initial commit

internal/reader/markdown.go

@@ -0,0 +1,51 @@
+package reader
+
+import (
+	htmltomarkdown "github.com/JohannesKaufmann/html-to-markdown/v2"
+	"github.com/JohannesKaufmann/html-to-markdown/v2/converter"
+	"github.com/JohannesKaufmann/html-to-markdown/v2/plugin/base"
+	"github.com/JohannesKaufmann/html-to-markdown/v2/plugin/commonmark"
+	"github.com/JohannesKaufmann/html-to-markdown/v2/plugin/strikethrough"
+	"github.com/JohannesKaufmann/html-to-markdown/v2/plugin/table"
+)
+
+// newConverter returns a Converter preconfigured with the plugins that match
+// typical web content. The domain (for resolving relative URLs) is applied
+// per-call via WithDomain, so the converter itself stays domain-agnostic.
+func newConverter() *converter.Converter {
+	return converter.NewConverter(
+		converter.WithPlugins(
+			base.NewBasePlugin(),
+			commonmark.NewCommonmarkPlugin(
+				commonmark.WithStrongDelimiter("**"),
+				commonmark.WithEmDelimiter("_"),
+				commonmark.WithBulletListMarker("-"),
+				commonmark.WithHeadingStyle(commonmark.HeadingStyleATX),
+				commonmark.WithCodeBlockFence("```"),
+				commonmark.WithHorizontalRule("---"),
+			),
+			strikethrough.NewStrikethroughPlugin(),
+			table.NewTablePlugin(
+				table.WithHeaderPromotion(true),
+				table.WithSkipEmptyRows(true),
+			),
+		),
+		converter.WithEscapeMode(converter.EscapeModeSmart),
+	)
+}
+
+// HTMLToMarkdown converts a full HTML document or fragment to markdown,
+// resolving relative URLs against baseURL. An empty baseURL leaves relative
+// URLs untouched. For convenience a base set of plugins (commonmark, tables,
+// strikethrough) is always enabled.
+func HTMLToMarkdown(html, baseURL string) (string, error) {
+	conv := newConverter()
+	if baseURL == "" {
+		return conv.ConvertString(html)
+	}
+	return conv.ConvertString(html, converter.WithDomain(baseURL))
+}
+
+// Ensure the htmltomarkdown import is referenced for IDE/links; the package
+// alias above keeps us flexible if we want to switch to htmltomarkdown.* APIs.
+var _ = htmltomarkdown.ConvertString