feat: hide relay reviews from spammer

src/services/fayan.service.ts

@@ -0,0 +1,43 @@
+import DataLoader from 'dataloader'
+
+class FayanService {
+  static instance: FayanService
+
+  private userPercentileDataLoader = new DataLoader<string, number | null>(async (userIds) => {
+    return await Promise.all(
+      userIds.map(async (userId) => {
+        try {
+          const res = await fetch(`https://fayan.jumble.social/${userId}`)
+          if (!res.ok) {
+            if (res.status === 404) {
+              return 0
+            }
+            return null
+          }
+          const data = await res.json()
+          if (typeof data.percentile === 'number') {
+            return data.percentile
+          }
+          return null
+        } catch {
+          return null
+        }
+      })
+    )
+  })
+
+  constructor() {
+    if (!FayanService.instance) {
+      FayanService.instance = this
+    }
+    return FayanService.instance
+  }
+
+  // null means server error
+  async fetchUserPercentile(userId: string): Promise<number | null> {
+    return await this.userPercentileDataLoader.load(userId)
+  }
+}
+
+const instance = new FayanService()
+export default instance