From 6bca085c655f99e954988fd91f140b28256e82aa Mon Sep 17 00:00:00 2001
From: Sean Teramae <steramae@nvidia.com>
Date: Wed, 12 Aug 2026 16:04:32 -0700
Subject: [PATCH] feat(studio): MetricTrendPanel

Signed-off-by: Sean Teramae <steramae@nvidia.com>
---
 .../MetricTrendPanel.stories.tsx              |  68 ++++++
 .../MetricTrendPanel.test.tsx                 |  84 +++++++
 .../charts/MetricTrendPanel/index.tsx         | 215 ++++++++++++++++++
 3 files changed, 367 insertions(+)
 create mode 100644 web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.stories.tsx
 create mode 100644 web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.test.tsx
 create mode 100644 web/packages/studio/src/components/charts/MetricTrendPanel/index.tsx

diff --git a/web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.stories.tsx b/web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.stories.tsx
new file mode 100644
index 0000000000..ac587ef8fd
--- /dev/null
+++ b/web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.stories.tsx
@@ -0,0 +1,68 @@
+// SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import type { Meta, StoryObj } from '@storybook/react';
+import {
+  MetricTrendPanel,
+  type MetricTrendPoint,
+} from '@studio/components/charts/MetricTrendPanel';
+
+/** Deterministic wobbly upward trend so the story renders the same every run. */
+const makePoints = (start: number, step: number, count = 30): MetricTrendPoint[] =>
+  Array.from({ length: count }, (_, i) => ({
+    label: `Day ${i + 1}`,
+    value: Number((start + i * step + (i % 3 === 0 ? -step : step) * 0.8).toFixed(1)),
+  }));
+
+const meta: Meta<typeof MetricTrendPanel> = {
+  title: 'Charts/MetricTrendPanel',
+  component: MetricTrendPanel,
+  args: {
+    title: 'Primary use cases',
+    description:
+      'Continuously evaluate every merge to main against the full Support-Bench v3 benchmark.',
+    comparisonLabel: 'vs. 7 days ago',
+    series: [
+      { id: 'solved', label: 'Solved', value: 78.4, delta: 3.3, points: makePoints(62, 0.55) },
+      {
+        id: 'helpfulness',
+        label: 'Helpfulness',
+        value: 84.1,
+        delta: 1.2,
+        points: makePoints(74, 0.35),
+      },
+      { id: 'tool-use', label: 'Tool Use', value: 69.2, delta: -2.4, points: makePoints(78, -0.3) },
+    ],
+  },
+  decorators: [
+    (Story) => (
+      <div className="max-w-4xl">
+        <Story />
+      </div>
+    ),
+  ],
+};
+
+export default meta;
+
+type Story = StoryObj<typeof MetricTrendPanel>;
+
+export const Default: Story = {
+  args: { onViewClick: () => {} },
+};
+
+export const SingleSeries: Story = {
+  args: {
+    series: [
+      { id: 'solved', label: 'Solved', value: 78.4, delta: 3.3, points: makePoints(62, 0.55) },
+    ],
+  },
+};
+
+export const NegativeDelta: Story = {
+  args: { selectedSeriesId: 'tool-use' },
+};
+
+export const Loading: Story = {
+  args: { isPending: true },
+};
diff --git a/web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.test.tsx b/web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.test.tsx
new file mode 100644
index 0000000000..182816d049
--- /dev/null
+++ b/web/packages/studio/src/components/charts/MetricTrendPanel/MetricTrendPanel.test.tsx
@@ -0,0 +1,84 @@
+// SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import {
+  MetricTrendPanel,
+  type MetricTrendSeries,
+} from '@studio/components/charts/MetricTrendPanel';
+import { fireEvent, render, screen } from '@studio/tests/util/render';
+
+const series: MetricTrendSeries[] = [
+  {
+    id: 'solved',
+    label: 'Solved',
+    value: 78.4,
+    delta: 3.3,
+    points: [
+      { label: 'Day 1', value: 70 },
+      { label: 'Day 2', value: 78.4 },
+    ],
+  },
+  {
+    id: 'tool-use',
+    label: 'Tool Use',
+    value: 69.2,
+    delta: -2.4,
+    points: [
+      { label: 'Day 1', value: 71 },
+      { label: 'Day 2', value: 69.2 },
+    ],
+  },
+];
+
+describe('MetricTrendPanel', () => {
+  it('renders the first series value and delta by default', () => {
+    render(
+      <MetricTrendPanel
+        title="Primary use cases"
+        series={series}
+        comparisonLabel="vs. 7 days ago"
+      />
+    );
+
+    expect(screen.getByText('78.4%')).toBeInTheDocument();
+    expect(screen.getByText('+3.3')).toBeInTheDocument();
+    expect(screen.getByText('vs. 7 days ago')).toBeInTheDocument();
+  });
+
+  it('switches series when a pill is clicked', () => {
+    render(<MetricTrendPanel title="Primary use cases" series={series} />);
+
+    fireEvent.click(screen.getByRole('button', { name: 'Tool Use' }));
+
+    expect(screen.getByText('69.2%')).toBeInTheDocument();
+    expect(screen.getByText('−2.4')).toBeInTheDocument();
+  });
+
+  it('stays on the controlled series and reports the change', () => {
+    const onSeriesChange = vi.fn();
+    render(
+      <MetricTrendPanel
+        title="Primary use cases"
+        series={series}
+        selectedSeriesId="solved"
+        onSeriesChange={onSeriesChange}
+      />
+    );
+
+    fireEvent.click(screen.getByRole('button', { name: 'Tool Use' }));
+
+    expect(onSeriesChange).toHaveBeenCalledWith('tool-use');
+    expect(screen.getByText('78.4%')).toBeInTheDocument();
+  });
+
+  it('calls onViewClick from the header action', () => {
+    const onViewClick = vi.fn();
+    render(
+      <MetricTrendPanel title="Primary use cases" series={series} onViewClick={onViewClick} />
+    );
+
+    fireEvent.click(screen.getByRole('button', { name: 'View' }));
+
+    expect(onViewClick).toHaveBeenCalledTimes(1);
+  });
+});
diff --git a/web/packages/studio/src/components/charts/MetricTrendPanel/index.tsx b/web/packages/studio/src/components/charts/MetricTrendPanel/index.tsx
new file mode 100644
index 0000000000..7567cefde5
--- /dev/null
+++ b/web/packages/studio/src/components/charts/MetricTrendPanel/index.tsx
@@ -0,0 +1,215 @@
+// SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import {
+  Button,
+  Flex,
+  PanelContent,
+  PanelHeader,
+  PanelRoot,
+  Stack,
+  Tag,
+  Text,
+} from '@nvidia/foundations-react-core';
+import { useNvColorMode } from '@studio/components/DagCanvas/useNvColorMode';
+import { StackedSkeleton } from '@studio/components/StackedSkeleton';
+import { Triangle } from 'lucide-react';
+import { FC, useId, useMemo, useState } from 'react';
+import { Area, AreaChart, ResponsiveContainer, Tooltip, XAxis, YAxis } from 'recharts';
+
+export interface MetricTrendPoint {
+  /** X-axis label for the point, shown in the tooltip. */
+  label: string;
+  value: number;
+}
+
+export interface MetricTrendSeries {
+  id: string;
+  /** Pill label, e.g. "Solved". */
+  label: string;
+  value: number;
+  /** Change over the compared period. Positive renders up, negative down. */
+  delta?: number;
+  points: MetricTrendPoint[];
+}
+
+interface Props {
+  title: string;
+  description?: string;
+  series: MetricTrendSeries[];
+  /** Qualifies the delta, e.g. "vs. 7 days ago". */
+  comparisonLabel?: string;
+  /** Controls the active pill. Leave undefined to let the panel manage it. */
+  selectedSeriesId?: string;
+  onSeriesChange?: (seriesId: string) => void;
+  onViewClick?: () => void;
+  viewLabel?: string;
+  formatValue?: (value: number) => string;
+  formatDelta?: (delta: number) => string;
+  chartHeight?: number;
+  isPending?: boolean;
+}
+
+const DEFAULT_CHART_HEIGHT = 160;
+
+/**
+ * The area fill sits on a near-black surface in dark mode, so the light-mode opacities
+ * wash out to almost nothing. Carry more of the accent color, and keep a floor at the
+ * bottom of the gradient so the fill stays readable all the way down.
+ */
+const AREA_GRADIENT = {
+  dark: { top: 0.65, mid: 0.3, bottom: 0.08 },
+  light: { top: 0.3, mid: 0.12, bottom: 0 },
+} as const;
+
+const formatPercent = (value: number): string => `${value.toFixed(1)}%`;
+
+const formatSignedDelta = (delta: number): string =>
+  `${delta > 0 ? '+' : delta < 0 ? '−' : ''}${Math.abs(delta).toFixed(1)}`;
+
+export const MetricTrendPanel: FC<Props> = ({
+  title,
+  description,
+  series,
+  comparisonLabel,
+  selectedSeriesId,
+  onSeriesChange,
+  onViewClick,
+  viewLabel = 'View',
+  formatValue = formatPercent,
+  formatDelta = formatSignedDelta,
+  chartHeight = DEFAULT_CHART_HEIGHT,
+  isPending = false,
+}) => {
+  // useId() emits colons, which are not valid inside an SVG `url(#...)` reference.
+  const gradientId = `metric-trend-${useId().replace(/:/g, '')}`;
+  const [internalSeriesId, setInternalSeriesId] = useState<string | undefined>(series[0]?.id);
+
+  const activeId = selectedSeriesId ?? internalSeriesId;
+  const active = useMemo(
+    () => series.find((s) => s.id === activeId) ?? series[0],
+    [series, activeId]
+  );
+
+  const selectSeries = (seriesId: string) => {
+    if (selectedSeriesId === undefined) {
+      setInternalSeriesId(seriesId);
+    }
+    onSeriesChange?.(seriesId);
+  };
+
+  const delta = active?.delta;
+  const isNegative = delta !== undefined && delta < 0;
+  const deltaColor = isNegative ? 'red' : 'green';
+  const lineColor = isNegative ? 'var(--text-color-accent-red)' : 'var(--text-color-brand)';
+  const colorMode = useNvColorMode();
+  const gradient = colorMode === 'dark' ? AREA_GRADIENT.dark : AREA_GRADIENT.light;
+
+  return (
+    <PanelRoot elevation="mid">
+      <PanelHeader className="items-start">
+        <Stack gap="density-xs" className="min-w-0 flex-1">
+          <Text kind="label/bold/xl">{title}</Text>
+          {description && (
+            <Text kind="body/regular/md" className="text-secondary">
+              {description}
+            </Text>
+          )}
+        </Stack>
+        {onViewClick && (
+          <Button kind="tertiary" size="small" className="shrink-0" onClick={onViewClick}>
+            {viewLabel}
+          </Button>
+        )}
+      </PanelHeader>
+
+      <PanelContent>
+        <Stack gap="density-lg">
+          <Text kind="display/lg">{active ? formatValue(active.value) : '—'}</Text>
+
+          <Flex align="center" gap="density-lg" wrap="wrap">
+            {delta !== undefined && (
+              <Flex align="center" gap="density-sm">
+                <Tag readOnly color={deltaColor} density="compact">
+                  <Triangle
+                    size={12}
+                    className={`fill-current ${isNegative ? 'rotate-180' : ''}`}
+                    aria-hidden
+                  />
+                  {formatDelta(delta)}
+                </Tag>
+                {comparisonLabel && (
+                  <Text kind="body/regular/md" className="text-secondary">
+                    {comparisonLabel}
+                  </Text>
+                )}
+              </Flex>
+            )}
+
+            {series.length > 1 && (
+              <Flex align="center" gap="density-sm" wrap="wrap" role="group" aria-label={title}>
+                {series.map((s) => {
+                  const isActive = s.id === active?.id;
+                  return (
+                    <Tag
+                      key={s.id}
+                      color={isActive ? 'green' : 'gray'}
+                      kind={isActive ? 'solid' : 'outline'}
+                      selected={isActive}
+                      aria-pressed={isActive}
+                      onClick={() => selectSeries(s.id)}
+                    >
+                      {s.label}
+                    </Tag>
+                  );
+                })}
+              </Flex>
+            )}
+          </Flex>
+        </Stack>
+      </PanelContent>
+
+      <div className="-mx-density-2xl -mb-density-2xl overflow-hidden rounded-b-density-xl">
+        {isPending || !active ? (
+          <StackedSkeleton count={1} height={chartHeight} className="w-full" />
+        ) : (
+          <ResponsiveContainer width="100%" height={chartHeight}>
+            <AreaChart data={active.points} margin={{ top: 4, right: 0, bottom: 0, left: 0 }}>
+              <defs>
+                <linearGradient id={gradientId} x1="0" y1="0" x2="0" y2="1">
+                  <stop offset="0%" stopColor={lineColor} stopOpacity={gradient.top} />
+                  <stop offset="55%" stopColor={lineColor} stopOpacity={gradient.mid} />
+                  <stop offset="100%" stopColor={lineColor} stopOpacity={gradient.bottom} />
+                </linearGradient>
+              </defs>
+              <XAxis dataKey="label" hide />
+              <YAxis domain={['dataMin', 'dataMax']} hide />
+              <Tooltip
+                cursor={{ stroke: 'var(--border-color-base)', strokeWidth: 1 }}
+                formatter={(value: number) => [formatValue(value), active.label]}
+                contentStyle={{
+                  fontSize: 12,
+                  backgroundColor: 'var(--background-color-component-tooltip)',
+                  borderColor: 'var(--border-color-base)',
+                  color: 'var(--text-color-base)',
+                }}
+                labelStyle={{ color: 'var(--text-color-base)' }}
+                itemStyle={{ color: 'var(--text-color-base)' }}
+              />
+              <Area
+                type="linear"
+                dataKey="value"
+                name={active.label}
+                stroke={lineColor}
+                strokeWidth={2}
+                fill={`url(#${gradientId})`}
+                dot={active.points.length <= 2}
+                isAnimationActive={false}
+              />
+            </AreaChart>
+          </ResponsiveContainer>
+        )}
+      </div>
+    </PanelRoot>
+  );
+};