/* Copyright © 2022 Seednode */ package cmd import ( "fmt" "io" "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 // You may not like it, but this is what peak string generation looks like. RefreshScriptTemplate string = `` HtmlTemplate string = `%v (%vx%v)Roulette selected: %v%v` ) 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, ",") } type appHandler func(http.ResponseWriter, *http.Request) error func (fn appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { if err := fn(w, r); err != nil { http.Error(w, err.Error(), 500) } } func notFound(w http.ResponseWriter, r *http.Request) error { w.WriteHeader(404) w.Header().Add("Content-Type", "text/html") htmlBody := ` Not Found 404 page not found ` _, err := io.WriteString(w, htmlBody) if err != nil { return err } return nil } func splitQueryParams(query string) []string { if query == "" { return []string{} } params := strings.Split(query, ",") for i := 0; i < len(params); i++ { params[i] = strings.ToLower(params[i]) } return params } func generateQueryParams(filters *Filters, sortOrder, refreshInterval string) (string, error) { refresh, err := strconv.Atoi(refreshInterval) if err != nil { return "", err } var hasParams bool var queryParams string if Filter || Sort || (refresh != 0) { queryParams += "?" } if Filter { queryParams += "include=" if filters.HasIncludes() { queryParams += filters.GetIncludes() } queryParams += "&exclude=" if filters.HasExcludes() { queryParams += filters.GetExcludes() } hasParams = true } if Sort { if hasParams { queryParams += "&" } queryParams += fmt.Sprintf("sort=%v", sortOrder) hasParams = true } if refresh != 0 { if hasParams { queryParams += "&" } queryParams += fmt.Sprintf("refresh=%v", refresh) } return queryParams, nil } 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") refreshInterval := r.URL.Query().Get("refresh") if refreshInterval == "" { refreshInterval = "0" } queryParams, err := generateQueryParams(filters, r.URL.Query().Get("sort"), refreshInterval) refreshScript := "" if refreshInterval != "0" { r, err := strconv.Atoi(refreshInterval) if err != nil { return err } refreshTimer := strconv.Itoa(r * 1000) refreshScript = fmt.Sprintf(RefreshScriptTemplate, queryParams, refreshTimer) } htmlBody := fmt.Sprintf(HtmlTemplate, fileName, dimensions.Width, dimensions.Height, queryParams, generateFilePath(filePath), dimensions.Width, dimensions.Height, fileName, refreshScript, ) formattedBody := gohtml.Format(htmlBody) _, err = io.WriteString(w, formattedBody) 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) } exists, err := fileExists(filePath) if err != nil { return err } if !exists { notFound(w, r) 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) appHandler { return func(w http.ResponseWriter, r *http.Request) error { err := serveStaticFile(w, r, paths) if err != nil { return err } return nil } } func serveHtmlHandler(paths []string, re regexp.Regexp, fileCache *[]string) appHandler { return func(w http.ResponseWriter, r *http.Request) error { refererUri, err := stripQueryParams(refererToUri(r.Referer())) if err != nil { return err } filters := Filters{} filters.Includes = splitQueryParams(r.URL.Query().Get("include")) filters.Excludes = splitQueryParams(r.URL.Query().Get("exclude")) sortOrder := r.URL.Query().Get("sort") refreshInterval := r.URL.Query().Get("refresh") if refreshInterval == "" { refreshInterval = "0" } if r.URL.Path == "/" { var filePath string var err error if refererUri != "" { filePath, err = getNextFile(refererUri, sortOrder, re) if err != nil { return err } } if filePath == "" { filePath, err = getNewFile(paths, &filters, sortOrder, re, fileCache) switch { case err != nil && err == ErrNoImagesFound: http.NotFound(w, r) case err != nil: return err } } queryParams, err := generateQueryParams(&filters, sortOrder, refreshInterval) if err != nil { return err } 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 { return err } if !exists { notFound(w, r) } image, err := isImage(filePath) if err != nil { return err } if !image { notFound(w, r) } dimensions, err := getImageDimensions(filePath) if err != nil { return err } err = serveHtml(w, r, filePath, dimensions, &filters) if err != nil { return err } } return nil } } func doNothing(http.ResponseWriter, *http.Request) {} func ServePage(args []string) error { fmt.Printf("roulette v%v\n\n", Version) paths, err := normalizePaths(args) if err != nil { return err } re := regexp.MustCompile(`(.+)([0-9]{3})(\..+)`) rand.Seed(time.Now().UnixNano()) fileCache := []string{} http.Handle("/", serveHtmlHandler(paths, *re, &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 }