refactor(usage): modularize UsagePage into separate section components

src/components/usage/hooks/useSparklines.ts

@@ -0,0 +1,138 @@
+import { useCallback, useMemo } from 'react';
+import { collectUsageDetails, extractTotalTokens } from '@/utils/usage';
+import type { UsagePayload } from './useUsageData';
+
+export interface SparklineData {
+  labels: string[];
+  datasets: [
+    {
+      data: number[];
+      borderColor: string;
+      backgroundColor: string;
+      fill: boolean;
+      tension: number;
+      pointRadius: number;
+      borderWidth: number;
+    }
+  ];
+}
+
+export interface SparklineBundle {
+  data: SparklineData;
+}
+
+export interface UseSparklinesOptions {
+  usage: UsagePayload | null;
+  loading: boolean;
+}
+
+export interface UseSparklinesReturn {
+  requestsSparkline: SparklineBundle | null;
+  tokensSparkline: SparklineBundle | null;
+  rpmSparkline: SparklineBundle | null;
+  tpmSparkline: SparklineBundle | null;
+  costSparkline: SparklineBundle | null;
+}
+
+export function useSparklines({ usage, loading }: UseSparklinesOptions): UseSparklinesReturn {
+  const buildLastHourSeries = useCallback(
+    (metric: 'requests' | 'tokens'): { labels: string[]; data: number[] } => {
+      if (!usage) return { labels: [], data: [] };
+      const details = collectUsageDetails(usage);
+      if (!details.length) return { labels: [], data: [] };
+
+      const windowMinutes = 60;
+      const now = Date.now();
+      const windowStart = now - windowMinutes * 60 * 1000;
+      const buckets = new Array(windowMinutes).fill(0);
+
+      details.forEach((detail) => {
+        const timestamp = Date.parse(detail.timestamp);
+        if (Number.isNaN(timestamp) || timestamp < windowStart) {
+          return;
+        }
+        const minuteIndex = Math.min(
+          windowMinutes - 1,
+          Math.floor((timestamp - windowStart) / 60000)
+        );
+        const increment = metric === 'tokens' ? extractTotalTokens(detail) : 1;
+        buckets[minuteIndex] += increment;
+      });
+
+      const labels = buckets.map((_, idx) => {
+        const date = new Date(windowStart + (idx + 1) * 60000);
+        const h = date.getHours().toString().padStart(2, '0');
+        const m = date.getMinutes().toString().padStart(2, '0');
+        return `${h}:${m}`;
+      });
+
+      return { labels, data: buckets };
+    },
+    [usage]
+  );
+
+  const buildSparkline = useCallback(
+    (
+      series: { labels: string[]; data: number[] },
+      color: string,
+      backgroundColor: string
+    ): SparklineBundle | null => {
+      if (loading || !series?.data?.length) {
+        return null;
+      }
+      const sliceStart = Math.max(series.data.length - 60, 0);
+      const labels = series.labels.slice(sliceStart);
+      const points = series.data.slice(sliceStart);
+      return {
+        data: {
+          labels,
+          datasets: [
+            {
+              data: points,
+              borderColor: color,
+              backgroundColor,
+              fill: true,
+              tension: 0.45,
+              pointRadius: 0,
+              borderWidth: 2
+            }
+          ]
+        }
+      };
+    },
+    [loading]
+  );
+
+  const requestsSparkline = useMemo(
+    () => buildSparkline(buildLastHourSeries('requests'), '#3b82f6', 'rgba(59, 130, 246, 0.18)'),
+    [buildLastHourSeries, buildSparkline]
+  );
+
+  const tokensSparkline = useMemo(
+    () => buildSparkline(buildLastHourSeries('tokens'), '#8b5cf6', 'rgba(139, 92, 246, 0.18)'),
+    [buildLastHourSeries, buildSparkline]
+  );
+
+  const rpmSparkline = useMemo(
+    () => buildSparkline(buildLastHourSeries('requests'), '#22c55e', 'rgba(34, 197, 94, 0.18)'),
+    [buildLastHourSeries, buildSparkline]
+  );
+
+  const tpmSparkline = useMemo(
+    () => buildSparkline(buildLastHourSeries('tokens'), '#f97316', 'rgba(249, 115, 22, 0.18)'),
+    [buildLastHourSeries, buildSparkline]
+  );
+
+  const costSparkline = useMemo(
+    () => buildSparkline(buildLastHourSeries('tokens'), '#f59e0b', 'rgba(245, 158, 11, 0.18)'),
+    [buildLastHourSeries, buildSparkline]
+  );
+
+  return {
+    requestsSparkline,
+    tokensSparkline,
+    rpmSparkline,
+    tpmSparkline,
+    costSparkline
+  };
+}