Add Advertiser and Discoverer to the Swift layer

PiperOrigin-RevId: 490301361

connections/clients/swift/NearbyConnections/Sources/Advertiser.swift

@@ -12,6 +12,135 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+import Foundation
 import NearbyCoreAdapter
 
-public class Advertiser {}
+/// Publishes an advertisement and notifies its delegate about connection requests from nearby
+/// endpoints.
+public class Advertiser {
+
+  /// The delegate object that handles advertising-related events.
+  public weak var delegate: AdvertiserDelegate?
+
+  /// The connection manager for this instance.
+  public let connectionManager: ConnectionManager
+
+  lazy var connection: InternalConnection? = {
+    let connection = InternalConnection()
+    connection.delegate = self
+    return connection
+  }()
+
+  /// Initializes the discoverer object.
+  ///
+  /// - Parameter connectionManager: The connection manager for this instance.
+  public init(connectionManager: ConnectionManager) {
+    self.connectionManager = connectionManager
+  }
+
+  /// Starts advertising the local endpoint.
+  ///
+  /// After this method is called (until you call `stopAdvertising()`), the framework calls your
+  /// delegate’s `advertiser(_:didReceiveConnectionRequestFrom:with:connectionRequestHandler:)`
+  /// method when remote endpoints request a connection.
+  public func startAdvertising(using context: Data) {
+    let options = GNCAdvertisingOptions(strategy: connectionManager.strategy.objc)
+    // TODO(b/257824412): Handle errors from completion handler.
+    GNCCoreAdapter.shared.startAdvertising(
+      asService: connectionManager.serviceID, endpointInfo: context,
+      options: options, delegate: connection)
+  }
+
+  /// Stops advertising the local endpoint.
+  public func stopAdvertising() {
+    // TODO(b/257824412): Handle errors from completion handler.
+    GNCCoreAdapter.shared.stopAdvertising()
+  }
+
+  deinit {
+    stopAdvertising()
+  }
+}
+
+extension Advertiser: InternalConnectionDelegate {
+
+  func connected(
+    toEndpoint endpointID: String, withEndpointInfo info: Data, authenticationToken: String
+  ) {
+    connectionManager.queue.async { [weak self] in
+      guard let self = self else { return }
+      self.delegate?.advertiser(self, didReceiveConnectionRequestFrom: endpointID, with: info) {
+        (accept) in
+        guard accept else {
+          // TODO(b/257824412): Handle errors from completion handler.
+          GNCCoreAdapter.shared.rejectConnectionRequest(fromEndpoint: endpointID)
+          return
+        }
+        self.connectionManager.delegate?.connectionManager(
+          self.connectionManager, didChangeTo: .connecting, for: endpointID)
+        self.connectionManager.delegate?.connectionManager(
+          self.connectionManager, didReceive: authenticationToken, from: endpointID
+        ) { accept in
+          guard accept else {
+            // TODO(b/257824412): Handle errors from completion handler.
+            GNCCoreAdapter.shared.rejectConnectionRequest(fromEndpoint: endpointID)
+            return
+          }
+          // TODO(b/257824412): Handle errors from completion handler.
+          GNCCoreAdapter.shared.acceptConnectionRequest(
+            fromEndpoint: endpointID, delegate: self.connectionManager.payload)
+
+        }
+      }
+    }
+  }
+
+  func acceptedConnection(toEndpoint endpointID: String) {
+    connectionManager.queue.async { [weak self] in
+      guard let connectionManager = self?.connectionManager else { return }
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didChangeTo: .connected, for: endpointID)
+    }
+  }
+
+  func rejectedConnection(toEndpoint endpointID: String, with status: GNCStatus) {
+    connectionManager.queue.async { [weak self] in
+      guard let connectionManager = self?.connectionManager else { return }
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didChangeTo: .rejected, for: endpointID)
+    }
+  }
+
+  func disconnected(fromEndpoint endpointID: String) {
+    connectionManager.queue.async { [weak self] in
+      guard let connectionManager = self?.connectionManager else { return }
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didChangeTo: .disconnected, for: endpointID)
+    }
+  }
+}
+
+/// The `AdvertiserDelegate` protocol defines methods that an `Advertiser` object’s delegate can
+/// implement to handle advertising-related events.
+///
+/// Delegate methods are executed on the `.main` queue by default, but a specific `DispatchQueue` on
+/// which to call the delegate methods can be passed to `ConnectionManager`.
+public protocol AdvertiserDelegate: AnyObject {
+
+  /// Called when a connection request is received from a nearby endpoint.
+  ///
+  /// Important: Accepting a connection request will not yet establish a connection that allows
+  /// data transference. The connection must first be verified by both parties via the
+  /// `ConnectionManagerDelegate`, before data can flow freely.
+  ///
+  /// - Parameters:
+  ///   - advertiser: The advertiser object that received a connection request.
+  ///   - endpointID: The endpoint ID of the nearby enpoint that requested the connection.
+  ///   - info: An arbitrary piece of data received from the nearby endpoint. This can be used to
+  ///     provide further information to the user about the nature of the invitation.
+  ///   - connectionRequestHandler: A block that your code must call to indicate whether the
+  ///     advertiser should accept or decline the connection request.
+  func advertiser(
+    _ advertiser: Advertiser, didReceiveConnectionRequestFrom endpointID: EndpointID,
+    with context: Data, connectionRequestHandler: @escaping (Bool) -> Void)
+}

connections/clients/swift/NearbyConnections/Sources/Discoverer.swift

@@ -12,6 +12,171 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+import Foundation
 import NearbyCoreAdapter
 
-public class Discoverer {}
+/// Searches for nearby endpoints and provides the ability to request connections to them.
+public class Discoverer {
+
+  /// The delegate object that handles discovery-related events.
+  public weak var delegate: DiscovererDelegate?
+
+  /// The connection manager for this instance.
+  public let connectionManager: ConnectionManager
+
+  lazy var connection: InternalConnection? = {
+    let connection = InternalConnection()
+    connection.delegate = self
+    return connection
+  }()
+
+  lazy var discovery: InternalDiscovery? = {
+    let discovery = InternalDiscovery()
+    discovery.delegate = self
+    return discovery
+  }()
+
+  /// Initializes the discoverer object.
+  ///
+  /// - Parameter connectionManager: The connection manager for this instance.
+  public init(connectionManager: ConnectionManager) {
+    self.connectionManager = connectionManager
+  }
+
+  /// Starts searching for nearby remote endpoints.
+  ///
+  /// After this method is called (until you call `stopDiscovery()`), the framework calls your
+  /// delegate’s `discoverer(_:didFind:with:)` and `discoverer(_:didLose:)` methods as new endpoints
+  /// are found and lost.
+  public func startDiscovery() {
+    let options = GNCDiscoveryOptions(strategy: connectionManager.strategy.objc)
+    // TODO(b/257824412): Handle errors from completion handler.
+    GNCCoreAdapter.shared.startDiscovery(
+      asService: connectionManager.serviceID, options: options, delegate: discovery)
+  }
+
+  /// Stops searching for nearby remote endpoints.
+  public func stopDiscovery() {
+    // TODO(b/257824412): Handle errors from completion handler.
+    GNCCoreAdapter.shared.stopDiscovery()
+  }
+
+  /// Requests a connection to a discovered remote endpoint.
+  ///
+  /// - Parameters:
+  ///   - endpointID: The ID of the endpoint to request a connection to.
+  ///   - context: An arbitrary piece of data that is passed to the nearby endpoint. This can be
+  ///     used to provide further information to the user about the nature of the invitation.
+  public func requestConnection(to endpointID: EndpointID, using context: Data) {
+    let options = GNCConnectionOptions()
+    // TODO(b/257824412): Handle errors from completion handler.
+    GNCCoreAdapter.shared.requestConnection(
+      toEndpoint: endpointID, endpointInfo: context,
+      options: options, delegate: connection)
+  }
+
+  deinit {
+    stopDiscovery()
+  }
+}
+
+extension Discoverer: InternalConnectionDelegate {
+
+  func connected(
+    toEndpoint endpointID: String, withEndpointInfo info: Data, authenticationToken: String
+  ) {
+    connectionManager.queue.async { [weak self] in
+      guard let connectionManager = self?.connectionManager else { return }
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didChangeTo: .connecting, for: endpointID)
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didReceive: authenticationToken, from: endpointID
+      ) { accept in
+        guard accept else {
+          // TODO(b/257824412): Handle errors from completion handler.
+          GNCCoreAdapter.shared.rejectConnectionRequest(fromEndpoint: endpointID)
+          return
+        }
+        // TODO(b/257824412): Handle errors from completion handler.
+        GNCCoreAdapter.shared.acceptConnectionRequest(
+          fromEndpoint: endpointID, delegate: connectionManager.payload)
+      }
+    }
+  }
+
+  func acceptedConnection(toEndpoint endpointID: String) {
+    connectionManager.queue.async { [weak self] in
+      guard let connectionManager = self?.connectionManager else { return }
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didChangeTo: .connected, for: endpointID)
+    }
+  }
+
+  func rejectedConnection(toEndpoint endpointID: String, with status: GNCStatus) {
+    connectionManager.queue.async { [weak self] in
+      guard let connectionManager = self?.connectionManager else { return }
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didChangeTo: .rejected, for: endpointID)
+    }
+  }
+
+  func disconnected(fromEndpoint endpointID: String) {
+    connectionManager.queue.async { [weak self] in
+      guard let connectionManager = self?.connectionManager else { return }
+      connectionManager.delegate?.connectionManager(
+        connectionManager, didChangeTo: .disconnected, for: endpointID)
+    }
+  }
+}
+
+extension Discoverer: InternalDiscoveryDelegate {
+
+  func foundEndpoint(_ endpointID: String, withEndpointInfo info: Data) {
+    connectionManager.queue.async { [weak self] in
+      guard let self = self else { return }
+      self.delegate?.discoverer(self, didFind: endpointID, with: info)
+    }
+  }
+
+  func lostEndpoint(_ endpointID: String) {
+    connectionManager.queue.async { [weak self] in
+      guard let self = self else { return }
+      self.delegate?.discoverer(self, didLose: endpointID)
+    }
+  }
+}
+
+/// The `DiscovererDelegate` protocol defines methods that a `Discoverer` object’s delegate can
+/// implement to handle discovery-related events.
+///
+/// Delegate methods are executed on the `.main` queue by default, but a specific `DispatchQueue` on
+/// which to call the delegate methods can be passed to `ConnectionManager`.
+public protocol DiscovererDelegate: AnyObject {
+
+  /// Called when a nearby endpoint is found.
+  ///
+  /// The endpoint ID provided to this delegate method can be used to request a connection with the
+  /// nearby endpoint.
+  ///
+  /// - Parameters:
+  ///   - discoverer: The discoverer object that found the nearby endpoint.
+  ///   - endpointID: The unique ID of the endpoint that was found.
+  ///   - context: An arbitrary piece of data received from the nearby endpoint. This can be used to
+  ///     provide further information to the user about the nature of the invitation.
+  func discoverer(_ discoverer: Discoverer, didFind endpointID: EndpointID, with context: Data)
+
+  /// Called when a nearby endpoint is lost.
+  ///
+  /// This callback informs your app that connection requests can no longer be sent to an endpoint,
+  /// and that your app should remove that endpoint from its user interface.
+  ///
+  /// Important: Because there is a delay between when a discovered endpoint disappears and when
+  /// Nearby Connections detects that it has left, the fact that your app has not yet received a
+  /// disappearance callback does not guarantee that it can communicate with the endpoint
+  /// successfully.
+  ///
+  /// - Parameters:
+  ///   - discoverer: The discoverer object that lost the nearby endpoint.
+  ///   - endpointID: The unique ID of the nearby endpoint that was lost.
+  func discoverer(_ discoverer: Discoverer, didLose endpointID: EndpointID)
+}