refactor: use link preview from nostr-services api

packages/app/src/External/index.ts

@@ -1,2 +1,40 @@
+import { throwIfOffline, unwrap } from "@snort/shared";
+
 export * from "./NostrBand";
 export * from "./SemisolDev";
+
+export abstract class JsonApi {
+  abstract url: string;
+  protected async getJson<T>(
+    path: string,
+    method?: "GET" | string,
+    body?: object,
+    headers?: { [key: string]: string },
+  ): Promise<T> {
+    throwIfOffline();
+    const rsp = await fetch(`${this.url}${path}`, {
+      method: method,
+      body: body ? JSON.stringify(body) : undefined,
+      headers: {
+        accept: "application/json",
+        ...(body ? { "content-type": "application/json" } : {}),
+        ...headers,
+      },
+    });
+
+    if (rsp.ok) {
+      const text = (await rsp.text()) as string | null;
+      if ((text?.length ?? 0) > 0) {
+        const obj = JSON.parse(unwrap(text));
+        if ("error" in obj) {
+          throw new Error(obj.error, obj.code);
+        }
+        return obj as T;
+      } else {
+        return {} as T;
+      }
+    } else {
+      throw new Error("Invalid response");
+    }
+  }
+}