Avoid fetching all stats metadata when there are no entities

Fetch all the data at once since it is not dependant

src/data/energy.ts

@@ -405,9 +405,8 @@ const getEnergyData = async (
     volume: lengthUnit === "km" ? "L" : "gal",
   };
 
-  const stats = {
+  const _energyStats = energyStatIds.length
-    ...(energyStatIds.length
+    ? fetchStatistics(
-      ? await fetchStatistics(
         hass!,
         startMinHour,
         end,
@@ -416,8 +415,8 @@ const getEnergyData = async (
         energyUnits,
         ["sum"]
       )
-      : {}),
+    : Promise.resolve({});
-    ...(waterStatIds.length
+  const _waterStats = waterStatIds.length
     ? await fetchStatistics(
         hass!,
         startMinHour,
@@ -427,12 +426,13 @@ const getEnergyData = async (
         waterUnits,
         ["sum"]
       )
-      : {}),
+    : Promise.resolve({});
-  };
 
-  let statsCompare;
   let startCompare;
   let endCompare;
+  let _energyStatsCompare = Promise.resolve({});
+  let _waterStatsCompare = Promise.resolve({});
+
   if (compare) {
     if (dayDifference > 27 && dayDifference < 32) {
       // When comparing a month, we want to start at the begining of the month
@@ -443,10 +443,8 @@ const getEnergyData = async (
 
     const compareStartMinHour = addHours(startCompare, -1);
     endCompare = addMilliseconds(start, -1);
-
+    if (energyStatIds.length) {
-    statsCompare = {
+      _energyStatsCompare = fetchStatistics(
-      ...(energyStatIds.length
-        ? await fetchStatistics(
         hass!,
         compareStartMinHour,
         endCompare,
@@ -454,10 +452,10 @@ const getEnergyData = async (
         period,
         energyUnits,
         ["sum"]
-          )
+      );
-        : {}),
+    }
-      ...(waterStatIds.length
+    if (waterStatIds.length) {
-        ? await fetchStatistics(
+      _waterStatsCompare = fetchStatistics(
         hass!,
         compareStartMinHour,
         endCompare,
@@ -465,16 +463,18 @@ const getEnergyData = async (
         period,
         waterUnits,
         ["sum"]
-          )
+      );
-        : {}),
+    }
-    };
   }
 
-  let fossilEnergyConsumption: FossilEnergyConsumption | undefined;
+  let _fossilEnergyConsumption:
-  let fossilEnergyConsumptionCompare: FossilEnergyConsumption | undefined;
+    | Promise<undefined>
-
+    | Promise<FossilEnergyConsumption> = Promise.resolve(undefined);
+  let _fossilEnergyConsumptionCompare:
+    | Promise<undefined>
+    | Promise<FossilEnergyConsumption> = Promise.resolve(undefined);
   if (co2SignalEntity !== undefined) {
-    fossilEnergyConsumption = await getFossilEnergyConsumption(
+    _fossilEnergyConsumption = getFossilEnergyConsumption(
       hass!,
       start,
       consumptionStatIDs,
@@ -483,7 +483,7 @@ const getEnergyData = async (
       dayDifference > 35 ? "month" : dayDifference > 2 ? "day" : "hour"
     );
     if (compare) {
-      fossilEnergyConsumptionCompare = await getFossilEnergyConsumption(
+      _fossilEnergyConsumptionCompare = getFossilEnergyConsumption(
         hass!,
         startCompare,
         consumptionStatIDs,
@@ -494,6 +494,35 @@ const getEnergyData = async (
     }
   }
 
+  const statsMetadata: Record<string, StatisticsMetaData> = {};
+  const _getStatisticMetadata: Promise<StatisticsMetaData[]> = allStatIDs.length
+    ? getStatisticMetadata(hass, allStatIDs)
+    : Promise.resolve([]);
+  const [
+    energyStats,
+    waterStats,
+    energyStatsCompare,
+    waterStatsCompare,
+    statsMetadataArray,
+    fossilEnergyConsumption,
+    fossilEnergyConsumptionCompare,
+  ] = await Promise.all([
+    _energyStats,
+    _waterStats,
+    _energyStatsCompare,
+    _waterStatsCompare,
+    _getStatisticMetadata,
+    _fossilEnergyConsumption,
+    _fossilEnergyConsumptionCompare,
+  ]);
+  const stats = { ...energyStats, ...waterStats };
+  const statsCompare = { ...energyStatsCompare, ...waterStatsCompare };
+  if (allStatIDs.length) {
+    statsMetadataArray.forEach((x) => {
+      statsMetadata[x.statistic_id] = x;
+    });
+  }
+
   Object.values(stats).forEach((stat) => {
     // if the start of the first value is after the requested period, we have the first data point, and should add a zero point
     if (stat.length && new Date(stat[0].start) > startMinHour) {
@@ -507,12 +536,6 @@ const getEnergyData = async (
     }
   });
 
-  const statsMetadataArray = await getStatisticMetadata(hass, allStatIDs);
-  const statsMetadata: Record<string, StatisticsMetaData> = {};
-  statsMetadataArray.forEach((x) => {
-    statsMetadata[x.statistic_id] = x;
-  });
-
   const data: EnergyData = {
     start,
     end,