From 865ce6f80ef44fa466c360672280cc43cba7cfa5 Mon Sep 17 00:00:00 2001
From: Gisle Aune <dev@gisle.me>
Date: Sun, 13 Aug 2017 16:21:07 +0200
Subject: [PATCH] Fixed path crash in static (same as resource), Added
 CompressedJSON response type.

---
 response/json.go | 32 ++++++++++++++++++++++++++++++++
 static.go        |  2 +-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/response/json.go b/response/json.go
index 53cabc2..692f849 100644
--- a/response/json.go
+++ b/response/json.go
@@ -1,10 +1,12 @@
 package response
 
 import (
+	"compress/gzip"
 	"encoding/json"
 	"fmt"
 	"log"
 	"net/http"
+	"strings"
 )
 
 // JSON makes a JSON response
@@ -22,5 +24,35 @@ func JSON(writer http.ResponseWriter, status int, data interface{}) {
 
 	writer.Header().Set("Content-Type", "application/json")
 	writer.WriteHeader(status)
+
 	writer.Write(jsonData)
 }
+
+// CompressedJSON makes a compressed JSON response, but only if the client supports it and the.
+// payload exceeds 1024 bytes.
+func CompressedJSON(writer http.ResponseWriter, request *http.Request, status int, data interface{}) {
+	jsonData, err := json.Marshal(data)
+
+	if err != nil {
+		log.Println("JSON Marshal failed: ", err.Error())
+
+		writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		writer.WriteHeader(503)
+		fmt.Fprint(writer, "JSON marshalling failed:", err.Error())
+		return
+	}
+
+	writer.Header().Set("Content-Type", "application/json")
+
+	if len(jsonData) > 1024 && strings.Contains(request.Header.Get("Accept-Encoding"), "gzip") {
+		writer.Header().Set("Content-Encoding", "gzip")
+		writer.WriteHeader(status)
+
+		gz := gzip.NewWriter(writer)
+		gz.Write(jsonData)
+		gz.Close()
+	} else {
+		writer.WriteHeader(status)
+		writer.Write(jsonData)
+	}
+}
diff --git a/static.go b/static.go
index 9b3bea7..6e0989d 100644
--- a/static.go
+++ b/static.go
@@ -22,7 +22,7 @@ func NewStatic(path string) *Static {
 func (static *Static) Handle(urlPath string, w http.ResponseWriter, req *http.Request, user *auth.User) bool {
 	// Get the subpath out of the path
 	subpath := req.URL.Path[len(urlPath):]
-	if subpath[0] == '/' {
+	if len(subpath) > 0 && subpath[0] == '/' {
 		subpath = subpath[1:]
 	}