From d6421c225ffa16e7005ee743e7f30cb55da112e8 Mon Sep 17 00:00:00 2001
From: Patrick Haun <patrick@bomgar.email>
Date: Sun, 13 Oct 2024 18:10:37 +0200
Subject: [PATCH] feat: add gzip

---
 server/middleware/cache.go          | 24 +++++++++++++++++++
 server/middleware/gzipmiddleware.go | 36 +++++++++++++++++++++++++++++
 server/server.go                    | 24 +++----------------
 3 files changed, 63 insertions(+), 21 deletions(-)
 create mode 100644 server/middleware/cache.go
 create mode 100644 server/middleware/gzipmiddleware.go

diff --git a/server/middleware/cache.go b/server/middleware/cache.go
new file mode 100644
index 0000000..53a246e
--- /dev/null
+++ b/server/middleware/cache.go
@@ -0,0 +1,24 @@
+package middleware
+
+import (
+	"net/http"
+	"time"
+)
+
+func CacheWhileServerIsRunning(next http.Handler) http.Handler {
+	startTime := time.Now().Truncate(time.Second)
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		ifModifiedSince := r.Header.Get("If-Modified-Since")
+		if ifModifiedSince != "" {
+			modTime, err := time.Parse(http.TimeFormat, ifModifiedSince)
+			if err == nil {
+				if !startTime.After(modTime) {
+					w.WriteHeader(http.StatusNotModified)
+					return
+				}
+			}
+		}
+		w.Header().Set("Last-Modified", startTime.UTC().Format(http.TimeFormat))
+		next.ServeHTTP(w, r)
+	})
+}
diff --git a/server/middleware/gzipmiddleware.go b/server/middleware/gzipmiddleware.go
new file mode 100644
index 0000000..80c7fb6
--- /dev/null
+++ b/server/middleware/gzipmiddleware.go
@@ -0,0 +1,36 @@
+package middleware
+
+import (
+	"compress/gzip"
+	"io"
+	"net/http"
+	"strings"
+)
+
+
+type gzipResponseWriter struct {
+	io.Writer
+	http.ResponseWriter
+}
+
+func (w gzipResponseWriter) Write(b []byte) (int, error) {
+	return w.Writer.Write(b)
+}
+
+func GzipMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
+			next.ServeHTTP(w, r)
+			return
+		}
+
+		w.Header().Set("Content-Encoding", "gzip")
+		w.Header().Add("Vary", "Accept-Encoding")
+
+		gz := gzip.NewWriter(w)
+		defer gz.Close()
+
+		gzw := gzipResponseWriter{Writer: gz, ResponseWriter: w}
+		next.ServeHTTP(gzw, r)
+	})
+}
diff --git a/server/server.go b/server/server.go
index f655c87..b7ed882 100644
--- a/server/server.go
+++ b/server/server.go
@@ -8,11 +8,11 @@ import (
 	"log/slog"
 	"net/http"
 	"os"
-	"time"
 
 	"github.com/brocode/neoweb/components"
 	"github.com/brocode/neoweb/key"
 	"github.com/brocode/neoweb/nvimwrapper"
+	"github.com/brocode/neoweb/server/middleware"
 )
 
 //go:embed static
@@ -113,31 +113,13 @@ func (s *Server) getEvents(w http.ResponseWriter, r *http.Request) {
 	slog.Info("Events client disconnected")
 }
 
-func cacheWhileServerIsRunning(next http.Handler) http.Handler {
-	startTime := time.Now().Truncate(time.Second)
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		ifModifiedSince := r.Header.Get("If-Modified-Since")
-		if ifModifiedSince != "" {
-			modTime, err := time.Parse(http.TimeFormat, ifModifiedSince)
-			if err == nil {
-				if !startTime.After(modTime) {
-					w.WriteHeader(http.StatusNotModified)
-					return
-				}
-			}
-		}
-		w.Header().Set("Last-Modified", startTime.UTC().Format(http.TimeFormat))
-		next.ServeHTTP(w, r)
-	})
-}
-
 func (s *Server) Start() {
 
 	mux := http.NewServeMux()
 
-	mux.Handle("GET /static/", cacheWhileServerIsRunning(http.FileServer(http.FS(staticFs))))
+	mux.Handle("GET /static/", middleware.CacheWhileServerIsRunning(middleware.GzipMiddleware(http.FileServer(http.FS(staticFs)))))
 
-	mux.HandleFunc("GET /", s.getRoot)
+	mux.Handle("GET /", middleware.GzipMiddleware(http.HandlerFunc(s.getRoot)))
 
 	mux.HandleFunc("POST /keypress", s.postKeypress)