/// <summary>
/// First step at server side
/// </summary>
/// <param name="clientFrame"></param>
/// <param name="serverName"></param>
/// <returns></returns>
public IFrame ServerNegotiate(HandshakeFrame clientFrame, string serverName)
{
var ourRequired = _registry.GetRequiredForHandshake();
var missingExtensionsThatTheClientRequire =
clientFrame.RequiredExtensions.Except(_registry.GetAllForHandshake(), new ExtensionNameComparer())
.ToList();
if (missingExtensionsThatTheClientRequire.Any())
{
return
(new ErrorFrame("Server to not support the following extensions: " +
string.Join(", ", missingExtensionsThatTheClientRequire)));
}
var missingExtensionsThatTheServerRequire =
ourRequired.Except(clientFrame.RequiredExtensions.Union(clientFrame.OptionalExtensions),
new ExtensionNameComparer()).ToList();
if (missingExtensionsThatTheServerRequire.Any())
{
return
(new ErrorFrame("Server requires the following extensions: " +
string.Join(", ", missingExtensionsThatTheServerRequire)));
}
var required = ourRequired.Union(clientFrame.RequiredExtensions).Distinct().ToList();
var chosenOptional =
_registry.GetOptionalForHandshake()
.Union(clientFrame.OptionalExtensions)
.Distinct()
.Except(required, new ExtensionNameComparer());
return(new HandshakeFrame
{
Identity = serverName,
VersionMajor = SharpMessagingServer.Major,
VersionMinor = SharpMessagingServer.Minor,
OptionalExtensions = chosenOptional.ToArray(),
RequiredExtensions = required.ToArray()
});
}