From bae304fdb0f656a31d73f13d0b130d0df33b97b9 Mon Sep 17 00:00:00 2001
From: Roderick van Domburg <roderick@vandomburg.net>
Date: Sun, 2 Oct 2022 00:00:30 +0200
Subject: [PATCH] Update zeroconf fields and publish active user

---
 discovery/src/lib.rs    | 13 ++++++------
 discovery/src/server.rs | 44 +++++++++++++++++++++++++++++++----------
 src/main.rs             |  3 ++-
 3 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/discovery/src/lib.rs b/discovery/src/lib.rs
index 718d9dec..3c01003b 100644
--- a/discovery/src/lib.rs
+++ b/discovery/src/lib.rs
@@ -77,13 +77,14 @@ impl From<DiscoveryError> for Error {
 }
 
 impl Builder {
-    /// Starts a new builder using the provided device id.
-    pub fn new(device_id: impl Into<String>) -> Self {
+    /// Starts a new builder using the provided device and client IDs.
+    pub fn new<T: Into<String>>(device_id: T, client_id: T) -> Self {
         Self {
             server_config: server::Config {
                 name: "Librespot".into(),
                 device_type: DeviceType::default(),
                 device_id: device_id.into(),
+                client_id: client_id.into(),
             },
             port: 0,
         }
@@ -141,13 +142,13 @@ impl Builder {
 
 impl Discovery {
     /// Starts a [`Builder`] with the provided device id.
-    pub fn builder(device_id: impl Into<String>) -> Builder {
-        Builder::new(device_id)
+    pub fn builder<T: Into<String>>(device_id: T, client_id: T) -> Builder {
+        Builder::new(device_id, client_id)
     }
 
     /// Create a new instance with the specified device id and default paramaters.
-    pub fn new(device_id: impl Into<String>) -> Result<Self, Error> {
-        Self::builder(device_id).launch()
+    pub fn new<T: Into<String>>(device_id: T, client_id: T) -> Result<Self, Error> {
+        Self::builder(device_id, client_id).launch()
     }
 }
 
diff --git a/discovery/src/server.rs b/discovery/src/server.rs
index 3edc2fb6..faea33a1 100644
--- a/discovery/src/server.rs
+++ b/discovery/src/server.rs
@@ -36,10 +36,12 @@ pub struct Config {
     pub name: Cow<'static, str>,
     pub device_type: DeviceType,
     pub device_id: String,
+    pub client_id: String,
 }
 
 struct RequestHandler {
     config: Config,
+    username: Option<String>,
     keys: DhLocalKeys,
     tx: mpsc::UnboundedSender<Credentials>,
 }
@@ -50,6 +52,7 @@ impl RequestHandler {
 
         let discovery = Self {
             config,
+            username: None,
             keys: DhLocalKeys::random(&mut rand::thread_rng()),
             tx,
         };
@@ -60,24 +63,45 @@ impl RequestHandler {
     fn handle_get_info(&self) -> Response<hyper::Body> {
         let public_key = base64::encode(&self.keys.public_key());
         let device_type: &str = self.config.device_type.into();
+        let mut active_user = String::new();
+        if let Some(username) = &self.username {
+            active_user = username.to_string();
+        }
 
+        // See: https://developer.spotify.com/documentation/commercial-hardware/implementation/guides/zeroconf/
         let body = json!({
             "status": 101,
-            "statusString": "ERROR-OK",
+            "statusString": "OK",
             "spotifyError": 0,
-            "version": crate::core::version::SEMVER,
+            // departing from the Spotify documentation, Google Cast uses "5.0.0"
+            "version": "2.9.0",
             "deviceID": (self.config.device_id),
-            "remoteName": (self.config.name),
-            "activeUser": "",
-            "publicKey": (public_key),
             "deviceType": (device_type),
-            "libraryVersion": crate::core::version::SEMVER,
-            "accountReq": "PREMIUM",
+            "remoteName": (self.config.name),
+            // valid value seen in the wild: "empty"
+            "publicKey": (public_key),
             "brandDisplayName": "librespot",
             "modelDisplayName": "librespot",
-            "resolverVersion": "0",
+            "libraryVersion": crate::core::version::SEMVER,
+            "resolverVersion": "1",
             "groupStatus": "NONE",
-            "voiceSupport": "NO",
+            // valid value documented & seen in the wild: "accesstoken"
+            // Using it will cause clients to fail to connect.
+            "tokenType": "default",
+            "clientID": (self.config.client_id),
+            "productID": 0,
+            // Other known scope: client-authorization-universal
+            // Comma-separated.
+            "scope": "streaming",
+            "availability": "",
+            "supported_drm_media_formats": [],
+            // TODO: bitmask but what are the flags?
+            "supported_capabilities": 1,
+            // undocumented but should still work
+            "accountReq": "PREMIUM",
+            "activeUser": active_user,
+            // others seen-in-the-wild:
+            // - "deviceAPI_isGroup": False
         })
         .to_string();
 
@@ -162,7 +186,7 @@ impl RequestHandler {
         let result = json!({
             "status": 101,
             "spotifyError": 0,
-            "statusString": "ERROR-OK"
+            "statusString": "OK",
         });
 
         let body = result.to_string();
diff --git a/src/main.rs b/src/main.rs
index 5cd19bd2..d5c53925 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1635,7 +1635,8 @@ async fn main() {
 
     if setup.enable_discovery {
         let device_id = setup.session_config.device_id.clone();
-        match librespot::discovery::Discovery::builder(device_id)
+        let client_id = setup.session_config.client_id.clone();
+        match librespot::discovery::Discovery::builder(device_id, client_id)
             .name(setup.connect_config.name.clone())
             .device_type(setup.connect_config.device_type)
             .port(setup.zeroconf_port)