// Package main is the command-line entrypoint for the distribusi command.
package main
import (
"bytes"
"encoding/base64"
"fmt"
"image/png"
"io/fs"
"io/ioutil"
"net/http"
"os"
"os/exec"
"path"
"path/filepath"
"sort"
"strings"
logrusStack "github.com/Gurpartap/logrus-stack"
"github.com/barasher/go-exiftool"
"github.com/disintegration/imaging"
"github.com/gabriel-vasile/mimetype"
"github.com/sirupsen/logrus"
"github.com/urfave/cli/v2"
)
// exiftooInstalled tells us if the exiftool binary is installed or not.
var exiftoolInstalled = true
// generatedInDistribusi is an internal marker to help recognise when
// distribusi-go has generated files.
var generatedInDistribusi = "../ "
div, err := mkDiv(c, "os/directory", href, "menu", false)
if err != nil {
return err
}
html = append(html, div)
}
for _, dir := range dirs {
fname := filepath.Base(dir)
if skip := shouldSkip(c, dir, ignore); skip {
continue
}
mtype := "os/directory"
href := fmt.Sprintf("%s/ ", fname, fname)
div, err := mkDiv(c, mtype, href, fname, false)
if err != nil {
return err
}
html = append(html, div)
}
for _, file := range files {
fname := filepath.Base(file)
if skip := shouldSkip(c, file, ignore); skip {
continue
}
mtype, err := getMtype(file)
if err != nil {
logrus.Debugf("failed to read mimetype of %s", file)
continue
}
unknown, href, err := getHref(c, file, mtype)
if err != nil {
logrus.Debugf("failed to generate href for %s", file)
continue
}
div, err := mkDiv(c, mtype, href, fname, unknown)
if err != nil {
logrus.Debugf("failed to generate div for %s", file)
continue
}
html = append(html, div)
}
if err := writeIndex(absPath, html, c.String("css")); err != nil {
logrus.Debugf("unable to generated %s, skipping", path.Join(absPath, "index.html"))
return nil
}
allDirs = append(allDirs, strings.Join(dirs, " "))
}
return nil
}); err != nil {
return err
}
logrus.Debugf("generated files in following paths: %s", strings.Join(allDirs, " "))
return nil
}
// removeIndex safely removes an index.html, making sure to check that
// distribusi generated it.
func removeIndex(fpath string) error {
file, err := os.ReadFile(fpath)
if err != nil {
return err
}
if strings.Contains(string(file), generatedInDistribusi) {
if err := os.Remove(fpath); err != nil {
return err
}
return nil
}
return nil
}
// getMtype determines file mimetype which helps to arrange HTML tags
// appropriate for the file type.
func getMtype(fpath string) (string, error) {
mtype, err := mimetype.DetectFile(fpath)
if err != nil {
return "", err
}
return mtype.String(), nil
}
// genThumb generates an in-memory image thumbnail and encodes it into a base64
// representation which is suitable for embedding in HTML pages.
func genThumb(c *cli.Context, fpath, caption string) (string, error) {
knownFailureExts := []string{".ico", ".svg", ".xcf"}
if sliceContains(knownFailureExts, filepath.Ext(fpath)) {
return "", fmt.Errorf("unable to generate thumbnail for %s", fpath)
}
imgSrc, err := imaging.Open(fpath, imaging.AutoOrientation(true))
if err != nil {
logrus.Debugf("failed to generate thumbnail for %s", fpath)
return "", err
}
img := imaging.Thumbnail(imgSrc, 450, 450, imaging.Lanczos)
buf := new(bytes.Buffer)
png.Encode(buf, img)
imgBase64Str := base64.StdEncoding.EncodeToString(buf.Bytes())
return imgBase64Str, nil
}
// getCaption retrieves an embedded image caption via exif-tool. If not
// exiftool is installed, we gracefully bail out. The caller is responsible for
// handling the alternative.
func getCaption(c *cli.Context, fpath string) (string, error) {
var caption string
if !exiftoolInstalled {
return "", nil
}
exif, err := exiftool.NewExiftool()
if err != nil {
return caption, fmt.Errorf("failed to initialise exiftool, saw %v", err)
}
defer exif.Close()
for _, finfo := range exif.ExtractMetadata(fpath) {
if finfo.Err != nil {
continue
}
for k, v := range finfo.Fields {
if k == "Comment" {
caption = fmt.Sprintf("%v", v)
}
}
}
return caption, nil
}
// parseMtype parses a mimetype string to simplify programmatic type lookups.
func parseMtype(mtype string) (string, string) {
stripCharset := strings.Split(mtype, ";")
splitTypes := strings.Split(stripCharset[0], "/")
ftype, stype := splitTypes[0], splitTypes[1]
return ftype, stype
}
// sliceContains checks if an element is present in a list.
func sliceContains(items []string, target string) bool {
for _, item := range items {
if item == target {
return true
}
}
return false
}
// trimFinalNewline trims newlines from the end of bytes just read from files.
func trimFinalNewline(contents []byte) string {
return strings.TrimSuffix(string(contents), "\n")
}
// getHref figures out which href tag corresponds to which file by navigating
// the mimetype. If a type of file is unknown, this is signalled via the bool
// return value.
func getHref(c *cli.Context, fpath string, mtype string) (bool, string, error) {
var href string
var caption string
var unknown bool
fname := filepath.Base(fpath)
ftype, stype := parseMtype(mtype)
if ftype == "text" {
fcontents, err := os.ReadFile(fpath)
if err != nil {
return unknown, href, err
}
if stype == "html" {
href = fmt.Sprintf("", fname, trimFinalNewline(fcontents))
} else {
href = fmt.Sprintf("%s ", trimFinalNewline(fcontents))
}
} else if ftype == "image" {
caption = ""
exifCaption, err := getCaption(c, fpath)
if err != nil {
return unknown, href, nil
}
if exifCaption != "" {
caption = exifCaption
}
if stype == "gif" {
href = fmt.Sprintf("%s ", stype, fname, fname)
} else {
href = fmt.Sprintf(
"%s %s ", stype, fname, fname)
}
} else if ftype == "audio" {
href = fmt.Sprintf(" Your browser does not support the audio element. ", fname, stype)
} else if ftype == "video" {
href = fmt.Sprintf(" ", fname, stype)
} else {
unknown = true
href = fmt.Sprintf("%s ", stype, fname, fname)
}
return unknown, href, nil
}
// mkDiv cosntructs a HTML div for inclusion in the generated index.html.
func mkDiv(c *cli.Context, mtype string, href, fname string, unknown bool) (string, error) {
var div string
filename := fmt.Sprintf("%s ", fname)
ftype, _ := parseMtype(mtype)
if ftype == "text" {
div = fmt.Sprintf("%s%s
", fname, ftype, href, filename)
} else if ftype == "os" {
div = fmt.Sprintf("%s
", fname, ftype, href)
} else {
if unknown {
// we really don't know what this is, so the filename is the href and we avoid adding it again
div = fmt.Sprintf("%s
", fname, ftype, href)
} else {
// images, videos, etc. still get a filename
div = fmt.Sprintf("%s%s
", fname, ftype, href, filename)
}
}
return div, nil
}
// writeIndex writes a new index.html.
func writeIndex(fpath string, html []string, styles string) error {
body := fmt.Sprintf(htmlBody, generatedInDistribusi, "", strings.Join(html, "\n"))
if styles != "" {
absPath, err := filepath.Abs(styles)
if err != nil {
return err
}
if _, err := os.Stat(absPath); !os.IsNotExist(err) {
contents, err := os.ReadFile(absPath)
if err != nil {
return nil
}
body = fmt.Sprintf(htmlBody, generatedInDistribusi, contents, strings.Join(html, "\n"))
}
}
HTMLPath := path.Join(fpath, "index.html")
contents := []byte(body)
if _, err := os.Stat(HTMLPath); err != nil {
if os.IsNotExist(err) {
if err := ioutil.WriteFile(HTMLPath, contents, 0644); err != nil {
logrus.Debugf("unable to write %s, skipping", HTMLPath)
return nil
}
} else {
logrus.Debugf("unable to read %s, skipping", HTMLPath)
return nil
}
} else {
file, err := os.ReadFile(HTMLPath)
if err != nil {
logrus.Debugf("unable to read %s, skipping", HTMLPath)
return nil
}
if strings.Contains(string(file), generatedInDistribusi) {
if err := ioutil.WriteFile(HTMLPath, contents, 0644); err != nil {
logrus.Debugf("unable to write %s, skipping", HTMLPath)
return nil
}
}
}
return nil
}
// serveHTTP serves a web server for browsing distribusi.
func serveHTTP(fpath string) error {
fs := http.FileServer(http.Dir(fpath))
http.Handle("/", fs)
logrus.Info("distribusi live @ http://localhost:3000")
if err := http.ListenAndServe(":3000", nil); err != nil {
return err
}
return nil
}
// wipeGeneratedFiles removes all distribusi generated files.
func wipeGeneratedFiles(dir string) error {
if err := filepath.WalkDir(dir, func(fpath string, dirEntry fs.DirEntry, err error) error {
fname := filepath.Base(fpath)
if fname == "index.html" {
if err := removeIndex(fpath); err != nil {
return err
}
}
return nil
}); err != nil {
return err
}
return nil
}
// shouldSkip checks if paths should be skipped over.
func shouldSkip(c *cli.Context, fpath string, ignore []string) bool {
if sliceContains(ignore, filepath.Base(fpath)) {
return true
}
fpaths := strings.Split(fpath, "/")
for _, part := range fpaths {
if strings.HasPrefix(part, ".") {
if !c.Bool("hidden") {
return true
}
}
}
return false
}
