BOOL FIRMessagingIsProductionApp()

in FirebaseMessaging/Sources/FIRMessagingUtilities.m [294:413]
97 lines of code
24 McCabe index (conditional complexity)

BOOL FIRMessagingIsProductionApp(void) {
  const BOOL defaultAppTypeProd = YES;

  NSError *error = nil;
  if ([GULAppEnvironmentUtil isSimulator]) {
    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstanceID014,
                            @"Running InstanceID on a simulator doesn't have APNS. "
                            @"Use prod profile by default.");
    return defaultAppTypeProd;
  }

  if ([GULAppEnvironmentUtil isFromAppStore]) {
    // Apps distributed via AppStore or TestFlight use the Production APNS certificates.
    return defaultAppTypeProd;
  }
#if TARGET_OS_OSX || TARGET_OS_MACCATALYST
  NSString *path = [[[[NSBundle mainBundle] resourcePath] stringByDeletingLastPathComponent]
      stringByAppendingPathComponent:@"embedded.provisionprofile"];
#elif TARGET_OS_IOS || TARGET_OS_TV || TARGET_OS_WATCH
  NSString *path = [[[NSBundle mainBundle] bundlePath]
      stringByAppendingPathComponent:@"embedded.mobileprovision"];
#endif

  if ([GULAppEnvironmentUtil isAppStoreReceiptSandbox] && !path.length) {
    // Distributed via TestFlight
    return defaultAppTypeProd;
  }

  NSMutableData *profileData = [NSMutableData dataWithContentsOfFile:path options:0 error:&error];

  if (!profileData.length || error) {
    NSString *errorString =
        [NSString stringWithFormat:@"Error while reading embedded mobileprovision %@", error];
    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstanceID014, @"%@", errorString);
    return defaultAppTypeProd;
  }

  // The "embedded.mobileprovision" sometimes contains characters with value 0, which signals the
  // end of a c-string and halts the ASCII parser, or with value > 127, which violates strict 7-bit
  // ASCII. Replace any 0s or invalid characters in the input.
  uint8_t *profileBytes = (uint8_t *)profileData.bytes;
  for (int i = 0; i < profileData.length; i++) {
    uint8_t currentByte = profileBytes[i];
    if (!currentByte || currentByte > 127) {
      profileBytes[i] = '.';
    }
  }

  NSString *embeddedProfile = [[NSString alloc] initWithBytesNoCopy:profileBytes
                                                             length:profileData.length
                                                           encoding:NSASCIIStringEncoding
                                                       freeWhenDone:NO];

  if (error || !embeddedProfile.length) {
    NSString *errorString =
        [NSString stringWithFormat:@"Error while reading embedded mobileprovision %@", error];
    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstanceID014, @"%@", errorString);
    return defaultAppTypeProd;
  }

  NSScanner *scanner = [NSScanner scannerWithString:embeddedProfile];
  NSString *plistContents;
  if ([scanner scanUpToString:@"<plist" intoString:nil]) {
    if ([scanner scanUpToString:@"</plist>" intoString:&plistContents]) {
      plistContents = [plistContents stringByAppendingString:@"</plist>"];
    }
  }

  if (!plistContents.length) {
    return defaultAppTypeProd;
  }

  NSData *data = [plistContents dataUsingEncoding:NSUTF8StringEncoding];
  if (!data.length) {
    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstanceID014,
                            @"Couldn't read plist fetched from embedded mobileprovision");
    return defaultAppTypeProd;
  }

  NSError *plistMapError;
  id plistData = [NSPropertyListSerialization propertyListWithData:data
                                                           options:NSPropertyListImmutable
                                                            format:nil
                                                             error:&plistMapError];
  if (plistMapError || ![plistData isKindOfClass:[NSDictionary class]]) {
    NSString *errorString =
        [NSString stringWithFormat:@"Error while converting assumed plist to dict %@",
                                   plistMapError.localizedDescription];
    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstanceID014, @"%@", errorString);
    return defaultAppTypeProd;
  }
  NSDictionary *plistMap = (NSDictionary *)plistData;

  if ([plistMap valueForKeyPath:@"ProvisionedDevices"]) {
    FIRMessagingLoggerDebug(kFIRMessagingMessageCodeInstanceID012,
                            @"Provisioning profile has specifically provisioned devices, "
                            @"most likely a Dev profile.");
  }

  NSString *apsEnvironment = [plistMap valueForKeyPath:kEntitlementsAPSEnvironmentKey];
  NSString *debugString __unused =
      [NSString stringWithFormat:@"APNS Environment in profile: %@", apsEnvironment];
  FIRMessagingLoggerDebug(kFIRMessagingMessageCodeInstanceID013, @"%@", debugString);

  // No aps-environment in the profile.
  if (!apsEnvironment.length) {
    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstanceID014,
                            @"No aps-environment set. If testing on a device APNS is not "
                            @"correctly configured. Please recheck your provisioning "
                            @"profiles. If testing on a simulator this is fine since APNS "
                            @"doesn't work on the simulator.");
    return defaultAppTypeProd;
  }

  if ([apsEnvironment isEqualToString:kAPSEnvironmentDevelopmentValue]) {
    return NO;
  }

  return defaultAppTypeProd;
}