func handleRequest()

in services/thumbnails/go/main.go [56:150]
84 lines of code
12 McCabe index (conditional complexity)

func handleRequest(env config) func(w http.ResponseWriter, r *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		ctx := r.Context()

		if r.URL.Path != "/" {
			http.Error(w, "404 not found.", http.StatusNotFound)
			return
		}
		if r.Method != "POST" {
			http.Error(w, "404 Not Found.", http.StatusNotFound)
			return
		}
		log.Printf("Got POST on /")

		defer r.Body.Close()
		pubSubMessage, err := ioutil.ReadAll(r.Body)
		if err != nil {
			http.Error(w, "Error reading body", http.StatusInternalServerError)
			return
		}
		log.Printf("Body: %s", string(pubSubMessage))

		var m struct {
			Message pubsub.Message `json:"message"`
		}
		err = json.Unmarshal(pubSubMessage, &m)
		if err != nil {
			log.Printf("Error reading pub/sub message: %v", err)
			http.Error(w, "Error reading pub/sub message", http.StatusInternalServerError)
			return
		}

		var obj struct {
			Bucket string `json:"bucket"`
			Name   string `json:"name"`
		}
		err = json.Unmarshal(m.Message.Data, &obj)
		if err != nil {
			log.Printf("Error reading pub/sub data: %v", err)
			http.Error(w, "Error reading pub/sub data", http.StatusInternalServerError)
			return
		}

		storageClient, err := storage.NewClient(ctx)
		if err != nil {
			log.Printf("Error getting storage client: %v", err)
			http.Error(w, "Error getting storage client", http.StatusInternalServerError)
			return
		}

		originalFile := filepath.Join(originalDir, obj.Name)
		err = downloadObject(ctx, storageClient, obj.Bucket, obj.Name, originalFile)
		if err != nil {
			http.Error(w, "Error downloading image from bucket", http.StatusInternalServerError)
			return
		}
		defer os.Remove(originalFile)
		log.Printf("Downloaded picture into %s", originalFile)

		imagick.Initialize()
		defer imagick.Terminate()
		mw := imagick.NewMagickWand()
		defer mw.Destroy()

		err = mw.ReadImage(originalFile)
		if err != nil {
			http.Error(w, "Error reading image from Image Magick", http.StatusInternalServerError)
			return
		}
		err = mw.ThumbnailImage(400, 400)
		if err != nil {
			http.Error(w, "Error creating thumbnail with Image Magick", http.StatusInternalServerError)
			return
		}

		thumbFile := filepath.Join(thumbnailDir, obj.Name)
		err = mw.WriteImage(thumbFile)
		if err != nil {
			http.Error(w, "Error saving thumbnail", http.StatusInternalServerError)
			return
		}
		defer os.Remove(thumbFile)
		log.Printf("Created local thumbnail in %s", thumbFile)

		err = uploadObject(ctx, storageClient, thumbFile, env.BucketThumbnails, obj.Name)
		if err != nil {
			http.Error(w, "Error creating thumbnail on bucket", http.StatusInternalServerError)
			return
		}

		log.Printf("Uploaded thumbnail to Cloud Storage bucket %s", env.BucketThumbnails)
		w.WriteHeader(http.StatusNoContent)
		fmt.Fprintf(w, "%s processed", obj.Name)
	}
}