fix(ledger): 修复时区黑洞，强制使用绝对字符串边界获取精准历史汇率

src/actions/snapshots.ts

@@ -213,71 +213,75 @@ export async function getEffectivePrice(
   return record?.price ?? null;
 }
 
-interface RateRecord {
-  rate: string;
-  fetchTime: Date;
-}
-
 async function buildDailyRatesMap(targetDateStr: string): Promise<Record<string, Big>> {
-  const allRates = await db
+  const boundaryString = `${targetDateStr} 23:59:59`;
+
+  // 获取 USD/CNY — 取目标时间点之前最后一条 USD->CNY 记录
+  const usdRecords = await db
     .select({
-      fromCurrency: exchangeRatesHistory.fromCurrency,
-      toCurrency: exchangeRatesHistory.toCurrency,
       rate: exchangeRatesHistory.rate,
       fetchTime: exchangeRatesHistory.fetchTime,
     })
     .from(exchangeRatesHistory)
-    .where(lte(exchangeRatesHistory.fetchTime, new Date(targetDateStr + 'T23:59:59')))
-    .orderBy(asc(exchangeRatesHistory.fetchTime));
+    .where(
+      and(
+        eq(exchangeRatesHistory.fromCurrency, 'USD'),
+        eq(exchangeRatesHistory.toCurrency, 'CNY'),
+        lte(exchangeRatesHistory.fetchTime, sql`${boundaryString}`)
+      )
+    )
+    .orderBy(desc(exchangeRatesHistory.fetchTime))
+    .limit(1);
 
-  const ratesCache = new Map<string, RateRecord[]>();
-  for (const rec of allRates) {
-    const key = `${rec.fromCurrency}_${rec.toCurrency}`;
-    if (!ratesCache.has(key)) {
-      ratesCache.set(key, []);
+  // 获取 HKD/CNY — 取目标时间点之前最后一条 HKD->CNY 记录
+  const hkdRecords = await db
+    .select({
+      rate: exchangeRatesHistory.rate,
+      fetchTime: exchangeRatesHistory.fetchTime,
+    })
+    .from(exchangeRatesHistory)
+    .where(
+      and(
+        eq(exchangeRatesHistory.fromCurrency, 'HKD'),
+        eq(exchangeRatesHistory.toCurrency, 'CNY'),
+        lte(exchangeRatesHistory.fetchTime, sql`${boundaryString}`)
+      )
+    )
+    .orderBy(desc(exchangeRatesHistory.fetchTime))
+    .limit(1);
+
+  // 若 HKD->CNY 不存在，尝试走 HKD->USD 再 USD->CNY 的交叉换算
+  let hkdRateStr: string | null = hkdRecords[0]?.rate ?? null;
+  if (!hkdRateStr) {
+    const hkdUsdRecords = await db
+      .select({
+        rate: exchangeRatesHistory.rate,
+        fetchTime: exchangeRatesHistory.fetchTime,
+      })
+      .from(exchangeRatesHistory)
+      .where(
+        and(
+          eq(exchangeRatesHistory.fromCurrency, 'HKD'),
+          eq(exchangeRatesHistory.toCurrency, 'USD'),
+          lte(exchangeRatesHistory.fetchTime, sql`${boundaryString}`)
+        )
+      )
+      .orderBy(desc(exchangeRatesHistory.fetchTime))
+      .limit(1);
+
+    const usdToCnyRate = usdRecords[0]?.rate ?? null;
+    if (hkdUsdRecords[0]?.rate && usdToCnyRate) {
+      hkdRateStr = new Big(hkdUsdRecords[0].rate).times(new Big(usdToCnyRate)).toString();
     }
-    ratesCache.get(key)!.push({ rate: rec.rate, fetchTime: rec.fetchTime });
   }
 
-  function getClosestRateForDate(currencyPair: string): string | null {
-    const records = ratesCache.get(currencyPair);
-    if (!records || records.length === 0) return null;
-    const endOfDay = new Date(targetDateStr + 'T23:59:59.999');
-    let closest: RateRecord | null = null;
-    for (const rec of records) {
-      if (rec.fetchTime <= endOfDay) {
-        closest = rec;
-      } else {
-        break;
-      }
-    }
-    return closest?.rate ?? null;
-  }
+  const usdRateStr = usdRecords[0]?.rate ?? null;
 
-  function resolveRate(from: string, to: string): string | null {
-    const directKey = `${from}_${to}`;
-    const directRate = getClosestRateForDate(directKey);
-    if (directRate) return directRate;
-
-    const usdKey = `USD_${to}`;
-    const usdRate = getClosestRateForDate(usdKey);
-    if (!usdRate) return null;
-    if (from === 'USD') return usdRate;
-
-    const fromToUsdKey = `${from}_USD`;
-    const fromToUsdRate = getClosestRateForDate(fromToUsdKey);
-    if (fromToUsdRate) {
-      return new Big(fromToUsdRate).times(new Big(usdRate)).toString();
-    }
-    return null;
-  }
-
-  const hkdRate = resolveRate('HKD', 'CNY');
-  const usdRate = resolveRate('USD', 'CNY');
+  console.log(`[FX Fetch] Date: ${targetDateStr}, USD: ${usdRateStr}, HKD: ${hkdRateStr}`);
 
   return {
-    USD: new Big(usdRate || '7.22'),
-    HKD: new Big(hkdRate || '0.92'),
+    USD: new Big(usdRateStr || '7.22'),
+    HKD: new Big(hkdRateStr || '0.92'),
     CNY: new Big(1),
   };
 }