feat(market): add CoinGecko market data panel with cached /api/market endpoint

app/api/market/route.ts

@@ -0,0 +1,87 @@
+import { NextRequest, NextResponse } from "next/server";
+import { z } from "zod";
+
+import { getRatesWithCache } from "@/lib/server/rates-cache";
+import {
+  getCryptoMarketWithCache,
+  getLastCachedCryptoMarket,
+  MARKET_CACHE_CONTROL_VALUE,
+} from "@/lib/server/market-cache";
+
+const querySchema = z.object({
+  code: z.string().trim().toUpperCase().min(1),
+});
+
+export const revalidate = 60;
+
+export async function GET(request: NextRequest) {
+  const searchParams = request.nextUrl.searchParams;
+  const queryResult = querySchema.safeParse({
+    code: searchParams.get("code") ?? "",
+  });
+
+  if (!queryResult.success) {
+    return NextResponse.json(
+      {
+        message:
+          queryResult.error.issues[0]?.message ?? "Invalid query parameters",
+      },
+      {
+        status: 400,
+      },
+    );
+  }
+
+  const { code } = queryResult.data;
+
+  try {
+    const rates = await getRatesWithCache();
+    const asset = rates.assets.find((item) => item.code === code);
+
+    if (!asset) {
+      return NextResponse.json(
+        { message: "Unsupported currency or asset code" },
+        { status: 404 },
+      );
+    }
+
+    if (asset.type !== "crypto" || !asset.providerId) {
+      return NextResponse.json(
+        { message: "Market data is available only for crypto assets" },
+        { status: 400 },
+      );
+    }
+
+    const market = await getCryptoMarketWithCache({
+      code: asset.code,
+      name: asset.name,
+      providerId: asset.providerId,
+    });
+
+    return NextResponse.json(market, {
+      status: 200,
+      headers: {
+        "Cache-Control": MARKET_CACHE_CONTROL_VALUE,
+      },
+    });
+  } catch (error) {
+    const fallback = getLastCachedCryptoMarket(code);
+
+    if (fallback) {
+      return NextResponse.json(fallback, {
+        status: 200,
+        headers: {
+          "Cache-Control": MARKET_CACHE_CONTROL_VALUE,
+          "X-Cache-Fallback": "stale-on-error",
+        },
+      });
+    }
+
+    const message =
+      error instanceof Error
+        ? error.message
+        : "Unexpected error while loading market data";
+
+    return NextResponse.json({ message }, { status: 500 });
+  }
+}