kot.pink
1// heavily inspired by: https://github.com/kaleocheng/goldmark-extensions
2
3package extension
4
5import (
6 "regexp"
7
8 "github.com/yuin/goldmark"
9 "github.com/yuin/goldmark/ast"
10 "github.com/yuin/goldmark/parser"
11 "github.com/yuin/goldmark/renderer"
12 "github.com/yuin/goldmark/renderer/html"
13 "github.com/yuin/goldmark/text"
14 "github.com/yuin/goldmark/util"
15)
16
17// An AtNode struct represents an AtNode
18type AtNode struct {
19 Handle string
20 ast.BaseInline
21}
22
23var _ ast.Node = &AtNode{}
24
25// Dump implements Node.Dump.
26func (n *AtNode) Dump(source []byte, level int) {
27 ast.DumpHelper(n, source, level, nil, nil)
28}
29
30// KindAt is a NodeKind of the At node.
31var KindAt = ast.NewNodeKind("At")
32
33// Kind implements Node.Kind.
34func (n *AtNode) Kind() ast.NodeKind {
35 return KindAt
36}
37
38var atRegexp = regexp.MustCompile(`(^|\s|\()(@)([a-zA-Z0-9.-]+)(\b)`)
39
40type atParser struct{}
41
42// NewAtParser return a new InlineParser that parses
43// at expressions.
44func NewAtParser() parser.InlineParser {
45 return &atParser{}
46}
47
48func (s *atParser) Trigger() []byte {
49 return []byte{'@'}
50}
51
52func (s *atParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
53 line, segment := block.PeekLine()
54 m := atRegexp.FindSubmatchIndex(line)
55 if m == nil {
56 return nil
57 }
58 atSegment := text.NewSegment(segment.Start, segment.Start+m[1])
59 block.Advance(m[1])
60 node := &AtNode{}
61 node.AppendChild(node, ast.NewTextSegment(atSegment))
62 node.Handle = string(atSegment.Value(block.Source())[1:])
63 return node
64}
65
66// atHtmlRenderer is a renderer.NodeRenderer implementation that
67// renders At nodes.
68type atHtmlRenderer struct {
69 html.Config
70}
71
72// NewAtHTMLRenderer returns a new AtHTMLRenderer.
73func NewAtHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
74 r := &atHtmlRenderer{
75 Config: html.NewConfig(),
76 }
77 for _, opt := range opts {
78 opt.SetHTMLOption(&r.Config)
79 }
80 return r
81}
82
83// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
84func (r *atHtmlRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
85 reg.Register(KindAt, r.renderAt)
86}
87
88func (r *atHtmlRenderer) renderAt(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
89 if entering {
90 w.WriteString(`<a href="/@`)
91 w.WriteString(n.(*AtNode).Handle)
92 w.WriteString(`" class="mention font-bold">`)
93 } else {
94 w.WriteString("</a>")
95 }
96 return ast.WalkContinue, nil
97}
98
99type atExt struct{}
100
101// At is an extension that allow you to use at expression like '@user.bsky.social' .
102var AtExt = &atExt{}
103
104func (e *atExt) Extend(m goldmark.Markdown) {
105 m.Parser().AddOptions(parser.WithInlineParsers(
106 util.Prioritized(NewAtParser(), 500),
107 ))
108 m.Renderer().AddOptions(renderer.WithNodeRenderers(
109 util.Prioritized(NewAtHTMLRenderer(), 500),
110 ))
111}