Attempt to implement checkbox shitter

internal/notes/notes.go

@@ -12,8 +12,14 @@ import (
 	"path/filepath"
 
 	"forgejo.gwairfelin.com/max/gonotes/internal/conf"
+	markdown "github.com/teekennedy/goldmark-markdown"
 	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
 	"github.com/yuin/goldmark/extension"
+	astext "github.com/yuin/goldmark/extension/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
 )
 
 // Note is the central data structure.  It can be Saved, Rendered and Loaded
@@ -50,7 +56,7 @@ func (n *Note) Render() {
 	n.BodyRendered = template.HTML(buf.String())
 }
 
-// Load a note from the disk. The path is derived from the title
+// LoadNote from the disk. The path is derived from the title
 func LoadNote(encodedTitle string) (*Note, error) {
 	filename := filepath.Join(conf.Conf.NotesDir, fmtPath(encodedTitle))
 	body, err := os.ReadFile(filename)
@@ -70,6 +76,79 @@ func (n *Note) EncodedTitle() string {
 	return base64.StdEncoding.EncodeToString([]byte(n.Title))
 }
 
+type toggleCheckboxTransformer struct{ nthBox int }
+
+func (t *toggleCheckboxTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
+	boxesFound := 0
+
+	// Walk to find checkbox, toggle checked status
+	ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
+		if !entering {
+			return ast.WalkContinue, nil
+		}
+
+		box, ok := n.(*astext.TaskCheckBox)
+		if !ok {
+			return ast.WalkContinue, nil
+		}
+
+		if boxesFound < t.nthBox {
+			boxesFound += 1
+			return ast.WalkContinue, nil
+		}
+
+		box.IsChecked = !box.IsChecked
+		return ast.WalkStop, nil
+	})
+}
+
+func (r *markdown.Renderer) renderTaskCheckBox(node ast.Node, entering bool) ast.WalkStatus {
+	if entering {
+		var itemPrefix []byte
+		l := r.rc.lists[len(r.rc.lists)-1]
+
+		if l.list.IsOrdered() {
+			itemPrefix = append(itemPrefix, []byte(fmt.Sprint(l.num))...)
+			r.rc.lists[len(r.rc.lists)-1].num += 1
+		}
+		itemPrefix = append(itemPrefix, l.list.Marker, ' ')
+		// Prefix the current line with the item prefix
+		r.rc.writer.PushPrefix(itemPrefix, 0, 0)
+		// Prefix subsequent lines with padding the same length as the item prefix
+		indentLen := int(max(r.config.NestedListLength, NestedListLengthMinimum))
+		indent := bytes.Repeat([]byte{' '}, indentLen)
+		r.rc.writer.PushPrefix(bytes.Repeat(indent, len(itemPrefix)), 1)
+	} else {
+		r.rc.writer.PopPrefix()
+		r.rc.writer.PopPrefix()
+	}
+	return ast.WalkContinue
+}
+
+func (n *Note) ToggleBox(nthBox int) {
+	log.Printf("Toggling %dth box", nthBox)
+
+	checkboxTransformer := toggleCheckboxTransformer{nthBox: nthBox}
+	transformer := util.Prioritized(&checkboxTransformer, 0)
+
+	renderer := markdown.NewRenderer()
+	renderer.Register(astext.KindTaskCheckBox, func(writer util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+	})
+
+	var buf bytes.Buffer
+	md := goldmark.New(
+		goldmark.WithExtensions(
+			extension.TaskList,
+		),
+		goldmark.WithRenderer(markdown.NewRenderer()),
+		goldmark.WithParserOptions(parser.WithASTTransformers(transformer)),
+	)
+
+	md.Convert(n.Body, &buf)
+	n.Body = buf.Bytes()
+	n.Save()
+}
+
 func DecodeTitle(encodedTitle string) string {
 	title, err := base64.StdEncoding.DecodeString(encodedTitle)
 	if err != nil {