Initial

18 files changed, 1175 insertions, 0 deletions

diff --git a/Firebase/Core/Private/FIRAnalyticsConfiguration+Internal.h b/Firebase/Core/Private/FIRAnalyticsConfiguration+Internal.h
new file mode 100644
index 0000000..6c57a0f
--- /dev/null
+++ b/Firebase/Core/Private/FIRAnalyticsConfiguration+Internal.h
@@ -0,0 +1,39 @@
+/*
+ * 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 "../FIRAnalyticsConfiguration.h"
+
+/// Values stored in analyticsEnabledState. Never alter these constants since they must match with
+/// values persisted to disk.
+typedef NS_ENUM(int64_t, FIRAnalyticsEnabledState) {
+  // 0 is the default value for keys not found stored in persisted config, so it cannot represent
+  // kFIRAnalyticsEnabledStateSetNo. It must represent kFIRAnalyticsEnabledStateNotSet.
+  kFIRAnalyticsEnabledStateNotSet = 0,
+  kFIRAnalyticsEnabledStateSetYes = 1,
+  kFIRAnalyticsEnabledStateSetNo = 2,
+};
+
+/// The user defaults key for the persisted measurementEnabledState value. FIRAPersistedConfig reads
+/// measurementEnabledState using this same key.
+static NSString *const kFIRAPersistedConfigMeasurementEnabledStateKey =
+    @"/google/measurement/measurement_enabled_state";
+
+static NSString *const kFIRAnalyticsConfigurationSetEnabledNotification =
+    @"FIRAnalyticsConfigurationSetEnabledNotification";
+static NSString *const kFIRAnalyticsConfigurationSetMinimumSessionIntervalNotification =
+    @"FIRAnalyticsConfigurationSetMinimumSessionIntervalNotification";
+static NSString *const kFIRAnalyticsConfigurationSetSessionTimeoutIntervalNotification =
+    @"FIRAnalyticsConfigurationSetSessionTimeoutIntervalNotification";
diff --git a/Firebase/Core/Private/FIRAppAssociationRegistration.h b/Firebase/Core/Private/FIRAppAssociationRegistration.h
new file mode 100644
index 0000000..3d697a7
--- /dev/null
+++ b/Firebase/Core/Private/FIRAppAssociationRegistration.h
@@ -0,0 +1,48 @@
+/*
+ * 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 <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** @class FIRAppAssociationRegistration
+    @brief Manages object associations as a singleton-dependent: At most one object is
+        registered for any given host/key pair, and the object shall be created on-the-fly when
+        asked for.
+ */
+@interface FIRAppAssociationRegistration<ObjectType> : NSObject
+
+/** @fn registeredObjectWithHost:key:creationBlock:
+    @brief Retrieves the registered object with a particular host and key.
+    @param host The host object.
+    @param key The key to specify the registered object on the host.
+    @param creationBlock The block to return the object to be registered if not already.
+        The block is executed immediately before this method returns if it is executed at all.
+        It can also be executed multiple times across different method invocations if previous
+        execution of the block returns @c nil.
+    @return The registered object for the host/key pair, or @c nil if no object is registered
+        and @c creationBlock returns @c nil.
+    @remarks The method is thread-safe but non-reentrant in the sense that attempting to call this
+        method again within the @c creationBlock with the same host/key pair raises an exception.
+        The registered object is retained by the host.
+ */
++ (nullable ObjectType)registeredObjectWithHost:(id)host
+                                            key:(NSString *)key
+                                  creationBlock:(ObjectType _Nullable (^)())creationBlock;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Firebase/Core/Private/FIRAppEnvironmentUtil.h b/Firebase/Core/Private/FIRAppEnvironmentUtil.h
new file mode 100644
index 0000000..ba4696c
--- /dev/null
+++ b/Firebase/Core/Private/FIRAppEnvironmentUtil.h
@@ -0,0 +1,48 @@
+/*
+ * 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 <Foundation/Foundation.h>
+
+#import <UIKit/UIKit.h>
+
+@interface FIRAppEnvironmentUtil : NSObject
+
+/// Indicates whether the app is from Apple Store or not. Returns NO if the app is on simulator,
+/// development environment or sideloaded.
++ (BOOL)isFromAppStore;
+
+/// Indicates whether the app is a Testflight app. Returns YES if the app has sandbox receipt.
+/// Returns NO otherwise.
++ (BOOL)isAppStoreReceiptSandbox;
+
+/// Indicates whether the app is on simulator or not at runtime depending on the device
+/// architecture.
++ (BOOL)isSimulator;
+
+/// The current device model. Returns an empty string if device model cannot be retrieved.
++ (NSString *)deviceModel;
+
+/// The current operating system version. Returns an empty string if the system version cannot be
+/// retrieved.
++ (NSString *)systemVersion;
+
+/// Indicates whether it is running inside an extension or an app.
++ (BOOL)isAppExtension;
+
+/// Returns the [UIApplication sharedApplication] if it is running on an app, not an extension.
++ (UIApplication *)sharedApplication;
+
+@end
diff --git a/Firebase/Core/Private/FIRAppInternal.h b/Firebase/Core/Private/FIRAppInternal.h
new file mode 100644
index 0000000..11b3bf6
--- /dev/null
+++ b/Firebase/Core/Private/FIRAppInternal.h
@@ -0,0 +1,140 @@
+/*
+ * 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 "FIRApp.h"
+#import "FIRErrors.h"
+
+/**
+ * The internal interface to FIRApp. This is meant for first-party integrators, who need to receive
+ * FIRApp notifications, log info about the success or failure of their configuration, and access
+ * other internal functionality of FIRApp.
+ *
+ * TODO(b/28296561): Restructure this header.
+ */
+NS_ASSUME_NONNULL_BEGIN
+
+typedef NS_ENUM(NSInteger, FIRConfigType) {
+  FIRConfigTypeCore = 1,
+  FIRConfigTypeSDK = 2,
+};
+
+/**
+ * Names of services provided by Firebase.
+ */
+extern NSString *const kFIRServiceAdMob;
+extern NSString *const kFIRServiceAuth;
+extern NSString *const kFIRServiceCrash;
+extern NSString *const kFIRServiceDatabase;
+extern NSString *const kFIRServiceDynamicLinks;
+extern NSString *const kFIRServiceInstanceID;
+extern NSString *const kFIRServiceInvites;
+extern NSString *const kFIRServiceMessaging;
+extern NSString *const kFIRServiceMeasurement;
+extern NSString *const kFIRServiceRemoteConfig;
+extern NSString *const kFIRServiceStorage;
+
+/**
+ * Names of services provided by the Google pod, but logged by the Firebase pod.
+ */
+extern NSString *const kGGLServiceAnalytics;
+extern NSString *const kGGLServiceSignIn;
+
+extern NSString *const kFIRDefaultAppName;
+extern NSString *const kFIRAppReadyToConfigureSDKNotification;
+extern NSString *const kFIRAppDeleteNotification;
+extern NSString *const kFIRAppIsDefaultAppKey;
+extern NSString *const kFIRAppNameKey;
+extern NSString *const kFIRGoogleAppIDKey;
+
+/** @typedef FIRTokenCallback
+    @brief The type of block which gets called when a token is ready.
+ */
+typedef void (^FIRTokenCallback)(NSString *_Nullable token, NSError *_Nullable error);
+
+/** @typedef FIRAppGetTokenImplementation
+    @brief The type of block which can provide an implementation for the @c getTokenWithCallback:
+        method.
+    @param forceRefresh Forces the token to be refreshed.
+    @param callback The block which should be invoked when the async call completes.
+ */
+typedef void (^FIRAppGetTokenImplementation)(BOOL forceRefresh, FIRTokenCallback callback);
+
+/** @typedef FIRAppGetUID
+    @brief The type of block which can provide an implementation for the @c getUID method.
+ */
+typedef NSString *_Nullable (^FIRAppGetUIDImplementation)();
+
+@interface FIRApp ()
+
+/** @property getTokenImplementation
+    @brief Gets or sets the block to use for the implementation of
+        @c getTokenForcingRefresh:withCallback:
+ */
+@property(nonatomic, copy) FIRAppGetTokenImplementation getTokenImplementation;
+
+/** @property getUIDImplementation
+    @brief Gets or sets the block to use for the implementation of @c getUID.
+ */
+@property(nonatomic, copy) FIRAppGetUIDImplementation getUIDImplementation;
+
+/**
+ * Creates an error for failing to configure a subspec service. This method is called by each
+ * FIRApp notification listener.
+ */
++ (NSError *)errorForSubspecConfigurationFailureWithDomain:(NSString *)domain
+                                                 errorCode:(FIRErrorCode)code
+                                                   service:(NSString *)service
+                                                    reason:(NSString *)reason;
+
+/**
+ * Used by each SDK to send logs about SDK configuration status to Clearcut.
+ */
+- (void)sendLogsWithServiceName:(NSString *)serviceName
+                        version:(NSString *)version
+                          error:(NSError *)error;
+
+/**
+ * Can be used by the unit tests in eack SDK to reset FIRApp. This method is thread unsafe.
+ */
++ (void)resetApps;
+
+/**
+ * Can be used by the unit tests in each SDK to set customized options.
+ */
+- (instancetype)initInstanceWithName:(NSString *)name options:(FIROptions *)options;
+
+/** @fn getTokenForcingRefresh:withCallback:
+    @brief Retrieves the Firebase authentication token, possibly refreshing it.
+    @param forceRefresh Forces a token refresh. Useful if the token becomes invalid for some reason
+        other than an expiration.
+    @param callback The block to invoke when the token is available.
+ */
+- (void)getTokenForcingRefresh:(BOOL)forceRefresh withCallback:(FIRTokenCallback)callback;
+
+/**
+ * Exposed for use by the Google pod. Configures the default app without sending notifications to
+ * other SDKs. Otherwise, behaves exactly like +configure.
+ */
++ (void)configureWithoutSendingNotification;
+
+/**
+ * Expose the UID of the current user for Firestore.
+ */
+- (nullable NSString *)getUID;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Firebase/Core/Private/FIRBundleUtil.h b/Firebase/Core/Private/FIRBundleUtil.h
new file mode 100644
index 0000000..4bfef8d
--- /dev/null
+++ b/Firebase/Core/Private/FIRBundleUtil.h
@@ -0,0 +1,57 @@
+/*
+ * 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 <Foundation/Foundation.h>
+
+/**
+ * This class provides utilities for accessing resources in bundles.
+ */
+@interface FIRBundleUtil : NSObject
+
+/**
+ * Finds all relevant bundles, starting with [NSBundle mainBundle].
+ */
++ (NSArray *)relevantBundles;
+
+/**
+ * Reads the options dictionary from one of the provided bundles.
+ *
+ * @param resourceName The resource name, e.g. @"GoogleService-Info".
+ * @param fileType The file type (extension), e.g. @"plist".
+ * @param bundles The bundles to expect, in priority order. See also
+ * +[FIRBundleUtil relevantBundles].
+ */
++ (NSString *)optionsDictionaryPathWithResourceName:(NSString *)resourceName
+                                        andFileType:(NSString *)fileType
+                                          inBundles:(NSArray *)bundles;
+
+/**
+ * Finds URL schemes defined in all relevant bundles, starting with those from
+ * [NSBundle mainBundle].
+ */
++ (NSArray *)relevantURLSchemes;
+
+/**
+ * Finds bundle identifiers in all relevant bundles, starting with those from [NSBundle mainBundle].
+ */
++ (NSSet *)relevantBundleIdentifiers;
+
+/**
+ * Checks if the bundle identifier exists in the given bundles.
+ */
++ (BOOL)hasBundleIdentifier:(NSString *)bundleIdentifier inBundles:(NSArray *)bundles;
+
+@end
diff --git a/Firebase/Core/Private/FIRErrorCode.h b/Firebase/Core/Private/FIRErrorCode.h
new file mode 100644
index 0000000..01d3c56
--- /dev/null
+++ b/Firebase/Core/Private/FIRErrorCode.h
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ */
+
+/** Error codes in Firebase error domain. */
+typedef NS_ENUM(NSInteger, FIRErrorCode) {
+  /**
+   * Unknown error.
+   */
+  FIRErrorCodeUnknown = 0,
+  /**
+   * Loading data from the GoogleService-Info.plist file failed. This is a fatal error and should
+   * not be ignored. Further calls to the API will fail and/or possibly cause crashes.
+   */
+  FIRErrorCodeInvalidPlistFile = -100,
+
+  /**
+   * Validating the Google App ID format failed.
+   */
+  FIRErrorCodeInvalidAppID = -101,
+
+  /**
+   * Error code for failing to configure a specific service.
+   */
+  FIRErrorCodeAdMobFailed = -110,
+  FIRErrorCodeAppInviteFailed = -112,
+  FIRErrorCodeCloudMessagingFailed = -113,
+  FIRErrorCodeConfigFailed = -114,
+  FIRErrorCodeDatabaseFailed = -115,
+  FIRErrorCodeCrashReportingFailed = -118,
+  FIRErrorCodeDurableDeepLinkFailed = -119,
+  FIRErrorCodeAuthFailed = -120,
+  FIRErrorCodeInstanceIDFailed = -121,
+  FIRErrorCodeStorageFailed = -123,
+
+  /**
+   * Error codes returned by Dynamic Links
+   */
+  FIRErrorCodeDynamicLinksStrongMatchNotAvailable = -124,
+  FIRErrorCodeDynamicLinksManualRetrievalNotEnabled = -125,
+  FIRErrorCodeDynamicLinksPendingLinkOnlyAvailableAtFirstLaunch = -126,
+  FIRErrorCodeDynamicLinksPendingLinkRetrievalAlreadyRunning = -127,
+};
diff --git a/Firebase/Core/Private/FIRErrors.h b/Firebase/Core/Private/FIRErrors.h
new file mode 100644
index 0000000..9a03575
--- /dev/null
+++ b/Firebase/Core/Private/FIRErrors.h
@@ -0,0 +1,43 @@
+/*
+ * 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 <Foundation/Foundation.h>
+
+#include "FIRErrorCode.h"
+
+extern NSString *const kFirebaseErrorDomain;
+extern NSString *const kFirebaseAdMobErrorDomain;
+extern NSString *const kFirebaseAppInviteErrorDomain;
+extern NSString *const kFirebaseAuthErrorDomain;
+extern NSString *const kFirebaseCloudMessagingErrorDomain;
+extern NSString *const kFirebaseConfigErrorDomain;
+extern NSString *const kFirebaseCoreErrorDomain;
+extern NSString *const kFirebaseCrashReportingErrorDomain;
+extern NSString *const kFirebaseDatabaseErrorDomain;
+extern NSString *const kFirebaseDurableDeepLinkErrorDomain;
+extern NSString *const kFirebaseInstanceIDErrorDomain;
+extern NSString *const kFirebasePerfErrorDomain;
+extern NSString *const kFirebaseStorageErrorDomain;
+
+/**
+ * Factory for a NSError in the Firebase error domain.
+ *
+ * @param domain   Domain of Firebase error.
+ * @param code     Error code that NSError should have.
+ * @param userInfo User info that NSError should have.
+ * @return An NSError in the Firebase domain.
+ */
+extern NSError *FIRCreateError(NSString *domain, FIRErrorCode code, NSDictionary *userInfo);
diff --git a/Firebase/Core/Private/FIRLogger.h b/Firebase/Core/Private/FIRLogger.h
new file mode 100644
index 0000000..2206c0a
--- /dev/null
+++ b/Firebase/Core/Private/FIRLogger.h
@@ -0,0 +1,115 @@
+/*
+ * 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 <Foundation/Foundation.h>
+
+#import "FIRLoggerLevel.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * The Firebase services used in Firebase logger.
+ */
+typedef NSString *const FIRLoggerService;
+
+extern FIRLoggerService kFIRLoggerABTesting;
+extern FIRLoggerService kFIRLoggerAdMob;
+extern FIRLoggerService kFIRLoggerAnalytics;
+extern FIRLoggerService kFIRLoggerAuth;
+extern FIRLoggerService kFIRLoggerCore;
+extern FIRLoggerService kFIRLoggerCrash;
+extern FIRLoggerService kFIRLoggerDatabase;
+extern FIRLoggerService kFIRLoggerDynamicLinks;
+extern FIRLoggerService kFIRLoggerInstanceID;
+extern FIRLoggerService kFIRLoggerInvites;
+extern FIRLoggerService kFIRLoggerMessaging;
+extern FIRLoggerService kFIRLoggerPerf;
+extern FIRLoggerService kFIRLoggerRemoteConfig;
+extern FIRLoggerService kFIRLoggerStorage;
+
+/**
+ * Enables or disables Analytics debug mode.
+ * If set to YES, the logging level for Analytics will be set to FIRLoggerLevelDebug.
+ * Enabling the debug mode has no effect if the app is running from App Store.
+ * (required) analytics debug mode flag.
+ */
+void FIRSetAnalyticsDebugMode(BOOL analyticsDebugMode);
+
+/**
+ * Changes the default logging level of FIRLoggerLevelNotice to a user-specified level.
+ * The default level cannot be set above FIRLoggerLevelNotice if the app is running from App Store.
+ * (required) log level (one of the FIRLoggerLevel enum values).
+ */
+void FIRSetLoggerLevel(FIRLoggerLevel loggerLevel);
+
+/**
+ * Checks if the specified logger level is loggable given the current settings.
+ * (required) log level (one of the FIRLoggerLevel enum values).
+ * (required) whether or not this function is called from the Analytics component.
+ */
+BOOL FIRIsLoggableLevel(FIRLoggerLevel loggerLevel, BOOL analyticsComponent);
+
+/**
+ * Logs a message to the Xcode console and the device log. If running from AppStore, will
+ * not log any messages with a level higher than FIRLoggerLevelNotice to avoid log spamming.
+ * (required) log level (one of the FIRLoggerLevel enum values).
+ * (required) service name of type FIRLoggerService.
+ * (required) message code starting with "I-" which means iOS, followed by a capitalized
+ *            three-character service identifier and a six digit integer message ID that is unique
+ *            within the service.
+ *            An example of the message code is @"I-COR000001".
+ * (required) message string which can be a format string.
+ * (optional) variable arguments list obtained from calling va_start, used when message is a format
+ *            string.
+ */
+extern void FIRLogBasic(FIRLoggerLevel level,
+                        FIRLoggerService service,
+                        NSString *messageCode,
+                        NSString *message,
+// On 64-bit simulators, va_list is not a pointer, so cannot be marked nullable
+// See: http://stackoverflow.com/q/29095469
+#if __LP64__ && TARGET_IPHONE_SIMULATOR
+                        va_list args_ptr
+#else
+                        va_list _Nullable args_ptr
+#endif
+                        );
+
+/**
+ * The following functions accept the following parameters in order:
+ * (required) service name of type FIRLoggerService.
+ * (required) message code starting from "I-" which means iOS, followed by a capitalized
+ *            three-character service identifier and a six digit integer message ID that is unique
+ *            within the service.
+ *            An example of the message code is @"I-COR000001".
+ *            See go/firebase-log-proposal for details.
+ * (required) message string which can be a format string.
+ * (optional) the list of arguments to substitute into the format string.
+ * Example usage:
+ * FIRLogError(kFIRLoggerCore, @"I-COR000001", @"Configuration of %@ failed.", app.name);
+ */
+extern void FIRLogError(FIRLoggerService service, NSString *messageCode, NSString *message, ...)
+    NS_FORMAT_FUNCTION(3, 4);
+extern void FIRLogWarning(FIRLoggerService service, NSString *messageCode, NSString *message, ...)
+    NS_FORMAT_FUNCTION(3, 4);
+extern void FIRLogNotice(FIRLoggerService service, NSString *messageCode, NSString *message, ...)
+    NS_FORMAT_FUNCTION(3, 4);
+extern void FIRLogInfo(FIRLoggerService service, NSString *messageCode, NSString *message, ...)
+    NS_FORMAT_FUNCTION(3, 4);
+extern void FIRLogDebug(FIRLoggerService service, NSString *messageCode, NSString *message, ...)
+    NS_FORMAT_FUNCTION(3, 4);
+
+NS_ASSUME_NONNULL_END
diff --git a/Firebase/Core/Private/FIRMutableDictionary.h b/Firebase/Core/Private/FIRMutableDictionary.h
new file mode 100644
index 0000000..ebe2d33
--- /dev/null
+++ b/Firebase/Core/Private/FIRMutableDictionary.h
@@ -0,0 +1,46 @@
+/*
+ * 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 Foundation;
+
+/// A mutable dictionary that provides atomic accessor and mutators.
+@interface FIRMutableDictionary : NSObject
+
+/// Returns an object given a key in the dictionary or nil if not found.
+- (id)objectForKey:(id)key;
+
+/// Updates the object given its key or adds it to the dictionary if it is not in the dictionary.
+- (void)setObject:(id)object forKey:(id<NSCopying>)key;
+
+/// Removes the object given its session ID from the dictionary.
+- (void)removeObjectForKey:(id)key;
+
+/// Removes all objects.
+- (void)removeAllObjects;
+
+/// Returns the number of current objects in the dictionary.
+- (NSUInteger)count;
+
+/// Returns an object given a key in the dictionary or nil if not found.
+- (id)objectForKeyedSubscript:(id<NSCopying>)key;
+
+/// Updates the object given its key or adds it to the dictionary if it is not in the dictionary.
+- (void)setObject:(id)obj forKeyedSubscript:(id<NSCopying>)key;
+
+/// Returns the immutable dictionary.
+- (NSDictionary *)dictionary;
+
+@end
diff --git a/Firebase/Core/Private/FIRNetwork.h b/Firebase/Core/Private/FIRNetwork.h
new file mode 100644
index 0000000..aac0bca
--- /dev/null
+++ b/Firebase/Core/Private/FIRNetwork.h
@@ -0,0 +1,87 @@
+/*
+ * 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 Foundation;
+
+#import "FIRNetworkConstants.h"
+#import "FIRNetworkLoggerProtocol.h"
+#import "FIRNetworkURLSession.h"
+
+/// Delegate protocol for FIRNetwork events.
+@protocol FIRNetworkReachabilityDelegate
+
+/// Tells the delegate to handle events when the network reachability changes to connected or not
+/// connected.
+- (void)reachabilityDidChange;
+
+@end
+
+/// The Network component that provides network status and handles network requests and responses.
+/// This is not thread safe.
+///
+/// NOTE:
+/// User must add FIRAnalytics handleEventsForBackgroundURLSessionID:completionHandler to the
+/// AppDelegate application:handleEventsForBackgroundURLSession:completionHandler:
+@interface FIRNetwork : NSObject
+
+/// Indicates if network connectivity is available.
+@property(nonatomic, readonly, getter=isNetworkConnected) BOOL networkConnected;
+
+/// Indicates if there are any uploads in progress.
+@property(nonatomic, readonly, getter=hasUploadInProgress) BOOL uploadInProgress;
+
+/// An optional delegate that can be used in the event when network reachability changes.
+@property(nonatomic, weak) id<FIRNetworkReachabilityDelegate> reachabilityDelegate;
+
+/// An optional delegate that can be used to log messages, warnings or errors that occur in the
+/// network operations.
+@property(nonatomic, weak) id<FIRNetworkLoggerDelegate> loggerDelegate;
+
+/// Indicates whether the logger should display debug messages.
+@property(nonatomic, assign) BOOL isDebugModeEnabled;
+
+/// The time interval in seconds for the network request to timeout.
+@property(nonatomic, assign) NSTimeInterval timeoutInterval;
+
+/// Initializes with the default reachability host.
+- (instancetype)init;
+
+/// Initializes with a custom reachability host.
+- (instancetype)initWithReachabilityHost:(NSString *)reachabilityHost;
+
+/// Handles events when background session with the given ID has finished.
++ (void)handleEventsForBackgroundURLSessionID:(NSString *)sessionID
+                            completionHandler:(FIRNetworkSystemCompletionHandler)completionHandler;
+
+/// Compresses and sends a POST request with the provided data to the URL. The session will be
+/// background session if usingBackgroundSession is YES. Otherwise, the POST session is default
+/// session. Returns a session ID or nil if an error occurs.
+- (NSString *)postURL:(NSURL *)url
+                   payload:(NSData *)payload
+                     queue:(dispatch_queue_t)queue
+    usingBackgroundSession:(BOOL)usingBackgroundSession
+         completionHandler:(FIRNetworkCompletionHandler)handler;
+
+/// Sends a GET request with the provided data to the URL. The session will be background session
+/// if usingBackgroundSession is YES. Otherwise, the GET session is default session. Returns a
+/// session ID or nil if an error occurs.
+- (NSString *)getURL:(NSURL *)url
+                   headers:(NSDictionary *)headers
+                     queue:(dispatch_queue_t)queue
+    usingBackgroundSession:(BOOL)usingBackgroundSession
+         completionHandler:(FIRNetworkCompletionHandler)handler;
+
+@end
diff --git a/Firebase/Core/Private/FIRNetworkConstants.h b/Firebase/Core/Private/FIRNetworkConstants.h
new file mode 100644
index 0000000..5878088
--- /dev/null
+++ b/Firebase/Core/Private/FIRNetworkConstants.h
@@ -0,0 +1,75 @@
+/*
+ * 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 Foundation;
+
+/// Error codes in Firebase Network error domain.
+/// Note: these error codes should never change. It would make it harder to decode the errors if
+/// we inadvertently altered any of these codes in a future SDK version.
+typedef NS_ENUM(NSInteger, FIRNetworkErrorCode) {
+  /// Unknown error.
+  FIRNetworkErrorCodeUnknown = 0,
+  /// Error occurs when the request URL is invalid.
+  FIRErrorCodeNetworkInvalidURL = 1,
+  /// Error occurs when request cannot be constructed.
+  FIRErrorCodeNetworkRequestCreation = 2,
+  /// Error occurs when payload cannot be compressed.
+  FIRErrorCodeNetworkPayloadCompression = 3,
+  /// Error occurs when session task cannot be created.
+  FIRErrorCodeNetworkSessionTaskCreation = 4,
+  /// Error occurs when there is no response.
+  FIRErrorCodeNetworkInvalidResponse = 5
+};
+
+#pragma mark - Network constants
+
+/// The prefix of the ID of the background session.
+extern NSString *const kFIRNetworkBackgroundSessionConfigIDPrefix;
+
+/// The sub directory to store the files of data that is being uploaded in the background.
+extern NSString *const kFIRNetworkApplicationSupportSubdirectory;
+
+/// Name of the temporary directory that stores files for background uploading.
+extern NSString *const kFIRNetworkTempDirectoryName;
+
+/// The period when the temporary uploading file can stay.
+extern const NSTimeInterval kFIRNetworkTempFolderExpireTime;
+
+/// The default network request timeout interval.
+extern const NSTimeInterval kFIRNetworkTimeOutInterval;
+
+/// The host to check the reachability of the network.
+extern NSString *const kFIRNetworkReachabilityHost;
+
+/// The key to get the error context of the UserInfo.
+extern NSString *const kFIRNetworkErrorContext;
+
+#pragma mark - Network Status Code
+
+extern const int kFIRNetworkHTTPStatusOK;
+extern const int kFIRNetworkHTTPStatusNoContent;
+extern const int kFIRNetworkHTTPStatusCodeMultipleChoices;
+extern const int kFIRNetworkHTTPStatusCodeMovedPermanently;
+extern const int kFIRNetworkHTTPStatusCodeFound;
+extern const int kFIRNetworkHTTPStatusCodeNotModified;
+extern const int kFIRNetworkHTTPStatusCodeMovedTemporarily;
+extern const int kFIRNetworkHTTPStatusCodeNotFound;
+extern const int kFIRNetworkHTTPStatusCodeCannotAcceptTraffic;
+extern const int kFIRNetworkHTTPStatusCodeUnavailable;
+
+#pragma mark - Error Domain
+
+extern NSString *const kFIRNetworkErrorDomain;
diff --git a/Firebase/Core/Private/FIRNetworkLoggerProtocol.h b/Firebase/Core/Private/FIRNetworkLoggerProtocol.h
new file mode 100644
index 0000000..7b7d094
--- /dev/null
+++ b/Firebase/Core/Private/FIRNetworkLoggerProtocol.h
@@ -0,0 +1,50 @@
+/*
+ * 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 Foundation;
+
+#import "FIRNetworkMessageCode.h"
+#import "../FIRLoggerLevel.h"
+
+/// The log levels used by FIRNetworkLogger.
+typedef NS_ENUM(NSInteger, FIRNetworkLogLevel) {
+  kFIRNetworkLogLevelError = FIRLoggerLevelError,
+  kFIRNetworkLogLevelWarning = FIRLoggerLevelWarning,
+  kFIRNetworkLogLevelInfo = FIRLoggerLevelInfo,
+  kFIRNetworkLogLevelDebug = FIRLoggerLevelDebug,
+};
+
+@protocol FIRNetworkLoggerDelegate<NSObject>
+
+@required
+/// Tells the delegate to log a message with an array of contexts and the log level.
+- (void)firNetwork_logWithLevel:(FIRNetworkLogLevel)logLevel
+                    messageCode:(FIRNetworkMessageCode)messageCode
+                        message:(NSString *)message
+                       contexts:(NSArray *)contexts;
+
+/// Tells the delegate to log a message with a context and the log level.
+- (void)firNetwork_logWithLevel:(FIRNetworkLogLevel)logLevel
+                    messageCode:(FIRNetworkMessageCode)messageCode
+                        message:(NSString *)message
+                        context:(id)context;
+
+/// Tells the delegate to log a message with the log level.
+- (void)firNetwork_logWithLevel:(FIRNetworkLogLevel)logLevel
+                    messageCode:(FIRNetworkMessageCode)messageCode
+                        message:(NSString *)message;
+
+@end
diff --git a/Firebase/Core/Private/FIRNetworkMessageCode.h b/Firebase/Core/Private/FIRNetworkMessageCode.h
new file mode 100644
index 0000000..30f562f
--- /dev/null
+++ b/Firebase/Core/Private/FIRNetworkMessageCode.h
@@ -0,0 +1,52 @@
+/*
+ * 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.
+ */
+
+// Make sure these codes do not overlap with any contained in the FIRAMessageCode enum.
+typedef NS_ENUM(NSInteger, FIRNetworkMessageCode) {
+  // FIRNetwork.m
+  kFIRNetworkMessageCodeNetwork000 = 900000,  // I-NET900000
+  kFIRNetworkMessageCodeNetwork001 = 900001,  // I-NET900001
+  kFIRNetworkMessageCodeNetwork002 = 900002,  // I-NET900002
+  kFIRNetworkMessageCodeNetwork003 = 900003,  // I-NET900003
+  // FIRNetworkURLSession.m
+  kFIRNetworkMessageCodeURLSession000 = 901000,  // I-NET901000
+  kFIRNetworkMessageCodeURLSession001 = 901001,  // I-NET901001
+  kFIRNetworkMessageCodeURLSession002 = 901002,  // I-NET901002
+  kFIRNetworkMessageCodeURLSession003 = 901003,  // I-NET901003
+  kFIRNetworkMessageCodeURLSession004 = 901004,  // I-NET901004
+  kFIRNetworkMessageCodeURLSession005 = 901005,  // I-NET901005
+  kFIRNetworkMessageCodeURLSession006 = 901006,  // I-NET901006
+  kFIRNetworkMessageCodeURLSession007 = 901007,  // I-NET901007
+  kFIRNetworkMessageCodeURLSession008 = 901008,  // I-NET901008
+  kFIRNetworkMessageCodeURLSession009 = 901009,  // I-NET901009
+  kFIRNetworkMessageCodeURLSession010 = 901010,  // I-NET901010
+  kFIRNetworkMessageCodeURLSession011 = 901011,  // I-NET901011
+  kFIRNetworkMessageCodeURLSession012 = 901012,  // I-NET901012
+  kFIRNetworkMessageCodeURLSession013 = 901013,  // I-NET901013
+  kFIRNetworkMessageCodeURLSession014 = 901014,  // I-NET901014
+  kFIRNetworkMessageCodeURLSession015 = 901015,  // I-NET901015
+  kFIRNetworkMessageCodeURLSession016 = 901016,  // I-NET901016
+  kFIRNetworkMessageCodeURLSession017 = 901017,  // I-NET901017
+  kFIRNetworkMessageCodeURLSession018 = 901018,  // I-NET901018
+  // FIRReachabilityChecker.m
+  kFIRNetworkMessageCodeReachabilityChecker000 = 902000,  // I-NET902000
+  kFIRNetworkMessageCodeReachabilityChecker001 = 902001,  // I-NET902001
+  kFIRNetworkMessageCodeReachabilityChecker002 = 902002,  // I-NET902002
+  kFIRNetworkMessageCodeReachabilityChecker003 = 902003,  // I-NET902003
+  kFIRNetworkMessageCodeReachabilityChecker004 = 902004,  // I-NET902004
+  kFIRNetworkMessageCodeReachabilityChecker005 = 902005,  // I-NET902005
+  kFIRNetworkMessageCodeReachabilityChecker006 = 902006,  // I-NET902006
+};
diff --git a/Firebase/Core/Private/FIRNetworkURLSession.h b/Firebase/Core/Private/FIRNetworkURLSession.h
new file mode 100644
index 0000000..d146de2
--- /dev/null
+++ b/Firebase/Core/Private/FIRNetworkURLSession.h
@@ -0,0 +1,57 @@
+/*
+ * 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 Foundation;
+
+#import "FIRNetworkLoggerProtocol.h"
+
+typedef void (^FIRNetworkCompletionHandler)(NSHTTPURLResponse *response, NSData *data,
+                                            NSError *error);
+typedef void (^FIRNetworkURLSessionCompletionHandler)(NSHTTPURLResponse *response, NSData *data,
+                                                      NSString *sessionID, NSError *error);
+typedef void (^FIRNetworkSystemCompletionHandler)(void);
+
+/// The protocol that uses NSURLSession for iOS >= 7.0 to handle requests and responses.
+@interface FIRNetworkURLSession
+    : NSObject<NSURLSessionDelegate, NSURLSessionTaskDelegate, NSURLSessionDownloadDelegate>
+
+/// Indicates whether the background network is enabled. Default value is NO.
+@property(nonatomic, getter=isBackgroundNetworkEnabled) BOOL backgroundNetworkEnabled;
+
+/// The logger delegate to log message, errors or warnings that occur during the network operations.
+@property(nonatomic, weak) id<FIRNetworkLoggerDelegate> loggerDelegate;
+
+/// Calls the system provided completion handler after the background session is finished.
++ (void)handleEventsForBackgroundURLSessionID:(NSString *)sessionID
+                            completionHandler:(FIRNetworkSystemCompletionHandler)completionHandler;
+
+/// Initializes with logger delegate.
+- (instancetype)initWithNetworkLoggerDelegate:(id<FIRNetworkLoggerDelegate>)networkLoggerDelegate
+    NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+/// Sends an asynchronous POST request and calls the provided completion handler when the request
+/// completes or when errors occur, and returns an ID of the session/connection.
+- (NSString *)sessionIDFromAsyncPOSTRequest:(NSURLRequest *)request
+                          completionHandler:(FIRNetworkURLSessionCompletionHandler)handler;
+
+/// Sends an asynchronous GET request and calls the provided completion handler when the request
+/// completes or when errors occur, and returns an ID of the session.
+- (NSString *)sessionIDFromAsyncGETRequest:(NSURLRequest *)request
+                         completionHandler:(FIRNetworkURLSessionCompletionHandler)handler;
+
+@end
diff --git a/Firebase/Core/Private/FIROptionsInternal.h b/Firebase/Core/Private/FIROptionsInternal.h
new file mode 100644
index 0000000..2b30248
--- /dev/null
+++ b/Firebase/Core/Private/FIROptionsInternal.h
@@ -0,0 +1,108 @@
+/*
+ * 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 "../FIROptions.h"
+
+/**
+ * Keys for the strings in the plist file.
+ */
+extern NSString *const kFIRAPIKey;
+extern NSString *const kFIRTrackingID;
+extern NSString *const kFIRGoogleAppID;
+extern NSString *const kFIRClientID;
+extern NSString *const kFIRGCMSenderID;
+extern NSString *const kFIRAndroidClientID;
+extern NSString *const kFIRDatabaseURL;
+extern NSString *const kFIRStorageBucket;
+extern NSString *const kFIRBundleID;
+extern NSString *const kFIRProjectID;
+
+/**
+ * Keys for the plist file name
+ */
+extern NSString *const kServiceInfoFileName;
+
+extern NSString *const kServiceInfoFileType;
+
+/**
+ * This header file exposes the initialization of FIROptions to internal use.
+ */
+@interface FIROptions ()
+
+/**
+ * resetDefaultOptions and initInternalWithOptionsDictionary: are exposed only for unit tests.
+ */
++ (void)resetDefaultOptions;
+
+/**
+ * Initializes the options with dictionary. The above strings are the keys of the dictionary.
+ * This is the designated initializer.
+ */
+- (instancetype)initInternalWithOptionsDictionary:(NSDictionary *)serviceInfoDictionary;
+
+/**
+ * defaultOptions and defaultOptionsDictionary are exposed in order to be used in FIRApp and
+ * other first party services.
+ */
++ (FIROptions *)defaultOptions;
+
++ (NSDictionary *)defaultOptionsDictionary;
+
+/**
+ * Whether or not Analytics Collection was enabled. Analytics Collection is enabled unless
+ * explicitly disabled in GoogleService-Info.plist.
+ */
+@property(nonatomic, readonly) BOOL isAnalyticsCollectionEnabled;
+
+/**
+ * Whether or not Analytics Collection was completely disabled. If YES, then
+ * isAnalyticsCollectionEnabled will be NO.
+ */
+@property(nonatomic, readonly) BOOL isAnalyticsCollectionDeactivated;
+
+/**
+ * The version ID of the client library, e.g. @"1100000".
+ */
+@property(nonatomic, readonly, copy) NSString *libraryVersionID;
+
+/**
+ * The flag indicating whether this object was constructed with the values in the default plist
+ * file.
+ */
+@property(nonatomic) BOOL usingOptionsFromDefaultPlist;
+
+/**
+ * Whether or not Measurement was enabled. Measurement is enabled unless explicitly disabled in
+ * GoogleService-Info.plist.
+ */
+@property(nonatomic, readonly) BOOL isMeasurementEnabled;
+
+/**
+ * Whether or not Analytics was enabled in the developer console.
+ */
+@property(nonatomic, readonly) BOOL isAnalyticsEnabled;
+
+/**
+ * Whether or not SignIn was enabled in the developer console.
+ */
+@property(nonatomic, readonly) BOOL isSignInEnabled;
+
+/**
+ * Whether or not editing is locked. This should occur after FIROptions has been set on a FIRApp.
+ */
+@property(nonatomic, getter=isEditingLocked) BOOL editingLocked;
+
+@end
diff --git a/Firebase/Core/Private/FIRReachabilityChecker+Internal.h b/Firebase/Core/Private/FIRReachabilityChecker+Internal.h
new file mode 100644
index 0000000..f82d103
--- /dev/null
+++ b/Firebase/Core/Private/FIRReachabilityChecker+Internal.h
@@ -0,0 +1,47 @@
+/*
+ * 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 "FIRReachabilityChecker.h"
+
+typedef SCNetworkReachabilityRef (*FIRReachabilityCreateWithNameFn)(CFAllocatorRef allocator,
+                                                                    const char *host);
+
+typedef Boolean (*FIRReachabilitySetCallbackFn)(SCNetworkReachabilityRef target,
+                                                SCNetworkReachabilityCallBack callback,
+                                                SCNetworkReachabilityContext *context);
+typedef Boolean (*FIRReachabilityScheduleWithRunLoopFn)(SCNetworkReachabilityRef target,
+                                                        CFRunLoopRef runLoop,
+                                                        CFStringRef runLoopMode);
+typedef Boolean (*FIRReachabilityUnscheduleFromRunLoopFn)(SCNetworkReachabilityRef target,
+                                                          CFRunLoopRef runLoop,
+                                                          CFStringRef runLoopMode);
+
+typedef void (*FIRReachabilityReleaseFn)(CFTypeRef cf);
+
+struct FIRReachabilityApi {
+  FIRReachabilityCreateWithNameFn createWithNameFn;
+  FIRReachabilitySetCallbackFn setCallbackFn;
+  FIRReachabilityScheduleWithRunLoopFn scheduleWithRunLoopFn;
+  FIRReachabilityUnscheduleFromRunLoopFn unscheduleFromRunLoopFn;
+  FIRReachabilityReleaseFn releaseFn;
+};
+
+@interface FIRReachabilityChecker (Internal)
+
+- (const struct FIRReachabilityApi *)reachabilityApi;
+- (void)setReachabilityApi:(const struct FIRReachabilityApi *)reachabilityApi;
+
+@end
diff --git a/Firebase/Core/Private/FIRReachabilityChecker.h b/Firebase/Core/Private/FIRReachabilityChecker.h
new file mode 100644
index 0000000..105cd3d
--- /dev/null
+++ b/Firebase/Core/Private/FIRReachabilityChecker.h
@@ -0,0 +1,83 @@
+/*
+ * 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 Foundation;
+@import SystemConfiguration;
+
+/// Reachability Status
+typedef enum {
+  kFIRReachabilityUnknown,  ///< Have not yet checked or been notified whether host is reachable.
+  kFIRReachabilityNotReachable,  ///< Host is not reachable.
+  kFIRReachabilityViaWifi,  ///< Host is reachable via Wifi.
+  kFIRReachabilityViaCellular,  ///< Host is reachable via cellular.
+} FIRReachabilityStatus;
+
+const NSString *FIRReachabilityStatusString(FIRReachabilityStatus status);
+
+@class FIRReachabilityChecker;
+@protocol FIRNetworkLoggerDelegate;
+
+/// Google Analytics iOS Reachability Checker.
+@protocol FIRReachabilityDelegate
+@required
+/// Called when network status has changed.
+- (void)reachability:(FIRReachabilityChecker *)reachability
+       statusChanged:(FIRReachabilityStatus)status;
+@end
+
+/// Google Analytics iOS Network Status Checker.
+@interface FIRReachabilityChecker : NSObject
+
+/// The last known reachability status, or FIRReachabilityStatusUnknown if the
+/// checker is not active.
+@property(nonatomic, readonly) FIRReachabilityStatus reachabilityStatus;
+/// The host to which reachability status is to be checked.
+@property(nonatomic, copy, readonly) NSString *host;
+/// The delegate to be notified of reachability status changes.
+@property(nonatomic, weak) id<FIRReachabilityDelegate> reachabilityDelegate;
+/// The delegate to be notified to log messages.
+@property(nonatomic, weak) id<FIRNetworkLoggerDelegate> loggerDelegate;
+/// `YES` if the reachability checker is active, `NO` otherwise.
+@property(nonatomic, readonly) BOOL isActive;
+
+/// Initialize the reachability checker. Note that you must call start to begin checking for and
+/// receiving notifications about network status changes.
+///
+/// @param reachabilityDelegate The delegate to be notified when reachability status to host
+/// changes.
+///
+/// @param loggerDelegate The delegate to send log messages to.
+///
+/// @param host The name of the host.
+///
+- (instancetype)initWithReachabilityDelegate:(id<FIRReachabilityDelegate>)reachabilityDelegate
+                              loggerDelegate:(id<FIRNetworkLoggerDelegate>)loggerDelegate
+                                    withHost:(NSString *)host;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+/// Start checking for reachability to the specified host. This has no effect if the status
+/// checker is already checking for connectivity.
+///
+/// @return `YES` if initiating status checking was successful or the status checking has already
+/// been initiated, `NO` otherwise.
+- (BOOL)start;
+
+/// Stop checking for reachability to the specified host. This has no effect if the status
+/// checker is not checking for connectivity.
+- (void)stop;
+
+@end
diff --git a/Firebase/Core/Private/FIRURLSchemeUtil.h b/Firebase/Core/Private/FIRURLSchemeUtil.h
new file mode 100644
index 0000000..d4fa961
--- /dev/null
+++ b/Firebase/Core/Private/FIRURLSchemeUtil.h
@@ -0,0 +1,25 @@
+/*
+ * 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 <Foundation/Foundation.h>
+
+/**
+ * Checks whether the URL schemes declared for Google SignIn are valid.
+ *
+ * @param urlSchemes The URL schemes to validate.
+ * @return YES if the schemes are valid; NO otherwise.
+ */
+extern BOOL fir_areURLSchemesValidForGoogleSignIn(NSArray *urlSchemes);