public ProxiesController(ILoggerService logger, IProxyQuery proxyQuery, IProxyCommand proxyCommand)
{
_logger = logger ?? throw new ArgumentNullException(nameof(logger));
_proxyQuery = proxyQuery ?? throw new ArgumentNullException(nameof(proxyQuery));
_proxyCommand = proxyCommand ?? throw new ArgumentNullException(nameof(proxyCommand));
}
/// <summary>
/// Parses, validates and dispatches messages from the client
/// </summary>
/// <param name="s">The raw message sent from the client</param>
/// <returns>the response to be returned to the client</returns>
private string HandleMessage(string s)
{
//parse the request from the client into an XML document
XmlDocument requestDocument = new XmlDocument();
//load the message into the document
requestDocument.LoadXml(s);
//get a reference to the command element node.
XmlNode commandNode = requestDocument.SelectSingleNode("/command");
//check that there is a command element
if (commandNode == null)
{
//if not, the message is formatted wrong and we cant recognize it.
//return an error message to send to the client
return(CreateErrorDocument("Input not recognized").OuterXml);
}
//create an XMLDocument to hold to response to be sent back to the client
XmlDocument responseDocument = new XmlDocument();
//create the top level response element
XmlNode responseElement = responseDocument.CreateNode(XmlNodeType.Element, "response", "");
//add the response element to the response document
responseDocument.AppendChild(responseElement);
//get the id for the command
string id = ExtractId(commandNode);
//create a new attribute named id
XmlAttribute idAttribute = responseDocument.CreateAttribute("id");
//set its value to the request id
idAttribute.Value = id;
//add the new id element to the response id
responseElement.Attributes.SetNamedItem(idAttribute);
//get child nodes from the request document. Each one should
//represent a command (there should be only one)
XmlNodeList children = commandNode.ChildNodes;
//IProxyCommand that contains the command sent from the client
IProxyCommand command = null;
//attribute tha holds response type
XmlAttribute typeAttribute = responseDocument.CreateAttribute("type");
//loop through all of the command nodes (usually only one)
foreach (XmlNode node in children)
{
//look at the node name. This will indicate the command
switch (node.Name)
{
//exececute command
case "exec":
{
//create a new ExecCommand instance
command = new ExecCommand();
//try and run the command
try
{
//pass in the response and request document, capture the response document
//with output from the command included
responseDocument = command.Exec(requestDocument, responseDocument);
//set the type attribute to success
typeAttribute.Value = "success";
//add the type attribute to the response document
responseDocument.FirstChild.Attributes.SetNamedItem(typeAttribute);
//return a string of XML representing the response document to send to
//the client
return(responseDocument.OuterXml);
}
catch (Exception e)
{
//something went wrong, create error document and send its xml to the client
return(CreateErrorDocument(e.Message, id).OuterXml);
}
}
//screenshot command
case "screenshot":
{
//create the screenshot command
command = new ScreenshotCommand();
try
{
//pass in the response and request document, capture the response document
//with output from the command included
responseDocument = command.Exec(requestDocument, responseDocument);
//set the type attribute to success
typeAttribute.Value = "success";
//add the type attribute to the response document
responseDocument.FirstChild.Attributes.SetNamedItem(typeAttribute);
//return a string of XML representing the response document to send to
//the client
return(responseDocument.OuterXml);
}
catch (Exception e)
{
//something went wrong, create error document and send its xml to the client
return(CreateErrorDocument(e.Message, id).OuterXml);
}
}
}
}
//if we get to here we didnt recognize the command, so we just return null
//todo: should this move to switch defaul
//todo: should be through an error?
return(null);
}