feat(server): create M3Us from shares (#3652)

model/share.go

@@ -1,6 +1,8 @@
 package model
 
 import (
+	"cmp"
+	"fmt"
 	"strings"
 	"time"
 
@@ -48,6 +50,19 @@ func (s Share) CoverArtID() ArtworkID {
 
 type Shares []Share
 
+// ToM3U8 exports the playlist to the Extended M3U8 format, as specified in
+// https://docs.fileformat.com/audio/m3u/#extended-m3u
+func (s Share) ToM3U8() string {
+	buf := strings.Builder{}
+	buf.WriteString("#EXTM3U\n")
+	buf.WriteString(fmt.Sprintf("#PLAYLIST:%s\n", cmp.Or(s.Description, s.ID)))
+	for _, t := range s.Tracks {
+		buf.WriteString(fmt.Sprintf("#EXTINF:%.f,%s - %s\n", t.Duration, t.Artist, t.Title))
+		buf.WriteString(t.Path + "\n")
+	}
+	return buf.String()
+}
+
 type ShareRepository interface {
 	Exists(id string) (bool, error)
 	Get(id string) (*Share, error)

server/public/handle_shares.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"net/http"
+	"path"
 
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
@@ -38,6 +39,26 @@ func (pub *Router) handleShares(w http.ResponseWriter, r *http.Request) {
 	server.IndexWithShare(pub.ds, ui.BuildAssets(), s)(w, r)
 }
 
+func (pub *Router) handleM3U(w http.ResponseWriter, r *http.Request) {
+	id, err := req.Params(r).String(":id")
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	// If it is not, consider it a share ID
+	s, err := pub.share.Load(r.Context(), id)
+	if err != nil {
+		checkShareError(r.Context(), w, err, id)
+		return
+	}
+
+	s = pub.mapShareToM3U(r, *s)
+	w.WriteHeader(http.StatusOK)
+	w.Header().Set("Content-Type", "audio/x-mpegurl")
+	_, _ = w.Write([]byte(s.ToM3U8()))
+}
+
 func checkShareError(ctx context.Context, w http.ResponseWriter, err error, id string) {
 	switch {
 	case errors.Is(err, model.ErrExpired):
@@ -63,3 +84,11 @@ func (pub *Router) mapShareInfo(r *http.Request, s model.Share) *model.Share {
 	}
 	return &s
 }
+
+func (pub *Router) mapShareToM3U(r *http.Request, s model.Share) *model.Share {
+	for i := range s.Tracks {
+		id := encodeMediafileShare(s, s.Tracks[i].ID)
+		s.Tracks[i].Path = publicURL(r, path.Join(consts.URLPathPublic, "s", id), nil)
+	}
+	return &s
+}

server/public/public.go

@@ -56,6 +56,7 @@ func (pub *Router) routes() http.Handler {
 			if conf.Server.EnableDownloads {
 				r.HandleFunc("/d/{id}", pub.handleDownloads)
 			}
+			r.HandleFunc("/{id}/m3u", pub.handleM3U)
 			r.HandleFunc("/{id}", pub.handleShares)
 			r.HandleFunc("/", pub.handleShares)
 			r.Handle("/*", pub.assetsHandler)