[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.

AltKit/Connections/ConnectionManager.swift

@@ -0,0 +1,160 @@
+//
+//  ConnectionManager.swift
+//  AltServer
+//
+//  Created by Riley Testut on 5/23/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import Network
+
+public protocol RequestHandler
+{
+    func handleAnisetteDataRequest(_ request: AnisetteDataRequest, for connection: Connection, completionHandler: @escaping (Result<AnisetteDataResponse, Error>) -> Void)
+    func handlePrepareAppRequest(_ request: PrepareAppRequest, for connection: Connection, completionHandler: @escaping (Result<InstallationProgressResponse, Error>) -> Void)
+    
+    func handleInstallProvisioningProfilesRequest(_ request: InstallProvisioningProfilesRequest, for connection: Connection,
+                                                  completionHandler: @escaping (Result<InstallProvisioningProfilesResponse, Error>) -> Void)
+    func handleRemoveProvisioningProfilesRequest(_ request: RemoveProvisioningProfilesRequest, for connection: Connection,
+                                                 completionHandler: @escaping (Result<RemoveProvisioningProfilesResponse, Error>) -> Void)
+    
+    func handleRemoveAppRequest(_ request: RemoveAppRequest, for connection: Connection, completionHandler: @escaping (Result<RemoveAppResponse, Error>) -> Void)
+}
+
+public protocol ConnectionHandler: AnyObject
+{
+    var connectionHandler: ((Connection) -> Void)? { get set }
+    var disconnectionHandler: ((Connection) -> Void)? { get set }
+    
+    func startListening()
+    func stopListening()
+}
+
+public class ConnectionManager<RequestHandlerType: RequestHandler>
+{
+    public let requestHandler: RequestHandlerType
+    public let connectionHandlers: [ConnectionHandler]
+    
+    public var isStarted = false
+    
+    private var connections = [Connection]()
+    
+    public init(requestHandler: RequestHandlerType, connectionHandlers: [ConnectionHandler])
+    {
+        self.requestHandler = requestHandler
+        self.connectionHandlers = connectionHandlers
+        
+        for handler in connectionHandlers
+        {
+            handler.connectionHandler = { [weak self] (connection) in
+                self?.prepare(connection)
+            }
+            
+            handler.disconnectionHandler = { [weak self] (connection) in
+                self?.disconnect(connection)
+            }
+        }
+    }
+    
+    public func start()
+    {
+        guard !self.isStarted else { return }
+        
+        for connectionHandler in self.connectionHandlers
+        {
+            connectionHandler.startListening()
+        }
+        
+        self.isStarted = true
+    }
+    
+    public func stop()
+    {
+        guard self.isStarted else { return }
+        
+        for connectionHandler in self.connectionHandlers
+        {
+            connectionHandler.stopListening()
+        }
+        
+        self.isStarted = false
+    }
+}
+
+private extension ConnectionManager
+{
+    func prepare(_ connection: Connection)
+    {
+        guard !self.connections.contains(where: { $0 === connection }) else { return }
+        self.connections.append(connection)
+        
+        self.handleRequest(for: connection)
+    }
+    
+    func disconnect(_ connection: Connection)
+    {
+        guard let index = self.connections.firstIndex(where: { $0 === connection }) else { return }
+        self.connections.remove(at: index)
+    }
+    
+    func handleRequest(for connection: Connection)
+    {
+        func finish<T: ServerMessageProtocol>(_ result: Result<T, Error>)
+        {
+            do
+            {
+                let response = try result.get()
+                connection.send(response, shouldDisconnect: true) { (result) in
+                    print("Sent response \(response) with result:", result)
+                }
+            }
+            catch
+            {
+                let response = ErrorResponse(error: ALTServerError(error))
+                connection.send(response, shouldDisconnect: true) { (result) in
+                    print("Sent error response \(response) with result:", result)
+                }
+            }
+        }
+        
+        connection.receiveRequest() { (result) in
+            print("Received request with result:", result)
+            
+            switch result
+            {
+            case .failure(let error): finish(Result<ErrorResponse, Error>.failure(error))
+                
+            case .success(.anisetteData(let request)):
+                self.requestHandler.handleAnisetteDataRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.prepareApp(let request)):
+                self.requestHandler.handlePrepareAppRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.beginInstallation): break
+                
+            case .success(.installProvisioningProfiles(let request)):
+                self.requestHandler.handleInstallProvisioningProfilesRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.removeProvisioningProfiles(let request)):
+                self.requestHandler.handleRemoveProvisioningProfilesRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.removeApp(let request)):
+                self.requestHandler.handleRemoveAppRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.unknown):
+                finish(Result<ErrorResponse, Error>.failure(ALTServerError(.unknownRequest)))
+            }
+        }
+    }
+}