rust/bt-bap-unicast: Make manager and client generic over GattTypes

- Update BapUnicastClient and BapUnicastManager to be generic over bt_gatt::GattTypes.
- Update add_peer to accept T::Client.
- Add bt-gatt with test-utils feature to dev-dependencies in Cargo.toml.
- Update unit tests to use FakeClient and FakeTypes.

Test: unit tests passed
Bug: 433288675
Change-Id: I66742aaaa697f03a37f735bc0e70f1266a6a6964
Reviewed-on: https://bluetooth-review.googlesource.com/c/bluetooth/+/3061

rust/bt-bap-unicast/Cargo.toml

diff --git a/rust/bt-bap-unicast/Cargo.toml b/rust/bt-bap-unicast/Cargo.toml
index a89c152..7773f3f 100644
--- a/rust/bt-bap-unicast/Cargo.toml
+++ b/rust/bt-bap-unicast/Cargo.toml
@@ -11,3 +11,6 @@
 bt-pacs.workspace = true
 futures.workspace = true
 thiserror.workspace = true
+
+[dev-dependencies]
+bt-gatt = { workspace = true, features = ["test-utils"] }

rust/bt-bap-unicast/src/client.rs

diff --git a/rust/bt-bap-unicast/src/client.rs b/rust/bt-bap-unicast/src/client.rs
index b4ace67..14bd217 100644
--- a/rust/bt-bap-unicast/src/client.rs
+++ b/rust/bt-bap-unicast/src/client.rs
@@ -3,17 +3,19 @@
 // found in the LICENSE file.
 
 use bt_common::PeerId;
+use bt_gatt::GattTypes;
 
 /// Represents a connection to a single peer and manages its audio streams.
-#[derive(Debug)]
-pub struct BapUnicastClient {
+pub struct BapUnicastClient<T: GattTypes> {
     peer_id: PeerId,
+    #[allow(unused)]
+    gatt_client: T::Client,
     // TODO: Add ASCS and PACS clients here.
 }
 
-impl BapUnicastClient {
-    pub fn new(peer_id: PeerId) -> Self {
-        Self { peer_id }
+impl<T: GattTypes> BapUnicastClient<T> {
+    pub fn new(peer_id: PeerId, gatt_client: T::Client) -> Self {
+        Self { peer_id, gatt_client }
     }
 
     pub fn peer_id(&self) -> PeerId {

rust/bt-bap-unicast/src/manager.rs

diff --git a/rust/bt-bap-unicast/src/manager.rs b/rust/bt-bap-unicast/src/manager.rs
index b33b427..6912b1e 100644
--- a/rust/bt-bap-unicast/src/manager.rs
+++ b/rust/bt-bap-unicast/src/manager.rs
@@ -5,27 +5,28 @@
 use crate::client::BapUnicastClient;
 use crate::types::Error;
 use bt_common::PeerId;
+use bt_gatt::GattTypes;
 use std::collections::HashMap;
 
 /// Manages multiple BAP Unicast peers.
-#[derive(Debug, Default)]
-pub struct BapUnicastManager {
-    peers: HashMap<PeerId, BapUnicastClient>,
+pub struct BapUnicastManager<T: GattTypes> {
+    peers: HashMap<PeerId, BapUnicastClient<T>>,
 }
 
-impl BapUnicastManager {
+impl<T: GattTypes> BapUnicastManager<T> {
     pub fn new() -> Self {
-        Self::default()
+        Self { peers: HashMap::new() }
     }
 
     /// Add a peer to the manager.
-    /// In the future, this will trigger discovery.
-    pub async fn add_peer(&mut self, peer_id: PeerId) -> Result<(), Error> {
+    /// Triggers the connection and discovery of PACS and ASCS on the remote
+    /// peer.
+    pub async fn add_peer(&mut self, peer_id: PeerId, gatt_client: T::Client) -> Result<(), Error> {
         if self.peers.contains_key(&peer_id) {
             return Err(Error::PeerAlreadyExists(peer_id));
         }
 
-        let client = BapUnicastClient::new(peer_id);
+        let client = BapUnicastClient::new(peer_id, gatt_client);
         self.peers.insert(peer_id, client);
         Ok(())
     }
@@ -43,14 +44,16 @@
 mod tests {
     use super::*;
     use bt_common::PeerId;
+    use bt_gatt::test_utils::{FakeClient, FakeTypes};
 
     #[test]
     fn test_add_remove_peer() {
-        let mut manager = BapUnicastManager::new();
+        let mut manager = BapUnicastManager::<FakeTypes>::new();
         let peer_id = PeerId(1);
+        let client = FakeClient::new();
 
-        assert!(futures::executor::block_on(manager.add_peer(peer_id)).is_ok());
-        assert!(futures::executor::block_on(manager.add_peer(peer_id)).is_err()); // Duplicate
+        assert!(futures::executor::block_on(manager.add_peer(peer_id, client.clone())).is_ok());
+        assert!(futures::executor::block_on(manager.add_peer(peer_id, client.clone())).is_err()); // Duplicate
 
         assert!(manager.remove_peer(peer_id).is_ok());
         assert!(manager.remove_peer(peer_id).is_err()); // Not found