Update ice server provider response format in iOS AppRTCMobile

webrtc/examples/objc/AppRTCMobile/ARDTURNClient.m

+/*
+ *  Copyright 2014 The WebRTC Project Authors. All rights reserved.

[magjed_webrtc, 2017/01/11 14:40:12]

Can you try reuploading with 'git cl upload --similarity=10' to see if you can
get the diff for this file working?

+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import "ARDTURNClient+Internal.h"
+
+#import "ARDUtilities.h"
+#import "RTCIceServer+JSON.h"
+
+// TODO(tkchin): move this to a configuration object.
+static NSString *kTURNRefererURLString = @"https://appr.tc";
+static NSString *kARDTURNClientErrorDomain = @"ARDTURNClient";
+static NSInteger kARDTURNClientErrorBadResponse = -1;
+
+@implementation ARDTURNClient {
+  NSURL *_url;
+}
+
+- (instancetype)initWithURL:(NSURL *)url {
+  NSParameterAssert([url absoluteString].length);
+  if (self = [super init]) {
+    _url = url;
+  }
+  return self;
+}
+
+- (void)requestServersWithCompletionHandler:
+    (void (^)(NSArray *turnServers, NSError *error))completionHandler {
+
+  NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:_url];
+  [NSURLConnection sendAsyncRequest:request
+                  completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
+      if (error) {
+        completionHandler(nil, error);
+        return;
+      }
+      NSDictionary *responseDict = [NSDictionary dictionaryWithJSONData:data];
+      NSString *iceServerUrl = responseDict[@"ice_server_url"];
+      [self makeTurnServerRequestToURL:[NSURL URLWithString:iceServerUrl]
+                 WithCompletionHandler:completionHandler];
+    }];
+}
+
+#pragma mark - Private
+
+- (void)makeTurnServerRequestToURL:(NSURL *)url
+             WithCompletionHandler:(void (^)(NSArray *turnServers,
+                                             NSError *error))completionHandler {
+  NSMutableURLRequest *iceServerRequest = [NSMutableURLRequest requestWithURL:url];
+  iceServerRequest.HTTPMethod = @"POST";
+  [iceServerRequest addValue:kTURNRefererURLString forHTTPHeaderField:@"referer"];
+  [NSURLConnection sendAsyncRequest:iceServerRequest
+                  completionHandler:^(NSURLResponse *response,
+                                      NSData *data,
+                                      NSError *error) {
+      if (error) {
+        completionHandler(nil, error);
+        return;
+      }
+      NSDictionary *turnResponseDict = [NSDictionary dictionaryWithJSONData:data];
+      NSMutableArray *turnServers = [NSMutableArray array];
+      [turnResponseDict[@"iceServers"] enumerateObjectsUsingBlock:
+                         ^(NSDictionary *obj, NSUInteger idx, BOOL *stop){
+          [turnServers addObject:[RTCIceServer serverFromJSONDictionary:obj]];
+        }];
+      if (!turnServers) {
+        NSError *responseError =
+          [[NSError alloc] initWithDomain:kARDTURNClientErrorDomain
+                                     code:kARDTURNClientErrorBadResponse
+                                 userInfo:@{
+            NSLocalizedDescriptionKey: @"Bad TURN response.",
+            }];
+        completionHandler(nil, responseError);
+        return;
+      }
+      completionHandler(turnServers, nil);
+    }];
+}
+
+@end