chrome-dev/main.go

// 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"
	"fmt"
	"html/template"
	"io"
	"log"
	"net/http"
	"os"
	"os/exec"
	"strings"
)

const VERSION = "v5"

var (
	flagVerbose       bool
	flagVersion       bool
	flagDebuggingPort int

	//go:embed static
	fs embed.FS
)

func main() {
	flag.BoolVar(&flagVerbose, "v", false, "verbose")
	flag.BoolVar(&flagVersion, "version", false, "Print version and exit")
	flag.IntVar(&flagDebuggingPort, "port", 9222, "Chrome debugging port")
	flag.Parse()

	if flagVersion {
		fmt.Println(VERSION)
		return
	}

	http.HandleFunc("/", pageIndex)
	http.HandleFunc("/css/main.css", pageCSS)

	http.HandleFunc("/browser/start", actionBrowserStart)

	http.HandleFunc("/start", actionStart)
	http.HandleFunc("/stop/{uuid}", actionStop)
	http.HandleFunc("/sites", actionSites)

	log.Println("Listen on [::]:5123")
	err := http.ListenAndServe("[::]:5123", nil)
	if err != nil {
		log.Println(err)
		os.Exit(1)
	}
}

func replaceTilde(str string) string { // {{{
	homedir, err := os.UserHomeDir()
	if err != nil {
		log.Println(err)
		return str
	}

	if str[0] == '~' {
		str = strings.Replace(str, "~", homedir, 1)
	}

	return str
} // }}}

func pageIndex(w http.ResponseWriter, r *http.Request) { // {{{
	var tmpl *template.Template
	var err error
	tmpl, err = template.ParseFS(fs, "static/html/index.html")
	if err != nil {
		w.Write([]byte(err.Error()))
		return
	}

	data := map[string]any{
		"Sites":   sites,
		"VERSION": VERSION,
	}
	tmpl.Execute(w, data)
} // }}}
func pageCSS(w http.ResponseWriter, r *http.Request) { // {{{
	w.Header().Add("Content-Type", "text/css")

	data, err := fs.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 actionBrowserStart(w http.ResponseWriter, r *http.Request) { // {{{
	body, _ := io.ReadAll(r.Body)
	userDataDir := replaceTilde(string(body))
	browser := exec.Command("google-chrome", "--user-data-dir="+string(userDataDir), fmt.Sprintf("--remote-debugging-port=%d", flagDebuggingPort))
	err := browser.Start()
	if err != nil {
		log.Println(err)
	} else {
		go browser.Wait()
	}
} // }}}
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
	expandedWatch := replaceTilde(req.Watch)
	wsURL := fmt.Sprintf("ws://127.0.0.1:%d", flagDebuggingPort)
	site, err = NewSite(wsURL, req.URL, expandedWatch)
	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)
} // }}}