init

internal/markdown/markdown.go

@@ -0,0 +1,72 @@
+package markdown
+
+import (
+	"bytes"
+	"sync"
+
+	"github.com/yuin/goldmark"
+	emoji "github.com/yuin/goldmark-emoji"
+	highlighting "github.com/yuin/goldmark-highlighting/v2"
+	"github.com/yuin/goldmark/extension"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer/html"
+)
+
+var (
+	renderers   = make(map[string]goldmark.Markdown)
+	renderersMu sync.RWMutex
+)
+
+func getRenderer(codeTheme string) goldmark.Markdown {
+	if codeTheme == "" {
+		codeTheme = "github"
+	}
+
+	renderersMu.RLock()
+	if md, ok := renderers[codeTheme]; ok {
+		renderersMu.RUnlock()
+		return md
+	}
+	renderersMu.RUnlock()
+
+	renderersMu.Lock()
+	defer renderersMu.Unlock()
+
+	if md, ok := renderers[codeTheme]; ok {
+		return md
+	}
+
+	md := goldmark.New(
+		goldmark.WithExtensions(
+			extension.GFM,
+			extension.Typographer,
+			emoji.Emoji,
+			highlighting.NewHighlighting(
+				highlighting.WithStyle(codeTheme),
+			),
+		),
+		goldmark.WithParserOptions(
+			parser.WithAutoHeadingID(),
+		),
+		goldmark.WithRendererOptions(
+			html.WithHardWraps(),
+			html.WithXHTML(),
+			html.WithUnsafe(),
+		),
+	)
+	renderers[codeTheme] = md
+	return md
+}
+
+func Render(source string) (string, error) {
+	return RenderWithTheme(source, "github")
+}
+
+func RenderWithTheme(source, codeTheme string) (string, error) {
+	md := getRenderer(codeTheme)
+	var buf bytes.Buffer
+	if err := md.Convert([]byte(source), &buf); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}