Support render markdown in the `<details>` about markdown HOT 2 OPEN

package renderer

import (
	"bytes"
	"io"

	"github.com/gomarkdown/markdown/ast"
)

type Details struct {
	ast.Container
}

var details = []byte("<details>")

func ParserHook(data []byte) (ast.Node, []byte, int) {
	if node, d, n := parseDetails(data); node != nil {
		return node, d, n
	}
	return nil, nil, 0
}

func parseDetails(data []byte) (ast.Node, []byte, int) {
	if !bytes.HasPrefix(data, sidenote) {
		return nil, nil, 0
	}
	i := bytes.Index(data, details)
	end := bytes.Index(data[i:], []byte("</details>"))
	if end < 0 {
		return nil, data, 0
	}
	end = end + i
	res := &Details{}
	return res, data[i:end], end + len([]byte("</details>"))
}

func renderDetails(w io.Writer, s *Details, entering bool) {
	if entering {
		io.WriteString(w, "<details>")
	} else {
		io.WriteString(w, "</details>")
	}
}

func RenderHook(w io.Writer, node ast.Node, entering bool) (ast.WalkStatus, bool) {
	if leafNode, ok := node.(*Details); ok {
		renderDetails(w, leafNode, entering)
		return ast.GoToNext, true
	}
	return ast.GoToNext, false
}