/****************************************************************************************************

 RepRapFirmware - Webserver

 This class serves a single-page web applications to the attached network.  This page forms the user's
 interface with the RepRap machine.  This software interprests returned values from the page and uses it
 to generate G Codes, which it sends to the RepRap.  It also collects values from the RepRap like
 temperature and uses those to construct the web page.

 The page itself - reprap.htm - uses Jquery.js to perform AJAX.  See:

 http://jquery.com/

 -----------------------------------------------------------------------------------------------------

 Version 0.2

 10 May 2013

 Adrian Bowyer
 RepRap Professional Ltd
 http://reprappro.com

 Licence: GPL

 -----------------------------------------------------------------------------------------------------

 The supported requests are GET requests for files (for which the root is the www directory on the
 SD card), and the following. These all start with "/rr_". Ordinary files used for the web interface
 must not have names starting "/rr_" or they will not be found.

 rr_connect?password=xxx
             Sent by the web interface software to establish an initial connection, indicating that
 	 	 	 any state variables relating to the web interface (e.g. file upload in progress) should
 	 	 	 be reset. This only happens if the password could be verified.

 rr_fileinfo Returns file information about the file being printed.

 rr_fileinfo?name=xxx
 	 	 	 Returns file information about a file on the SD card or a JSON-encapsulated response
 	 	 	 with err = 1 if the passed filename was invalid.

 rr_status	 New-style status response, in which temperatures, axis positions and extruder positions
 	 	 	 are returned in separate variables. Another difference is that extruder positions are
 	 	 	 returned as absolute positions instead of relative to the previous gcode. A client
 	 	 	 may also request different status responses by specifying the "type" keyword, followed
 	 	 	 by a custom status response type. Also see "M105 S1".

 rr_files?dir=xxx&flagDirs={1/0}
 	 	 	 Returns a listing of the filenames in the /gcode directory of the SD card. 'dir' is a
 	 	 	 directory path relative to the root of the SD card. If the 'dir' variable is not present,
 	 	 	 it defaults to the /gcode directory. If flagDirs is set to 1, all directories will be
			 prefixed by an asterisk.

 rr_reply    Returns the last-known G-code reply as plain text (not encapsulated as JSON).

 rr_configfile
			 Sends the config file as plain text (not encapsulated as JSON either).

 rr_upload?name=xxx
 	 	 	 Upload a specified file using a POST request. The payload of this request has to be
 	 	 	 the file content. Only one file may be uploaded at once. When the upload has finished,
 	 	 	 a JSON response with the variable "err" will be returned, which will be 0 if the job
 	 	 	 has finished without problems, it will be set to 1 otherwise.

 rr_upload_begin?name=xxx
 	 	 	 Indicates that we wish to upload the specified file. xxx is the filename relative
 	 	 	 to the root of the SD card. The directory component of the filename must already
 	 	 	 exist. Returns variables ubuff (= max upload data we can accept in the next message)
 	 	 	 and err (= 0 if the file was created successfully, nonzero if there was an error).

 rr_upload_data?data=xxx
 	 	 	 Provides a data block for the file upload. Returns the samwe variables as rr_upload_begin,
 	 	 	 except that err is only zero if the file was successfully created and there has not been
 	 	 	 a file write error yet. This response is returned before attempting to write this data block.

 rr_upload_end
 	 	 	 Indicates that we have finished sending upload data. The server closes the file and reports
 	 	 	 the overall status in err. It may also return ubuff again.

 rr_upload_cancel
 	 	 	 Indicates that the user wishes to cancel the current upload. Returns err and ubuff.

 rr_delete?name=xxx
			 Delete file xxx. Returns err (zero if successful).

 rr_mkdir?dir=xxx
			 Create a new directory xxx. Return err (zero if successful).

 rr_move?old=xxx&new=yyy
			 Rename an old file xxx to yyy. May also be used to move a file to another directory.

 ****************************************************************************************************/

#include "RepRapFirmware.h"

//***************************************************************************************************

const char* overflowResponse = "overflow";
const char* badEscapeResponse = "bad escape";


//********************************************************************************************
//
//**************************** Generic Webserver implementation ******************************
//
//********************************************************************************************



// Constructor and initialisation
Webserver::Webserver(Platform* p, Network *n) : platform(p), network(n), webserverActive(false),
	readingConnection(nullptr)
{
	httpInterpreter = new HttpInterpreter(p, this, n);
	ftpInterpreter = new FtpInterpreter(p, this, n);
	telnetInterpreter = new TelnetInterpreter(p, this, n);
}

void Webserver::Init()
{
	// initialise the webserver class
	lastTime = platform->Time();
	longWait = lastTime;
	webserverActive = true;

	// initialise all protocol handlers
	httpInterpreter->ResetState();
	ftpInterpreter->ResetState();
	telnetInterpreter->ResetState();
}


// Deal with input/output from/to the client (if any)
void Webserver::Spin()
{
	if (webserverActive)
	{
		// Check if we can purge any HTTP sessions
		httpInterpreter->CheckSessions();

		// Check if we can actually send something back to the client
		if (OutputBuffer::GetBytesLeft(nullptr) == 0)
		{
			platform->ClassReport(longWait);
			return;
		}

		// We must ensure that we have exclusive access to LWIP
		if (!network->Lock())
		{
			platform->ClassReport(longWait);
			return;
		}

		// See if we have new data to process
		NetworkTransaction *transaction = network->GetTransaction(readingConnection);
		if (transaction != nullptr)
		{
			if (!transaction->LostConnection())
			{
				// Take care of different protocol types here
				ProtocolInterpreter *interpreter;
				uint16_t localPort = transaction->GetLocalPort();
				switch (localPort)
				{
					case FTP_PORT:		/* FTP */
						interpreter = ftpInterpreter;
						break;

					case TELNET_PORT:	/* Telnet */
						interpreter = telnetInterpreter;
						break;

					default:			/* HTTP and FTP data */
						if (localPort == network->GetHttpPort())
						{
							interpreter = httpInterpreter;
						}
						else
						{
							interpreter = ftpInterpreter;
						}
						break;
				}

				// For protocols other than HTTP it is important to send a HELO message
				TransactionStatus status = transaction->GetStatus();
				if (status == connected)
				{
					interpreter->ConnectionEstablished();
					transaction->Discard();
				}
				// Graceful disconnects are handled here, because prior NetworkTransactions might still contain valid
				// data. That's why it's a bad idea to close these connections immediately in the Network class.
				else if (status == disconnected)
				{
					// This will call the disconnect events and effectively close the connection
					transaction->Discard();
				}
				// Check for fast uploads
				else if (interpreter->DoingFastUpload())
				{
					if (!interpreter->DoFastUpload(transaction))
					{
						// Ensure this connection won't block everything if anything goes wrong
						readingConnection = nullptr;
					}
				}
				// Check if we need to send data to a Telnet client
				else if (interpreter == telnetInterpreter && telnetInterpreter->HasDataToSend())
				{
					telnetInterpreter->SendGCodeReply(transaction);
				}
				// Process other messages (unless this is an HTTP request which may need special treatment)
				else if (interpreter != httpInterpreter || httpInterpreter->IsReady())
				{
					for(size_t i = 0; i < 500; i++)
					{
						char c;
						if (transaction->Read(c))
						{
							// Each ProtocolInterpreter must take care of the current NetworkTransaction and remove
							// it from the ready transactions by either calling SendAndClose() or CloseRequest().
							if (interpreter->CharFromClient(c))
							{
								readingConnection = nullptr;
								break;
							}
						}
						else
						{
							// We ran out of data before finding a complete request.
							// This happens when the incoming message length exceeds the TCP MSS.
							// Check if we need to process another packet on the same connection.
							readingConnection = (interpreter->NeedMoreData()) ? transaction->GetConnection() : nullptr;
							transaction->Discard();
							break;
						}
					}
				}
				// else the HTTP server is not ready
			}
			else
			{
				platform->MessageF(HOST_MESSAGE, "Webserver: Skipping zombie transaction with status %d\n", transaction->GetStatus());
				transaction->Discard();
			}
		}
		network->Unlock();		// unlock LWIP again
	}
	platform->ClassReport(longWait);
}

void Webserver::Exit()
{
	httpInterpreter->CancelUpload();
	ftpInterpreter->CancelUpload();

	platform->Message(GENERIC_MESSAGE, "Webserver class exited.\n");
	webserverActive = false;
}

void Webserver::Diagnostics()
{
	platform->Message(GENERIC_MESSAGE, "Webserver Diagnostics:\n");
	httpInterpreter->Diagnostics();
	ftpInterpreter->Diagnostics();
	telnetInterpreter->Diagnostics();
}

bool Webserver::GCodeAvailable(const WebSource source) const
{
	switch (source)
	{
		case WebSource::HTTP:
			return httpInterpreter->GCodeAvailable();

		case WebSource::Telnet:
			return telnetInterpreter->GCodeAvailable();
	}

	return false;
}

char Webserver::ReadGCode(const WebSource source)
{
	switch (source)
	{
		case WebSource::HTTP:
			return httpInterpreter->ReadGCode();

		case WebSource::Telnet:
			return telnetInterpreter->ReadGCode();
	}

	return 0;
}

void Webserver::HandleGCodeReply(const WebSource source, OutputBuffer *reply)
{
	switch (source)
	{
		case WebSource::HTTP:
			httpInterpreter->HandleGCodeReply(reply);
			break;

		case WebSource::Telnet:
			telnetInterpreter->HandleGCodeReply(reply);
			break;
	}
}

void Webserver::HandleGCodeReply(const WebSource source, const char *reply)
{
	switch (source)
	{
		case WebSource::HTTP:
			httpInterpreter->HandleGCodeReply(reply);
			break;

		case WebSource::Telnet:
			telnetInterpreter->HandleGCodeReply(reply);
			break;
	}
}

uint16_t Webserver::GetGCodeBufferSpace(const WebSource source) const
{
	switch (source)
	{
		case WebSource::HTTP:
			return httpInterpreter->GetGCodeBufferSpace();

		case WebSource::Telnet:
			return telnetInterpreter->GetGCodeBufferSpace();
	}

	return 0;
}

// Handle immediate disconnects here (cs will be freed after this call)
void Webserver::ConnectionLost(const ConnectionState *cs)
{
	// See which connection caused this event
	uint32_t remoteIP = cs->GetRemoteIP();
	uint16_t remotePort = cs->GetRemotePort();
	uint16_t localPort = cs->GetLocalPort();

	// Inform protocol handlers that this connection has been lost
	ProtocolInterpreter *interpreter;
	switch (localPort)
	{
		case FTP_PORT:		/* FTP */
			interpreter = ftpInterpreter;
			break;

		case TELNET_PORT:	/* Telnet */
			interpreter = telnetInterpreter;
			break;

		default:			/* HTTP and FTP data */
			if (localPort == network->GetHttpPort())
			{
				interpreter = httpInterpreter;
				break;
			}
			else if (localPort == network->GetDataPort())
			{
				interpreter = ftpInterpreter;
				break;
			}

			platform->MessageF(HOST_MESSAGE, "Error: Webserver should handle disconnect event at local port %d, but no handler was found!\n", localPort);
			return;
	}

	if (reprap.Debug(moduleWebserver))
	{
		platform->MessageF(HOST_MESSAGE, "ConnectionLost called for local port %d (remote port %d)\n", localPort, remotePort);
	}
	interpreter->ConnectionLost(remoteIP, remotePort, localPort);

	// If our reading connection is lost, it will be no longer important which connection is read from first.
	if (cs == readingConnection)
	{
		readingConnection = nullptr;
	}
}


//********************************************************************************************
//
//********************** Generic Procotol Interpreter implementation *************************
//
//********************************************************************************************

ProtocolInterpreter::ProtocolInterpreter(Platform *p, Webserver *ws, Network *n)
	: platform(p), webserver(ws), network(n)
{
	uploadState = notUploading;
	filenameBeingUploaded[0] = 0;
}

// Start writing to a new file
bool ProtocolInterpreter::StartUpload(FileStore *file)
{
	CancelUpload();

	if (file != nullptr)
	{
		fileBeingUploaded.Set(file);
		uploadState = uploadOK;
		return true;
	}

	uploadState = uploadError;
	platform->Message(HOST_MESSAGE, "Could not open file while starting upload!\n");
	return false;
}

void ProtocolInterpreter::CancelUpload()
{
	if (fileBeingUploaded.IsLive())
	{
		fileBeingUploaded.Close();		// cancel any pending file upload
		if (strlen(filenameBeingUploaded) != 0)
		{
			platform->GetMassStorage()->Delete("0:/", filenameBeingUploaded);
		}
	}
	filenameBeingUploaded[0] = 0;
	uploadState = notUploading;
}

bool ProtocolInterpreter::DoFastUpload(NetworkTransaction *transaction)
{
	if (IsUploading())
	{
		char *buffer;
		unsigned int len;
		if (transaction->ReadBuffer(buffer, len))
		{
			// Write uploaded data immediately to the file
			if (!fileBeingUploaded.Write(buffer, len))
			{
				platform->Message(HOST_MESSAGE, "Could not write upload data!\n");
				uploadState = uploadError;
			}
			transaction->Discard();
		}
	}
	else if (transaction->DataLength() > 0)
	{
		platform->Message(HOST_MESSAGE, "Webserver: Closing invalid data connection\n");
		transaction->Commit(false);
		return false;
	}

	return true;
}

void ProtocolInterpreter::FinishUpload(uint32_t fileLength)
{
	// Flush remaining data for FSO
	if (uploadState == uploadOK && !fileBeingUploaded.Flush())
	{
		uploadState = uploadError;
		platform->Message(HOST_MESSAGE, "Could not flush remaining data while finishing upload!\n");
	}

	// Check the file length is as expected
	if (uploadState == uploadOK && fileLength != 0 && fileBeingUploaded.Length() != fileLength)
	{
		uploadState = uploadError;
		platform->MessageF(HOST_MESSAGE, "Uploaded file size is different (%u vs. expected %u Bytes)!\n", fileBeingUploaded.Length(), fileLength);
	}

	// Close the file
	if (!fileBeingUploaded.Close())
	{
		uploadState = uploadError;
		platform->Message(HOST_MESSAGE, "Could not close the upload file while finishing upload!\n");
	}

	// Delete file if an error has occurred
	if (uploadState == uploadError && strlen(filenameBeingUploaded) != 0)
	{
		platform->GetMassStorage()->Delete("0:/", filenameBeingUploaded);
	}
	filenameBeingUploaded[0] = 0;
}



//********************************************************************************************
//
// *********************** HTTP interpreter for the Webserver class **************************
//
//********************************************************************************************



Webserver::HttpInterpreter::HttpInterpreter(Platform *p, Webserver *ws, Network *n)
	: ProtocolInterpreter(p, ws, n), state(doingCommandWord), numSessions(0), clientsServed(0)
{
	gcodeReadIndex = gcodeWriteIndex = 0;
	gcodeReply = new OutputStack();
	uploadingTextData = false;
	processingDeferredRequest = false;
	numContinuationBytes = seq = 0;
}

void Webserver::HttpInterpreter::Diagnostics()
{
	platform->MessageF(GENERIC_MESSAGE, "HTTP sessions: %d of %d\n", numSessions, maxHttpSessions);
}

// File Uploads

bool Webserver::HttpInterpreter::DoFastUpload(NetworkTransaction *transaction)
{
	// Attempt to write one pbuf entry in one go
	if (IsUploading())
	{
		char *buffer;
		unsigned int len;
		if (transaction->ReadBuffer(buffer, len))
		{
			WriteUploadedData(buffer, len);
			uploadedBytes += len;
		}
		else
		{
			transaction->Discard();
		}
	}
	else if (transaction->DataLength() > 0)
	{
		platform->Message(HOST_MESSAGE, "Webserver: Closing invalid data connection\n");
		transaction->Commit(false);
		return false;
	}

	// See if the upload has finished
	if (uploadState != uploadOK || uploadedBytes >= postFileLength)
	{
		// Reset POST upload state for this client
		uint32_t remoteIP = transaction->GetRemoteIP();
		for(size_t i = 0; i < numSessions; i++)
		{
			if (sessions[i].ip == remoteIP && sessions[i].isPostUploading)
			{
				sessions[i].isPostUploading = false;
				break;
			}
		}

		// We're done, flush the remaining upload data and send the JSON response
		FinishUpload(postFileLength);
		SendJsonResponse("upload");
		uploadState = notUploading;
	}

	return (uploadState != uploadError);
}

bool Webserver::HttpInterpreter::DoingFastUpload() const
{
	if (state == doingPost)
	{
		// Always finish the current request before checking for fast POST uploads
		return false;
	}

	uint32_t remoteIP = network->GetTransaction()->GetRemoteIP();
	uint16_t remotePort = network->GetTransaction()->GetRemotePort();
	for(size_t i = 0; i < numSessions; i++)
	{
		if (sessions[i].ip == remoteIP && sessions[i].isPostUploading)
		{
			return (remotePort == sessions[i].postPort);
		}
	}
	return false;
}

bool Webserver::HttpInterpreter::StartUpload(FileStore *file)
{
	numContinuationBytes = 0;
	return ProtocolInterpreter::StartUpload(file);
}

void Webserver::HttpInterpreter::WriteUploadedData(const char *buffer, unsigned int length)
{
	// Count the number of UTF8 continuation bytes. We may need it to adjust the expected file length.
	if (uploadingTextData)
	{
		unsigned int bytesToCheck = length;
		const char *data = buffer;
		while (bytesToCheck != 0)
		{
			if ((*data & 0xC0) == 0x80)
			{
				++numContinuationBytes;
			}
			++data;
			--bytesToCheck;
		}
	}

	// Write uploaded data immediately to the file
	if (!fileBeingUploaded.Write(buffer, length))
	{
		platform->Message(HOST_MESSAGE, "Could not write upload data!\n");
		uploadState = uploadError;
	}
}

void Webserver::HttpInterpreter::CancelUpload()
{
	CancelUpload(network->GetTransaction()->GetRemoteIP());
}

void Webserver::HttpInterpreter::CancelUpload(uint32_t remoteIP)
{
	for(size_t i = 0; i < numSessions; i++)
	{
		if (sessions[i].ip == remoteIP && sessions[i].isPostUploading)
		{
			sessions[i].isPostUploading = false;
			sessions[i].lastQueryTime = platform->Time();
			break;
		}
	}

	ProtocolInterpreter::CancelUpload();
}

// Output to the client

// Start sending a file or a JSON response.
void Webserver::HttpInterpreter::SendFile(const char* nameOfFileToSend)
{
	NetworkTransaction *transaction = network->GetTransaction();

	if (nameOfFileToSend[0] == '/')
	{
		++nameOfFileToSend;						// all web files are relative to the /www folder, so remove the leading '/'
		if (nameOfFileToSend[0] == 0)
		{
			nameOfFileToSend = INDEX_PAGE_FILE;
		}
	}
	FileStore *fileToSend = platform->GetFileStore(platform->GetWebDir(), nameOfFileToSend, false);
	if (fileToSend == nullptr)
	{
		nameOfFileToSend = FOUR04_PAGE_FILE;
		fileToSend = platform->GetFileStore(platform->GetWebDir(), nameOfFileToSend, false);
		if (fileToSend == nullptr)
		{
			RejectMessage("not found", 404);
			return;
		}
	}
	transaction->SetFileToWrite(fileToSend);

	transaction->Write("HTTP/1.1 200 OK\n");

	const char* contentType;
	bool zip = false;
	if (StringEndsWith(nameOfFileToSend, ".png"))
	{
		contentType = "image/png";
	}
	else if (StringEndsWith(nameOfFileToSend, ".ico"))
	{
		contentType = "image/x-icon";
	}
	else if (StringEndsWith(nameOfFileToSend, ".js"))
	{
		contentType = "application/javascript";
	}
	else if (StringEndsWith(nameOfFileToSend, ".css"))
	{
		contentType = "text/css";
	}
	else if (StringEndsWith(nameOfFileToSend, ".htm") || StringEndsWith(nameOfFileToSend, ".html"))
	{
		contentType = "text/html";
	}
	else if (StringEndsWith(nameOfFileToSend, ".zip"))
	{
		contentType = "application/zip";
		zip = true;
	}
	else
	{
		contentType = "application/octet-stream";
	}
	transaction->Printf("Content-Type: %s\n", contentType);

	if (zip && fileToSend != nullptr)
	{
		transaction->Write("Content-Encoding: gzip\n");
		transaction->Printf("Content-Length: %lu\n", fileToSend->Length());
	}

	transaction->Write("Connection: close\n\n");
	transaction->Commit(false);
}

void Webserver::HttpInterpreter::SendConfigFile(NetworkTransaction *transaction)
{
	FileStore *configFile = platform->GetFileStore(platform->GetSysDir(), platform->GetConfigFile(), false);

	transaction->Write("HTTP/1.1 200 OK\n");
	transaction->Write("Content-Type: text/plain\n");
	transaction->Printf("Content-Length: %u\n", (configFile != nullptr) ? configFile->Length() : 0);
	transaction->Write("Connection: close\n\n");
	transaction->SetFileToWrite(configFile);
	transaction->Commit(false);
}

void Webserver::HttpInterpreter::SendGCodeReply(NetworkTransaction *transaction)
{
	// Do we need to keep the G-Code reply for other clients?
	bool clearReply = false;
	if (!gcodeReply->IsEmpty())
	{
		clientsServed++;
		if (clientsServed < numSessions)
		{
			// Yes - make sure the Network class doesn't discard its buffers yet
			// NB: This must happen here, because NetworkTransaction::Write() might already release OutputBuffers
			gcodeReply->IncreaseReferences(1);
		}
		else
		{
			// No - clean up again later
			clearReply = true;
		}

		if (reprap.Debug(moduleWebserver))
		{
			platform->MessageF(HOST_MESSAGE, "Serving client %d of %d\n", clientsServed, numSessions);
		}
	}

	// Send the whole G-Code reply as plain text to the client
	transaction->Write("HTTP/1.1 200 OK\n");
	transaction->Write("Cache-Control: no-cache, no-store, must-revalidate\n");
	transaction->Write("Pragma: no-cache\n");
	transaction->Write("Expires: 0\n");
	transaction->Write("Content-Type: text/plain\n");
	transaction->Printf("Content-Length: %u\n", gcodeReply->DataLength());
	transaction->Write("Connection: close\n\n");
	transaction->Write(gcodeReply);
	transaction->Commit(false);

	// Possibly clean up the G-code reply once again
	if (clearReply)
	{
		gcodeReply->Clear();
	}
}

void Webserver::HttpInterpreter::SendJsonResponse(const char* command)
{
	NetworkTransaction *transaction = network->GetTransaction();

	// Try to authorize the user automatically to retain compatibility with the old web interface
	if (!IsAuthenticated() && reprap.NoPasswordSet())
	{
		Authenticate();
	}

	// rr_reply is treated differently, because it (currently) responds as "text/plain"
	if (IsAuthenticated() && StringEquals(command, "reply"))
	{
		SendGCodeReply(transaction);
		return;
	}

	// rr_configfile sends the config as plain text well
	if (IsAuthenticated() && StringEquals(command, "configfile"))
	{
		SendConfigFile(transaction);
		return;
	}

	// We need a valid output buffer to process this request...
	OutputBuffer *jsonResponse;
	if (!OutputBuffer::Allocate(jsonResponse))
	{
		// Should never happen
		network->GetTransaction()->Commit(false);
		return;
	}

	// See if we can find a suitable JSON response
	bool keepOpen = false;
	bool mayKeepOpen;
	bool found;
	if (numQualKeys == 0)
	{
		found = GetJsonResponse(command, jsonResponse, "", "", 0, mayKeepOpen);
	}
	else
	{
		found = GetJsonResponse(command, jsonResponse, qualifiers[0].key, qualifiers[0].value, qualifiers[1].key - qualifiers[0].value - 1, mayKeepOpen);
	}

	// Check the special case of a deferred request
	if (processingDeferredRequest)
	{
		// GetJsonResponse() must free the allocated OutputBuffer before we get here
		return;
	}

	// React to whether or not a JSON response could be found
	if (!found)
	{
		if (!IsAuthenticated())
		{
			// Send an error message and stop here
			RejectMessage("Not authorized", 500);
			return;
		}
		else
		{
			platform->MessageF(HOST_MESSAGE, "KnockOut request: %s not recognised\n", command);
		}
	}

	if (mayKeepOpen)
	{
		// Check that the browser wants to persist the connection too
		for (size_t i = 0; i < numHeaderKeys; ++i)
		{
			if (StringEquals(headers[i].key, "Connection"))
			{
				// Comment out the following line to disable persistent connections
				keepOpen = StringEquals(headers[i].value, "keep-alive");
				break;
			}
		}
	}

	transaction->Write("HTTP/1.1 200 OK\n");
	transaction->Write("Cache-Control: no-cache, no-store, must-revalidate\n");
	transaction->Write("Pragma: no-cache\n");
	transaction->Write("Expires: 0\n");
	transaction->Write("Content-Type: application/json\n");
	transaction->Printf("Content-Length: %u\n", (jsonResponse != nullptr) ? jsonResponse->Length() : 0);
	transaction->Printf("Connection: %s\n\n", keepOpen ? "keep-alive" : "close");
	transaction->Write(jsonResponse);

	transaction->Commit(keepOpen);
}

bool Webserver::HttpInterpreter::IsReady()
{
	// We want to send a response, but we need memory for that. If there isn't enough available, see if we can truncate the G-Code reply
	while (OutputBuffer::GetBytesLeft(nullptr) < minHttpResponseSize)
	{
		if (gcodeReply->IsEmpty())
		{
			// We cannot truncate any G-Code reply, so try again later
			return false;
		}

		if (OutputBuffer::Truncate(gcodeReply->GetFirstItem(), minHttpResponseSize) == 0)
		{
			// Truncating didn't work out, but see if we can free up a few more bytes by releasing the first reply item
			OutputBuffer::ReleaseAll(gcodeReply->Pop());
		}
	}

	// If we're already processing a request, we must not parse its content again
	if (processingDeferredRequest)
	{
		ProcessMessage();
		return false;
	}
	return true;
}

//----------------------------------------------------------------------------------------------------

// Input from the client

// Get the Json response for this command.
// 'value' is null-terminated, but we also pass its length in case it contains embedded nulls, which matters when uploading files.
bool Webserver::HttpInterpreter::GetJsonResponse(const char* request, OutputBuffer *&response, const char* key, const char* value, size_t valueLength, bool& keepOpen)
{
	keepOpen = false;	// assume we don't want to persist the connection
	bool found = true;	// assume success

	if (StringEquals(request, "connect") && StringEquals(key, "password"))
	{
		if (IsAuthenticated())
		{
			// This IP is already authenticated, no need to check the password again
			response->copy("{\"err\":0}");
		}
		else if (reprap.CheckPassword(value))
		{
			if (Authenticate())
			{
				// This is only possible if we have at least one HTTP session left
				response->copy("{\"err\":0}");
			}
			else
			{
				// Otherwise report an error
				response->copy("{\"err\":2}");
			}
		}
		else
		{
			// Wrong password
			response->copy("{\"err\":1}");
		}
	}
	else if (!IsAuthenticated())
	{
		// Return error message if the user could not be authenticated
		found = false;
	}
	else
	{
		UpdateAuthentication();

		if (StringEquals(request, "disconnect"))
		{
			RemoveAuthentication();
			response->copy("{\"err\":0}");
		}
		else if (StringEquals(request, "status"))
		{
			int type = 0;
			if (StringEquals(key, "type"))
			{
				// New-style JSON status responses
				type = atoi(value);
				if (type < 1 || type > 3)
				{
					type = 1;
				}

				OutputBuffer::Release(response);
				response = reprap.GetStatusResponse(type, ResponseSource::HTTP);
			}
			else
			{
				// Deprecated
				OutputBuffer::Release(response);
				response = reprap.GetLegacyStatusResponse(1, 0);
			}
		}
		else if (StringEquals(request, "gcode") && StringEquals(key, "gcode"))
		{
			LoadGcodeBuffer(value);
			response->printf("{\"buff\":%u}", GetGCodeBufferSpace());
		}
		else if (StringEquals(request, "upload"))
		{
			response->printf("{\"err\":%d}", (uploadState == uploadOK && uploadedBytes == postFileLength) ? 0 : 1);
		}
		else if (StringEquals(request, "upload_begin") && StringEquals(key, "name"))
		{
			FileStore *file = platform->GetFileStore("0:/", value, true);
			if (StartUpload(file))
			{
				strncpy(filenameBeingUploaded, value, ARRAY_SIZE(filenameBeingUploaded));
				filenameBeingUploaded[ARRAY_UPB(filenameBeingUploaded)] = 0;
				uploadingTextData = (numQualKeys < 2 || !StringEquals(qualifiers[1].key, "type") ||
										!StringEquals(qualifiers[1].value, "binary"));
			}

			GetJsonUploadResponse(response);
		}
		else if (StringEquals(request, "upload_data") && StringEquals(key, "data"))
		{
			WriteUploadedData(value, valueLength);
			uploadedBytes += valueLength;

			GetJsonUploadResponse(response);
			keepOpen = true;
		}
		else if (StringEquals(request, "upload_end") && StringEquals(key, "size"))
		{
			uint32_t fileLength = strtoul(value, nullptr, 10);
			FinishUpload(fileLength);

			GetJsonUploadResponse(response);
			uploadState = notUploading;
		}
		else if (StringEquals(request, "upload_cancel"))
		{
			CancelUpload();
			response->copy("{\"err\":0}");
		}
		else if (StringEquals(request, "delete") && StringEquals(key, "name"))
		{
			bool ok = platform->GetMassStorage()->Delete("0:/", value);
			response->printf("{\"err\":%d}", (ok) ? 0 : 1);
		}
		else if (StringEquals(request, "files"))
		{
			const char* dir = (StringEquals(key, "dir")) ? value : platform->GetGCodeDir();
			bool flagDirs = false;
			if (numQualKeys >= 2)
			{
				if (StringEquals(qualifiers[1].key, "flagDirs"))
				{
					flagDirs = StringEquals(qualifiers[1].value, "1");
				}
			}
			OutputBuffer::Release(response);
			response = reprap.GetFilesResponse(dir, flagDirs);
		}
		else if (StringEquals(request, "fileinfo"))
		{
			OutputBuffer::Release(response);
			if (reprap.GetPrintMonitor()->GetFileInfoResponse(StringEquals(key, "name") ? value : nullptr, response))
			{
				processingDeferredRequest = false;
			}
			else
			{
				network->GetTransaction()->Defer();
				processingDeferredRequest = true;
			}
		}
		else if (StringEquals(request, "move"))
		{
			if (numQualKeys >= 2)
			{
				if (StringEquals(key, "old") && StringEquals(qualifiers[1].key, "new"))
				{
					response->printf("{\"err\":%d}", platform->GetMassStorage()->Rename(value, qualifiers[1].value) ? 0 : 1);
				}
				else
				{
					response->printf("{\"err\":1}");
				}
			}
			else
			{
				response->printf("{\"err\":1}");
			}
		}
		else if (StringEquals(request, "mkdir") && StringEquals(key, "dir"))
		{
			bool ok = (platform->GetMassStorage()->MakeDirectory(value));
			response->printf("{\"err\":%d}", (ok) ? 0 : 1);
		}
		else if (StringEquals(request, "config"))
		{
			OutputBuffer::Release(response);
			response = reprap.GetConfigResponse();
		}
		else
		{
			found = false;
		}
	}

	return found;
}

void Webserver::HttpInterpreter::GetJsonUploadResponse(OutputBuffer *response)
{
	response->printf("{\"ubuff\":%u,\"err\":%d}", webUploadBufferSize, (uploadState == uploadOK) ? 0 : 1);
}

void Webserver::HttpInterpreter::ResetState()
{
	clientPointer = 0;
	state = doingCommandWord;
	numCommandWords = 0;
	numQualKeys = 0;
	numHeaderKeys = 0;
	commandWords[0] = clientMessage;
	processingDeferredRequest = false;
}

bool Webserver::HttpInterpreter::NeedMoreData()
{
	if (state == doingPost)
	{
		// At this stage we've processed the first chunk of a POST upload request. Store the
		// initial payload and reset the HTTP reader again in order to process new requests
		WriteUploadedData(clientMessage + (clientPointer - uploadedBytes), uploadedBytes);
		if (reprap.Debug(moduleWebserver))
		{
			platform->MessageF(HOST_MESSAGE, "Wrote %lu bytes of file\n", uploadedBytes);
		}
		ResetState();
		return false;
	}
	else if (!IsAuthenticated() && (!numCommandWords || !StringEquals(commandWords[0], "connect")))
	{
		// It makes very little sense to allow unknown connections to block our HTTP reader, however
		// connect requests may take up more than one TCP_MSS if a long cookie value is passed.
		ResetState();
		return false;
	}
	return true;
}

void Webserver::HttpInterpreter::ConnectionLost(uint32_t remoteIP, uint16_t remotePort, uint16_t localPort)
{
	// If the connection was lost before the request had been completed, reset our state here
	if (webserver->readingConnection != nullptr && webserver->readingConnection->GetRemotePort() == remotePort)
	{
		if (processingDeferredRequest)
		{
			if (numQualKeys != 0 && StringEquals(qualifiers[0].key, "name"))
			{
				// If we're still parsing a file while the disconnect occurred, stop it
				reprap.GetPrintMonitor()->StopParsing(qualifiers[0].value);
			}
		}

		ResetState();
	}

	// Deal with aborted POST uploads. Note that we also check the remote port here,
	// because the client *might* have two instances of the web interface running.
	if (uploadState == uploadOK)
	{
		for(size_t i = 0; i < numSessions; i++)
		{
			if (sessions[i].ip == remoteIP && sessions[i].isPostUploading && sessions[i].postPort == remotePort)
			{
				if (reprap.Debug(moduleWebserver))
				{
					platform->MessageF(HOST_MESSAGE, "POST upload for '%s' has been cancelled!\n", filenameBeingUploaded);
				}
				CancelUpload(remoteIP);
				break;
			}
		}
	}
}

// Process a character from the client
// Rewritten as a state machine by dc42 to increase capability and speed, and reduce RAM requirement.
// On entry:
//  There is space for at least 1 character in clientMessage.
// On return:
//	If we return false:
//		We want more characters. There is space for at least 1 character in clientMessage.
//	If we return true:
//		We have processed the message and sent the reply. No more characters may be read from this message.
// Whenever this calls ProcessMessage:
//	The first line has been split up into words. Variables numCommandWords and commandWords give the number of words we found
//  and the pointers to each word. The second word is treated specially. It is assumed to be a filename followed by an optional
//  qualifier comprising key/value pairs. Both may include %xx escapes, and the qualifier may include + to mean space. We store
//  a pointer to the filename without qualifier in commandWords[1]. We store the qualifier key/value pointers in array 'qualifiers'
//  and the number of them in numQualKeys.
//  The remaining lines have been parsed as header name/value pairs. Pointers to them are stored in array 'headers' and the number
//  of them in numHeaders.
// If one of our arrays is about to overflow, or the message is not in a format we expect, then we call RejectMessage with an
// appropriate error code and string.
bool Webserver::HttpInterpreter::CharFromClient(char c)
{
	switch(state)
	{
		case doingCommandWord:
			switch(c)
			{
				case '\n':
					clientMessage[clientPointer++] = 0;
					++numCommandWords;
					numHeaderKeys = 0;
					headers[0].key = clientMessage + clientPointer;
					state = doingHeaderKey;
					break;
				case '\r':
					break;
				case ' ':
				case '\t':
					clientMessage[clientPointer++] = 0;
					if (numCommandWords < maxCommandWords)
					{
						++numCommandWords;
						commandWords[numCommandWords] = clientMessage + clientPointer;
						if (numCommandWords == 1)
						{
							state = doingFilename;
						}
					}
					else
					{
						return RejectMessage("too many command words");
					}
					break;
				default:
					clientMessage[clientPointer++] = c;
					break;
			}
			break;

		case doingFilename:
			switch(c)
			{
				case '\n':
					clientMessage[clientPointer++] = 0;
					++numCommandWords;
					numQualKeys = 0;
					numHeaderKeys = 0;
					headers[0].key = clientMessage + clientPointer;
					state = doingHeaderKey;
					break;
				case '?':
					clientMessage[clientPointer++] = 0;
					++numCommandWords;
					numQualKeys = 0;
					qualifiers[0].key = clientMessage + clientPointer;
					state = doingQualifierKey;
					break;
				case '%':
					state = doingFilenameEsc1;
					break;
				case '\r':
					break;
				case ' ':
				case '\t':
					clientMessage[clientPointer++] = 0;
					if (numCommandWords < maxCommandWords)
					{
						++numCommandWords;
						commandWords[numCommandWords] = clientMessage + clientPointer;
						state = doingCommandWord;
					}
					else
					{
						return RejectMessage("too many command words");
					}
					break;
				default:
					clientMessage[clientPointer++] = c;
					break;
			}
			break;

		case doingQualifierKey:
			switch(c)
			{
				case '=':
					clientMessage[clientPointer++] = 0;
					qualifiers[numQualKeys].value = clientMessage + clientPointer;
					++numQualKeys;
					state = doingQualifierValue;
					break;
				case '\n':	// key with no value
				case ' ':
				case '\t':
				case '\r':
				case '%':	// none of our keys needs escaping, so treat an escape within a key as an error
				case '&':	// key with no value
					return RejectMessage("bad qualifier key");
				default:
					clientMessage[clientPointer++] = c;
					break;
			}
			break;

		case doingQualifierValue:
			switch(c)
			{
				case '\n':
					clientMessage[clientPointer++] = 0;
					qualifiers[numQualKeys].key = clientMessage + clientPointer;	// so that we can read the whole value even if it contains a null
					numHeaderKeys = 0;
					headers[0].key = clientMessage + clientPointer;
					state = doingHeaderKey;
					break;
				case ' ':
				case '\t':
					clientMessage[clientPointer++] = 0;
					qualifiers[numQualKeys].key = clientMessage + clientPointer;	// so that we can read the whole value even if it contains a null
					commandWords[numCommandWords] = clientMessage + clientPointer;
					state = doingCommandWord;
					break;
				case '\r':
					break;
				case '%':
					state = doingQualifierValueEsc1;
					break;
				case '&':
					// Another variable is coming
					clientMessage[clientPointer++] = 0;
					qualifiers[numQualKeys].key = clientMessage + clientPointer;	// so that we can read the whole value even if it contains a null
					if (numQualKeys < maxQualKeys)
					{
						state = doingQualifierKey;
					}
					else
					{
						return RejectMessage("too many keys in qualifier");
					}
					break;
				case '+':
					clientMessage[clientPointer++] = ' ';
					break;
				default:
					clientMessage[clientPointer++] = c;
					break;
			}
			break;

		case doingFilenameEsc1:
		case doingQualifierValueEsc1:
			if (c >= '0' && c <= '9')
			{
				decodeChar = (c - '0') << 4;
				state = (HttpState)(state + 1);
			}
			else if (c >= 'A' && c <= 'F')
			{
				decodeChar = (c - ('A' - 10)) << 4;
				state = (HttpState)(state + 1);
			}
			else
			{
				return RejectMessage(badEscapeResponse);
			}
			break;

		case doingFilenameEsc2:
		case doingQualifierValueEsc2:
			if (c >= '0' && c <= '9')
			{
				clientMessage[clientPointer++] = decodeChar | (c - '0');
				state = (HttpState)(state - 2);
			}
			else if (c >= 'A' && c <= 'F')
			{
				clientMessage[clientPointer++] = decodeChar | (c - ('A' - 10));
				state = (HttpState)(state - 2);
			}
			else
			{
				return RejectMessage(badEscapeResponse);
			}
			break;

		case doingHeaderKey:
			switch(c)
			{
				case '\n':
					if (clientMessage + clientPointer == headers[numHeaderKeys].key)	// if the key hasn't started yet, then this is the blank line at the end
					{
						if (ProcessMessage())
						{
							return true;
						}
					}
					else
					{
						return RejectMessage("unexpected newline");
					}
					break;
				case '\r':
					break;
				case ':':
					if (numHeaderKeys == maxHeaders - 1)
					{
						return RejectMessage("too many header key-value pairs");
					}
					clientMessage[clientPointer++] = 0;
					headers[numHeaderKeys].value = clientMessage + clientPointer;
					++numHeaderKeys;
					state = expectingHeaderValue;
					break;
				default:
					clientMessage[clientPointer++] = c;
					break;
			}
			break;

		case expectingHeaderValue:
			if (c == ' ' || c == '\t')
			{
				break;		// ignore spaces between header key and value
			}
			state = doingHeaderValue;
			// no break

		case doingHeaderValue:
			if (c == '\n')
			{
				state = doingHeaderContinuation;
			}
			else if (c != '\r')
			{
				clientMessage[clientPointer++] = c;
			}
			break;

		case doingHeaderContinuation:
			switch(c)
			{
				case ' ':
				case '\t':
					// It's a continuation of the previous value
					clientMessage[clientPointer++] = c;
					state = doingHeaderValue;
					break;
				case '\n':
					// It's the blank line
					clientMessage[clientPointer] = 0;
					if (ProcessMessage())
					{
						return true;
					}
					// no break
				case '\r':
					break;
				default:
					// It's a new key
					if (clientPointer + 3 <= ARRAY_SIZE(clientMessage))
					{
						clientMessage[clientPointer++] = 0;
						headers[numHeaderKeys].key = clientMessage + clientPointer;
						clientMessage[clientPointer++] = c;
						state = doingHeaderKey;
					}
					else
					{
						return RejectMessage(overflowResponse);
					}
					break;
			}
			break;

		case doingPost:
			clientMessage[clientPointer++] = c;
			uploadedBytes++;

			if (uploadedBytes == postFileLength)
			{
				WriteUploadedData(clientMessage + (clientPointer - uploadedBytes), uploadedBytes);
				FinishUpload(postFileLength);

				SendJsonResponse("upload");

				// Reset state
				uint32_t remoteIP = network->GetTransaction()->GetRemoteIP();
				for(size_t i = 0; i < numSessions; i++)
				{
					if (sessions[i].ip == remoteIP && sessions[i].isPostUploading)
					{
						sessions[i].isPostUploading = false;
						sessions[i].lastQueryTime = platform->Time();
						break;
					}
				}
				uploadState = notUploading;
				ResetState();

				return true;
			}

			break;

		default:
			break;
	}

	if (clientPointer == ARRAY_SIZE(clientMessage))
	{
		return RejectMessage(overflowResponse);
	}
	return false;
}

// Process the message received so far. We have reached the end of the headers.
// Return true if the message is complete, false if we want to continue receiving data (i.e. postdata)
bool Webserver::HttpInterpreter::ProcessMessage()
{
	if (reprap.Debug(moduleWebserver))
	{
		platform->MessageF(HOST_MESSAGE, "HTTP req, command words {", numCommandWords);
		for (size_t i = 0; i < numCommandWords; ++i)
		{
			platform->MessageF(HOST_MESSAGE, " %s", commandWords[i]);
		}
		platform->Message(HOST_MESSAGE, " }, parameters {");

		for (size_t i = 0; i < numQualKeys; ++i)
		{
			platform->MessageF(HOST_MESSAGE, " %s=%s", qualifiers[i].key, qualifiers[i].value);
		}
		platform->Message(HOST_MESSAGE, " }\n");
	}

	if (numCommandWords < 2)
	{
		return RejectMessage("too few command words");
	}

	if (StringEquals(commandWords[0], "GET"))
	{
		if (StringStartsWith(commandWords[1], KO_START))
		{
			SendJsonResponse(commandWords[1] + KO_FIRST);
		}
		else if (commandWords[1][0] == '/' && StringStartsWith(commandWords[1] + 1, KO_START))
		{
			SendJsonResponse(commandWords[1] + 1 + KO_FIRST);
		}
		else
		{
			SendFile(commandWords[1]);
		}

		if (!processingDeferredRequest)
		{
			// Usually we're done here, but we must process deferred requests multiple times
			ResetState();
		}
		return true;
	}
	else if (IsAuthenticated() && StringEquals(commandWords[0], "POST"))
	{
		bool isUploadRequest = (StringEquals(commandWords[1], KO_START "upload"));
		isUploadRequest |= (commandWords[1][0] == '/' && StringEquals(commandWords[1] + 1, KO_START "upload"));
		if (isUploadRequest)
		{
			if (numQualKeys > 0 && StringEquals(qualifiers[0].key, "name"))
			{
				// We cannot upload more than one file at once
				if (uploadState == uploadOK)
				{
					return RejectMessage("cannot upload more than one file at once");
				}

				// See how many bytes we expect to read
				bool contentLengthFound = false;
				for(size_t i=0; i<numHeaderKeys; i++)
				{
					if (StringEquals(headers[i].key, "Content-Length"))
					{
						postFileLength = atoi(headers[i].value);
						contentLengthFound = true;
						break;
					}
				}

				// Start POST file upload
				if (contentLengthFound)
				{
					FileStore *file = platform->GetFileStore("0:/", qualifiers[0].value, true);
					if (StartUpload(file))
					{
						if (reprap.Debug(moduleWebserver))
						{
							platform->MessageF(HOST_MESSAGE, "Start uploading file %s length %lu\n", qualifiers[0].value, postFileLength);
						}
						// Start new file upload
						uploadingTextData = false;
						uploadedBytes = numContinuationBytes = 0;

						strncpy(filenameBeingUploaded, qualifiers[0].value, ARRAY_SIZE(filenameBeingUploaded));
						filenameBeingUploaded[ARRAY_UPB(filenameBeingUploaded)] = 0;

						// Set POST variables only if we actually need to store data
						if (postFileLength > 0)
						{
							uint32_t remoteIP = network->GetTransaction()->GetRemoteIP();
							uint16_t remotePort = network->GetTransaction()->GetRemotePort();
							for(size_t i = 0; i < numSessions; i++)
							{
								if (sessions[i].ip == remoteIP)
								{
									sessions[i].postPort = remotePort;
									sessions[i].isPostUploading = true;
									break;
								}
							}
							
							// Align the client pointer on a 32-bit boundary for HSMCI efficiency.
							// To remain efficient, the browser should send POSTDATA in multiples of 4 bytes.
							clientPointer += 3;
							clientPointer -= reinterpret_cast<size_t>(clientMessage + clientPointer) & 3;
							state = doingPost;

							return false;
						}

						// User has uploaded an empty file - we should have finished here already
						FinishUpload(0);
						SendJsonResponse("upload");
						return true;
					}
					return RejectMessage("could not start file upload");
				}
			}
			return RejectMessage("invalid POST upload request");
		}
		return RejectMessage("only rr_upload is supported for POST requests");
	}
	else
	{
		return RejectMessage("Unknown message type or not authenticated");
	}
}

// Reject the current message. Always returns true to indicate that we should stop reading the message.
bool Webserver::HttpInterpreter::RejectMessage(const char* response, unsigned int code)
{
	platform->MessageF(HOST_MESSAGE, "Webserver: rejecting message with: %s\n", response);

	NetworkTransaction *transaction = network->GetTransaction();
	transaction->Printf("HTTP/1.1 %u %s\nConnection: close\n\n", code, response);
	transaction->Commit(false);

	ResetState();

	return true;
}

// Authenticate current IP and return true on success
bool Webserver::HttpInterpreter::Authenticate()
{
	if (numSessions < maxHttpSessions)
	{
		sessions[numSessions].ip = network->GetTransaction()->GetRemoteIP();
		sessions[numSessions].lastQueryTime = platform->Time();
		sessions[numSessions].isPostUploading = false;
		numSessions++;
		return true;
	}
	return false;
}

bool Webserver::HttpInterpreter::IsAuthenticated() const
{
	const uint32_t remoteIP = network->GetTransaction()->GetRemoteIP();
	for(size_t i = 0; i < numSessions; i++)
	{
		if (sessions[i].ip == remoteIP)
		{
			return true;
		}
	}
	return false;
}

void Webserver::HttpInterpreter::UpdateAuthentication()
{
	const uint32_t remoteIP = network->GetTransaction()->GetRemoteIP();
	for(size_t i = 0; i < numSessions; i++)
	{
		if (sessions[i].ip == remoteIP)
		{
			sessions[i].lastQueryTime = platform->Time();
			break;
		}
	}
}

void Webserver::HttpInterpreter::RemoveAuthentication()
{
	const uint32_t remoteIP = network->GetTransaction()->GetRemoteIP();
	for(int i=(int)numSessions - 1; i>=0; i--)
	{
		if (sessions[i].ip == remoteIP)
		{
			for (size_t k = i + 1; k < numSessions; ++k)
			{
				memcpy(&sessions[k - 1], &sessions[k], sizeof(HttpSession));
			}
			numSessions--;
			break;
		}
	}
}

void Webserver::HttpInterpreter::CheckSessions()
{
	// Check if any HTTP session can be purged
	const float time = platform->Time();
	for (int i = numSessions - 1; i >=0 ; i--)
	{
		if (!sessions[i].isPostUploading && (time - sessions[i].lastQueryTime) > httpSessionTimeout)
		{
			for (size_t k = i + 1; k < numSessions; ++k)
			{
				memcpy(&sessions[k - 1], &sessions[k], sizeof(HttpSession));
			}
			numSessions--;
			clientsServed++;	// assume the disconnected client hasn't fetched the G-Code reply yet
		}
	}

	// If we cannot send the G-Code reply to anyone, we may free up some run-time space by dumping it
	if (numSessions == 0 || clientsServed >= numSessions)
	{
		while (!gcodeReply->IsEmpty())
		{
			OutputBuffer::ReleaseAll(gcodeReply->Pop());
		}
		clientsServed = 0;
	}
}

// Process a received string of gcodes
void Webserver::HttpInterpreter::LoadGcodeBuffer(const char* gc)
{
	char gcodeTempBuf[GCODE_LENGTH];
	uint16_t gtp = 0;
	bool inComment = false;
	for (;;)
	{
		char c = *gc++;
		if (c == 0)
		{
			gcodeTempBuf[gtp] = 0;
			ProcessGcode(gcodeTempBuf);
			return;
		}

		if (c == '\n')
		{
			gcodeTempBuf[gtp] = 0;
			ProcessGcode(gcodeTempBuf);
			gtp = 0;
			inComment = false;
		}
		else
		{
			if (c == ';')
			{
				inComment = true;
			}

			if (gtp == ARRAY_UPB(gcodeTempBuf))
			{
				// gcode is too long, we haven't room for another character and a null
				if (c != ' ' && !inComment)
				{
					platform->Message(HOST_MESSAGE, "Error: GCode local buffer overflow in HTTP webserver.\n");
					return;
				}
				// else we're either in a comment or the current character is a space.
				// If we're in a comment, we'll silently truncate it.
				// If the current character is a space, we'll wait until we see a non-comment character before reporting an error,
				// in case the next character is end-of-line or the start of a comment.
			}
			else
			{
				gcodeTempBuf[gtp++] = c;
			}
		}
	}
}

// Process a null-terminated gcode
// We intercept one M Codes so we can deal with emergencies.  That
// way things don't get out of sync, and - as a file name can contain
// a valid G code (!) - confusion is avoided.
void Webserver::HttpInterpreter::ProcessGcode(const char* gc)
{
	if (StringStartsWith(gc, "M112") && !isdigit(gc[4]))	// emergency stop
	{
		reprap.EmergencyStop();
		gcodeReadIndex = gcodeWriteIndex;					// clear the buffer
		reprap.GetGCodes()->Reset();
	}
	else
	{
		StoreGcodeData(gc, strlen(gc) + 1);
	}
}

// Process a received string of gcodes
void Webserver::HttpInterpreter::StoreGcodeData(const char* data, uint16_t len)
{
	if (len > GetGCodeBufferSpace())
	{
		platform->Message(HOST_MESSAGE, "Error: GCode buffer overflow in HTTP Webserver!\n");
	}
	else
	{
		uint16_t remaining = gcodeBufferLength - gcodeWriteIndex;
		if (len <= remaining)
		{
			memcpy(gcodeBuffer + gcodeWriteIndex, data, len);
		}
		else
		{
			memcpy(gcodeBuffer + gcodeWriteIndex, data, remaining);
			memcpy(gcodeBuffer, data + remaining, len - remaining);
		}
		gcodeWriteIndex = (gcodeWriteIndex + len) % gcodeBufferLength;
	}
}

// Feeding G Codes to the GCodes class
char Webserver::HttpInterpreter::ReadGCode()
{
	char c;
	if (gcodeReadIndex == gcodeWriteIndex)
	{
		c = 0;
	}
	else
	{
		c = gcodeBuffer[gcodeReadIndex];
		gcodeReadIndex = (gcodeReadIndex + 1u) % gcodeBufferLength;
	}
	return c;
}

// Handle a G Code reply from the GCodes class
void Webserver::HttpInterpreter::HandleGCodeReply(OutputBuffer *reply)
{
	if (reply != nullptr)
	{
		if (numSessions > 0)
		{
			// FIXME: This might cause G-code responses to be sent twice to fast HTTP clients, but
			// I (chrishamm) cannot think of a nicer way to deal with slow clients at the moment...
			gcodeReply->Push(reply);
			clientsServed = 0;
			seq++;
		}
		else
		{
			// Don't use buffers that may never get released...
			OutputBuffer::ReleaseAll(reply);
		}
	}
}

void Webserver::HttpInterpreter::HandleGCodeReply(const char *reply)
{
	if (numSessions > 0)
	{
		OutputBuffer *buffer = gcodeReply->GetLastItem();
		if (buffer == nullptr || buffer->IsReferenced())
		{
			if (!OutputBuffer::Allocate(buffer))
			{
				// No more space available, stop here
				return;
			}
			gcodeReply->Push(buffer);
		}

		buffer->cat(reply);
		seq++;
	}
}


//********************************************************************************************
//
//************************* FTP interpreter for the Webserver class **************************
//
//********************************************************************************************

Webserver::FtpInterpreter::FtpInterpreter(Platform *p, Webserver *ws, Network *n)
	: ProtocolInterpreter(p, ws, n), state(authenticating), clientPointer(0)
{
	connectedClients = 0;
	strcpy(currentDir, "/");
}

void Webserver::FtpInterpreter::Diagnostics()
{
	platform->MessageF(GENERIC_MESSAGE, "FTP connections: %d, state %d\n", connectedClients, state);
}

void Webserver::FtpInterpreter::ConnectionEstablished()
{
	connectedClients++;
	if (reprap.Debug(moduleWebserver))
	{
		platform->Message(HOST_MESSAGE, "Webserver: FTP connection established!\n");
	}

	// Is this a new connection on the data port?
	NetworkTransaction *transaction = network->GetTransaction();
	if (transaction->GetLocalPort() != FTP_PORT)
	{
		if (state == waitingForPasvPort)
		{
			// Yes - save it for the main request
			network->SaveDataConnection();
			state = pasvPortConnected;
		}
		else
		{
			// Should never get here...
			transaction->Commit(false);
		}
		return;
	}

	// A client is trying to connect to the main FTP port
	switch (state)
	{
		case idle:
		case authenticated:		// added by DC because without it, we can't transfer any files with FileZilla
			// We can safely deal with one connection on the main FTP port
			state = authenticating;
			SendReply(220, "RepRapFirmware FTP server", true);
			break;

		default:
			// But don't allow multiple ones, this could mess things up
			SendReply(421, "Only one client can be connected at a time.", false);
			return;
	}
}

void Webserver::FtpInterpreter::ConnectionLost(uint32_t remoteIP, uint16_t remotePort, uint16_t localPort)
{
	connectedClients--;

	if (localPort != FTP_PORT)
	{
		// Close the data port
		network->CloseDataPort();

		// Send response
		if (network->AcquireFTPTransaction())
		{
			if (state == doingPasvIO)
			{
				if (uploadState != uploadError)
				{
					SendReply(226, "Transfer complete.");
				}
				else
				{
					SendReply(526, "Upload failed!");
				}
			}
			else
			{
				SendReply(550, "Lost data connection!");
			}
		}

		// Do file handling
		if (IsUploading())
		{
			FinishUpload(0);
			uploadState = notUploading;
		}
		state = authenticated;
	}
	else if (connectedClients == 0)
	{
		// Last one gone now...
		ResetState();
	}
}

bool Webserver::FtpInterpreter::CharFromClient(char c)
{
	if (clientPointer == ARRAY_UPB(clientMessage))
	{
		clientPointer = 0;
		platform->Message(HOST_MESSAGE, "Webserver: Buffer overflow in FTP server!\n");
		return true;
	}

	switch (c)
	{
		case 0:
			break;

		case '\r':
		case '\n':
			clientMessage[clientPointer++] = 0;

			if (reprap.Debug(moduleWebserver))
			{
				platform->MessageF(HOST_MESSAGE, "FtpInterpreter::ProcessLine called with state %d:\n%s\n", state, clientMessage);
			}

			if (clientPointer > 1) // only process a new line if we actually received data
			{
				ProcessLine();
				clientPointer = 0;
				return true;
			}

			if (reprap.Debug(moduleWebserver))
			{
				platform->Message(HOST_MESSAGE, "FtpInterpreter::ProcessLine call finished.\n");
			}

			clientPointer = 0;
			break;

		default:
			clientMessage[clientPointer++] = c;
			break;
	}

	return false;
}

void Webserver::FtpInterpreter::ResetState()
{
	clientPointer = 0;
	strcpy(currentDir, "/");

	network->CloseDataPort();
	CancelUpload();

	state = idle;
}

bool Webserver::FtpInterpreter::DoingFastUpload() const
{
	return (IsUploading() && network->GetTransaction()->GetLocalPort() == network->GetDataPort());
}

// return true if an error has occurred, false otherwise
void Webserver::FtpInterpreter::ProcessLine()
{
	switch (state)
	{
		case idle:
		case authenticating:
			// don't check the user name
			if (StringStartsWith(clientMessage, "USER"))
			{
				SendReply(331, "Please specify the password.");
			}
			// but check the password
			else if (StringStartsWith(clientMessage, "PASS"))
			{
				char pass[PASSWORD_LENGTH];
				int pass_length = 0;
				bool reading_pass = false;
				for(size_t i = 4; i < clientPointer && i < PASSWORD_LENGTH + 3; i++)
				{
					reading_pass |= (clientMessage[i] != ' ' && clientMessage[i] != '\t');
					if (reading_pass)
					{
						pass[pass_length++] = clientMessage[i];
					}
				}
				pass[pass_length] = 0;

				if (reprap.CheckPassword(pass))
				{
					state = authenticated;
					SendReply(230, "Login successful.");
				}
				else
				{
					SendReply(530, "Login incorrect.", false);
				}
			}
			// if it's different, send response 500 to indicate we don't know the code (might be AUTH or so)
			else
			{
				SendReply(500, "Unknown login command.");
			}

			break;

		case authenticated:
			// get system type
			if (StringEquals(clientMessage, "SYST"))
			{
				SendReply(215, "UNIX Type: L8");
			}
			// get features
			else if (StringEquals(clientMessage, "FEAT"))
			{
				SendFeatures();
			}
			// get current dir
			else if (StringEquals(clientMessage, "PWD"))
			{
				snprintf(ftpResponse, ftpResponseLength, "\"%s\"", currentDir);
				SendReply(257, ftpResponse);
			}
			// set current dir
			else if (StringStartsWith(clientMessage, "CWD"))
			{
				ReadFilename(3);
				ChangeDirectory(filename);
			}
			// change to parent of current directory
			else if (StringEquals(clientMessage, "CDUP"))
			{
				ChangeDirectory("..");
			}
			// switch transfer mode (sends response, but doesn't have any effects)
			else if (StringStartsWith(clientMessage, "TYPE"))
			{
				for(unsigned int i=4; i<clientPointer; i++)
				{
					if (clientMessage[i] == 'I')
					{
						SendReply(200, "Switching to Binary mode.");
						return;
					}

					if (clientMessage[i] == 'A')
					{
						SendReply(200, "Switching to ASCII mode.");
						return;
					}
				}

				SendReply(500, "Unknown command.");
			}
			// enter passive mode mode
			else if (StringEquals(clientMessage, "PASV"))
			{
				/* get local IP address */
				const byte *ip_address = network->IPAddress();

				/* open random port > 1023 */
				rand();
				uint16_t pasv_port = random(1024, 65535);
				network->OpenDataPort(pasv_port);
				portOpenTime = platform->Time();
				state = waitingForPasvPort;

				/* send FTP response */
				snprintf(ftpResponse, ftpResponseLength, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)",
						ip_address[0], ip_address[1], ip_address[2], ip_address[3],
						pasv_port / 256, pasv_port % 256);
				SendReply(227, ftpResponse);
			}
			// PASV commands are not supported in this state
			else if (StringEquals(clientMessage, "LIST") || StringStartsWith(clientMessage, "RETR") || StringStartsWith(clientMessage, "STOR"))
			{
				SendReply(425, "Use PASV first.");
			}
			// delete file
			else if (StringStartsWith(clientMessage, "DELE"))
			{
				ReadFilename(4);
				if (platform->GetMassStorage()->Delete(currentDir, filename))
				{
					SendReply(250, "Delete operation successful.");
				}
				else
				{
					SendReply(550, "Delete operation failed.");
				}
			}
			// delete directory
			else if (StringStartsWith(clientMessage, "RMD"))
			{
				ReadFilename(3);
				if (platform->GetMassStorage()->Delete(currentDir, filename))
				{
					SendReply(250, "Remove directory operation successful.");
				}
				else
				{
					SendReply(550, "Remove directory operation failed.");
				}
			}
			// make new directory
			else if (StringStartsWith(clientMessage, "MKD"))
			{
				ReadFilename(3);
				const char *location = (filename[0] == '/')
										? filename
											: platform->GetMassStorage()->CombineName(currentDir, filename);

				if (platform->GetMassStorage()->MakeDirectory(location))
				{
					snprintf(ftpResponse, ftpResponseLength, "\"%s\" created", location);
					SendReply(257, ftpResponse);
				}
				else
				{
					SendReply(550, "Create directory operation failed.");
				}
			}
			// rename file or directory
			else if (StringStartsWith(clientMessage, "RNFR"))
			{
				ReadFilename(4);
				if (filename[0] != '/')
				{
					const char *temp = platform->GetMassStorage()->CombineName(currentDir, filename);
					strncpy(filename, temp, FILENAME_LENGTH);
					filename[FILENAME_LENGTH - 1] = 0;
				}

				if (platform->GetMassStorage()->FileExists(filename))
				{
					SendReply(350, "Ready to RNTO.");
				}
				else
				{
					SendReply(550, "Invalid file or directory.");
				}
			}
			else if (StringStartsWith(clientMessage, "RNTO"))
			{
				// Copy origin path to temp oldFilename and read new path
				char oldFilename[FILENAME_LENGTH];
				strncpy(oldFilename, filename, FILENAME_LENGTH);
				oldFilename[FILENAME_LENGTH - 1] = 0;
				ReadFilename(4);

				const char *newFilename = platform->GetMassStorage()->CombineName(currentDir, filename);
				if (platform->GetMassStorage()->Rename(oldFilename, newFilename))
				{
					SendReply(250, "Rename successful.");
				}
				else
				{
					SendReply(500, "Could not rename file or directory.");
				}
			}
			// no op
			else if (StringEquals(clientMessage, "NOOP"))
			{
				SendReply(200, "NOOP okay.");
			}
			// end connection
			else if (StringEquals(clientMessage, "QUIT"))
			{
				SendReply(221, "Goodbye.", false);
				ResetState();
			}
			// unknown
			else
			{
				SendReply(500, "Unknown command.");
			}

			break;

		case waitingForPasvPort:
			if (!reprap.Debug(moduleWebserver) && platform->Time() - portOpenTime > ftpPasvPortTimeout)
			{
				SendReply(425, "Failed to establish connection.");

				network->CloseDataPort();
				state = authenticated;
			}
			else
			{
				network->WaitForDataConection();
			}

			break;

		case pasvPortConnected:
			// save current connection state so we can send '226 Transfer complete.' when ConnectionLost() is called
			network->SaveFTPConnection();

			// list directory entries
			if (StringEquals(clientMessage, "LIST"))
			{
				// send response via main port
				strncpy(ftpResponse, "150 Here comes the directory listing.\r\n", ftpResponseLength);
				NetworkTransaction *transaction = network->GetTransaction();
				transaction->Write(ftpResponse);
				transaction->Commit(true);

				// send file list via data port
				if (network->AcquireDataTransaction())
				{
					NetworkTransaction *dataTransaction = network->GetTransaction();

					FileInfo fileInfo;
					if (platform->GetMassStorage()->FindFirst(currentDir, fileInfo))
					{
						char line[ftpFileListLineLength];

						do {
							// Example for a typical UNIX-like file list:
							// "drwxr-xr-x    2 ftp      ftp             0 Apr 11 2013 bin\r\n"
							char dirChar = (fileInfo.isDirectory) ? 'd' : '-';
							const uint8_t month = (fileInfo.month == 0) ? 1 : fileInfo.month; // without this check FileZilla won't display incomplete uploads properly
							snprintf(line, ARRAY_SIZE(line), "%crw-rw-rw- 1 ftp ftp %13lu %s %02d %04d %s\r\n",
									dirChar, fileInfo.size, platform->GetMassStorage()->GetMonthName(month),
									fileInfo.day, fileInfo.year, fileInfo.fileName);

							// Fortunately we don't need to bother with output buffer chunks any more...
							dataTransaction->Write(line);
						} while (platform->GetMassStorage()->FindNext(fileInfo));
					}

					dataTransaction->Commit(false);
					state = doingPasvIO;
				}
				else
				{
					SendReply(500, "Unknown error.");
					network->CloseDataPort();
					state = authenticated;
				}
			}
			// upload a file
			else if (StringStartsWith(clientMessage, "STOR"))
			{
				ReadFilename(4);

				FileStore *file = platform->GetFileStore(currentDir, filename, true);
				if (StartUpload(file))
				{
					strncpy(filenameBeingUploaded, filename, ARRAY_SIZE(filenameBeingUploaded));
					filenameBeingUploaded[ARRAY_UPB(filenameBeingUploaded)] = 0;

					SendReply(150, "OK to send data.");
					state = doingPasvIO;
				}
				else
				{
					SendReply(550, "Failed to open file.");
					network->CloseDataPort();
					state = authenticated;
				}
			}
			// download a file
			else if (StringStartsWith(clientMessage, "RETR"))
			{
				ReadFilename(4);

				FileStore *file = platform->GetFileStore(currentDir, filename, false);
				if (file == nullptr)
				{
					SendReply(550, "Failed to open file.");
				}
				else
				{
					snprintf(ftpResponse, ftpResponseLength, "Opening data connection for %s (%lu bytes).", filename, file->Length());
					SendReply(150, ftpResponse);

					if (network->AcquireDataTransaction())
					{
						// send the file via data port
						NetworkTransaction *dataTransaction = network->GetTransaction();
						dataTransaction->SetFileToWrite(file);
						dataTransaction->Commit(false);
						state = doingPasvIO;
					}
					else
					{
						file->Close();
						SendReply(500, "Unknown error.");
						network->CloseDataPort();
						state = authenticated;
					}
				}
			}
			// unknown command
			else
			{
				SendReply(500, "Unknown command.");
				network->CloseDataPort();
				state = authenticated;
			}

			break;

		case doingPasvIO:
			// abort current transfer
			if (StringEquals(clientMessage, "ABOR"))
			{
				if (IsUploading())
				{
					CancelUpload();
					SendReply(226, "ABOR successful.");
				}
				else
				{
					network->CloseDataPort();
					SendReply(226, "ABOR successful.");
				}
			}
			// unknown command
			else
			{
				SendReply(500, "Unknown command.");
				network->CloseDataPort();
				state = authenticated;
			}

			break;
	}
}

void Webserver::FtpInterpreter::SendReply(int code, const char *message, bool keepConnection)
{
	NetworkTransaction *transaction = network->GetTransaction();
	transaction->Printf("%d %s\r\n", code, message);
	transaction->Commit(keepConnection);
}

void Webserver::FtpInterpreter::SendFeatures()
{
	NetworkTransaction *transaction = network->GetTransaction();
	transaction->Write("211-Features:\r\n");
	transaction->Write("PASV\r\n");		// support PASV mode
	transaction->Write("211 End\r\n");
	transaction->Commit(true);
}

void Webserver::FtpInterpreter::ReadFilename(uint16_t start)
{
	int filenameLength = 0;
	bool readingPath = false;
	for(int i = start; i < (int)clientPointer && filenameLength < (int)(FILENAME_LENGTH - 1); i++)
	{
		switch (clientMessage[i])
		{
			// ignore quotes
			case '"':
			case '\'':
				break;

			// skip whitespaces unless the actual filename is being read
			case ' ':
			case '\t':
				if (readingPath)
				{
					filename[filenameLength++] = clientMessage[i];
				}
				break;

			// read path name
			default:
				readingPath = true;
				filename[filenameLength++] = clientMessage[i];
				break;
		}
	}
	filename[filenameLength] = 0;
}

void Webserver::FtpInterpreter::ChangeDirectory(const char *newDirectory)
{
	char combinedPath[FILENAME_LENGTH];

	if (newDirectory[0] != 0)
	{
		/* Prepare the new directory path */
		if (newDirectory[0] == '/') // absolute path
		{
			strncpy(combinedPath, newDirectory, FILENAME_LENGTH);
			combinedPath[FILENAME_LENGTH - 1] = 0;
		}
		else // relative path
		{
			if (StringEquals(newDirectory, "..")) // go up
			{
				if (StringEquals(currentDir, "/"))
				{
					// we're already at the root, so we can't go up any more
					SendReply(550, "Failed to change directory.");
					return;
				}
				else
				{
					strncpy(combinedPath, currentDir, FILENAME_LENGTH);
					for(int i=strlen(combinedPath) -2; i>=0; i--)
					{
						if (combinedPath[i] == '/')
						{
							combinedPath[i +1] = 0;
							break;
						}
					}
				}
			}
			else // go to child directory
			{
				strncpy(combinedPath, currentDir, FILENAME_LENGTH);
				if (strlen(currentDir) > 1)
				{
					strncat(combinedPath, "/", FILENAME_LENGTH - strlen(combinedPath) - 1);
				}
				strncat(combinedPath, newDirectory, FILENAME_LENGTH - strlen(combinedPath) - 1);
			}
		}

		/* Make sure the new path does not end with a '/', because FatFs won't see the directory otherwise */
		if (StringEndsWith(combinedPath, "/") && strlen(combinedPath) > 1)
		{
			combinedPath[strlen(combinedPath) -1] = 0;
		}

		/* Verify path and change it */
		if (platform->GetMassStorage()->DirectoryExists(combinedPath))
		{
			strncpy(currentDir, combinedPath, FILENAME_LENGTH);
			SendReply(250, "Directory successfully changed.");
		}
		else
		{
			SendReply(550, "Failed to change directory.");
		}
	}
	else
	{
		SendReply(550, "Failed to change directory.");
	}
}


//********************************************************************************************
//
//*********************** Telnet interpreter for the Webserver class *************************
//
//********************************************************************************************

Webserver::TelnetInterpreter::TelnetInterpreter(Platform *p, Webserver *ws, Network *n)
	: ProtocolInterpreter(p, ws, n)
{
	connectedClients = 0;
	gcodeReadIndex = gcodeWriteIndex = 0;
	gcodeReply = nullptr;
	ResetState();
}

void Webserver::TelnetInterpreter::Diagnostics()
{
	platform->MessageF(GENERIC_MESSAGE, "Telnet connections: %d\n", connectedClients);
}

void Webserver::TelnetInterpreter::ConnectionEstablished()
{
	connectedClients++;
	NetworkTransaction *transaction = network->GetTransaction();

	// Only one client may be connected via Telnet at once, so check this first
	if (state != idle)
	{
		transaction->Write("Sorry, only one client may be connected via Telnet at once.\r\n");
		transaction->Commit(false);
		return;
	}
	state = justConnected;
	connectTime = platform->Time();

	// Check whether we need a password to log in
	if (reprap.NoPasswordSet())
	{
		// Don't send a login prompt if no password is set, so we don't mess up Pronterface
		transaction->Discard();
	}
	else
	{
		transaction->Write("RepRapFirmware Telnet interface\r\n\r\n");
		transaction->Write("Please enter your password:\r\n");
		transaction->Write("> ");
		transaction->Commit(true);
	}
}

void Webserver::TelnetInterpreter::ConnectionLost(uint32_t remoteIP, uint16_t remotePort, uint16_t localPort)
{
	connectedClients--;
	if (connectedClients == 0)
	{
		ResetState();

		// Don't save up output buffers if they can't be sent
		OutputBuffer::ReleaseAll(gcodeReply);
		gcodeReply = nullptr;
	}
}

bool Webserver::TelnetInterpreter::CharFromClient(char c)
{
	// If this is likely to be a Telnet setup message (with some garbage in it), dump the first
	// received packet and move on to the next state
	if (state == justConnected)
	{
		if (reprap.NoPasswordSet())
		{
			state = authenticated;
			network->SaveTelnetConnection();
		}
		else
		{
			state = authenticating;
		}

		if (platform->Time() - connectTime < telnetSetupDuration)
		{
			network->GetTransaction()->Discard();
			return true;
		}
	}

	// Otherwise try to read one line at a time
	switch (c)
	{
		case 0:
			break;

		case '\r':
		case '\n':
			if (clientPointer != 0)
			{
				clientMessage[clientPointer] = 0;
				ProcessLine();
				clientPointer = 0;
			}
			return true;

		default:
			clientMessage[clientPointer++] = c;
			if (clientPointer == ARRAY_UPB(clientMessage))
			{
				clientPointer = 0;
				platform->Message(HOST_MESSAGE, "Webserver: Buffer overflow in Telnet server!\n");
				return true;
			}
			break;
	}

	return false;
}

void Webserver::TelnetInterpreter::ResetState()
{
	state = idle;
	connectTime = 0.0;
	clientPointer = 0;
}

void Webserver::TelnetInterpreter::ProcessLine()
{
	NetworkTransaction *transaction = network->GetTransaction();
	switch (state)
	{
		case idle:
		case justConnected:
			// Should never get here...

		case authenticating:
			if (reprap.CheckPassword(clientMessage))
			{
				network->SaveTelnetConnection();
				state = authenticated;

				transaction->Write("Log in successful!\r\n");
				transaction->Commit(true);
			}
			else
			{
				transaction->Write("Invalid password.\r\n> ");
				transaction->Commit(true);
			}
			break;

		case authenticated:
			// Special commands for Telnet
			if (StringEquals(clientMessage, "exit") || StringEquals(clientMessage, "quit"))
			{
				transaction->Write("Goodbye.\r\n");
				transaction->Commit(false);
			}
			// All other commands are processed by the Webserver
			else
			{
				ProcessGcode(clientMessage);
				if (HasDataToSend())
				{
					SendGCodeReply(transaction);
				}
				else
				{
					transaction->Discard();
				}
			}
			break;
	}
}

// Process a null-terminated gcode
// We intercept one M Codes so we can deal with emergencies.  That
// way things don't get out of sync, and - as a file name can contain
// a valid G code (!) - confusion is avoided.
void Webserver::TelnetInterpreter::ProcessGcode(const char* gc)
{
	if (StringStartsWith(gc, "M112") && !isdigit(gc[4]))	// emergency stop
	{
		reprap.EmergencyStop();
		gcodeReadIndex = gcodeWriteIndex;					// clear the buffer
		reprap.GetGCodes()->Reset();
	}
	else
	{
		StoreGcodeData(gc, strlen(gc) + 1);
	}
}

// Process a received string of gcodes
void Webserver::TelnetInterpreter::StoreGcodeData(const char* data, uint16_t len)
{
	if (len > GetGCodeBufferSpace())
	{
		platform->Message(HOST_MESSAGE, "Error: GCode buffer overflow in Telnet Webserver!\n");
	}
	else
	{
		uint16_t remaining = gcodeBufferLength - gcodeWriteIndex;
		if (len <= remaining)
		{
			memcpy(gcodeBuffer + gcodeWriteIndex, data, len);
		}
		else
		{
			memcpy(gcodeBuffer + gcodeWriteIndex, data, remaining);
			memcpy(gcodeBuffer, data + remaining, len - remaining);
		}
		gcodeWriteIndex = (gcodeWriteIndex + len) % gcodeBufferLength;
	}
}

// Feeding G Codes to the GCodes class
char Webserver::TelnetInterpreter::ReadGCode()
{
	char c;
	if (gcodeReadIndex == gcodeWriteIndex)
	{
		c = 0;
	}
	else
	{
		c = gcodeBuffer[gcodeReadIndex];
		gcodeReadIndex = (gcodeReadIndex + 1u) % gcodeBufferLength;
	}
	return c;
}

// Handle a G-Code reply from the GCodes class; replace \n with \r\n
void Webserver::TelnetInterpreter::HandleGCodeReply(OutputBuffer *reply)
{
	if (reply != nullptr && state >= authenticated && network->AcquireTelnetTransaction())
	{
		// We need a valid OutputBuffer to start the conversion
		if (gcodeReply == nullptr)
		{
			OutputBuffer *buffer;
			if (!OutputBuffer::Allocate(buffer))
			{
				OutputBuffer::Truncate(reply, OUTPUT_BUFFER_SIZE);
				if (!OutputBuffer::Allocate(buffer))
				{
					// If we're really short on memory, release the G-Code reply instantly
					OutputBuffer::ReleaseAll(reply);
					return;
				}
			}
			gcodeReply = buffer;
		}

		// Write entire content to new output buffers, but this time with \r\n instead of \n
		do {
			const char *data = reply->Data();
			for(size_t i = 0; i < reply->DataLength(); i++)
			{
				if (*data == '\n')
				{
					gcodeReply->cat('\r');
				}

				gcodeReply->cat(*data);
				data++;
			}
			reply = OutputBuffer::Release(reply);
		} while (reply != nullptr);
	}
	else
	{
		// Don't use buffers that may never get released...
		OutputBuffer::ReleaseAll(reply);
	}
}

void Webserver::TelnetInterpreter::HandleGCodeReply(const char *reply)
{
	if (reply != nullptr && state >= authenticated && network->AcquireTelnetTransaction())
	{
		// We need a valid OutputBuffer to start the conversion
		if (gcodeReply == nullptr)
		{
			OutputBuffer *buffer;
			if (!OutputBuffer::Allocate(buffer))
			{
				// No more space available to store this reply, stop here
				return;
			}
			gcodeReply = buffer;
		}

		// Write entire content to new output buffers, but this time with \r\n instead of \n
		while (*reply != 0)
		{
			if (*reply == '\n' && gcodeReply->cat('\r') == 0)
			{
				// No more space available, stop here
				return;
			}
			if (gcodeReply->cat(*reply) == 0)
			{
				// No more space available, stop here
				return;
			}
			reply++;
		};
	}
}

void Webserver::TelnetInterpreter::SendGCodeReply(NetworkTransaction *transaction)
{
	transaction->Write(gcodeReply);
	gcodeReply = nullptr;

	transaction->Commit(true);
}

// vim: ts=4:sw=4