Phase 3: OpenSubsonic core (response envelope, error codes 42-44, getOpenSubsonicExtensions) and apiKeyAuthentication extension with tokenInfo, web API key management

internal/subsonic/model.go

@@ -28,6 +28,14 @@ type Response struct {
 	Status  string   `xml:"status,attr" json:"status"`
 	Version string   `xml:"version,attr" json:"version"`
 
+	// OpenSubsonic core response additions (always populated): the
+	// server's real product name and build version, and a flag
+	// confirming OpenSubsonic support so clients can detect it from any
+	// response, not just getOpenSubsonicExtensions.
+	Type          string `xml:"type,attr" json:"type"`
+	ServerVersion string `xml:"serverVersion,attr" json:"serverVersion"`
+	OpenSubsonic  bool   `xml:"openSubsonic,attr" json:"openSubsonic"`
+
 	Error *Error `xml:"error,omitempty" json:"error,omitempty"`
 
 	License               *License               `xml:"license,omitempty" json:"license,omitempty"`
@@ -72,16 +80,57 @@ type Response struct {
 	NewestPodcasts        *NewestPodcasts        `xml:"newestPodcasts,omitempty" json:"newestPodcasts,omitempty"`
 	ScanStatus            *ScanStatus            `xml:"scanStatus,omitempty" json:"scanStatus,omitempty"`
 	Lyrics                *Lyrics                `xml:"lyrics,omitempty" json:"lyrics,omitempty"`
+
+	// OpenSubsonic extensions.
+	OpenSubsonicExtensions []OpenSubsonicExtension `xml:"openSubsonicExtensions,omitempty" json:"openSubsonicExtensions,omitempty"`
+	TokenInfo              *TokenInfo              `xml:"tokenInfo,omitempty" json:"tokenInfo,omitempty"`
+	PodcastEpisode         *PodcastEpisode         `xml:"podcastEpisode,omitempty" json:"podcastEpisode,omitempty"`
+	LyricsList             *LyricsList             `xml:"lyricsList,omitempty" json:"lyricsList,omitempty"`
+	PlayQueueByIndex       *PlayQueueByIndex       `xml:"playQueueByIndex,omitempty" json:"playQueueByIndex,omitempty"`
+	// SonicMatch is a top-level array (not wrapped in an object) on both
+	// getSonicSimilarTracks and findSonicPath, per the OpenSubsonic
+	// schema — the two endpoints are otherwise unrelated, so there is no
+	// shared wrapper type to name it after.
+	SonicMatch        []SonicMatch       `xml:"sonicMatch,omitempty" json:"sonicMatch,omitempty"`
+	TranscodeDecision *TranscodeDecision `xml:"transcodeDecision,omitempty" json:"transcodeDecision,omitempty"`
 }
 
+// OpenSubsonicExtension describes one extension this server supports,
+// as returned by getOpenSubsonicExtensions.
+type OpenSubsonicExtension struct {
+	Name     string `xml:"name,attr" json:"name"`
+	Versions []int  `xml:"versions" json:"versions"`
+}
+
+type TokenInfo struct {
+	Username string `xml:"username,attr" json:"username"`
+}
+
+// ServerName is the real product name advertised in every response's
+// "type" attribute, per the OpenSubsonic base response additions.
+const ServerName = "vibesonic"
+
+// AppVersion is VibeSonic's own build version, advertised in every
+// response's "serverVersion" attribute. Overridable at link time
+// (matching cmd/vibesonic's version variable); defaults to "dev".
+var AppVersion = "dev"
+
 func newResponse() *Response {
-	return &Response{Xmlns: "http://subsonic.org/restapi", Status: "ok", Version: ServerVersion}
+	return &Response{
+		Xmlns:         "http://subsonic.org/restapi",
+		Status:        "ok",
+		Version:       ServerVersion,
+		Type:          ServerName,
+		ServerVersion: AppVersion,
+		OpenSubsonic:  true,
+	}
 }
 
 // Error is the payload of a failed response.
 type Error struct {
 	Code    int    `xml:"code,attr" json:"code"`
 	Message string `xml:"message,attr" json:"message"`
+	HelpURL string `xml:"helpUrl,attr,omitempty" json:"helpUrl,omitempty"`
 }
 
 // --- System ---