From 8fa5ab4c94b14e5e5df5789baf8ea664f4c89251 Mon Sep 17 00:00:00 2001
From: Gaubee <GaubeeBangeel@Gmail.com>
Date: Mon, 22 Dec 2025 14:50:47 +0800
Subject: [PATCH] feat: add useExchangeRateQuery hook with TanStack Query

- Create useExchangeRateQuery hook with:
  - 5min staleTime: replaces manual cache logic
  - Shared cache across components
  - Request deduplication
- Keep existing useExchangeRate for backward compatibility

Closes #46
---
 src/queries/index.ts                   |  6 ++
 src/queries/use-exchange-rate-query.ts | 78 ++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 src/queries/use-exchange-rate-query.ts

diff --git a/src/queries/index.ts b/src/queries/index.ts
index e2d16d379..56b637acd 100644
--- a/src/queries/index.ts
+++ b/src/queries/index.ts
@@ -13,3 +13,9 @@ export {
   useRefreshBalance,
   balanceQueryKeys,
 } from './use-balance-query'
+
+export {
+  useExchangeRateQuery,
+  getExchangeRate,
+  exchangeRateQueryKeys,
+} from './use-exchange-rate-query'
diff --git a/src/queries/use-exchange-rate-query.ts b/src/queries/use-exchange-rate-query.ts
new file mode 100644
index 000000000..bc1f54781
--- /dev/null
+++ b/src/queries/use-exchange-rate-query.ts
@@ -0,0 +1,78 @@
+import { useQuery } from '@tanstack/react-query'
+import { useMemo } from 'react'
+import { currencyExchangeService, type ExchangeRateResponse } from '@/services'
+
+/**
+ * Exchange Rate Query Keys
+ */
+export const exchangeRateQueryKeys = {
+  all: ['exchangeRate'] as const,
+  rate: (baseCurrency: string, targetCurrencies: string[]) =>
+    ['exchangeRate', baseCurrency.toUpperCase(), targetCurrencies.sort().join(',')] as const,
+}
+
+function normalizeCurrencyCode(code: string): string {
+  return code.trim().toUpperCase()
+}
+
+/**
+ * Exchange Rate Query Hook
+ *
+ * 特性：
+ * - 5min staleTime：替代手动缓存
+ * - 共享缓存：多个组件使用同一 base+targets 时共享数据
+ * - 请求去重：同时发起的相同请求会被合并
+ */
+export function useExchangeRateQuery(
+  baseCurrency: string,
+  targetCurrencies: string[]
+) {
+  const normalizedBase = useMemo(() => normalizeCurrencyCode(baseCurrency), [baseCurrency])
+  const normalizedTargets = useMemo(
+    () => [...new Set(targetCurrencies.map(normalizeCurrencyCode))].filter((c) => c !== normalizedBase),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [targetCurrencies.join(','), normalizedBase]
+  )
+
+  const query = useQuery({
+    queryKey: exchangeRateQueryKeys.rate(normalizedBase, normalizedTargets),
+    queryFn: async (): Promise<ExchangeRateResponse> => {
+      if (normalizedTargets.length === 0) {
+        const datePart = new Date().toISOString().split('T')[0]
+        return {
+          base: normalizedBase,
+          date: datePart ?? new Date().toISOString().slice(0, 10),
+          rates: {},
+        }
+      }
+
+      return currencyExchangeService.getExchangeRates({
+        baseCurrency: normalizedBase,
+        targetCurrencies: normalizedTargets,
+      })
+    },
+    enabled: !!normalizedBase,
+    staleTime: 5 * 60 * 1000, // 5 分钟内认为数据新鲜
+    gcTime: 10 * 60 * 1000, // 10 分钟缓存
+    refetchOnWindowFocus: true,
+  })
+
+  return {
+    data: query.data ?? null,
+    isLoading: query.isLoading,
+    isFetching: query.isFetching,
+    error: query.error?.message ?? null,
+    updatedAt: query.dataUpdatedAt || null,
+  }
+}
+
+/**
+ * Get exchange rate for a single currency
+ */
+export function getExchangeRate(
+  data: ExchangeRateResponse | null,
+  targetCurrency: string
+): number | undefined {
+  const normalizedTarget = normalizeCurrencyCode(targetCurrency)
+  return data?.rates[normalizedTarget]
+}