support http header "range" (needed for videos in safari)

README.md

@@ -96,7 +96,13 @@ service photo-bot enable
 service photo-bot start
 ```
 
+## Useful notes
 
+Video autoplay is tricky:
+
+- On Firefox, you have to interact with the page first (click somewhere in the page)
+- On Safari, you have to [explicitly enable auto-play for this website](https://support.apple.com/fr-fr/guide/safari/ibrw29c6ecf8/mac)
+- On Chrome, it seems to be enabled out-of-the-box
 
 ## Documentation
 

http.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"html/template"
-	"io"
 	"io/ioutil"
 	"log"
 	"net/http"
@@ -200,14 +199,14 @@ func (bot *PhotoBot) HandleGetMedia(w http.ResponseWriter, r *http.Request, albu
 		albumName = ""
 	}
 
-	fd, err := bot.MediaStore.OpenFile(albumName, mediaFilename)
+	fd, modtime, err := bot.MediaStore.OpenFile(albumName, mediaFilename)
 	if err != nil {
 		log.Printf("MediaStore.OpenFile: %s", err)
 		bot.HandleError(w, r)
 		return
 	}
 	defer fd.Close()
-	io.Copy(w, fd) // Best effort
+	http.ServeContent(w, r, mediaFilename, modtime, fd)
 }
 
 func (bot *PhotoBot) ServeHTTP(w http.ResponseWriter, r *http.Request) {

media_store.go

@@ -122,12 +122,23 @@ func (store *MediaStore) ListAlbums() (AlbumList, error) {
 	return albums, nil
 }
 
-func (store *MediaStore) OpenFile(albumName string, filename string) (*os.File, error) {
+func (store *MediaStore) OpenFile(albumName string, filename string) (*os.File, time.Time, error) {
 	if albumName == "" {
 		albumName = ".current"
 	}
 
-	return os.OpenFile(filepath.Join(store.StoreLocation, albumName, filename), os.O_RDONLY, 0600)
+	path := filepath.Join(store.StoreLocation, albumName, filename)
+	stat, err := os.Stat(path)
+	if err != nil {
+		return nil, time.Time{}, err
+	}
+
+	fd, err := os.OpenFile(path, os.O_RDONLY, 0600)
+	if err != nil {
+		return nil, time.Time{}, err
+	}
+
+	return fd, stat.ModTime(), nil
 }
 
 func (store *MediaStore) GetAlbum(name string, metadataOnly bool) (*Album, error) {