Add company overview skeleton and cache

lib/server/prices.ts

@@ -1,4 +1,14 @@
 const YAHOO_BASE = 'https://query1.finance.yahoo.com/v8/finance/chart';
+const QUOTE_CACHE_TTL_MS = 1000 * 60;
+const PRICE_HISTORY_CACHE_TTL_MS = 1000 * 60 * 15;
+
+type CacheEntry<T> = {
+  expiresAt: number;
+  value: T;
+};
+
+const quoteCache = new Map<string, CacheEntry<number>>();
+const priceHistoryCache = new Map<string, CacheEntry<Array<{ date: string; close: number }>>>();
 
 function buildYahooChartUrl(ticker: string, params: string) {
   return `${YAHOO_BASE}/${encodeURIComponent(ticker.trim().toUpperCase())}?${params}`;
@@ -17,7 +27,12 @@ function fallbackQuote(ticker: string) {
 
 export async function getQuote(ticker: string): Promise<number> {
   const normalizedTicker = ticker.trim().toUpperCase();
+  const cached = quoteCache.get(normalizedTicker);
+  if (cached && cached.expiresAt > Date.now()) {
+    return cached.value;
+  }
 
+  let quote = fallbackQuote(normalizedTicker);
   try {
     const response = await fetch(buildYahooChartUrl(normalizedTicker, 'interval=1d&range=1d'), {
       headers: {
@@ -27,7 +42,11 @@ export async function getQuote(ticker: string): Promise<number> {
     });
 
     if (!response.ok) {
-      return fallbackQuote(normalizedTicker);
+      quoteCache.set(normalizedTicker, {
+        value: quote,
+        expiresAt: Date.now() + QUOTE_CACHE_TTL_MS
+      });
+      return quote;
     }
 
     const payload = await response.json() as {
@@ -38,13 +57,23 @@ export async function getQuote(ticker: string): Promise<number> {
 
     const price = payload.chart?.result?.[0]?.meta?.regularMarketPrice;
     if (typeof price !== 'number' || !Number.isFinite(price)) {
-      return fallbackQuote(normalizedTicker);
+      quoteCache.set(normalizedTicker, {
+        value: quote,
+        expiresAt: Date.now() + QUOTE_CACHE_TTL_MS
+      });
+      return quote;
     }
-
-    return price;
+    quote = price;
   } catch {
-    return fallbackQuote(normalizedTicker);
+    // fall through to cached fallback
   }
+
+  quoteCache.set(normalizedTicker, {
+    value: quote,
+    expiresAt: Date.now() + QUOTE_CACHE_TTL_MS
+  });
+
+  return quote;
 }
 
 export async function getQuoteOrNull(ticker: string): Promise<number | null> {
@@ -145,6 +174,10 @@ export async function getHistoricalClosingPrices(ticker: string, dates: string[]
 
 export async function getPriceHistory(ticker: string): Promise<Array<{ date: string; close: number }>> {
   const normalizedTicker = ticker.trim().toUpperCase();
+  const cached = priceHistoryCache.get(normalizedTicker);
+  if (cached && cached.expiresAt > Date.now()) {
+    return cached.value;
+  }
 
   try {
     const response = await fetch(buildYahooChartUrl(normalizedTicker, 'interval=1wk&range=20y'), {
@@ -190,6 +223,10 @@ export async function getPriceHistory(ticker: string): Promise<Array<{ date: str
       .filter((entry): entry is { date: string; close: number } => entry !== null);
 
     if (points.length > 0) {
+      priceHistoryCache.set(normalizedTicker, {
+        value: points,
+        expiresAt: Date.now() + PRICE_HISTORY_CACHE_TTL_MS
+      });
       return points;
     }
   } catch {
@@ -201,7 +238,7 @@ export async function getPriceHistory(ticker: string): Promise<Array<{ date: str
 
   const totalWeeks = 20 * 52;
 
-  return Array.from({ length: totalWeeks }, (_, index) => {
+  const syntheticHistory = Array.from({ length: totalWeeks }, (_, index) => {
     const step = (totalWeeks - 1) - index;
     const date = new Date(now - step * 7 * 24 * 60 * 60 * 1000).toISOString();
     const wave = Math.sin(index / 8) * 0.06;
@@ -213,4 +250,20 @@ export async function getPriceHistory(ticker: string): Promise<Array<{ date: str
       close: Number(close.toFixed(2))
     };
   });
+
+  priceHistoryCache.set(normalizedTicker, {
+    value: syntheticHistory,
+    expiresAt: Date.now() + PRICE_HISTORY_CACHE_TTL_MS
+  });
+
+  return syntheticHistory;
 }
+
+export const __pricesInternals = {
+  PRICE_HISTORY_CACHE_TTL_MS,
+  QUOTE_CACHE_TTL_MS,
+  resetCaches() {
+    quoteCache.clear();
+    priceHistoryCache.clear();
+  }
+};