feat: support autoplay context in spclient

proto/autoplay_context_request.proto

@@ -0,0 +1,10 @@
+syntax = "proto2";
+
+package spotify.player;
+
+option go_package = "go-librespot/proto/spotify/player";
+
+message AutoplayContextRequest {
+    required string context_uri = 1;
+    repeated string recent_track_uri = 2;
+}

spclient/context_resolver.go

@@ -17,27 +17,34 @@ type ContextResolver struct {
 	ctx *connectpb.Context
 }
 
-func NewContextResolver(sp *Spclient, ctx *connectpb.Context) (*ContextResolver, error) {
+func NewContextResolver(sp *Spclient, ctx *connectpb.Context) (_ *ContextResolver, err error) {
 	typ := librespot.InferSpotifyIdTypeFromContextUri(ctx.Uri)
-	if len(ctx.Pages) > 0 {
-		return &ContextResolver{sp, typ, ctx}, nil
-	} else {
-		newCtx, err := sp.ContextResolve(ctx.Uri)
+	if len(ctx.Pages) == 0 {
+		ctx, err = sp.ContextResolve(ctx.Uri)
 		if err != nil {
 			return nil, fmt.Errorf("failed resolving context %s: %w", ctx.Uri, err)
-		} else if newCtx.Loading {
-			return nil, fmt.Errorf("context %s is loading", newCtx.Uri)
+		} else if ctx.Loading {
+			return nil, fmt.Errorf("context %s is loading", ctx.Uri)
 		}
 
-		if newCtx.Metadata == nil {
-			newCtx.Metadata = map[string]string{}
+		if ctx.Metadata == nil {
+			ctx.Metadata = map[string]string{}
 		}
 		for key, val := range ctx.Metadata {
-			newCtx.Metadata[key] = val
+			ctx.Metadata[key] = val
 		}
+	}
 
-		return &ContextResolver{sp, typ, newCtx}, nil
+	autoplay := strings.HasPrefix(ctx.Uri, "spotify:station:")
+	for _, page := range ctx.Pages {
+		for _, track := range page.Tracks {
+			if autoplay {
+				track.Metadata["autoplay.is_autoplay"] = "true"
+			}
+		}
 	}
+
+	return &ContextResolver{sp, typ, ctx}, nil
 }
 
 func (r *ContextResolver) Type() librespot.SpotifyIdType {

spclient/spclient.go

@@ -11,6 +11,7 @@ import (
 	connectpb "go-librespot/proto/spotify/connectstate"
 	storagepb "go-librespot/proto/spotify/download"
 	metadatapb "go-librespot/proto/spotify/metadata"
+	playerpb "go-librespot/proto/spotify/player"
 	"google.golang.org/protobuf/proto"
 	"io"
 	"net/http"
@@ -272,3 +273,33 @@ func (c *Spclient) ContextResolve(uri string) (*connectpb.Context, error) {
 
 	return &context, nil
 }
+
+func (c *Spclient) ContextResolveAutoplay(reqProto *playerpb.AutoplayContextRequest) (*connectpb.Context, error) {
+	reqBody, err := proto.Marshal(reqProto)
+	if err != nil {
+		return nil, fmt.Errorf("failed marshalling AutoplayContextRequest: %w", err)
+	}
+
+	resp, err := c.request("POST", "/context-resolve/v1/autoplay", nil, nil, reqBody)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("invalid status code from context resolve autoplay: %d", resp.StatusCode)
+	}
+
+	respBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed reading response body: %w", err)
+	}
+
+	var context connectpb.Context
+	if err := json.Unmarshal(respBytes, &context); err != nil {
+		return nil, fmt.Errorf("failed json unmarshalling Context: %w", err)
+	}
+
+	return &context, nil
+}