feat(markdown): interprate callout

1 files changed, 92 insertions, 0 deletions

diff --git a/markdown/ast_callout.go b/markdown/ast_callout.go
new file mode 100644
index 0000000..769d714
--- /dev/null
+++ b/markdown/ast_callout.go
@@ -0,0 +1,92 @@
+package markdown
+
+import (
+	"errors"
+	"html/template"
+	"strings"
+
+	"git.anhgelus.world/anhgelus/small-web/dom"
+)
+
+var (
+	ErrInvalidCallout = errors.New("invalid callout")
+)
+
+type astCallout struct {
+	kind    string
+	title   *astParagraph
+	content []*astParagraph
+}
+
+func (a *astCallout) Eval(opt *Option) (template.HTML, *ParseError) {
+	inner := dom.NewContentElement("div", make([]dom.Element, 0))
+	for _, c := range a.content {
+		ct, err := c.Eval(opt)
+		if err != nil {
+			return "", err
+		}
+		inner.Contents = append(inner.Contents, dom.NewParagraph(
+			template.HTML(strings.TrimSpace(string(ct))),
+		))
+	}
+
+	titleContent, err := a.title.Eval(opt)
+	if err != nil {
+		return "", err
+	}
+	titleContent = template.HTML(strings.TrimSpace(string(titleContent)))
+	if len(titleContent) == 0 {
+		titleContent = template.HTML(a.kind)
+	}
+	title := dom.NewLiteralContentElement("h4", titleContent)
+
+	callout := dom.NewContentElement("div", make([]dom.Element, 2))
+	callout.Contents[0] = title
+	callout.Contents[1] = inner
+	callout.SetAttribute("data-kind", a.kind)
+	callout.ClassList().Add("callout")
+	return callout.Render(), nil
+}
+
+func callout(lxs *lexers) (block, *ParseError) {
+	callout := new(astCallout)
+	if lxs.Current().Value != "[!" {
+		return paragraph(lxs, false)
+	}
+	if !lxs.Next() {
+		return nil, &ParseError{lxs: *lxs, internal: ErrInvalidCallout}
+	}
+	callout.kind = strings.ToLower(lxs.Current().Value)
+	if !lxs.Next() || lxs.Current().Type != lexerCallout || lxs.Current().Value != "]" {
+		return nil, &ParseError{lxs: *lxs, internal: ErrInvalidCallout}
+	}
+	var err *ParseError
+	callout.title, err = paragraph(lxs, true)
+	if err != nil {
+		return nil, err
+	}
+	n := 0
+	for lxs.Next() && n < 2 {
+		current := lxs.Current()
+		n = 0
+		switch current.Type {
+		case lexerBreak:
+			n = len(current.Value)
+		case lexerQuote:
+		case lexerLiteral, lexerModifier, lexerCode, lexerExternal:
+			p, err := paragraph(lxs, true)
+			if err != nil {
+				return nil, err
+			}
+			lxs.Before()
+			callout.content = append(callout.content, p)
+			n++
+		default:
+			// because the code did not use it
+			lxs.Before()
+			return callout, nil
+		}
+	}
+	lxs.Before()
+	return callout, nil
+}