1 files changed, 65 insertions, 0 deletions
diff --git a/readme_to_html.go b/readme_to_html.go
new file mode 100644
index 0000000..29c61ca
--- /dev/null
+++ b/readme_to_html.go
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// SPDX-FileContributor: Runxi Yu <https://runxiyu.org>
+
+package main
+
+import (
+	"bytes"
+	"html"
+	"html/template"
+	"strings"
+
+	"github.com/go-git/go-git/v5/plumbing/object"
+	"github.com/microcosm-cc/bluemonday"
+	"github.com/niklasfasching/go-org/org"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
+)
+
+var markdown_converter = goldmark.New(goldmark.WithExtensions(extension.GFM))
+
+func render_readme_at_tree(tree *object.Tree) (readme_filename string, readme_content template.HTML) {
+	var readme_rendered_unsafe bytes.Buffer
+	var readme_file *object.File
+	var readme_file_contents string
+	var err error
+
+	if readme_file, err = tree.File("README"); err == nil {
+		if readme_file_contents, err = readme_file.Contents(); err != nil {
+			return "Error fetching README", string_escape_html("Unable to fetch contents of README: " + err.Error())
+		}
+
+		return "README", template.HTML("<pre>" + html.EscapeString(readme_file_contents) + "</pre>") //#nosec G203
+	}
+
+	if readme_file, err = tree.File("README.md"); err == nil {
+		if readme_file_contents, err = readme_file.Contents(); err != nil {
+			return "Error fetching README", string_escape_html("Unable to fetch contents of README: " + err.Error())
+		}
+
+		if err = markdown_converter.Convert([]byte(readme_file_contents), &readme_rendered_unsafe); err != nil {
+			return "Error fetching README", string_escape_html("Unable to render README: " + err.Error())
+		}
+
+		return "README.md", template.HTML(bluemonday.UGCPolicy().SanitizeBytes(readme_rendered_unsafe.Bytes())) //#nosec G203
+	}
+
+	if readme_file, err = tree.File("README.org"); err == nil {
+		if readme_file_contents, err = readme_file.Contents(); err != nil {
+			return "Error fetching README", string_escape_html("Unable to fetch contents of README: " + err.Error())
+		}
+
+		org_html, err := org.New().Parse(strings.NewReader(readme_file_contents), readme_filename).Write(org.NewHTMLWriter())
+		if err != nil {
+			return "Error fetching README", string_escape_html("Unable to render README: " + err.Error())
+		}
+
+		return "README.org", template.HTML(bluemonday.UGCPolicy().Sanitize(org_html)) //#nosec G203
+	}
+
+	return "", ""
+}
+
+func string_escape_html(s string) template.HTML {
+	return template.HTML(html.EscapeString(s)) //#nosec G203
+}