process balancing: better implementation (wip)

internal/pkg/prinery/markdown.go

@@ -0,0 +1,68 @@
+package prinery
+
+import (
+	"bytes"
+	"fmt"
+	"html/template"
+	"io/ioutil"
+	"path/filepath"
+
+	"github.com/microcosm-cc/bluemonday"
+	"github.com/russross/blackfriday/v2"
+	"github.com/thecodingmachine/gotenberg/internal/pkg/xerror"
+	"github.com/thecodingmachine/gotenberg/internal/pkg/xlog"
+	"github.com/thecodingmachine/gotenberg/internal/pkg/xrand"
+)
+
+func newMarkdownPrinter(logger xlog.Logger, fpath string, opts ChromePrintOptions) (printer, error) {
+	const op string = "prinery.newMarkdownPrinter"
+	resolver := func() (string, error) {
+		tmpl, err := template.
+			New(filepath.Base(fpath)).
+			Funcs(template.FuncMap{"toHTML": markdownToHTML}).
+			ParseFiles(fpath)
+		if err != nil {
+			return "", err
+		}
+		dirPath := filepath.Dir(fpath)
+		data := &templateData{DirPath: dirPath}
+		logger.DebugOp(op, "converting Markdown files to HTML...")
+		var buffer bytes.Buffer
+		if err := tmpl.Execute(&buffer, data); err != nil {
+			return "", err
+		}
+		baseFilename := xrand.Get()
+		dst := fmt.Sprintf("%s/%s.html", dirPath, baseFilename)
+		logger.DebugOp(op, "writing the HTML from previous conversion(s) into new file...")
+		if err := ioutil.WriteFile(dst, buffer.Bytes(), 0644); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("file://%s", dst), nil
+	}
+	URL, err := resolver()
+	if err != nil {
+		return nil, xerror.New(op, err)
+	}
+	return chromePrinter{
+		logger: logger,
+		url:    URL,
+		opts:   opts,
+	}, nil
+}
+
+type templateData struct {
+	DirPath string
+}
+
+func markdownToHTML(dirPath, filename string) (template.HTML, error) {
+	const op string = "prinery.markdownToHTML"
+	fpath := fmt.Sprintf("%s/%s", dirPath, filename)
+	b, err := ioutil.ReadFile(fpath)
+	if err != nil {
+		return "", xerror.New(op, err)
+	}
+	unsafe := blackfriday.Run(b)
+	content := bluemonday.UGCPolicy().SanitizeBytes(unsafe)
+	/* #nosec */
+	return template.HTML(content), nil
+}