commit b7cd3080160bd630d49041d187d78cf78e57b798
Author: Magnus Åhall <magnus.ahall@gibon.se>
Date:   Mon Nov 10 08:18:54 2025 +0100

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5da3471
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+chrome-dev
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..b6a9251
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,18 @@
+module chrome-dev
+
+go 1.25.4
+
+require (
+	github.com/chromedp/chromedp v0.14.2
+	github.com/google/uuid v1.6.0
+)
+
+require (
+	github.com/chromedp/cdproto v0.0.0-20250724212937-08a3db8b4327 // indirect
+	github.com/chromedp/sysutil v1.1.0 // indirect
+	github.com/go-json-experiment/json v0.0.0-20250725192818-e39067aee2d2 // indirect
+	github.com/gobwas/httphead v0.1.0 // indirect
+	github.com/gobwas/pool v0.2.1 // indirect
+	github.com/gobwas/ws v1.4.0 // indirect
+	golang.org/x/sys v0.34.0 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..f41ace3
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,23 @@
+github.com/chromedp/cdproto v0.0.0-20250724212937-08a3db8b4327 h1:UQ4AU+BGti3Sy/aLU8KVseYKNALcX9UXY6DfpwQ6J8E=
+github.com/chromedp/cdproto v0.0.0-20250724212937-08a3db8b4327/go.mod h1:NItd7aLkcfOA/dcMXvl8p1u+lQqioRMq/SqDp71Pb/k=
+github.com/chromedp/chromedp v0.14.2 h1:r3b/WtwM50RsBZHMUm9fsNhhzRStTHrKdr2zmwbZSzM=
+github.com/chromedp/chromedp v0.14.2/go.mod h1:rHzAv60xDE7VNy/MYtTUrYreSc0ujt2O1/C3bzctYBo=
+github.com/chromedp/sysutil v1.1.0 h1:PUFNv5EcprjqXZD9nJb9b/c9ibAbxiYo4exNWZyipwM=
+github.com/chromedp/sysutil v1.1.0/go.mod h1:WiThHUdltqCNKGc4gaU50XgYjwjYIhKWoHGPTUfWTJ8=
+github.com/go-json-experiment/json v0.0.0-20250725192818-e39067aee2d2 h1:iizUGZ9pEquQS5jTGkh4AqeeHCMbfbjeb0zMt0aEFzs=
+github.com/go-json-experiment/json v0.0.0-20250725192818-e39067aee2d2/go.mod h1:TiCD2a1pcmjd7YnhGH0f/zKNcCD06B029pHhzV23c2M=
+github.com/gobwas/httphead v0.1.0 h1:exrUm0f4YX0L7EBwZHuCF4GDp8aJfVeBrlLQrs6NqWU=
+github.com/gobwas/httphead v0.1.0/go.mod h1:O/RXo79gxV8G+RqlR/otEwx4Q36zl9rqC5u12GKvMCM=
+github.com/gobwas/pool v0.2.1 h1:xfeeEhW7pwmX8nuLVlqbzVc7udMDrwetjEv+TZIz1og=
+github.com/gobwas/pool v0.2.1/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
+github.com/gobwas/ws v1.4.0 h1:CTaoG1tojrh4ucGPcoJFiAQUAsEWekEWvLy7GsVNqGs=
+github.com/gobwas/ws v1.4.0/go.mod h1:G3gNqMNtPppf5XUz7O4shetPpcZ1VJ7zt18dlUeakrc=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/ledongthuc/pdf v0.0.0-20220302134840-0c2507a12d80 h1:6Yzfa6GP0rIo/kULo2bwGEkFvCePZ3qHDDTC3/J9Swo=
+github.com/ledongthuc/pdf v0.0.0-20220302134840-0c2507a12d80/go.mod h1:imJHygn/1yfhB7XSJJKlFZKl/J+dCPAknuiaGOshXAs=
+github.com/orisano/pixelmatch v0.0.0-20220722002657-fb0b55479cde h1:x0TT0RDC7UhAVbbWWBzr41ElhJx5tXPWkIHA2HWPRuw=
+github.com/orisano/pixelmatch v0.0.0-20220722002657-fb0b55479cde/go.mod h1:nZgzbfBr3hhjoZnS66nKrHmduYNpc34ny7RK4z5/HM0=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
+golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..1774e8d
--- /dev/null
+++ b/main.go
@@ -0,0 +1,138 @@
+// Command remote is a chromedp example demonstrating how to connect to an
+// existing Chrome DevTools instance using a remote WebSocket URL.
+package main
+
+import (
+	// Standard
+	"embed"
+	"encoding/json"
+	"flag"
+	"html/template"
+	"io"
+	"log"
+	"net/http"
+	"os"
+)
+
+var (
+	flagVerbose bool
+	flagWsURL   string
+	flagWatch   string
+
+	//go:embed static
+	fs embed.FS
+)
+
+func main() {
+	flag.BoolVar(&flagVerbose, "v", false, "verbose")
+	flag.StringVar(&flagWsURL, "ws", "ws://127.0.0.1:9222", "devtools url")
+	flag.StringVar(&flagWatch, "watch", "", "Files to watch")
+	flag.Parse()
+
+	http.HandleFunc("/", pageIndex)
+	http.HandleFunc("/css/main.css", pageCSS)
+
+	http.HandleFunc("/start", actionStart)
+	http.HandleFunc("/stop/{uuid}", actionStop)
+	http.HandleFunc("/sites", actionSites)
+
+	log.Println("Listen on [::]:5123")
+	http.ListenAndServe("[::]:5123", nil)
+}
+
+func pageIndex(w http.ResponseWriter, r *http.Request) { // {{{
+	var tmpl *template.Template
+	var err error
+	if false {
+		tmpl, err = template.ParseFS(fs, "static/html/index.html")
+	}
+	tmpl, err = template.ParseFiles("static/html/index.html")
+	if err != nil {
+		w.Write([]byte(err.Error()))
+		return
+	}
+
+	tmpl.Execute(w, sites)
+} // }}}
+func pageCSS(w http.ResponseWriter, r *http.Request) { // {{{
+	w.Header().Add("Content-Type", "text/css")
+
+	//data, err := fs.ReadFile("static/css/main.css")
+	data, err := os.ReadFile("static/css/main.css")
+	if err != nil {
+		w.Write([]byte(err.Error()))
+		return
+	}
+	w.Write(data)
+} // }}}
+func actionSites(w http.ResponseWriter, r *http.Request) { // {{{
+	j, _ := json.Marshal(struct {
+		OK bool
+		Sites map[string]*Site
+	}{
+		true,
+		sites,
+	})
+	w.Write(j)
+} // }}}
+
+func actionStart(w http.ResponseWriter, r *http.Request) { // {{{
+	var req struct {
+		URL   string
+		Watch string
+	}
+
+	body, _ := io.ReadAll(r.Body)
+	err := json.Unmarshal(body, &req)
+	if err != nil {
+		j, _ := json.Marshal(struct {
+			OK    bool
+			Error string
+		}{
+			false,
+			err.Error(),
+		})
+		w.Write(j)
+		return
+	}
+
+	var site Site
+	site, err = NewSite(flagWsURL, req.URL, req.Watch)
+	if err != nil {
+		log.Println(err)
+	}
+
+	j, _ := json.Marshal(struct {
+		OK   bool
+		Site Site
+	}{
+		true,
+		site,
+	})
+	w.Write(j)
+} // }}}
+func actionStop(w http.ResponseWriter, r *http.Request) { // {{{
+	siteUUID := r.PathValue("uuid")
+
+	site, found := sites[siteUUID]
+	if !found {
+		j, _ := json.Marshal(struct {
+			OK    bool
+			Error string
+		}{
+			false,
+			"Site not found",
+		})
+		w.Write(j)
+		return
+	}
+
+	site.StopLoop = true
+
+	j, _ := json.Marshal(struct {
+		OK bool
+	}{
+		true,
+	})
+	w.Write(j)
+} // }}}
diff --git a/site.go b/site.go
new file mode 100644
index 0000000..8f785b0
--- /dev/null
+++ b/site.go
@@ -0,0 +1,117 @@
+package main
+
+import (
+	// External
+	"github.com/chromedp/cdproto/target"
+	"github.com/chromedp/chromedp"
+	"github.com/google/uuid"
+
+	// Standard
+	"context"
+	"fmt"
+	"log"
+	"os/exec"
+	"sync"
+)
+
+var (
+	sites    map[string]*Site
+	siteLock *sync.Mutex
+)
+
+type Site struct {
+	UUID      string
+	URL       string
+	Watch     string
+	WatchLoop *exec.Cmd `json:"-"`
+	StopLoop  bool
+	Context   context.Context `json:"-"`
+}
+
+func init() {
+	siteLock = &sync.Mutex{}
+	sites = make(map[string]*Site)
+}
+
+func NewSite(wsURL, url, watch string) (s Site, err error) {
+	s.UUID = uuid.NewString()
+	s.URL = url
+	s.Watch = watch
+
+	allocatorContext, _ := chromedp.NewRemoteAllocator(context.Background(), wsURL)
+
+	// Used to optionally enable debugging output.
+	var opts []chromedp.ContextOption
+	if flagVerbose {
+		opts = append(opts, chromedp.WithDebugf(log.Printf))
+	}
+	s.Context, _ = chromedp.NewContext(allocatorContext, opts...)
+
+	// A tab is started up and navigated to in order to get a context for this instance.
+	if err = chromedp.Run(
+		s.Context,
+		chromedp.Navigate(url),
+	); err != nil {
+		err = fmt.Errorf("Failed getting body of %s: %v", url, err)
+		return
+	}
+
+	siteLock.Lock()
+	sites[s.UUID] = &s
+	defer siteLock.Unlock()
+
+	// chromedp.Run crashes something really hard and undetectable with recover().
+	// ListenBrowser gives the possibility to cancel the watch loop.
+	chromedp.ListenBrowser(s.Context, func(ev any) {
+		_, event1 := ev.(*target.EventDetachedFromTarget)
+		_, event2 := ev.(*target.EventTargetCrashed)
+		_, event3 := ev.(*target.EventTargetDestroyed)
+		if event1 || event2 || event3 {
+			log.Printf("Stopping loop for %s\n", s.UUID)
+			s.StopLoop = true
+			if s.WatchLoop != nil {
+				log.Printf("Killing inotifywait for %s\n", s.UUID)
+				s.WatchLoop.Process.Kill()
+			}
+
+		}
+	})
+
+	// Start watching file/dir for changes.
+	go s.watchLoop()
+
+	return
+}
+
+func (s *Site) watchLoop() {
+	for !s.StopLoop {
+		log.Println("Starting watching " + s.Watch)
+		s.WatchLoop = exec.Command("inotifywait", "-e", "close_write", s.Watch)
+		if err := s.WatchLoop.Run(); err != nil {
+			log.Println(err)
+		}
+		s.ReloadCSS()
+	}
+	log.Printf("Stopping watch loop [%s]\n", s.UUID)
+}
+
+func (s *Site) ReloadCSS() {
+	var buf []byte
+
+	cssReloadScript := chromedp.Evaluate(`
+		(()=>{
+			const stylesheets = document.querySelectorAll('link[rel="stylesheet"]')
+			for (const ss of stylesheets) {
+				const url = URL.parse(ss.href, location.protocol + '//' + location.host) 
+				const nextReloadCounter = parseInt(url.searchParams.get('reload') || 0) + 1
+				url.searchParams.set('reload', nextReloadCounter)
+				ss.href = url.toString()
+			}
+		})()
+		`, &buf)
+
+	err := chromedp.Run(s.Context, cssReloadScript)
+	if err != nil {
+		fmt.Println(err)
+	}
+}
diff --git a/static/css/main.css b/static/css/main.css
new file mode 100644
index 0000000..23014e8
--- /dev/null
+++ b/static/css/main.css
@@ -0,0 +1,40 @@
+body {
+	font-family: sans-serif;
+	margin: 32px;
+}
+
+input {
+	font-size: 1em;
+}
+
+.new {
+	width: 400px;
+}
+
+.sites {
+	display: grid;
+	grid-template-columns: repeat(3, min-content);
+	grid-gap: 8px 16px;
+	margin-top: 32px;
+
+	div {
+		white-space: nowrap;
+
+		&.dead {
+			color: #aaa;
+		}
+	}
+
+	.header {
+		font-weight: bold;
+	}
+
+	.line {
+		grid-column: 1 / -1;
+		border-bottom: 1px solid #ccc;
+	}
+
+	.stop {
+		cursor: pointer;
+	}
+}
diff --git a/static/html/index.html b/static/html/index.html
new file mode 100644
index 0000000..3418ceb
--- /dev/null
+++ b/static/html/index.html
@@ -0,0 +1,63 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+	<meta charset="UTF-8">
+	<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
+	<link rel="stylesheet" type="text/css" href="/css/main.css">
+</head>
+<script>
+	function newSite() {
+		const url = document.querySelector('.new.url').value
+		const watch = document.querySelector('.new.watch').value
+		fetch('/start', {
+			method: 'POST',
+			body: JSON.stringify({url, watch}),
+		})
+			.then(() => location.reload())
+
+	}
+
+	function stopSite(uuid) {
+		fetch(`/stop/${uuid}`)
+			.then(() => location.reload())
+	}
+
+	function siteStatus() {
+		fetch('/sites')
+			.then(data => data.json())
+			.then(json => {
+				for (const uuid of Object.keys(json.Sites)) {
+					const site = json.Sites[uuid]
+					if (site.StopLoop) {
+						document.querySelector(`.url[data-uuid="${uuid}"]`)?.classList.add('dead')
+						document.querySelector(`.watch[data-uuid="${uuid}"]`)?.classList.add('dead')
+					}
+				}
+			})
+	}
+
+	setInterval(siteStatus, 2000)
+</script>
+
+<body>
+	<input type="text" class="new url" placeholder="https://example.com" value="https://scan.euterm.n44.se">
+	<input type="text" class="new watch" placeholder="~/example.com/css/"
+		value="/home/magnus/repo/euterm/euscan/static/css">
+	<button onclick="newSite()">Start</button>
+
+	<div class="sites">
+		<div class="header">UUID</div>
+		<div class="header">URL</div>
+		<div class="header"></div>
+
+		{{ range . }}
+		<div class="line"></div>
+		<div class="url {{ if .StopLoop }}dead{{ end }}" data-uuid="{{ .UUID }}">{{ .URL }}</div>
+		<div class="watch {{ if .StopLoop }}dead{{ end }}" data-uuid="{{ .UUID }}">{{ .Watch }}</div>
+		<div class="stop" onclick="stopSite('{{ .UUID }}')">❌</div>
+		{{ end }}
+	</div>
+</body>
+
+</html>