Add get Auth domain RPC (#214)

* Add get Auth domain RPC

* Fixes indentation

* Addresses comments

* ran tests on Example/Firebase.xcodeproj

9 files changed, 250 insertions, 26 deletions

diff --git a/Firebase/Auth/Source/RPCs/FIRAuthBackend.h b/Firebase/Auth/Source/RPCs/FIRAuthBackend.h
index b560644..65f93ce 100644
--- a/Firebase/Auth/Source/RPCs/FIRAuthBackend.h
+++ b/Firebase/Auth/Source/RPCs/FIRAuthBackend.h
@@ -21,6 +21,8 @@
 @class FIRCreateAuthURIResponse;
 @class FIRGetAccountInfoRequest;
 @class FIRGetAccountInfoResponse;
+@class FIRGetProjectConfigRequest;
+@class FIRGetProjectConfigResponse;
 @class FIRGetOOBConfirmationCodeRequest;
 @class FIRGetOOBConfirmationCodeResponse;
 @class FIRResetPasswordRequest;
@@ -79,6 +81,16 @@ typedef void (^FIRCreateAuthURIResponseCallback)
 typedef void (^FIRGetAccountInfoResponseCallback)
     (FIRGetAccountInfoResponse *_Nullable response, NSError *_Nullable error);
 
+/** @typedef FIRGetProjectConfigResponseCallback
+    @brief The type of block used to return the result of a call to the getProjectInfo
+        endpoint.
+    @param response The received response, if any.
+    @param error The error which occurred, if any.
+    @remarks One of response or error will be non-nil.
+ */
+typedef void (^FIRGetProjectConfigResponseCallback)
+    (FIRGetProjectConfigResponse *_Nullable response, NSError *_Nullable error);
+
 /** @typedef FIRSetAccountInfoResponseCallback
     @brief The type of block used to return the result of a call to the setAccountInfo
         endpoint.
@@ -233,6 +245,15 @@ typedef void (^FIRVerifyClientResponseCallback)
 + (void)getAccountInfo:(FIRGetAccountInfoRequest *)request
               callback:(FIRGetAccountInfoResponseCallback)callback;
 
+/** @fn getProjectConfig:callback:
+    @brief Calls the getProjectConfig endpoint, which returns configuration information for a given
+        project.
+    @param request An object wrapping the backend get request.
+    @param callback The callback.
+ */
++ (void)getProjectConfig:(FIRGetProjectConfigRequest *)request
+                callback:(FIRGetProjectConfigResponseCallback)callback;
+
 /** @fn setAccountInfo:callback:
     @brief Calls the setAccountInfo endpoint, which is responsible for setting account info for a
         user, for example, to sign up a new user with email and password.
@@ -389,6 +410,15 @@ typedef void (^FIRVerifyClientResponseCallback)
 - (void)getAccountInfo:(FIRGetAccountInfoRequest *)request
               callback:(FIRGetAccountInfoResponseCallback)callback;
 
+/** @fn getProjectConfig:callback:
+    @brief Calls the getProjectInfo endpoint, which returns configuration information for a given
+        project.
+    @param request The request parameters.
+    @param callback The callback.
+ */
+- (void)getProjectConfig:(FIRGetProjectConfigRequest *)request
+                callback:(FIRGetProjectConfigResponseCallback)callback;
+
 /** @fn setAccountInfo:callback:
     @brief Calls the setAccountInfo endpoint, which is responsible for setting account info for a
         user, for example, to sign up a new user with email and password.
diff --git a/Firebase/Auth/Source/RPCs/FIRAuthBackend.m b/Firebase/Auth/Source/RPCs/FIRAuthBackend.m
index 0964d3f..0387a1a 100644
--- a/Firebase/Auth/Source/RPCs/FIRAuthBackend.m
+++ b/Firebase/Auth/Source/RPCs/FIRAuthBackend.m
@@ -31,6 +31,8 @@
 #import "FIRGetAccountInfoResponse.h"
 #import "FIRGetOOBConfirmationCodeRequest.h"
 #import "FIRGetOOBConfirmationCodeResponse.h"
+#import "FIRGetProjectConfigRequest.h"
+#import "FIRGetProjectConfigResponse.h"
 #import "FIRResetPasswordRequest.h"
 #import "FIRResetPasswordResponse.h"
 #import "FIRSendVerificationCodeRequest.h"
@@ -398,6 +400,11 @@ static id<FIRAuthBackendImplementation> gBackendImplementation;
   [[self implementation] getAccountInfo:request callback:callback];
 }
 
++ (void)getProjectConfig:(FIRGetProjectConfigRequest *)request
+                callback:(FIRGetProjectConfigResponseCallback)callback {
+  [[self implementation] getProjectConfig:request callback:callback];
+}
+
 + (void)setAccountInfo:(FIRSetAccountInfoRequest *)request
               callback:(FIRSetAccountInfoResponseCallback)callback {
   [[self implementation] setAccountInfo:request callback:callback];
@@ -544,6 +551,18 @@ static id<FIRAuthBackendImplementation> gBackendImplementation;
   }];
 }
 
+- (void)getProjectConfig:(FIRGetProjectConfigRequest *)request
+                callback:(FIRGetProjectConfigResponseCallback)callback {
+  FIRGetProjectConfigResponse *response = [[FIRGetProjectConfigResponse alloc] init];
+  [self postWithRequest:request response:response callback:^(NSError *error) {
+    if (error) {
+      callback(nil, error);
+    } else {
+      callback(response, nil);
+    }
+  }];
+}
+
 - (void)setAccountInfo:(FIRSetAccountInfoRequest *)request
               callback:(FIRSetAccountInfoResponseCallback)callback {
   FIRSetAccountInfoResponse *response = [[FIRSetAccountInfoResponse alloc] init];
@@ -713,33 +732,36 @@ static id<FIRAuthBackendImplementation> gBackendImplementation;
                response:(id<FIRAuthRPCResponse>)response
                callback:(void (^)(NSError *error))callback {
   NSError *error;
-  id postBody = [request unencodedHTTPRequestBodyWithError:&error];
-  if (!postBody) {
-    callback([FIRAuthErrorUtils RPCRequestEncodingErrorWithUnderlyingError:error]);
-    return;
-  }
-  NSJSONWritingOptions JSONWritingOptions = 0;
-  #if DEBUG
-    JSONWritingOptions |= NSJSONWritingPrettyPrinted;
-  #endif
-
   NSData *bodyData;
-  if ([NSJSONSerialization isValidJSONObject:postBody]) {
-    bodyData = [NSJSONSerialization dataWithJSONObject:postBody
-                                               options:JSONWritingOptions
-                                                 error:&error];
+  if ([request containsPostBody]) {
+    id postBody = [request unencodedHTTPRequestBodyWithError:&error];
+    if (!postBody) {
+      callback([FIRAuthErrorUtils RPCRequestEncodingErrorWithUnderlyingError:error]);
+      return;
+    }
+
+    NSJSONWritingOptions JSONWritingOptions = 0;
+    #if DEBUG
+      JSONWritingOptions |= NSJSONWritingPrettyPrinted;
+    #endif
+
+    if ([NSJSONSerialization isValidJSONObject:postBody]) {
+      bodyData = [NSJSONSerialization dataWithJSONObject:postBody
+                                                 options:JSONWritingOptions
+                                                   error:&error];
+      if (!bodyData) {
+        // This is an untested case. This happens exclusively when there is an error in the framework
+        // implementation of dataWithJSONObject:options:error:. This shouldn't normally occur as
+        // isValidJSONObject: should return NO in any case we should encounter an error.
+        error = [FIRAuthErrorUtils JSONSerializationErrorWithUnderlyingError:error];
+      }
+    } else {
+      error = [FIRAuthErrorUtils JSONSerializationErrorForUnencodableType];
+    }
     if (!bodyData) {
-      // This is an untested case. This happens exclusively when there is an error in the framework
-      // implementation of dataWithJSONObject:options:error:. This shouldn't normally occur as
-      // isValidJSONObject: should return NO in any case we should encounter an error.
-      error = [FIRAuthErrorUtils JSONSerializationErrorWithUnderlyingError:error];
+      callback(error);
+      return;
     }
-  } else {
-    error = [FIRAuthErrorUtils JSONSerializationErrorForUnencodableType];
-  }
-  if (!bodyData) {
-    callback(error);
-    return;
   }
 
   [_RPCIssuer asyncPostToURLWithRequestConfiguration:[request requestConfiguration]
diff --git a/Firebase/Auth/Source/RPCs/FIRAuthRPCRequest.h b/Firebase/Auth/Source/RPCs/FIRAuthRPCRequest.h
index cde0bd8..9ca4f44 100644
--- a/Firebase/Auth/Source/RPCs/FIRAuthRPCRequest.h
+++ b/Firebase/Auth/Source/RPCs/FIRAuthRPCRequest.h
@@ -30,6 +30,15 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (NSURL *)requestURL;
 
+@optional
+
+/** @fn containsPostBody
+    @brief Returns whether the request contains a post body or not. Requests without a post body
+        are get requests.
+    @remarks The default implementation returns YES.
+ */
+- (BOOL)containsPostBody;
+
 /** @fn UnencodedHTTPRequestBodyWithError:
     @brief Creates unencoded HTTP body representing the request.
     @param error An out field for an error which occurred constructing the request.
@@ -37,8 +46,6 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (nullable id)unencodedHTTPRequestBodyWithError:(NSError *_Nullable *_Nullable)error;
 
-@optional
-
 /** @fn requestConfiguration
     @brief Obtains the request configurations if available.
     @return Returns the request configurations.
diff --git a/Firebase/Auth/Source/RPCs/FIRGetProjectConfigRequest.h b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigRequest.h
new file mode 100644
index 0000000..7c37e8d
--- /dev/null
+++ b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigRequest.h
@@ -0,0 +1,41 @@
+/*
+ * 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 "FIRIdentityToolkitRequest.h"
+
+#import "FIRAuthRPCRequest.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FIRGetProjectConfigRequest : FIRIdentityToolkitRequest<FIRAuthRPCRequest>
+
+/** @fn initWithEndpoint:requestConfiguration:
+    @brief Please use initWithRequestConfiguration:
+ */
+- (nullable instancetype)initWithEndpoint:(NSString *)endpoint
+                     requestConfiguration:(FIRAuthRequestConfiguration *)requestConfiguration
+                         NS_UNAVAILABLE;
+
+/** @fn initWithTemporaryProof:phoneNumberAPIKey
+    @brief Designated initializer.
+    @param requestConfiguration An object containing configurations to be added to the request.
+ */
+- (nullable instancetype)initWithRequestConfiguration:
+    (FIRAuthRequestConfiguration *)requestConfiguration NS_DESIGNATED_INITIALIZER;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Firebase/Auth/Source/RPCs/FIRGetProjectConfigRequest.m b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigRequest.m
new file mode 100644
index 0000000..8d92e9b
--- /dev/null
+++ b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigRequest.m
@@ -0,0 +1,42 @@
+/*
+ * 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 "FIRGetProjectConfigRequest.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** @var kGetProjectConfigEndPoint
+    @brief The "getProjectConfig" endpoint.
+ */
+static NSString *const kGetProjectConfigEndPoint = @"getProjectConfig";
+
+@implementation FIRGetProjectConfigRequest
+
+- (nullable instancetype)initWithRequestConfiguration:
+    (FIRAuthRequestConfiguration *)requestConfiguration {
+  NSString *APIKey = requestConfiguration.APIKey;
+  NSString *getProjectConfigURL =
+      [NSString stringWithFormat:@"%@?key=%@", kGetProjectConfigEndPoint, APIKey];
+  return [super initWithEndpoint:getProjectConfigURL requestConfiguration:requestConfiguration];
+}
+
+- (BOOL)containsPostBody {
+  return NO;
+}
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Firebase/Auth/Source/RPCs/FIRGetProjectConfigResponse.h b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigResponse.h
new file mode 100644
index 0000000..317ec81
--- /dev/null
+++ b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigResponse.h
@@ -0,0 +1,36 @@
+/*
+ * 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 "FIRAuthRPCResponse.h"
+
+/** @class FIRGetProjectConfigResponse
+    @brief Represents the response from the getProjectConfig endpoint.
+ */
+@interface FIRGetProjectConfigResponse : NSObject <FIRAuthRPCResponse>
+
+/** @property projectID
+    @brief The unique ID pertaining to the current project.
+ */
+@property(nonatomic, strong, readonly, nullable) NSString *projectID;
+
+/** @property authorizedDomains
+    @brief A list of domains whitelisted for the current project.
+ */
+@property(nonatomic, strong, readonly, nullable) NSArray *authorizedDomains;
+
+@end
diff --git a/Firebase/Auth/Source/RPCs/FIRGetProjectConfigResponse.m b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigResponse.m
new file mode 100644
index 0000000..259a4fb
--- /dev/null
+++ b/Firebase/Auth/Source/RPCs/FIRGetProjectConfigResponse.m
@@ -0,0 +1,38 @@
+/*
+ * 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 "FIRGetProjectConfigResponse.h"
+
+@implementation FIRGetProjectConfigResponse
+
+- (BOOL)setWithDictionary:(NSDictionary *)dictionary
+                    error:(NSError *_Nullable *_Nullable)error {
+  _projectID = [dictionary[@"projectId"] copy];
+  id authorizedDomains = dictionary[@"authorizedDomains"];
+  if ([authorizedDomains isKindOfClass:[NSString class]]) {
+    NSData *data = [authorizedDomains dataUsingEncoding:NSUTF8StringEncoding];
+    authorizedDomains = [NSJSONSerialization JSONObjectWithData:data
+                                                       options:NSJSONReadingMutableLeaves
+                                                         error:nil];
+  }
+  if ([authorizedDomains isKindOfClass:[NSArray class]]) {
+    _authorizedDomains = [[NSArray alloc] initWithArray:authorizedDomains
+                                              copyItems:YES];
+  }
+  return YES;
+}
+
+@end
diff --git a/Firebase/Auth/Source/RPCs/FIRIdentityToolkitRequest.m b/Firebase/Auth/Source/RPCs/FIRIdentityToolkitRequest.m
index c897066..a1ab482 100644
--- a/Firebase/Auth/Source/RPCs/FIRIdentityToolkitRequest.m
+++ b/Firebase/Auth/Source/RPCs/FIRIdentityToolkitRequest.m
@@ -43,6 +43,10 @@ static NSString *gAPIHost = @"www.googleapis.com";
   return self;
 }
 
+- (BOOL)containsPostBody {
+  return YES;
+}
+
 - (NSURL *)requestURL {
   NSString *URLString = [NSString stringWithFormat:kAPIURLFormat, gAPIHost, _endpoint, _APIKey];
   NSURL *URL = [NSURL URLWithString:URLString];
diff --git a/Firebase/Auth/Source/RPCs/FIRSecureTokenRequest.m b/Firebase/Auth/Source/RPCs/FIRSecureTokenRequest.m
index 9c39e1e..786ea6c 100644
--- a/Firebase/Auth/Source/RPCs/FIRSecureTokenRequest.m
+++ b/Firebase/Auth/Source/RPCs/FIRSecureTokenRequest.m
@@ -126,6 +126,10 @@ static NSString *gAPIHost = @"securetoken.googleapis.com";
   return URL;
 }
 
+- (BOOL)containsPostBody {
+  return YES;
+}
+
 - (nullable id)unencodedHTTPRequestBodyWithError:(NSError *_Nullable *_Nullable)error {
   NSMutableDictionary *postBody = [@{
     kGrantTypeKey : [[self class] grantTypeStringWithGrantType:_grantType]