feat: cache marka api responses

lib/marka/index.ts

@@ -1,3 +1,4 @@
+import { createCache } from "../cache.ts";
 import { MARKA_API_KEY } from "../env.ts";
 import { getImage } from "../image.ts";
 import { GenericResource } from "./schema.ts";
@@ -24,32 +25,62 @@ async function addImageToResource<T extends GenericResource>(
   return resource as T;
 }
 
-export async function fetchResource<T extends GenericResource>(
+type Resource = GenericResource & {
+  content: GenericResource["content"] & Array<GenericResource>;
+};
+
+const fetchCache = createCache<Resource>("marka");
+const cacheLock = new Map<string, Promise<Resource>>();
+async function cachedFetch(
+  url: string,
+): Promise<Resource | undefined> {
+  if (fetchCache.has(url)) {
+    return fetchCache.get(url);
+  }
+  if (cacheLock.has(url)) {
+    return cacheLock.get(url);
+  }
+  const response = (async () => {
+    const response = await fetch(url);
+    const res = await response.json();
+    fetchCache.set(url, res);
+    return res;
+  })();
+  cacheLock.set(
+    url,
+    response,
+  );
+  const res = await response;
+  if (!res) {
+    cacheLock.delete(url);
+  }
+  return res;
+}
+
+export async function fetchResource<T extends Resource>(
   resource: string,
 ): Promise<T | undefined> {
   try {
-    const response = await fetch(
-      `${url}/resources/${resource}`,
-    );
-    const res = await response.json();
+    const d = `${url}/resources/${resource}`;
+    const res = await cachedFetch(d);
+    if (!res) return;
     return addImageToResource<T>(res);
   } catch (_e) {
     return;
   }
 }
 
-export async function listResources<T = GenericResource>(
+export async function listResources<T extends GenericResource>(
   resource: string,
 ): Promise<T[]> {
   try {
-    const response = await fetch(
-      `${url}/resources/${resource}`,
-    );
-    const list = await response.json();
+    const d = `${url}/resources/${resource}`;
+    const list = await cachedFetch(d);
+    if (!list) return [];
     return Promise.all(
       list?.content
-        .filter((a: GenericResource) => a?.content?._type)
-        .map((res: GenericResource) => addImageToResource(res)),
+        .filter((a) => a?.content?._type)
+        .map((res) => addImageToResource(res) as Promise<T>),
     );
   } catch (_e) {
     return [];

lib/string.ts

@@ -1,4 +1,13 @@
-export function formatDate(date: Date): string {
+export function formatDate(date?: string | Date): string {
+  if (!date) return "";
+  if (typeof date === "string") {
+    try {
+      const d = new Date(date);
+      return formatDate(d);
+    } catch (_e) {
+      return "";
+    }
+  }
   const options = { year: "numeric", month: "long", day: "numeric" } as const;
   return new Intl.DateTimeFormat("en-US", options).format(date);
 }