feat: rewrite render

pkg/md/md.go

@@ -0,0 +1,130 @@
+package md
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Elem interface {
+	String() string
+}
+
+type JoinType struct {
+	elems []Elem
+	with  string
+}
+
+func (p JoinType) String() string {
+	s := ""
+	for _, e := range p.elems {
+		s += p.with + e.String()
+	}
+	return strings.TrimPrefix(s, p.with)
+}
+
+func Paragraph(elems ...Elem) JoinType {
+	return JoinType{elems: elems, with: " "}
+}
+
+func Doc(elems ...Elem) JoinType {
+	return JoinType{elems: elems, with: "\n\n"}
+}
+
+type TextType struct {
+	content string
+}
+
+func (t TextType) String() string {
+	return t.content
+}
+
+func Text(text string) TextType {
+	return TextType{content: text}
+}
+
+type HeadlineType struct {
+	level   int
+	content string
+}
+
+func (h HeadlineType) String() string {
+	return strings.Repeat("#", h.level) + " " + h.content
+}
+
+func Headline(level int, content string) HeadlineType {
+	return HeadlineType{
+		level:   level,
+		content: content,
+	}
+}
+
+type SurroundType struct {
+	body     Elem
+	surround string
+}
+
+func (s SurroundType) String() string {
+	return s.surround + s.body.String() + s.surround
+}
+
+func Bold(e Elem) SurroundType {
+	return SurroundType{body: e, surround: "**"}
+}
+
+func Italic(e Elem) SurroundType {
+	return SurroundType{body: e, surround: "*"}
+}
+
+func Code(e Elem) SurroundType {
+	return SurroundType{body: e, surround: "`"}
+}
+
+type CodeBlockType struct {
+	lang    string
+	snippet string
+}
+
+func (c CodeBlockType) String() string {
+	return fmt.Sprintf("```%s\n%s\n```", c.lang, c.snippet)
+}
+
+func CodeBlock(lang, snippet string) CodeBlockType {
+	return CodeBlockType{lang: lang, snippet: snippet}
+}
+
+type ListType struct {
+	elems []Elem
+}
+
+func (l ListType) String() string {
+	s := ""
+	for _, e := range l.elems {
+		switch t := e.(type) {
+		case ListType:
+			s += "\n  " + strings.Join(strings.Split(t.String(), "\n"), "\n  ")
+		default:
+			s += "\n* " + t.String()
+		}
+	}
+	return strings.TrimPrefix(s, "\n")
+}
+
+func List(elems ...Elem) ListType {
+	return ListType{elems: elems}
+}
+
+type LinkType struct {
+	desc Elem
+	href string
+}
+
+func (l LinkType) String() string {
+	return fmt.Sprintf("[%s](%s)", l.desc.String(), l.href)
+}
+
+func Link(desc Elem, href string) LinkType {
+	return LinkType{
+		desc: desc,
+		href: href,
+	}
+}