package rui
import (
"bytes"
"context"
_ "embed"
"fmt"
"io"
"log"
"math/rand"
"net/http"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"strings"
"time"
)
//go:embed app_scripts.js
var defaultScripts string
//go:embed app_styles.css
var appStyles string
//go:embed defaultTheme.rui
var defaultThemeText string
// Application - app interface
type Application interface {
Finish()
nextSessionID() int
removeSession(id int)
}
type application struct {
server *http.Server
params AppParams
createContentFunc func(Session) SessionContent
sessions map[int]Session
}
// AppParams defines parameters of the app
type AppParams struct {
// Title - title of the app window/tab
Title string
// TitleColor - background color of the app window/tab (applied only for Safari and Chrome for Android)
TitleColor Color
// Icon - the icon file name
Icon string
// CertFile - path of a certificate for the server must be provided
// if neither the Server's TLSConfig.Certificates nor TLSConfig.GetCertificate are populated.
// If the certificate is signed by a certificate authority, the certFile should be the concatenation
// of the server's certificate, any intermediates, and the CA's certificate.
CertFile string
// KeyFile - path of a private key for the server must be provided
// if neither the Server's TLSConfig.Certificates nor TLSConfig.GetCertificate are populated.
KeyFile string
// Redirect80 - if true then the function of redirect from port 80 to 443 is created
Redirect80 bool
}
func (app *application) getStartPage() string {
buffer := allocStringBuilder()
defer freeStringBuilder(buffer)
buffer.WriteString(`
`)
buffer.WriteString(app.params.Title)
buffer.WriteString("")
if app.params.Icon != "" {
buffer.WriteString(`
`)
}
if app.params.TitleColor != 0 {
buffer.WriteString(`
`)
}
buffer.WriteString(`
`)
return buffer.String()
}
func (app *application) Finish() {
for _, session := range app.sessions {
session.close()
}
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
if err := app.server.Shutdown(ctx); err != nil {
log.Println(err.Error())
}
}
func (app *application) nextSessionID() int {
n := rand.Intn(0x7FFFFFFE) + 1
_, ok := app.sessions[n]
for ok {
n = rand.Intn(0x7FFFFFFE) + 1
_, ok = app.sessions[n]
}
return n
}
func (app *application) removeSession(id int) {
delete(app.sessions, id)
}
func (app *application) ServeHTTP(w http.ResponseWriter, req *http.Request) {
if ProtocolInDebugLog {
DebugLogF("%s %s", req.Method, req.URL.Path)
}
switch req.Method {
case "GET":
switch req.URL.Path {
case "/":
w.WriteHeader(http.StatusOK)
io.WriteString(w, app.getStartPage())
case "/ws":
if brige := CreateSocketBrige(w, req); brige != nil {
go app.socketReader(brige)
}
default:
filename := req.URL.Path[1:]
if size := len(filename); size > 0 && filename[size-1] == '/' {
filename = filename[:size-1]
}
if !serveResourceFile(filename, w, req) &&
!serveDownloadFile(filename, w, req) {
w.WriteHeader(http.StatusNotFound)
}
}
}
}
func (app *application) socketReader(brige WebBrige) {
var session Session
events := make(chan DataObject, 1024)
for {
message, ok := brige.ReadMessage()
if !ok {
events <- NewDataObject("disconnect")
return
}
if ProtocolInDebugLog {
DebugLog(message)
}
if obj := ParseDataText(message); obj != nil {
command := obj.Tag()
switch command {
case "startSession":
answer := ""
if session, answer = app.startSession(obj, events, brige); session != nil {
if !brige.WriteMessage(answer) {
return
}
session.onStart()
go sessionEventHandler(session, events, brige)
}
case "reconnect":
if sessionText, ok := obj.PropertyValue("session"); ok {
if sessionID, err := strconv.Atoi(sessionText); err == nil {
if session = app.sessions[sessionID]; session != nil {
session.setBrige(events, brige)
answer := allocStringBuilder()
defer freeStringBuilder(answer)
session.writeInitScript(answer)
if !brige.WriteMessage(answer.String()) {
return
}
session.onReconnect()
go sessionEventHandler(session, events, brige)
return
}
DebugLogF("Session #%d not exists", sessionID)
} else {
ErrorLog(`strconv.Atoi(sessionText) error: ` + err.Error())
}
} else {
ErrorLog(`"session" key not found`)
}
answer := ""
if session, answer = app.startSession(obj, events, brige); session != nil {
if !brige.WriteMessage(answer) {
return
}
session.onStart()
go sessionEventHandler(session, events, brige)
}
case "answer":
session.handleAnswer(obj)
case "imageLoaded":
session.imageManager().imageLoaded(obj, session)
case "imageError":
session.imageManager().imageLoadError(obj, session)
default:
events <- obj
}
}
}
}
func sessionEventHandler(session Session, events chan DataObject, brige WebBrige) {
for {
data := <-events
switch command := data.Tag(); command {
case "disconnect":
session.onDisconnect()
return
case "session-close":
session.onFinish()
session.App().removeSession(session.ID())
brige.Close()
case "session-pause":
session.onPause()
case "session-resume":
session.onResume()
case "root-size":
session.handleRootSize(data)
case "resize":
session.handleResize(data)
default:
session.handleViewEvent(command, data)
}
}
}
func (app *application) startSession(params DataObject, events chan DataObject, brige WebBrige) (Session, string) {
if app.createContentFunc == nil {
return nil, ""
}
session := newSession(app, app.nextSessionID(), "", params)
session.setBrige(events, brige)
if !session.setContent(app.createContentFunc(session), session) {
return nil, ""
}
app.sessions[session.ID()] = session
answer := allocStringBuilder()
defer freeStringBuilder(answer)
answer.WriteString("sessionID = '")
answer.WriteString(strconv.Itoa(session.ID()))
answer.WriteString("';\n")
session.writeInitScript(answer)
answerText := answer.String()
if ProtocolInDebugLog {
DebugLog("Start session:")
DebugLog(answerText)
}
return session, answerText
}
var apps = []*application{}
// StartApp - create the new application and start it
func StartApp(addr string, createContentFunc func(Session) SessionContent, params AppParams) {
app := new(application)
app.params = params
app.sessions = map[int]Session{}
app.createContentFunc = createContentFunc
apps = append(apps, app)
redirectAddr := ""
if index := strings.IndexRune(addr, ':'); index >= 0 {
redirectAddr = addr[:index] + ":80"
} else {
redirectAddr = addr + ":80"
if params.CertFile != "" && params.KeyFile != "" {
addr += ":443"
} else {
addr += ":80"
}
}
app.server = &http.Server{Addr: addr}
http.Handle("/", app)
serverRun := func(err error) {
if err != nil {
if err == http.ErrServerClosed {
log.Println(err)
} else {
log.Fatal(err)
}
}
}
if params.CertFile != "" && params.KeyFile != "" {
if params.Redirect80 {
redirectTLS := func(w http.ResponseWriter, r *http.Request) {
http.Redirect(w, r, "https://"+addr+r.RequestURI, http.StatusMovedPermanently)
}
go func() {
serverRun(http.ListenAndServe(redirectAddr, http.HandlerFunc(redirectTLS)))
}()
}
serverRun(app.server.ListenAndServeTLS(params.CertFile, params.KeyFile))
} else {
serverRun(app.server.ListenAndServe())
}
}
func FinishApp() {
for _, app := range apps {
app.Finish()
}
apps = []*application{}
}
func OpenBrowser(url string) bool {
var err error
switch runtime.GOOS {
case "linux":
for _, provider := range []string{"xdg-open", "x-www-browser", "www-browser"} {
if _, err = exec.LookPath(provider); err == nil {
if exec.Command(provider, url).Start(); err == nil {
return true
}
}
}
case "windows":
err = exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
case "darwin":
err = exec.Command("open", url).Start()
default:
err = fmt.Errorf("unsupported platform")
}
return err != nil
}
type downloadFile struct {
filename string
path string
data []byte
}
var currentDownloadId = int(rand.Int31())
var downloadFiles = map[string]downloadFile{}
func (session *sessionData) startDownload(file downloadFile) {
currentDownloadId++
id := strconv.Itoa(currentDownloadId)
downloadFiles[id] = file
session.runScript(fmt.Sprintf(`startDowndload("%s", "%s")`, id, file.filename))
}
func serveDownloadFile(id string, w http.ResponseWriter, r *http.Request) bool {
if file, ok := downloadFiles[id]; ok {
delete(downloadFiles, id)
if file.data != nil {
http.ServeContent(w, r, file.filename, time.Now(), bytes.NewReader(file.data))
return true
} else if _, err := os.Stat(file.path); err == nil {
http.ServeFile(w, r, file.path)
return true
}
}
return false
}
// DownloadFile starts downloading the file on the client side.
func (session *sessionData) DownloadFile(path string) {
if _, err := os.Stat(path); err != nil {
ErrorLog(err.Error())
return
}
_, filename := filepath.Split(path)
session.startDownload(downloadFile{
filename: filename,
path: path,
data: nil,
})
}
// DownloadFileData starts downloading the file on the client side. Arguments specify the name of the downloaded file and its contents
func (session *sessionData) DownloadFileData(filename string, data []byte) {
if data == nil {
ErrorLog("Invalid download data. Must be not nil.")
return
}
session.startDownload(downloadFile{
filename: filename,
path: "",
data: data,
})
}