From c24d574f9049cbea4e42208498149b204a873ff5 Mon Sep 17 00:00:00 2001
From: Christophe Gagnier <Moustachauve@users.noreply.github.com>
Date: Thu, 28 Jan 2021 22:16:36 -0500
Subject: [PATCH] Add Cache-Control to index

---
 wled00/wled_server.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/wled00/wled_server.cpp b/wled00/wled_server.cpp
index 4970248f..1e9e9c36 100644
--- a/wled00/wled_server.cpp
+++ b/wled00/wled_server.cpp
@@ -229,14 +229,32 @@ void serveIndexOrWelcome(AsyncWebServerRequest *request)
   }
 }
 
+bool handleIfNoneMatchCacheHeader(AsyncWebServerRequest* request)
+{
+  AsyncWebHeader* header = request->getHeader("If-None-Match");
+  if (header && header->value() == String(VERSION)) {
+    request->send(304);
+    return true;
+  }
+  return false;
+}
+
+bool setStaticContentCacheHeaders(AsyncWebServerResponse *response)
+{
+  response->addHeader(F("Cache-Control"),"max-age=2592000");
+  response->addHeader(F("ETag"), String(VERSION));
+}
 
 void serveIndex(AsyncWebServerRequest* request)
 {
   if (handleFileRead(request, "/index.htm")) return;
 
+  if (handleIfNoneMatchCacheHeader(request)) return;
+
   AsyncWebServerResponse *response = request->beginResponse_P(200, "text/html", PAGE_index, PAGE_index_L);
 
   response->addHeader(F("Content-Encoding"),"gzip");
+  setStaticContentCacheHeaders(response);
   
   request->send(response);
 }