From bd717bccc2a723cbcf5f90351d3359e0dc4bd1da Mon Sep 17 00:00:00 2001
From: arnaucode <idoctnef@openmailbox.org>
Date: Tue, 20 Jun 2017 18:12:15 +0200
Subject: [PATCH] implemented resizing of new images before saving

---
 README.md          | 10 ++++++++
 handlers.go        | 35 ++++++++++------------------
 imageOperations.go | 57 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+), 23 deletions(-)
 create mode 100644 imageOperations.go

diff --git a/README.md b/README.md
index e21caeb..8580d11 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,12 @@
 # goImgCDN
 CDN for images, written in Go lang
+
+upload example (with curl):
+```
+curl -F file=@./image1.png http://127.0.0.1:3050/image
+```
+
+to get image:
+```
+http://127.0.0.1:3050/images/image1.png
+```
diff --git a/handlers.go b/handlers.go
index 993e47c..bca91b9 100644
--- a/handlers.go
+++ b/handlers.go
@@ -2,13 +2,9 @@ package main
 
 import (
 	"fmt"
-	"image"
 	"image/jpeg"
-	"image/png"
 	"io/ioutil"
 	"net/http"
-	"os"
-	"strings"
 
 	"github.com/gorilla/mux"
 )
@@ -20,34 +16,17 @@ func Index(w http.ResponseWriter, r *http.Request) {
 func ImageShow(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	imageName := vars["imageName"]
-	//fmt.Fprintln(w, "Image show:", imageName)
-	var imageExtension = strings.Split(imageName, ".")[1]
 
-	file, err := os.Open(imageName)
+	file, err := ioutil.ReadFile(imageName)
 	if err != nil {
-		//log.Fatal(err)
-		//fmt.Fprintln(w, "la imatge no existeix al server")
 		fmt.Fprintln(w, err)
 	}
 
-	var img image.Image
-	switch imageExtension {
-	case "png":
-		img, err = png.Decode(file)
-	case "jpg":
-		img, err = jpeg.Decode(file)
-	case "jpeg":
-		img, err = jpeg.Decode(file)
-	default:
-		img = nil
-	}
+	img, err := dataToImage(file, imageName)
 
 	if err != nil {
-		//log.Fatal(err)
 		fmt.Fprintln(w, "la imatge no existeix al server")
 	} else {
-		file.Close()
-
 		jpeg.Encode(w, img, nil) // Write to the ResponseWriter
 	}
 }
@@ -61,6 +40,16 @@ func NewImage(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		fmt.Println(err)
 	}
+
+	img, err := dataToImage(data, handler.Filename)
+	if err != nil {
+		fmt.Fprintln(w, "error al processar la imatge")
+	}
+	img = Resize(img)
+	data, err = imageToData(img, handler.Filename)
+	if err != nil {
+		fmt.Fprintln(w, "error al processar la imatge")
+	}
 	err = ioutil.WriteFile(handler.Filename, data, 0777)
 	if err != nil {
 		fmt.Println(err)
diff --git a/imageOperations.go b/imageOperations.go
new file mode 100644
index 0000000..5456ab3
--- /dev/null
+++ b/imageOperations.go
@@ -0,0 +1,57 @@
+package main
+
+import (
+	"bytes"
+	"image"
+	"image/jpeg"
+	"image/png"
+	"strings"
+
+	"github.com/nfnt/resize"
+)
+
+func dataToImage(data []byte, imageName string) (image.Image, error) {
+	reader := bytes.NewReader(data)
+	var imageExtension = strings.Split(imageName, ".")[1]
+	var img image.Image
+	var err error
+	switch imageExtension {
+	case "png":
+		img, err = png.Decode(reader)
+	case "jpg":
+		img, err = jpeg.Decode(reader)
+	case "jpeg":
+		img, err = jpeg.Decode(reader)
+	default:
+		img = nil
+	}
+	if err != nil {
+		return img, err
+	}
+	return img, err
+}
+
+func imageToData(img image.Image, imageName string) ([]byte, error) {
+	buf := new(bytes.Buffer)
+	var imageExtension = strings.Split(imageName, ".")[1]
+	var err error
+	switch imageExtension {
+	case "png":
+		err = png.Encode(buf, img)
+	case "jpg":
+		err = jpeg.Encode(buf, img, nil)
+	case "jpeg":
+		err = jpeg.Encode(buf, img, nil)
+	default:
+		img = nil
+	}
+	if err != nil {
+		return buf.Bytes(), err
+	}
+	return buf.Bytes(), err
+}
+
+func Resize(img image.Image) image.Image {
+	r := resize.Resize(160, 0, img, resize.Lanczos3)
+	return r
+}