorder period, for the cost `change` fetch (same span as the store).
     readonly _periodPastDays:   number;
     readonly _storeFetchPeriod: StatPeriod;
+    //Scrub state, so the chip reads the cost at the hovered time (like the other chips) rather than only live.
+    readonly _selectedTime: Date | null;
+    readonly _isLiveMode:   boolean;
     requestUpdate(): void;
     //Recorder `change` series for the cost (`stat_cost`) + compensation (`stat_compensation`) statistics, summed
     //across flows. Δ per bucket is money, so a rate is Δ / bucketHours. Null until first fetch (or none configured).
@@ -133,13 +136,18 @@ export function refreshCostLive(host: CostHost): void
 {
     host._currency = String(host.hass?.config?.currency ?? '€');
 
-    //1) Universal path: HA's own cost statistics (correct for any tariff, incl. Tempo + a total-cost sensor). Live
-    //   is the most recent committed bucket's net rate. Preferred whenever cost stats are configured.
-    const fromStats = latestCostRate(host);
-    if (fromStats !== null)
+    //1) Universal path: HA's own cost statistics (correct for any tariff, incl. Tempo + a total-cost sensor).
+    //   Scrub-aware like every other chip: the rate at the hovered instant while scrubbing, else the most recent
+    //   committed bucket when live.
+    if (host._costImportSeries || host._costExportSeries)
     {
-        if (host._costRate !== fromStats) { host._costRate = fromStats; }
-        return;
+        const scrubMs = (host._selectedTime && !host._isLiveMode) ? host._selectedTime.getTime() : null;
+        const fromStats = scrubMs !== null ? costRateAt(host, scrubMs) : latestCostRate(host);
+        if (fromStats !== null)
+        {
+            if (host._costRate !== fromStats) { host._costRate = fromStats; }
+            return;
+        }
     }
 
     //2) Fallback: a single configured PRICE x live power (no cost statistic, e.g. only a static/current price set).