Initial

go.mod

@@ -0,0 +1,5 @@
+module hedgedoc-watcher
+
+go 1.14
+
+require github.com/russross/blackfriday/v2 v2.1.0

go.sum

@@ -0,0 +1,2 @@
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=

hedgedoc-watcher.go

@@ -0,0 +1,127 @@
+///bin/sh -c true; exec /usr/bin/env go run "$0" "$@"
+package main
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/url"
+	"os"
+	"os/exec"
+	"path"
+	"strings"
+	"text/template"
+	"time"
+
+	"github.com/russross/blackfriday/v2"
+)
+
+const (
+	DL_LIMIT     = 15 * 1024 * 1024
+	CACHE_FOLDER = "cache"
+)
+
+const RSS_TEMPLATE string = `<?xml version="1.0" encoding="UTF-8"?>
+<rss version="2.0" xmlns:content="http://purl.org/rss/1.0/modules/content/">
+<channel>
+<title><![CDATA[ {{.ID}} ]]></title>
+<link><![CDATA[ {{.Server}}/{{.ID}} ]]></link>
+<description><![CDATA[ {{.ID}} ]]></description>
+
+    <item>
+      <title><![CDATA[ {{.Server}}/{{.ID}} ]]></title>
+      <content:encoded><![CDATA[ {{.Content}} ]]></content:encoded>
+      <guid><![CDATA[ {{.Server}}/{{.ID}}/{{.Modified.Format "20060102-150405"}} ]]></guid>
+      <link><![CDATA[ {{.Server}}/{{.ID}} ]]></link>
+      <pubDate>{{.Modified.Format "Mon, 02 Jan 2006 15:04:05 -0700"}}</pubDate>
+    </item>
+
+</channel>
+</rss>
+`
+
+func optPanic(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (n *Note) filename() string {
+	return path.Join(CACHE_FOLDER, n.ID)
+}
+
+func (n *Note) setContent() {
+	cmd := exec.Command("hedgedoc", "export", "--md", n.ID)
+	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, "HEDGEDOC_SERVER="+n.Server)
+	if n.CookiesFile != "" {
+		cmd.Env = append(cmd.Env, "HEDGEDOC_COOKIES_FILE="+n.CookiesFile)
+	}
+	filename, err := cmd.Output()
+	optPanic(err)
+	b, err := ioutil.ReadFile(strings.TrimSpace(string(filename)))
+	optPanic(err)
+	n.Content = string(blackfriday.Run(b))
+	n.Modified = time.Now()
+}
+
+func unmarshalNoteObject(filename string) Note {
+	bytes, err := ioutil.ReadFile(filename)
+	if err != nil {
+		bytes = []byte{}
+	}
+	var noteObject Note
+	err = json.Unmarshal(bytes, &noteObject)
+	if err != nil {
+		noteObject = Note{}
+	}
+	return noteObject
+}
+
+func marshalNoteObject(filename string, note Note) {
+	bytes, err := json.MarshalIndent(note, "", "  ")
+	optPanic(err)
+	err = ioutil.WriteFile(filename, bytes, 0644)
+	optPanic(err)
+}
+
+func (newNote *Note) genRSS() {
+	var chosen Note
+	oldNote := unmarshalNoteObject(newNote.filename())
+	if oldNote.Content != newNote.Content {
+		chosen = *newNote
+	} else {
+		chosen = oldNote
+	}
+	err := rssTemplate.Execute(os.Stdout, chosen)
+	optPanic(err)
+	marshalNoteObject(newNote.filename(), chosen)
+}
+
+type Note struct {
+	Server      string
+	ID          string
+	Content     string
+	Modified    time.Time
+	CookiesFile string
+}
+
+func NewNote(server string, ID string) *Note {
+	n := &Note{Server: server, ID: ID}
+	n.setContent()
+	return n
+}
+
+var rssTemplate *template.Template
+
+func rssify(noteURL string) {
+	u, err := url.Parse(noteURL)
+	optPanic(err)
+	NewNote(u.Scheme+"://"+u.Host, u.Path[1:]).genRSS()
+}
+
+func main() {
+	rssTemplate = template.Must(template.New("rss").Parse(RSS_TEMPLATE))
+	os.Mkdir(CACHE_FOLDER, 0755)
+	// todo: Cookie-file flag
+	rssify(os.Args[1])
+}