[AltServer] Moves core ConnectionManager logic to AltKit

Refactors ConnectionManager to use arbitrary RequestHandlers and ConnectionHandlers. This allows the core AltServer request logic to be shared across different targets with different connection types.

AltServer/Connections/WiredConnectionHandler.swift

@@ -0,0 +1,116 @@
+//
+//  WiredConnectionHandler.swift
+//  AltServer
+//
+//  Created by Riley Testut on 6/1/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import AltKit
+
+class WiredConnectionHandler: ConnectionHandler
+{
+    var connectionHandler: ((Connection) -> Void)?
+    var disconnectionHandler: ((Connection) -> Void)?
+    
+    private var notificationConnections = [ALTDevice: NotificationConnection]()
+    
+    func startListening()
+    {
+        NotificationCenter.default.addObserver(self, selector: #selector(WiredConnectionHandler.deviceDidConnect(_:)), name: .deviceManagerDeviceDidConnect, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(WiredConnectionHandler.deviceDidDisconnect(_:)), name: .deviceManagerDeviceDidDisconnect, object: nil)
+    }
+    
+    func stopListening()
+    {
+        NotificationCenter.default.removeObserver(self, name: .deviceManagerDeviceDidConnect, object: nil)
+        NotificationCenter.default.removeObserver(self, name: .deviceManagerDeviceDidDisconnect, object: nil)
+    }
+}
+
+private extension WiredConnectionHandler
+{
+    func startNotificationConnection(to device: ALTDevice)
+    {
+        ALTDeviceManager.shared.startNotificationConnection(to: device) { (connection, error) in
+            guard let connection = connection else { return }
+
+            let notifications: [CFNotificationName] = [.wiredServerConnectionAvailableRequest, .wiredServerConnectionStartRequest]
+            connection.startListening(forNotifications: notifications.map { String($0.rawValue) }) { (success, error) in
+                guard success else { return }
+
+                connection.receivedNotificationHandler = { [weak self, weak connection] (notification) in
+                    guard let self = self, let connection = connection else { return }
+                    self.handle(notification, for: connection)
+                }
+
+                self.notificationConnections[device] = connection
+            }
+        }
+    }
+
+    func stopNotificationConnection(to device: ALTDevice)
+    {
+        guard let connection = self.notificationConnections[device] else { return }
+        connection.disconnect()
+
+        self.notificationConnections[device] = nil
+    }
+
+    func handle(_ notification: CFNotificationName, for connection: NotificationConnection)
+    {
+        switch notification
+        {
+        case .wiredServerConnectionAvailableRequest:
+            connection.sendNotification(.wiredServerConnectionAvailableResponse) { (success, error) in
+                if let error = error, !success
+                {
+                    print("Error sending wired server connection response.", error)
+                }
+                else
+                {
+                    print("Sent wired server connection available response!")
+                }
+            }
+
+        case .wiredServerConnectionStartRequest:
+            ALTDeviceManager.shared.startWiredConnection(to: connection.device) { (wiredConnection, error) in
+                if let wiredConnection = wiredConnection
+                {
+                    print("Started wired server connection!")
+                    self.connectionHandler?(wiredConnection)
+                    
+                    var observation: NSKeyValueObservation?
+                    observation = wiredConnection.observe(\.isConnected) { [weak self] (connection, change) in
+                        guard !connection.isConnected else { return }
+                        self?.disconnectionHandler?(connection)
+                        
+                        observation?.invalidate()
+                    }
+                }
+                else if let error = error
+                {
+                    print("Error starting wired server connection.", error)
+                }
+            }
+
+        default: break
+        }
+    }
+}
+
+private extension WiredConnectionHandler
+{
+    @objc func deviceDidConnect(_ notification: Notification)
+    {
+        guard let device = notification.object as? ALTDevice else { return }
+        self.startNotificationConnection(to: device)
+    }
+
+    @objc func deviceDidDisconnect(_ notification: Notification)
+    {
+        guard let device = notification.object as? ALTDevice else { return }
+        self.stopNotificationConnection(to: device)
+    }
+}