Replaces AltSign cocoapod with Swift package

AltServer/Connections/ALTNotificationConnection.mm

@@ -0,0 +1,94 @@
+//
+//  ALTNotificationConnection.m
+//  AltServer
+//
+//  Created by Riley Testut on 1/10/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+#import "ALTNotificationConnection+Private.h"
+
+#import "NSError+ALTServerError.h"
+
+void ALTDeviceReceivedNotification(const char *notification, void *user_data);
+
+@implementation ALTNotificationConnection
+
+- (instancetype)initWithDevice:(ALTDevice *)device client:(np_client_t)client
+{
+    self = [super init];
+    if (self)
+    {
+        _device = [device copy];
+        _client = client;
+    }
+    
+    return self;
+}
+
+- (void)dealloc
+{
+    [self disconnect];
+}
+
+- (void)disconnect
+{
+    np_client_free(self.client);
+    _client = nil;
+}
+
+- (void)startListeningForNotifications:(NSArray<NSString *> *)notifications completionHandler:(void (^)(BOOL, NSError * _Nullable))completionHandler
+{
+    dispatch_async(dispatch_get_global_queue(QOS_CLASS_UTILITY, 0), ^{
+        const char **notificationNames = (const char **)malloc((notifications.count + 1) * sizeof(char *));
+        for (int i = 0; i < notifications.count; i++)
+        {
+            NSString *name = notifications[i];
+            notificationNames[i] = name.UTF8String;
+        }
+        notificationNames[notifications.count] = NULL; // Must have terminating NULL entry.
+        
+        np_error_t result = np_observe_notifications(self.client, notificationNames);
+        if (result != NP_E_SUCCESS)
+        {
+            return completionHandler(NO, [NSError errorWithDomain:AltServerErrorDomain code:ALTServerErrorLostConnection userInfo:nil]);
+        }
+        
+        result = np_set_notify_callback(self.client, ALTDeviceReceivedNotification, (__bridge void *)self);
+        if (result != NP_E_SUCCESS)
+        {
+            return completionHandler(NO, [NSError errorWithDomain:AltServerErrorDomain code:ALTServerErrorLostConnection userInfo:nil]);
+        }
+        
+        completionHandler(YES, nil);
+        
+        free(notificationNames);
+    });
+}
+
+- (void)sendNotification:(CFNotificationName)notification completionHandler:(void (^)(BOOL, NSError * _Nullable))completionHandler
+{
+    dispatch_async(dispatch_get_global_queue(QOS_CLASS_UTILITY, 0), ^{
+        np_error_t result = np_post_notification(self.client, [(__bridge NSString *)notification UTF8String]);
+        if (result == NP_E_SUCCESS)
+        {
+            completionHandler(YES, nil);
+        }
+        else
+        {
+            completionHandler(NO, [NSError errorWithDomain:AltServerErrorDomain code:ALTServerErrorLostConnection userInfo:nil]);
+        }
+    });
+}
+
+@end
+
+void ALTDeviceReceivedNotification(const char *notification, void *user_data)
+{
+    ALTNotificationConnection *connection = (__bridge ALTNotificationConnection *)user_data;
+    
+    if (connection.receivedNotificationHandler)
+    {
+        connection.receivedNotificationHandler((__bridge CFNotificationName)@(notification));
+    }
+}