From c746f0bae5168a8245abeaf94387d426536491d4 Mon Sep 17 00:00:00 2001
From: "Sven.Schmalle" <sven.schmalle@ta-logistic.de>
Date: Thu, 21 Nov 2019 10:08:17 +0100
Subject: [PATCH] =?UTF-8?q?Thumbnail-generierung=20f=C3=BCr=20dir=20Fotos?=
 =?UTF-8?q?=20mit=20eingebaut?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md      |  3 ++-
 main.go        | 55 +++++++++++++++++++++++++++++++++++++++++++++++++-
 web/index.html |  2 +-
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 48037e0..065a6e0 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,7 @@ Zum Kompilieren folgende Go-Abhängigkeiten installieren:
  - `go get github.com/gorilla/mux`
  - `go get github.com/boombuler/barcode`
  - `go get github.com/boombuler/barcode/qr`
-
+ - `go get github.com/disintegration/imaging`
+ 
 Kompilieren mit: `go build main.go`
 
diff --git a/main.go b/main.go
index 780310b..a11ad83 100644
--- a/main.go
+++ b/main.go
@@ -9,9 +9,11 @@ import (
 	"net/http"
 	"os"
 	"path"
+	"strings"
 
 	"github.com/boombuler/barcode"
 	"github.com/boombuler/barcode/qr"
+	"github.com/disintegration/imaging"
 	"github.com/gorilla/mux"
 )
 
@@ -24,6 +26,7 @@ func main() {
 	router := mux.NewRouter()
 	router.HandleFunc("/folder/{foldername:.*}", GetFolderContent).Methods("GET")
 	router.HandleFunc("/qr/{qrlink:.*}", GetQRCode).Methods("GET")
+	router.HandleFunc("/thumb/{imgname:.*}", GetThumbNail).Methods("GET")
 	router.PathPrefix("/img/").Handler(http.StripPrefix("/img/", http.FileServer(http.Dir("C:/Fotos")))).Methods("GET")
 	router.PathPrefix("/").Handler(http.FileServer(http.Dir("web"))).Methods("GET")
 	log.Fatal(http.ListenAndServe(":8000", router))
@@ -41,7 +44,9 @@ func GetFolderContent(w http.ResponseWriter, r *http.Request) {
 
 	var dateien []string
 	for _, f := range files {
-		dateien = append(dateien, f.Name())
+		if !strings.HasSuffix(f.Name(), ".thumb.jpg") {
+			dateien = append(dateien, f.Name())
+		}
 	}
 
 	json.NewEncoder(w).Encode(dateien)
@@ -66,3 +71,51 @@ func GetQRCode(w http.ResponseWriter, r *http.Request) {
 	// Datei ausgeben
 	png.Encode(w, qrCode)
 }
+
+func GetThumbNail(w http.ResponseWriter, r *http.Request) {
+
+	// Variablen auswerten
+	params := mux.Vars(r)
+	pIMGName := params["imgname"]
+
+	// Das Thumbnail soll nur generiert werden wenn es noch nicht existiert
+	if !fileExists(StartUpPath + "/" + pIMGName + ".thumb.jpg") {
+		//  Originaldatei öffnen, welche angefragt wird
+		src, err := imaging.Open(StartUpPath + "/" + pIMGName)
+		if err != nil {
+			log.Fatalf("failed to open image: %v", err)
+		}
+
+		// Foto auf 200px skalieren
+		src = imaging.Resize(src, 200, 0, imaging.NearestNeighbor)
+
+		err = imaging.Save(src, StartUpPath+"/"+pIMGName+".thumb.jpg")
+		if err != nil {
+			log.Fatalf("failed to save image: %v", err)
+		}
+
+		// Datei ausgeben
+		png.Encode(w, src)
+	} else {
+
+		src, err := imaging.Open(StartUpPath + "/" + pIMGName + ".thumb.jpg")
+		if err != nil {
+			log.Fatalf("failed to open image: %v", err)
+		}
+
+		// Datei ausgeben
+		png.Encode(w, src)
+	}
+}
+
+//--------------------------------------------------------------------------
+// Hilfsfunktionen
+//--------------------------------------------------------------------------
+
+func fileExists(filename string) bool {
+	info, err := os.Stat(filename)
+	if os.IsNotExist(err) {
+		return false
+	}
+	return !info.IsDir()
+}
diff --git a/web/index.html b/web/index.html
index 5109a68..99b62c1 100644
--- a/web/index.html
+++ b/web/index.html
@@ -64,7 +64,7 @@
 					for ( var i = 0, l = content.length; i < l; i++ ) {
 						var ObjInhalt = content[i];	
 						$("#Ordner").append(""+
-						"<img src=\""+ServerAPI+"/img/"+folder+"/"+ObjInhalt+"\" width=100 height=100>"+
+						"<img src=\""+ServerAPI+"/thumb/"+folder+"/"+ObjInhalt+"\" width=200>"+
 						"<a href=\""+ServerAPI+"/img/"+folder+"/"+ObjInhalt+"\">"+
 						ObjInhalt+"</a><hr>");
 					}