1 files changed, 162 insertions, 0 deletions
diff --git a/Firebase/Database/Login/FAuthTokenProvider.m b/Firebase/Database/Login/FAuthTokenProvider.m
new file mode 100644
index 0000000..e406ae7
--- /dev/null
+++ b/Firebase/Database/Login/FAuthTokenProvider.m
@@ -0,0 +1,162 @@
+/*
+ * Copyright 2017 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FAuthTokenProvider.h"
+#import "FUtilities.h"
+#import "FIRDatabaseQuery_Private.h"
+#import "FIRNoopAuthTokenProvider.h"
+
+static NSString *const FIRAuthStateDidChangeInternalNotification = @"FIRAuthStateDidChangeInternalNotification";
+static NSString *const FIRAuthStateDidChangeInternalNotificationTokenKey = @"FIRAuthStateDidChangeInternalNotificationTokenKey";
+
+
+/**
+ * This is a hack that defines all the methods we need from FIRFirebaseApp. At runtime we use reflection to get an
+ * actual instance of FIRFirebaseApp. Since protocols don't carry any runtime information and selectors are invoked
+ * by name we can write code against this protocol as long as the method signatures of FIRFirebaseApp don't change.
+ */
+@protocol FIRFirebaseAppLike <NSObject>
+
+- (void)getTokenForcingRefresh:(BOOL)forceRefresh withCallback:(void (^)(NSString *_Nullable token, NSError *_Nullable error))callback;
+
+@end
+
+
+/**
+ * This is a hack that defines all the methods we need from FIRAuth.
+ */
+@protocol FIRFirebaseAuthLike <NSObject>
+
+- (id<FIRFirebaseAppLike>) app;
+
+@end
+
+/**
+ * This is a hack that copies the definitions of Firebear error codes. If the error codes change in the original code, this
+ * will break at runtime due to undefined behavior!
+ */
+typedef NS_ENUM(NSUInteger, FIRErrorCode) {
+    /*! @var FIRErrorCodeNoAuth
+     @brief Represents the case where an auth-related message was sent to a @c FIRFirebaseApp
+     instance which has no associated @c FIRAuth instance.
+     */
+    FIRErrorCodeNoAuth,
+
+    /*! @var FIRErrorCodeNoSignedInUser
+     @brief Represents the case where an attempt was made to fetch a token when there is no signed
+     in user.
+     */
+    FIRErrorCodeNoSignedInUser,
+};
+
+
+@interface FAuthStateListenerWrapper : NSObject
+
+@property (nonatomic, copy) fbt_void_nsstring listener;
+
+@property (nonatomic, weak) id<FIRFirebaseAppLike> app;
+
+@end
+
+@implementation FAuthStateListenerWrapper
+
+- (instancetype) initWithListener:(fbt_void_nsstring)listener app:(id<FIRFirebaseAppLike>)app {
+    self = [super init];
+    if (self != nil) {
+        self->_listener = listener;
+        self->_app = app;
+        [[NSNotificationCenter defaultCenter] addObserver:self
+                                                 selector:@selector(authStateDidChangeNotification:)
+                                                     name:FIRAuthStateDidChangeInternalNotification
+                                                   object:nil];
+    }
+    return self;
+}
+
+- (void) authStateDidChangeNotification:(NSNotification *)notification {
+    id<FIRFirebaseAuthLike> auth = notification.object;
+    if (auth.app == self->_app) {
+        NSDictionary *userInfo = notification.userInfo;
+        NSString *token = userInfo[FIRAuthStateDidChangeInternalNotificationTokenKey];
+        dispatch_async([FIRDatabaseQuery sharedQueue], ^{
+            self.listener(token);
+        });
+    }
+}
+
+- (void) dealloc {
+    [[NSNotificationCenter defaultCenter] removeObserver:self];
+}
+
+@end
+
+
+@interface FIRFirebearAuthTokenProvider : NSObject <FAuthTokenProvider>
+
+@property (nonatomic, strong) id<FIRFirebaseAppLike> app;
+/** Strong references to the auth listeners as they are only weak in FIRFirebaseApp */
+@property (nonatomic, strong) NSMutableArray *authListeners;
+
+- (instancetype) initWithFirebaseApp:(id<FIRFirebaseAppLike>)app;
+
+@end
+
+@implementation FIRFirebearAuthTokenProvider
+
+- (instancetype) initWithFirebaseApp:(id<FIRFirebaseAppLike>)app {
+    self = [super init];
+    if (self != nil) {
+        self->_app = app;
+        self->_authListeners = [NSMutableArray array];
+    }
+    return self;
+}
+
+- (void) fetchTokenForcingRefresh:(BOOL)forceRefresh withCallback:(fbt_void_nsstring_nserror)callback {
+    // TODO: Don't fetch token if there is no current user
+    [self.app getTokenForcingRefresh:forceRefresh withCallback:^(NSString * _Nullable token, NSError * _Nullable error) {
+        dispatch_async([FIRDatabaseQuery sharedQueue], ^{
+            if (error != nil) {
+                if (error.code == FIRErrorCodeNoAuth) {
+                    FFLog(@"I-RDB073001", @"Firebase Auth is not configured, not going to use authentication.");
+                    callback(nil, nil);
+                } else if (error.code == FIRErrorCodeNoSignedInUser) {
+                    // No signed in user is an expected case, callback as success with no token
+                    callback(nil, nil);
+                } else {
+                    callback(nil, error);
+                }
+            } else {
+                callback(token, nil);
+            }
+        });
+    }];
+}
+
+- (void) listenForTokenChanges:(_Nonnull fbt_void_nsstring)listener {
+    FAuthStateListenerWrapper *wrapper = [[FAuthStateListenerWrapper alloc] initWithListener:listener app:self.app];
+    [self.authListeners addObject:wrapper];
+}
+
+@end
+
+@implementation FAuthTokenProvider
+
++ (id<FAuthTokenProvider>) authTokenProviderForApp:(id)app {
+    return [[FIRFirebearAuthTokenProvider alloc] initWithFirebaseApp:app];
+}
+
+@end