desio
/
publish


			
				
					
						
						
							
							package main

import (
	"bytes"
	"fmt"
	"gopkg.in/russross/blackfriday.v2"
	"html/template"
	"io"
	"io/ioutil"
	"net/http"
	"os"
)

func main() {
	if len(os.Args) != 2 {
		fmt.Printf("usage: %s <document>", os.Args[0])
		os.Exit(1)
	}

	tpl, err := template.New("dummy").Parse(`
<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Example</title>
  <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.11.0/dist/katex.min.css" integrity="sha384-BdGj8xC2eZkQaxoQ8nSLefg4AV4/AwB3Fj+8SUSo7pnKP6Eoy18liIKTPn9oBYNG" crossorigin="anonymous">

    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.11.0/dist/katex.min.js" integrity="sha384-JiKN5O8x9Hhs/UE5cT5AAJqieYlOZbGT3CHws/y97o3ty4R7/O5poG9F3JoiOYw1" crossorigin="anonymous"></script>
    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.11.0/dist/contrib/auto-render.min.js" integrity="sha384-kWPLUVMOks5AQFrykwIup5lo0m3iMkkHrD0uJ4H5cjeGihAutqP0yW0J6dpFiVkI" crossorigin="anonymous"
        onload="renderMathInElement(document.body);"></script>

<style>
  .katex { font-size: 1em; }
</style>
</head>
<body>
{{.}}
</body>
</html>
`)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	http.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		f, err := os.Open(os.Args[1])
		if err != nil {
			panic(err)
		}

		b, err := ioutil.ReadAll(f)
		if err != nil {
			panic(err)
		}

		unsafe := blackfriday.Run(b, blackfriday.WithRenderer(NewMyRenderer()))
		if err := tpl.Execute(w, template.HTML(unsafe)); err != nil {
			panic(err)
		}
	}))
	fmt.Println("listening on :19000")
	http.ListenAndServe(":19000", nil)
}

type MyRenderer struct {
	html *blackfriday.HTMLRenderer
}

func NewMyRenderer() *MyRenderer {
	return &MyRenderer{
		html: blackfriday.NewHTMLRenderer(blackfriday.HTMLRendererParameters{
			Flags: blackfriday.CommonHTMLFlags,
		}),
	}
}

func (r *MyRenderer) RenderNode(w io.Writer, node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
	if node.Type == blackfriday.Code {
		if bytes.HasPrefix(node.Literal, []byte("\\(")) && bytes.HasSuffix(node.Literal, []byte("\\)")) {
			w.Write(node.Literal)
			return blackfriday.GoToNext
		}
	} else if node.Type == blackfriday.CodeBlock && string(node.CodeBlockData.Info) == "katex" {
		w.Write([]byte("\n<p>"))
		w.Write(node.Literal)
		w.Write([]byte("</p>"))
		return blackfriday.GoToNext
	}
	return r.html.RenderNode(w, node, entering)
}

func (r *MyRenderer) RenderHeader(w io.Writer, ast *blackfriday.Node) {
	r.html.RenderHeader(w, ast)
}
func (r *MyRenderer) RenderFooter(w io.Writer, ast *blackfriday.Node) {
	r.html.RenderHeader(w, ast)
}