POST endpoint for importing m3u playlists - #2078 (#2273)

* wip: API endpoint for creating playlists from m3u files

* wip: get user id from context

* temporarily disable failing test

* custom logic for playlist route to accomodate m3u content type

* incorporate playlist parsing into existing logic in core

* re-enable test

* fix locally failing test

* Address requested changes.

* Improve ImportFile tests.

* Remove ownerID as a parameter of ImportM3U.

* Write tests for ImportM3U.

* Separate ImportM3U test into two.

* Test OwnerID and playlist Name.

---------

Co-authored-by: Sam Watson <SwatsonCodes@users.noreply.github.com>
Co-authored-by: caiocotts <caio@cotts.com.br>

server/nativeapi/playlists.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/deluan/rest"
 	"github.com/go-chi/chi/v5"
+	"github.com/navidrome/navidrome/core"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils"
@@ -42,6 +43,26 @@ func getPlaylist(ds model.DataStore) http.HandlerFunc {
 	}
 }
 
+func createPlaylistFromM3U(playlists core.Playlists) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		ctx := r.Context()
+		pls, err := playlists.ImportM3U(ctx, r.Body)
+		if err != nil {
+			log.Error(r.Context(), "Error parsing playlist", err)
+			// TODO: consider returning StatusBadRequest for playlists that are malformed
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		w.WriteHeader(http.StatusCreated)
+		_, err = w.Write([]byte(pls.ToM3U8()))
+		if err != nil {
+			log.Error(ctx, "Error sending m3u contents", err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+	}
+}
+
 func handleExportPlaylist(ds model.DataStore) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		ctx := r.Context()