/// <summary>
/// Analyzes an incoming request message payload to discover what kind of
/// message is embedded in it and returns the type, or null if no match is found.
/// </summary>
/// <param name="recipient">The intended or actual recipient of the request message.</param>
/// <param name="fields">The name/value pairs that make up the message payload.</param>
/// <returns>
/// A newly instantiated <see cref="IProtocolMessage"/>-derived object that this message can
/// deserialize to. Null if the request isn't recognized as a valid protocol message.
/// </returns>
IDirectedProtocolMessage IMessageFactory.GetNewRequestMessage(MessageReceivingEndpoint recipient, IDictionary <string, string> fields)
{
Requires.NotNull(recipient, "recipient");
Requires.NotNull(fields, "fields");
throw new NotImplementedException();
}
/// <summary>
/// Analyzes an incoming request message payload to discover what kind of
/// message is embedded in it and returns the type, or null if no match is found.
/// </summary>
/// <param name="recipient">The intended or actual recipient of the request message.</param>
/// <param name="fields">The name/value pairs that make up the message payload.</param>
/// <returns>
/// A newly instantiated <see cref="IProtocolMessage"/>-derived object that this message can
/// deserialize to. Null if the request isn't recognized as a valid protocol message.
/// </returns>
public virtual IDirectedProtocolMessage GetNewRequestMessage(MessageReceivingEndpoint recipient, IDictionary <string, string> fields)
{
MessageDescription matchingType = this.GetMessageDescription(recipient, fields);
if (matchingType != null)
{
return(this.InstantiateAsRequest(matchingType, recipient));
}
else
{
return(null);
}
}
/// <summary>
/// Gets the message type that best fits the given incoming request data.
/// </summary>
/// <param name="recipient">The recipient of the incoming data. Typically not used, but included just in case.</param>
/// <param name="fields">The data of the incoming message.</param>
/// <returns>
/// The message type that matches the incoming data; or <c>null</c> if no match.
/// </returns>
/// <exception cref="ProtocolException">May be thrown if the incoming data is ambiguous.</exception>
protected virtual MessageDescription GetMessageDescription(MessageReceivingEndpoint recipient, IDictionary <string, string> fields)
{
Requires.NotNull(recipient, "recipient");
Requires.NotNull(fields, "fields");
var matches = this.requestMessageTypes.Keys
.Where(message => message.CheckMessagePartsPassBasicValidation(fields))
.OrderByDescending(message => CountInCommon(message.Mapping.Keys, fields.Keys))
.ThenByDescending(message => message.Mapping.Count)
.CacheGeneratedResults();
var match = matches.FirstOrDefault();
if (match != null)
{
return(match);
}
else
{
// No message type matches the incoming data.
return(null);
}
}
/// <summary>
/// Instantiates the given request message type.
/// </summary>
/// <param name="messageDescription">The message description.</param>
/// <param name="recipient">The recipient.</param>
/// <returns>The instantiated message. Never null.</returns>
protected virtual IDirectedProtocolMessage InstantiateAsRequest(MessageDescription messageDescription, MessageReceivingEndpoint recipient)
{
Requires.NotNull(messageDescription, "messageDescription");
Requires.NotNull(recipient, "recipient");
Contract.Ensures(Contract.Result <IDirectedProtocolMessage>() != null);
ConstructorInfo ctor = this.requestMessageTypes[messageDescription];
return((IDirectedProtocolMessage)ctor.Invoke(new object[] { recipient.Location, messageDescription.MessageVersion }));
}