From 73171bd98fb8dfe6986d39f4417e7eff3336e3a8 Mon Sep 17 00:00:00 2001
From: Sven Walter <s.walter@rebuy.com>
Date: Fri, 23 Sep 2022 08:03:46 +0200
Subject: [PATCH] add cdnmirror

---
 cmd/cdnmirror/main.go    | 115 +++++++++++++++++++++++++++++++++++++++
 pkg/webutil/cdnmirror.go |  43 +++++++++++++++
 2 files changed, 158 insertions(+)
 create mode 100644 cmd/cdnmirror/main.go
 create mode 100644 pkg/webutil/cdnmirror.go

diff --git a/cmd/cdnmirror/main.go b/cmd/cdnmirror/main.go
new file mode 100644
index 0000000..af519d8
--- /dev/null
+++ b/cmd/cdnmirror/main.go
@@ -0,0 +1,115 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+
+	"github.com/evanw/esbuild/pkg/api"
+	"github.com/pkg/errors"
+	"github.com/rebuy-de/rebuy-go-sdk/v4/pkg/cmdutil"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+const targetPathPrefix = `assets/cdnmirror`
+
+func main() {
+	defer cmdutil.HandleExit()
+	if err := NewRootCommand().Execute(); err != nil {
+		logrus.Fatal(err)
+	}
+}
+
+func NewRootCommand() *cobra.Command {
+	return cmdutil.New(
+		"cdnmirror SOURCE_NAME..", "Downloads assets from CDNs so the server can serve them directly.",
+		cmdutil.WithLogVerboseFlag(),
+		cmdutil.WithRun(Generate),
+	)
+}
+
+func Generate(ctx context.Context, cmd *cobra.Command, args []string) {
+	err := os.MkdirAll(targetPathPrefix, 0755)
+	cmdutil.Must(err)
+
+	writeGitignore()
+
+	for _, name := range args {
+		source := resolve(name)
+		download(source)
+	}
+}
+
+func writeGitignore() {
+	filename := path.Join(targetPathPrefix, ".gitignore")
+
+	buf := new(bytes.Buffer)
+	fmt.Fprintln(buf, "*")
+	fmt.Fprintln(buf, "!.gitignore")
+
+	err := ioutil.WriteFile(filename, buf.Bytes(), 0644)
+	cmdutil.Must(err)
+}
+
+func resolve(name string) webutil.CDNMirrorSource {
+	switch name {
+	case "@hotwired/turbo":
+		return webutil.CDNMirrorSourceHotwiredTurbo()
+	case "bootstrap":
+		return webutil.CDNMirrorSourceBootstrap()
+	case "font-awesome-sprites":
+		return webutil.CDNMirrorSourceFontAwesomeSprites()
+	case "bulma":
+		return webutil.CDNMirrorSourceBulma()
+	default:
+		cmdutil.Must(errors.Errorf("invalid source name"))
+		return webutil.CDNMirrorSource{}
+	}
+}
+
+func download(source webutil.CDNMirrorSource) {
+	targetFile := filepath.FromSlash(path.Join(targetPathPrefix, source.Target))
+
+	resp, err := http.Get(source.URL)
+	cmdutil.Must(err)
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		cmdutil.Must(fmt.Errorf(resp.Status))
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	cmdutil.Must(err)
+
+	var code string
+
+	switch source.Minify {
+	case webutil.CDNMirrorMinifyJS:
+		result := api.Transform(string(body), api.TransformOptions{
+			MinifyWhitespace:  true,
+			MinifyIdentifiers: true,
+			MinifySyntax:      true,
+		})
+		if len(result.Errors) != 0 {
+			cmdutil.Must(errors.Errorf("%#v", result.Errors))
+		}
+		code = string(result.Code)
+
+	default:
+		code = string(body)
+	}
+
+	f, err := os.Create(targetFile)
+	cmdutil.Must(err)
+	defer f.Close()
+
+	_, err = io.WriteString(f, code)
+	cmdutil.Must(err)
+}
diff --git a/pkg/webutil/cdnmirror.go b/pkg/webutil/cdnmirror.go
new file mode 100644
index 0000000..25031b1
--- /dev/null
+++ b/pkg/webutil/cdnmirror.go
@@ -0,0 +1,43 @@
+package webutil
+
+type CDNMirrorSource struct {
+	URL    string
+	Target string
+	Minify CDNMirrorMinifier
+}
+
+type CDNMirrorMinifier string
+
+const (
+	CDNMirrorMinifyJS  = "js"
+	CDNMirrorMinifyCSS = "css"
+)
+
+func CDNMirrorSourceHotwiredTurbo() CDNMirrorSource {
+	return CDNMirrorSource{
+		URL:    "https://unpkg.com/@hotwired/turbo@7.1.0/dist/turbo.es2017-umd.js",
+		Target: "hotwired-turbo-7.1.0-min.js",
+		Minify: CDNMirrorMinifyJS,
+	}
+}
+
+func CDNMirrorSourceBootstrap() CDNMirrorSource {
+	return CDNMirrorSource{
+		URL:    "https://unpkg.com/bootstrap@5.1.3/dist/css/bootstrap.min.css",
+		Target: "bootstrap-5.1.3-min.css",
+	}
+}
+
+func CDNMirrorSourceFontAwesomeSprites() CDNMirrorSource {
+	return CDNMirrorSource{
+		URL:    "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.2/sprites/solid.svg",
+		Target: "font-awesome-6.1.2-sprites-solid.svg",
+	}
+}
+
+func CDNMirrorSourceBulma() CDNMirrorSource {
+	return CDNMirrorSource{
+		URL:    "https://cdn.jsdelivr.net/npm/bulma@0.9.4/css/bulma.min.css",
+		Target: "bulma-0.7.4.min.css",
+	}
+}