/* Copyright © 2022 Seednode */ package cmd import ( "fmt" "io" "log" "math/rand" "net/http" "net/url" "os" "path/filepath" "regexp" "runtime" "strconv" "strings" "time" "github.com/yosssi/gohtml" ) const ( LogDate string = `2006-01-02T15:04:05.000-07:00` Prefix string = `/src` RedirectStatusCode int = http.StatusSeeOther ) type Regexes struct { Alphanumeric *regexp.Regexp Filename *regexp.Regexp } type Filters struct { Includes []string Excludes []string } func (f *Filters) IsEmpty() bool { return !(f.HasIncludes() && f.HasExcludes()) } func (f *Filters) HasIncludes() bool { return len(f.Includes) != 0 } func (f *Filters) GetIncludes() string { return strings.Join(f.Includes, ",") } func (f *Filters) HasExcludes() bool { return len(f.Excludes) != 0 } func (f *Filters) GetExcludes() string { return strings.Join(f.Excludes, ",") } func notFound(w http.ResponseWriter, r *http.Request, filePath string) error { startTime := time.Now() if Verbose { fmt.Printf("%v | Unavailable file %v requested by %v\n", startTime.Format(LogDate), filePath, r.RemoteAddr, ) } w.WriteHeader(404) w.Header().Add("Content-Type", "text/html") var htmlBody strings.Builder htmlBody.WriteString(``) htmlBody.WriteString(``) htmlBody.WriteString(`Not Found`) htmlBody.WriteString(`404 page not found`) _, err := io.WriteString(w, gohtml.Format(htmlBody.String())) if err != nil { return err } return nil } func getRefreshInterval(r *http.Request) string { refreshInterval := r.URL.Query().Get("refresh") if refreshInterval == "" { refreshInterval = "0" } num, err := strconv.Atoi(refreshInterval) if err != nil || num < 0 { refreshInterval = "0" } return refreshInterval } func getSortOrder(r *http.Request) string { sortOrder := r.URL.Query().Get("sort") if !(sortOrder == "asc" || sortOrder == "desc") { sortOrder = "" } return sortOrder } func splitQueryParams(query string, regexes *Regexes) []string { results := []string{} if query == "" { return results } params := strings.Split(query, ",") for i := 0; i < len(params); i++ { if regexes.Alphanumeric.MatchString(params[i]) { results = append(results, strings.ToLower(params[i])) } } return results } func generateQueryParams(filters *Filters, sortOrder, refreshInterval string) string { var hasParams bool var queryParams strings.Builder queryParams.WriteString("?") if Filter { queryParams.WriteString("include=") if filters.HasIncludes() { queryParams.WriteString(filters.GetIncludes()) } queryParams.WriteString("&exclude=") if filters.HasExcludes() { queryParams.WriteString(filters.GetExcludes()) } hasParams = true } if Sort { if hasParams { queryParams.WriteString("&") } queryParams.WriteString(fmt.Sprintf("sort=%v", sortOrder)) hasParams = true } if hasParams { queryParams.WriteString("&") } queryParams.WriteString(fmt.Sprintf("refresh=%v", refreshInterval)) return queryParams.String() } func stripQueryParams(u string) (string, error) { uri, err := url.Parse(u) if err != nil { return "", err } uri.RawQuery = "" escapedUri, err := url.QueryUnescape(uri.String()) if err != nil { return "", err } if runtime.GOOS == "windows" { return strings.TrimPrefix(escapedUri, "/"), nil } return escapedUri, nil } func generateFilePath(filePath string) string { htmlBody := Prefix if runtime.GOOS == "windows" { htmlBody += "/" } htmlBody += filePath return htmlBody } func refererToUri(referer string) string { parts := strings.SplitAfterN(referer, "/", 4) if len(parts) < 4 { return "" } return "/" + parts[3] } func serveHtml(w http.ResponseWriter, r *http.Request, filePath string, dimensions *Dimensions, filters *Filters) error { fileName := filepath.Base(filePath) w.Header().Add("Content-Type", "text/html") sortOrder := getSortOrder(r) refreshInterval := getRefreshInterval(r) queryParams := generateQueryParams(filters, sortOrder, refreshInterval) var htmlBody strings.Builder htmlBody.WriteString(``) htmlBody.WriteString(``) htmlBody.WriteString(fmt.Sprintf(`%v (%vx%v)`, fileName, dimensions.Width, dimensions.Height)) htmlBody.WriteString(``) if refreshInterval != "0" { r, err := strconv.Atoi(refreshInterval) if err != nil { return err } refreshTimer := strconv.Itoa(r * 1000) htmlBody.WriteString(fmt.Sprintf("", queryParams, refreshTimer)) } htmlBody.WriteString(fmt.Sprintf(`Roulette selected: %v`, queryParams, generateFilePath(filePath), dimensions.Width, dimensions.Height, fileName)) htmlBody.WriteString(``) _, err := io.WriteString(w, gohtml.Format(htmlBody.String())) if err != nil { return err } return nil } func serveStaticFile(w http.ResponseWriter, r *http.Request, paths []string) error { PrefixedFilePath, err := stripQueryParams(r.URL.Path) if err != nil { return err } filePath, err := filepath.EvalSymlinks(strings.TrimPrefix(PrefixedFilePath, Prefix)) if err != nil { return err } if !pathIsValid(filePath, paths) { notFound(w, r, filePath) return nil } exists, err := fileExists(filePath) if err != nil { return err } if !exists { notFound(w, r, filePath) return nil } startTime := time.Now() buf, err := os.ReadFile(filePath) if err != nil { return err } w.Write(buf) if Verbose { fmt.Printf("%v | Served %v (%v) to %v in %v\n", startTime.Format(LogDate), filePath, humanReadableSize(len(buf)), r.RemoteAddr, time.Since(startTime).Round(time.Microsecond), ) } return nil } func serveStaticFileHandler(paths []string) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { err := serveStaticFile(w, r, paths) if err != nil { log.Fatal(err) } } } func serveHtmlHandler(paths []string, regexes *Regexes, fileCache *[]string) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { refererUri, err := stripQueryParams(refererToUri(r.Referer())) if err != nil { log.Fatal(err) } filters := Filters{} filters.Includes = splitQueryParams(r.URL.Query().Get("include"), regexes) filters.Excludes = splitQueryParams(r.URL.Query().Get("exclude"), regexes) sortOrder := getSortOrder(r) refreshInterval := getRefreshInterval(r) if r.URL.Path == "/" { var filePath string var err error if refererUri != "" { filePath, err = getNextFile(refererUri, sortOrder, regexes) if err != nil { log.Fatal(err) } } if filePath == "" { filePath, err = getNewFile(paths, &filters, sortOrder, regexes, fileCache) switch { case err != nil && err == ErrNoImagesFound: notFound(w, r, filePath) return case err != nil: log.Fatal(err) } } queryParams := generateQueryParams(&filters, sortOrder, refreshInterval) newUrl := fmt.Sprintf("http://%v%v%v", r.Host, preparePath(filePath), queryParams, ) http.Redirect(w, r, newUrl, RedirectStatusCode) } else { filePath := r.URL.Path if runtime.GOOS == "windows" { filePath = strings.TrimPrefix(filePath, "/") } exists, err := fileExists(filePath) if err != nil { log.Fatal(err) } if !exists { notFound(w, r, filePath) return } image, err := isImage(filePath) if err != nil { log.Fatal(err) } if !image { notFound(w, r, filePath) return } dimensions, err := getImageDimensions(filePath) if err != nil { log.Fatal(err) } err = serveHtml(w, r, filePath, dimensions, &filters) if err != nil { log.Fatal(err) } } } } func doNothing(http.ResponseWriter, *http.Request) {} func generateRegularExpressions() *Regexes { r := Regexes{} r.Filename = regexp.MustCompile(`(.+)([0-9]{3})(\..+)`) r.Alphanumeric = regexp.MustCompile(`^[a-zA-Z0-9]*$`) return &r } func ServePage(args []string) error { fmt.Printf("roulette v%v\n\n", Version) paths, err := normalizePaths(args) if err != nil { return err } regexes := generateRegularExpressions() rand.Seed(time.Now().UnixNano()) fileCache := []string{} http.Handle("/", serveHtmlHandler(paths, regexes, &fileCache)) http.Handle(Prefix+"/", http.StripPrefix(Prefix, serveStaticFileHandler(paths))) http.HandleFunc("/favicon.ico", doNothing) err = http.ListenAndServe(":"+strconv.FormatInt(int64(Port), 10), nil) if err != nil { return err } return nil }