From a4641b848054d0b791be9b655890161cc8b0823d Mon Sep 17 00:00:00 2001
From: nymkappa <vialjoris@hotmail.com>
Date: Mon, 11 Jul 2022 09:53:32 +0200
Subject: [PATCH] Set /block API cache duration according to block age

---
 backend/src/routes.ts | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/backend/src/routes.ts b/backend/src/routes.ts
index aeda734e1..0bd3aa7cf 100644
--- a/backend/src/routes.ts
+++ b/backend/src/routes.ts
@@ -761,7 +761,19 @@ class Routes {
   public async getBlock(req: Request, res: Response) {
     try {
       const block = await blocks.$getBlock(req.params.hash);
-      res.setHeader('Expires', new Date(Date.now() + 1000 * 600).toUTCString());
+
+      const blockAge = new Date().getTime() / 1000 - block.timestamp;
+      const day = 24 * 3600;
+      let cacheDuration;
+      if (blockAge > 365 * day) {
+        cacheDuration = 30 * day;
+      } else if (blockAge > 30 * day) {
+        cacheDuration = 10 * day;
+      } else {
+        cacheDuration = 600
+      }
+
+      res.setHeader('Expires', new Date(Date.now() + 1000 * cacheDuration).toUTCString());
       res.json(block);
     } catch (e) {
       res.status(500).send(e instanceof Error ? e.message : e);