[firebase_messaging] Add macOS support

[cbenhagen]

Description

Add macOS support.

Related Issues

#1653

Checklist

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• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• If the pull request affects only one plugin, the PR title starts with the name of the plugin in brackets (e.g. [cloud_firestore])
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See Contributor Guide).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (flutter analyze) does not report any problems on my PR.
• I read and followed the Flutter Style Guide.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy.
• I updated CHANGELOG.md to add a description of the change.
• I signed the CLA.
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• Yes, this is a breaking change (please indicate a breaking change in CHANGELOG.md and increment major revision).
• No, this is not a breaking change.

[cbenhagen]

Diff for convenience as git will not show it due to the symlink:

--- FLTFirebaseMessagingPlugin-old.m	2020-06-27 19:20:25.000000000 +0200
+++ FLTFirebaseMessagingPlugin.m	2020-06-27 19:30:54.000000000 +0200
@@ -1,6 +1,7 @@
 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
+#include <TargetConditionals.h>
 
 #import <UserNotifications/UserNotifications.h>
 
@@ -10,7 +11,7 @@
 
 NSString *const kGCMMessageIDKey = @"gcm.message_id";
 
-#if defined(__IPHONE_10_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0
+#if TARGET_OS_OSX || (defined(__IPHONE_10_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0)
 @interface FLTFirebaseMessagingPlugin () <FIRMessagingDelegate>
 @end
 #endif
@@ -37,7 +38,10 @@
                                   binaryMessenger:[registrar messenger]];
   FLTFirebaseMessagingPlugin *instance =
       [[FLTFirebaseMessagingPlugin alloc] initWithChannel:channel];
+// TODO(cbenhagen): Enable for macOS when https://github.com/flutter/flutter/issues/41471 is done.
+#if TARGET_OS_IPHONE
   [registrar addApplicationDelegate:instance];
+#endif
   [registrar addMethodCallDelegate:instance channel:channel];
 
   SEL sel = NSSelectorFromString(@"registerLibrary:withVersion:");
@@ -66,7 +70,7 @@
   NSString *method = call.method;
   if ([@"requestNotificationPermissions" isEqualToString:method]) {
     NSDictionary *arguments = call.arguments;
-    if (@available(iOS 10.0, *)) {
+    if (@available(macOS 10.14, iOS 10.0, *)) {
       UNAuthorizationOptions authOptions = 0;
       NSNumber *provisional = arguments[@"provisional"];
       if ([arguments[@"sound"] boolValue]) {
@@ -80,7 +84,7 @@
       }
 
       NSNumber *isAtLeastVersion12;
-      if (@available(iOS 12, *)) {
+      if (@available(macOS 10.14, iOS 12, *)) {
         isAtLeastVersion12 = [NSNumber numberWithBool:YES];
         if ([provisional boolValue]) authOptions |= UNAuthorizationOptionProvisional;
       } else {
@@ -116,9 +120,13 @@
                               }];
                           result([NSNumber numberWithBool:granted]);
                         }];
-
+#if TARGET_OS_IPHONE
       [[UIApplication sharedApplication] registerForRemoteNotifications];
+#else
+      [[NSApplication sharedApplication] registerForRemoteNotifications];
+#endif
     } else {
+#if TARGET_OS_IPHONE
       UIUserNotificationType notificationTypes = 0;
       if ([arguments[@"sound"] boolValue]) {
         notificationTypes |= UIUserNotificationTypeSound;
@@ -136,10 +144,29 @@
 
       [[UIApplication sharedApplication] registerForRemoteNotifications];
       result([NSNumber numberWithBool:YES]);
+#else
+      NSRemoteNotificationType notificationTypes = 0;
+      if ([arguments[@"sound"] boolValue]) {
+        notificationTypes |= NSRemoteNotificationTypeSound;
+      }
+      if ([arguments[@"alert"] boolValue]) {
+        notificationTypes |= NSRemoteNotificationTypeAlert;
+      }
+      if ([arguments[@"badge"] boolValue]) {
+        notificationTypes |= NSRemoteNotificationTypeBadge;
+      }
+
+      [[NSApplication sharedApplication] registerForRemoteNotificationTypes:notificationTypes];
+      result([NSNumber numberWithBool:YES]);
+#endif
     }
   } else if ([@"configure" isEqualToString:method]) {
     [FIRMessaging messaging].shouldEstablishDirectChannel = true;
+#if TARGET_OS_IPHONE
     [[UIApplication sharedApplication] registerForRemoteNotifications];
+#else
+    [[NSApplication sharedApplication] unregisterForRemoteNotifications];
+#endif
     if (_launchNotification != nil && _launchNotification[kGCMMessageIDKey]) {
       [_channel invokeMethod:@"onLaunch" arguments:_launchNotification];
     }
@@ -173,7 +200,11 @@
         NSLog(@"deleteInstanceID, error: %@", error);
         result([NSNumber numberWithBool:NO]);
       } else {
+#if TARGET_OS_IPHONE
         [[UIApplication sharedApplication] unregisterForRemoteNotifications];
+#else
+        [[NSApplication sharedApplication] unregisterForRemoteNotifications];
+#endif
         result([NSNumber numberWithBool:YES]);
       }
     }];
@@ -189,7 +220,7 @@
   }
 }
 
-#if defined(__IPHONE_10_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0
+#if TARGET_OS_OSX || (defined(__IPHONE_10_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0)
 // Received data message on iOS 10 devices while app is in the foreground.
 // Only invoked if method swizzling is enabled.
 - (void)applicationReceivedRemoteMessage:(FIRMessagingRemoteMessage *)remoteMessage {
@@ -235,6 +266,7 @@
 
 #pragma mark - AppDelegate
 
+#if TARGET_OS_IPHONE
 - (BOOL)application:(UIApplication *)application
     didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
   if (launchOptions != nil) {
@@ -308,4 +340,36 @@
   [_channel invokeMethod:@"onMessage" arguments:remoteMessage.appData];
 }
 
+#else
+- (void)applicationDidFinishLaunching:(NSNotification *)notification {
+  if (notification != nil) {
+    _launchNotification = notification.userInfo[NSApplicationLaunchUserNotificationKey];
+  }
+}
+
+- (void)applicationDidEnterBackground:(NSApplication *)application {
+  _resumingFromBackground = YES;
+}
+
+- (void)applicationDidBecomeActive:(NSApplication *)application {
+  _resumingFromBackground = NO;
+}
+
+- (BOOL)application:(NSApplication *)application
+    didReceiveRemoteNotification:(NSDictionary *)userInfo {
+  [self didReceiveRemoteNotification:userInfo];
+  return YES;
+}
+
+- (void)messaging:(nonnull FIRMessaging *)messaging
+    didReceiveRegistrationToken:(nonnull NSString *)fcmToken {
+  [_channel invokeMethod:@"onToken" arguments:fcmToken];
+}
+
+- (void)messaging:(FIRMessaging *)messaging
+    didReceiveMessage:(FIRMessagingRemoteMessage *)remoteMessage {
+  [_channel invokeMethod:@"onMessage" arguments:remoteMessage.appData];
+}
+#endif
+
 @end

[cbenhagen]

For some reason UserAgent.h sometimes is searched in the darwin directory. @AndroidNils is having the same issue on #1705.

@franciscojma86 || @collinjackson do you have an idea why? I am sure I must be forgetting something stupid.

[nilsreichardt]

For some reason UserAgent.h sometimes is searched in the darwin directory. @AndroidNils is having the same issue on #1705.

@franciscojma86 || @collinjackson do you have an idea why? I am sure I must be forgetting something stupid.

Any updates?

[nilsreichardt]

For some reason UserAgent.h sometimes is searched in the darwin directory. @AndroidNils is having the same issue on #1705.
@franciscojma86 || @collinjackson do you have an idea why? I am sure I must be forgetting something stupid.

Any updates?

@cbenhagen There is a fix for this issue as a PR: #2099 👍

[cbenhagen]

@collinjackson / @kroikie / @franciscojma86 can I ask you to review this?