webrtc/talk/examples/objc/AppRTCDemo/ARDSignalingMessage.m

/*
 * libjingle
 * Copyright 2014, Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#import "ARDSignalingMessage.h"

#import "ARDUtilities.h"
#import "RTCICECandidate+JSON.h"
#import "RTCSessionDescription+JSON.h"

static NSString const *kARDSignalingMessageTypeKey = @"type";

@implementation ARDSignalingMessage

@synthesize type = _type;

- (instancetype)initWithType:(ARDSignalingMessageType)type {
  if (self = [super init]) {
    _type = type;
  }
  return self;
}

- (NSString *)description {
  return [[NSString alloc] initWithData:[self JSONData]
                               encoding:NSUTF8StringEncoding];
}

+ (ARDSignalingMessage *)messageFromJSONString:(NSString *)jsonString {
  NSDictionary *values = [NSDictionary dictionaryWithJSONString:jsonString];
  if (!values) {
    NSLog(@"Error parsing signaling message JSON.");
    return nil;
  }

  NSString *typeString = values[kARDSignalingMessageTypeKey];
  ARDSignalingMessage *message = nil;
  if ([typeString isEqualToString:@"candidate"]) {
    RTCICECandidate *candidate =
        [RTCICECandidate candidateFromJSONDictionary:values];
    message = [[ARDICECandidateMessage alloc] initWithCandidate:candidate];
  } else if ([typeString isEqualToString:@"offer"] ||
             [typeString isEqualToString:@"answer"]) {
    RTCSessionDescription *description =
        [RTCSessionDescription descriptionFromJSONDictionary:values];
    message =
        [[ARDSessionDescriptionMessage alloc] initWithDescription:description];
  } else if ([typeString isEqualToString:@"bye"]) {
    message = [[ARDByeMessage alloc] init];
  } else {
    NSLog(@"Unexpected type: %@", typeString);
  }
  return message;
}

- (NSData *)JSONData {
  return nil;
}

@end

@implementation ARDICECandidateMessage

@synthesize candidate = _candidate;

- (instancetype)initWithCandidate:(RTCICECandidate *)candidate {
  if (self = [super initWithType:kARDSignalingMessageTypeCandidate]) {
    _candidate = candidate;
  }
  return self;
}

- (NSData *)JSONData {
  return [_candidate JSONData];
}

@end

@implementation ARDSessionDescriptionMessage

@synthesize sessionDescription = _sessionDescription;

- (instancetype)initWithDescription:(RTCSessionDescription *)description {
  ARDSignalingMessageType type = kARDSignalingMessageTypeOffer;
  NSString *typeString = description.type;
  if ([typeString isEqualToString:@"offer"]) {
    type = kARDSignalingMessageTypeOffer;
  } else if ([typeString isEqualToString:@"answer"]) {
    type = kARDSignalingMessageTypeAnswer;
  } else {
    NSAssert(NO, @"Unexpected type: %@", typeString);
  }
  if (self = [super initWithType:type]) {
    _sessionDescription = description;
  }
  return self;
}

- (NSData *)JSONData {
  return [_sessionDescription JSONData];
}

@end

@implementation ARDByeMessage

- (instancetype)init {
  return [super initWithType:kARDSignalingMessageTypeBye];
}

- (NSData *)JSONData {
  NSDictionary *message = @{
    @"type": @"bye"
  };
  return [NSJSONSerialization dataWithJSONObject:message
                                         options:NSJSONWritingPrettyPrinted
                                           error:NULL];
}

@end