výkon: dashboard ve 2 vlnách (status hned, plán/telemetrie async), stale data bez blikání

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/hooks/useDashboardData.ts

@@ -169,6 +169,7 @@ export function useDashboardData(siteId: number | null) {
   const [negPrices, setNegPrices] = useState<NegPriceItem[]>([])
   const [error, setError] = useState<string | null>(null)
   const [ready, setReady] = useState(false)
+  const [slotsReady, setSlotsReady] = useState(false)
 
   const wsRef = useRef<WebSocket | null>(null)
   const siteIdRef = useRef(siteId)
@@ -182,27 +183,40 @@ export function useDashboardData(siteId: number | null) {
       setLiveMetrics(null)
       setError(null)
       setReady(true)
+      setSlotsReady(true)
       return
     }
 
     const windowStart = floorSlotUtcMs(Date.now()) - SLOT_COUNT_BACK * SLOT_MS
     const nIdx = currentSlotIndexInWindow(windowStart)
 
+    // Vlna 1 — kritická: vw_site_status (+ TČ) je rychlé, UI se odemkne hned.
+    let status: SiteStatusRow | null = null
+    try {
+      const [statusArr, hpArr] = await Promise.all([
+        getJson<SiteStatusRow[]>('/vw_site_status', { site_id: `eq.${siteId}` }),
+        getJson<HeatPumpLatestRow[]>('/vw_latest_heat_pump', { site_id: `eq.${siteId}` }),
+      ])
+      status = Array.isArray(statusArr) && statusArr[0] ? statusArr[0]! : null
+      const hp = Array.isArray(hpArr) && hpArr[0] ? hpArr[0]! : null
+      setLiveMetrics(buildLiveMetrics(status, hp))
+      setError(null)
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'Chyba načítání dashboardu')
+    } finally {
+      setReady(true)
+    }
+
+    // Vlna 2 — extended: plán, telemetrie, audit, ceny. Při refetchi zůstávají
+    // zobrazená stale data (sloty se přepíšou až novými daty, žádné blikání).
     try {
       const todayPrague = pragueCalendarDay()
-      const dates = new Set<string>()
-      for (let i = 0; i < TOTAL_SLOTS; i++) {
-        const ms = windowStart + i * SLOT_MS
-        dates.add(pragueCalendarDay(new Date(ms)))
-      }
 
       const [
         planMaybe,
-        statusArr,
         telemetry15m7d,
         auditHourly,
         modeLog,
-        hpArr,
         priceRows,
       ] = await Promise.all([
         getCurrentPlan(siteId).catch((e: unknown) => {
@@ -211,7 +225,6 @@ export function useDashboardData(siteId: number | null) {
           }
           throw e
         }),
-        getJson<SiteStatusRow[]>('/vw_site_status', { site_id: `eq.${siteId}` }),
         getJson<Telemetry15m7dRow[]>('/vw_telemetry_15m_7d', {
           site_id: `eq.${siteId}`,
           slot_start: `gte.${new Date(windowStart).toISOString()}`,
@@ -227,7 +240,6 @@ export function useDashboardData(siteId: number | null) {
           order: 'activated_at.asc',
           limit: '200',
         }),
-        getJson<HeatPumpLatestRow[]>('/vw_latest_heat_pump', { site_id: `eq.${siteId}` }),
         // Ceny bereme přes FastAPI range endpoint (PostgREST /rest je u vás chráněné → 401).
         getSitePricesSlotsRange(
           siteId,
@@ -236,10 +248,6 @@ export function useDashboardData(siteId: number | null) {
         ),
       ])
 
-      const status = Array.isArray(statusArr) && statusArr[0] ? statusArr[0]! : null
-      const hp = Array.isArray(hpArr) && hpArr[0] ? hpArr[0]! : null
-      setLiveMetrics(buildLiveMetrics(status, hp))
-
       const plan = planMaybe as { intervals: PlanningIntervalDto[] }
       const planBySlot = new Map<string, PlanningIntervalDto>()
       for (const iv of plan.intervals) {
@@ -403,13 +411,16 @@ export function useDashboardData(siteId: number | null) {
       setError(null)
     } catch (e) {
       setError(e instanceof Error ? e.message : 'Chyba načítání dashboardu')
-      setSlots([])
+      // Sloty neměnit — během chyby refetche zůstávají zobrazená poslední data.
     } finally {
-      setReady(true)
+      setSlotsReady(true)
     }
   }, [siteId])
 
   useEffect(() => {
+    // Změna lokality: data staré site nesmí zůstat zobrazená.
+    setSlots([])
+    setSlotsReady(false)
     void load()
     const id = window.setInterval(() => void load(), POLL_FULL_MS)
     return () => window.clearInterval(id)
@@ -526,6 +537,7 @@ export function useDashboardData(siteId: number | null) {
     negPrices,
     error,
     ready,
+    slotsReady,
     reload: load,
     liveMetrics,
     buyNow,

frontend/src/pages/Dashboard.tsx

@@ -315,7 +315,7 @@ export function Dashboard() {
         </section>
 
         <section>
-          {data.slots.length === 0 && data.ready ? (
+          {data.slots.length === 0 && data.slotsReady ? (
             <div className="rounded-xl border border-slate-800 bg-slate-900/40 px-4 py-8 text-center text-sm text-slate-500">
               Nedostatek dat pro graf (zkontrolujte plán a telemetrii).
             </div>
@@ -348,7 +348,7 @@ export function Dashboard() {
           )}
         </section>
 
-        {data.slots.length > 0 && data.ready ? (
+        {data.slots.length > 0 && data.slotsReady ? (
           <section>
             <StatePanel slots={data.slots} nowIndex={data.nowIndex} />
           </section>