Fix duplicate legend items when comparing energy data (#25610)

src/components/chart/ha-chart-base.ts

@@ -220,11 +220,11 @@ export class HaChartBase extends LitElement {
       return nothing;
     }
     const datasets = ensureArray(this.data);
-    const items = (legend.data ||
-      datasets
+    const items: LegendComponentOption["data"] =
+      legend.data ||
+      ((datasets
         .filter((d) => (d.data as any[])?.length && (d.id || d.name))
-        .map((d) => d.name ?? d.id) ||
-      []) as string[];
+        .map((d) => d.name ?? d.id) || []) as string[]);
 
     const isMobile = window.matchMedia(
       "all and (max-width: 450px), all and (max-height: 500px)"
@@ -239,20 +239,32 @@ export class HaChartBase extends LitElement {
       })}
     >
       <ul>
-        ${items.map((item: string, index: number) => {
+        ${items.map((item, index) => {
           if (!this.expandLegend && index >= overflowLimit) {
             return nothing;
           }
+          let itemStyle: Record<string, any> = {};
+          let name = "";
+          if (typeof item === "string") {
+            name = item;
             const dataset = datasets.find(
               (d) => d.id === item || d.name === item
             );
-          const color = dataset?.color as string;
-          const borderColor = dataset?.itemStyle?.borderColor as string;
+            itemStyle = {
+              color: dataset?.color as string,
+              ...(dataset?.itemStyle as { borderColor?: string }),
+            };
+          } else {
+            name = item.name ?? "";
+            itemStyle = item.itemStyle ?? {};
+          }
+          const color = itemStyle?.color as string;
+          const borderColor = itemStyle?.borderColor as string;
           return html`<li
-            .name=${item}
+            .name=${name}
             @click=${this._legendClick}
-            class=${classMap({ hidden: this._hiddenDatasets.has(item) })}
-            .title=${item}
+            class=${classMap({ hidden: this._hiddenDatasets.has(name) })}
+            .title=${name}
           >
             <div
               class="bullet"
@@ -261,7 +273,7 @@ export class HaChartBase extends LitElement {
                 borderColor: borderColor || color,
               })}
             ></div>
-            <div class="label">${item}</div>
+            <div class="label">${name}</div>
           </li>`;
         })}
         ${items.length > overflowLimit

src/panels/lovelace/cards/energy/hui-energy-devices-detail-graph-card.ts

@@ -6,6 +6,7 @@ import { customElement, property, state } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
 import memoizeOne from "memoize-one";
 import type { BarSeriesOption } from "echarts/charts";
+import type { LegendComponentOption } from "echarts/components";
 import { getGraphColorByIndex } from "../../../../common/color/colors";
 import { getEnergyColor } from "./common/color";
 import "../../../../components/ha-card";
@@ -54,6 +55,8 @@ export class HuiEnergyDevicesDetailGraphCard
 
   @state() private _data?: EnergyData;
 
+  @state() private _legendData?: LegendComponentOption["data"];
+
   @state() private _start = startOfToday();
 
   @state() private _end = endOfToday();
@@ -185,6 +188,7 @@ export class HuiEnergyDevicesDetailGraphCard
         legend: {
           show: true,
           type: "custom",
+          data: this._legendData,
           selected: this._hiddenStats.reduce((acc, stat) => {
             acc[stat] = false;
             return acc;
@@ -310,6 +314,13 @@ export class HuiEnergyDevicesDetailGraphCard
     );
 
     datasets.push(...processedData);
+    this._legendData = processedData.map((d) => ({
+      name: d.name as string,
+      itemStyle: {
+        color: d.color as string,
+        borderColor: d.itemStyle?.borderColor as string,
+      },
+    }));
 
     if (showUntracked) {
       const untrackedData = this._processUntracked(
@@ -319,6 +330,13 @@ export class HuiEnergyDevicesDetailGraphCard
         false
       );
       datasets.push(untrackedData);
+      this._legendData.push({
+        name: untrackedData.name as string,
+        itemStyle: {
+          color: untrackedData.color as string,
+          borderColor: untrackedData.itemStyle?.borderColor as string,
+        },
+      });
     }
 
     fillDataGapsAndRoundCaps(datasets);