have get_metadata_4_track() call new get_ext_metadata()

TODO: parsing a successful response
always returns a 400 response

Author: Googolplexed0

librespot/core.py

@@ -57,6 +57,8 @@
 from librespot.proto import Keyexchange_pb2 as Keyexchange
 from librespot.proto import Metadata_pb2 as Metadata
 from librespot.proto import Playlist4External_pb2 as Playlist4External
+from librespot.proto.ExtendedMetadata_pb2 import EntityRequest, BatchedEntityRequest, ExtensionQuery
+from librespot.proto.ExtensionKind_pb2 import ExtensionKind
 from librespot.proto.ExplicitContentPubsub_pb2 import UserAttributesUpdate
 from librespot.proto.spotify.login5.v3 import Login5_pb2 as Login5
 from librespot.proto.spotify.login5.v3.credentials import Credentials_pb2 as Login5Credentials
@@ -190,19 +192,27 @@ def put_connect_state(self, connection_id: str,
             self.logger.warning("PUT state returned {}. headers: {}".format(
                 response.status_code, response.headers))
 
+    def get_ext_metadata(self, extension_kind: ExtensionKind, uri: str):
+        query = ExtensionQuery(extension_kind=extension_kind)
+        req = EntityRequest(entity_uri=uri, query=[query,])
+        batch = BatchedEntityRequest(entity_request=[req,])
+        headers = CaseInsensitiveDict({"content-type": "application/x-protobuf"})
+        response = self.send("POST", "/extended-metadata/v0/extended-metadata",
+                             headers, batch.SerializeToString())
+        return response
+
     def get_metadata_4_track(self, track: TrackId) -> Metadata.Track:
         """
 
         :param track: TrackId:
 
         """
-        response = self.sendToUrl("GET", "https://spclient.wg.spotify.com",
-                             "/metadata/4/track/{}".format(track.hex_id()),
-                             None, None)
+        response = self.get_ext_metadata(ExtensionKind.TRACK_V4, track.to_spotify_uri())
         ApiClient.StatusCodeException.check_status(response)
         body = response.content
         if body is None:
             raise RuntimeError()
+        # TODO: update parsing of successful response
         proto = Metadata.Track()
         proto.ParseFromString(body)
         return proto

librespot/proto/EntityExtensionData_pb2.py

@@ -0,0 +1,38 @@
+// Extracted from: Spotify 1.2.52.442 (windows)
+
+syntax = "proto3";
+
+package spotify.extendedmetadata;
+
+import "google/protobuf/any.proto";
+
+option cc_enable_arenas = true;
+option java_multiple_files = true;
+option optimize_for = CODE_SIZE;
+option java_package = "com.spotify.extendedmetadata.proto";
+
+message EntityExtensionDataHeader {
+    int32 status_code = 1;
+    string etag = 2;
+    string locale = 3;
+    int64 cache_ttl_in_seconds = 4;
+    int64 offline_ttl_in_seconds = 5;
+}
+
+message EntityExtensionData {
+    EntityExtensionDataHeader header = 1;
+    string entity_uri = 2;
+    google.protobuf.Any extension_data = 3;
+}
+
+message PlainListAssoc {
+    repeated string entity_uri = 1;
+}
+
+message AssocHeader {
+}
+
+message Assoc {
+    AssocHeader header = 1;
+    PlainListAssoc plain_list = 2;
+}

librespot/proto/ExtendedMetadata_pb2.py

@@ -0,0 +1,59 @@
+syntax = "proto3";
+
+package spotify.extendedmetadata;
+
+import "extension_kind.proto";
+import "entity_extension_data.proto";
+
+option cc_enable_arenas = true;
+option java_multiple_files = true;
+option optimize_for = CODE_SIZE;
+option java_package = "com.spotify.extendedmetadata.proto";
+
+message ExtensionQuery {
+    ExtensionKind extension_kind = 1;
+    string etag = 2;
+}
+
+message EntityRequest {
+    string entity_uri = 1;
+    repeated ExtensionQuery query = 2;
+}
+
+message BatchedEntityRequestHeader {
+    string country = 1;
+    string catalogue = 2;
+    bytes task_id = 3;
+}
+
+message BatchedEntityRequest {
+    BatchedEntityRequestHeader header = 1;
+    repeated EntityRequest entity_request = 2;
+}
+
+message EntityExtensionDataArrayHeader {
+    int32 provider_error_status = 1;
+    int64 cache_ttl_in_seconds = 2;
+    int64 offline_ttl_in_seconds = 3;
+    ExtensionType extension_type = 4;
+}
+
+message EntityExtensionDataArray {
+    EntityExtensionDataArrayHeader header = 1;
+    ExtensionKind extension_kind = 2;
+    repeated EntityExtensionData extension_data = 3;
+}
+
+message BatchedExtensionResponseHeader {
+}
+
+message BatchedExtensionResponse {
+    BatchedExtensionResponseHeader header = 1;
+    repeated EntityExtensionDataArray extended_metadata = 2;
+}
+
+enum ExtensionType {
+    UNKNOWN = 0;
+    GENERIC = 1;
+    ASSOC = 2;
+}