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

 RepRapFirmware network comms to ESP8266-based device

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

#include "Network.h"
#include "Platform.h"
#include "RepRap.h"
#include "HttpResponder.h"
#include "FtpResponder.h"
#include "TelnetResponder.h"
#include "WifiFirmwareUploader.h"

// Define exactly one of the following as 1, the other as zero
// The PDC seems to be too slow to work reliably without getting transmit underruns, so we use the DMAC now.
#define USE_PDC		0		// use peripheral DMA controller
#define USE_DMAC	1		// use general DMA controller

#if USE_PDC
#include "pdc.h"
#endif

#if USE_DMAC
#include "dmac.h"
#endif

#include "matrix.h"

const uint32_t WifiResponseTimeoutMillis = 200;
const uint32_t WiFiStartupMillis = 300;
const uint32_t WiFiStableMillis = 100;

const unsigned int MaxHttpConnections = 4;

const Port DefaultPortNumbers[NumProtocols] = { DefaultHttpPort, DefaultFtpPort, DefaultTelnetPort };
const char * const ProtocolNames[NumProtocols] = { "HTTP", "FTP", "TELNET" };

// Forward declarations of static functions
static void spi_dma_disable();
static bool spi_dma_check_rx_complete();

struct MessageBufferOut
{
	MessageHeaderSamToEsp hdr;
	uint8_t data[MaxDataLength];	// data to send
};

struct MessageBufferIn
{
	MessageHeaderEspToSam hdr;
	uint8_t data[MaxDataLength];	// data to send
};

static MessageBufferOut bufferOut;
static MessageBufferIn bufferIn;
static volatile bool transferPending = false;

#if 0
static void debugPrintBuffer(const char *msg, void *buf, size_t dataLength)
{
	const size_t MaxDataToPrint = 20;
	const uint8_t * const data = reinterpret_cast<const uint8_t *>(buf);
	debugPrintf("%s %02x %02x %02x %02x %04x %04x %08x",
		msg,
		data[0], data[1], data[2], data[3],
		*reinterpret_cast<const uint16_t*>(data + 4), *reinterpret_cast<const uint16_t*>(data + 6),
		*reinterpret_cast<const uint32_t*>(data + 8));
	if (dataLength != 0)
	{
		debugPrintf(" ");
		for (size_t i = 0; i < min<size_t>(dataLength, MaxDataToPrint); ++i)
		{
			debugPrintf("%02x", data[i + 12]);
		}
		if (dataLength > MaxDataToPrint)
		{
			debugPrintf("...");
		}
	}
	debugPrintf("\n");
}
#endif

static void EspTransferRequestIsr()
{
	reprap.GetNetwork().EspRequestsTransfer();
}

static inline void EnableEspInterrupt()
{
	attachInterrupt(EspTransferRequestPin, EspTransferRequestIsr, RISING);
}

static inline void DisableEspInterrupt()
{
	detachInterrupt(EspTransferRequestPin);
}

/*-----------------------------------------------------------------------------------*/
// WiFi interface class

Network::Network(Platform& p) : platform(p), nextResponderToPoll(nullptr), uploader(nullptr), currentSocket(0), ftpDataPort(0),
		state(NetworkState::disabled), requestedMode(WiFiState::disabled), currentMode(WiFiState::disabled), activated(false),
		espStatusChanged(false), spiTxUnderruns(0), spiRxOverruns(0)
{
	for (size_t i = 0; i < NumProtocols; ++i)
	{
		portNumbers[i] = DefaultPortNumbers[i];
		protocolEnabled[i] = (i == HttpProtocol);
	}

	// Create the responders
	responders = telnetResponder = new TelnetResponder(nullptr);
	responders = ftpResponder = new FtpResponder(responders);
	for (unsigned int i = 0; i < NumHttpResponders; ++i)
	{
		responders = new HttpResponder(responders);
	}

	strcpy(ssid, "(unknown)");
	strcpy(wiFiServerVersion, "(unknown)");
}

void Network::Init()
{
	// Make sure the ESP8266 is held in the reset state
	ResetWiFi();
	longWait = platform.Time();
	lastTickMillis = millis();

	NetworkBuffer::AllocateBuffers(NetworkBufferCount);

	SetIPAddress(DefaultIpAddress, DefaultNetMask, DefaultGateway);
	strcpy(hostname, HOSTNAME);

	for (size_t i = 0; i < NumTcpSockets; ++i)
	{
		sockets[i].Init(i);
	}

	uploader = new WifiFirmwareUploader(Serial1);
	currentSocket = 0;
}

void Network::EnableProtocol(int protocol, int port, int secure, StringRef& reply)
{
	if (secure != 0 && secure != -1)
	{
		reply.copy("Error: this firmware does not support TLS");
	}
	else if (protocol >= 0 && protocol < (int)NumProtocols)
	{
		const Port portToUse = (port < 0) ? DefaultPortNumbers[protocol] : port;
		if (portToUse != portNumbers[protocol] && state == NetworkState::active)
		{
			// We need to shut down and restart the protocol if it is active because the port number has changed
			ShutdownProtocol(protocol);
			protocolEnabled[protocol] = false;
		}
		portNumbers[protocol] = portToUse;
		if (!protocolEnabled[protocol])
		{
			protocolEnabled[protocol] = true;
			if (state == NetworkState::active)
			{
				StartProtocol(protocol);
				// mDNS announcement is done by the WiFi Server firmware
			}
		}
		ReportOneProtocol(protocol, reply);
	}
	else
	{
		reply.copy("Invalid protocol parameter");
	}
}

void Network::DisableProtocol(int protocol, StringRef& reply)
{
	if (protocol >= 0 && protocol < (int)NumProtocols)
	{
		if (state == NetworkState::active)
		{
			ShutdownProtocol(protocol);
		}
		protocolEnabled[protocol] = false;
		ReportOneProtocol(protocol, reply);
	}
	else
	{
		reply.copy("Invalid protocol parameter");
	}
}

void Network::StartProtocol(Protocol protocol)
{
	switch(protocol)
	{
	case HttpProtocol:
		SendListenCommand(portNumbers[protocol], protocol, MaxHttpConnections);
		break;

	case FtpProtocol:
		SendListenCommand(portNumbers[protocol], protocol, 1);
		break;

	case TelnetProtocol:
		SendListenCommand(portNumbers[protocol], protocol, 1);
		break;

	default:
		break;
	}
}

void Network::ShutdownProtocol(Protocol protocol)
{
	for (NetworkResponder* r = responders; r != nullptr; r = r->GetNext())
	{
		r->Terminate(protocol);
	}
	switch(protocol)
	{
	case HttpProtocol:
		SendListenCommand(portNumbers[protocol], protocol, 0);
		TerminateSockets(portNumbers[protocol]);
		break;

	case FtpProtocol:
		SendListenCommand(portNumbers[protocol], protocol, 0);
		TerminateSockets(portNumbers[protocol]);
		if (ftpDataPort != 0)
		{
			TerminateSockets(ftpDataPort);
		}
		break;

	case TelnetProtocol:
		SendListenCommand(portNumbers[protocol], protocol, 0);
		TerminateSockets(portNumbers[protocol]);
		break;

	default:
		break;
	}
}

// Report the protocols and ports in use
void Network::ReportProtocols(StringRef& reply) const
{
	reply.Clear();
	for (size_t i = 0; i < NumProtocols; ++i)
	{
		if (i != 0)
		{
			reply.cat('\n');
		}
		ReportOneProtocol(i, reply);
	}
}

void Network::ReportOneProtocol(Protocol protocol, StringRef& reply) const
{
	if (protocolEnabled[protocol])
	{
		reply.catf("%s is enabled on port %u", ProtocolNames[protocol], portNumbers[protocol]);
	}
	else
	{
		reply.catf("%s is disabled", ProtocolNames[protocol]);
	}
}

// This is called at the end of config.g processing.
// Start the network if it was enabled
void Network::Activate()
{
	if (!activated)
	{
		activated = true;
		if (requestedMode != WiFiState::disabled)
		{
			Start();
		}
		else
		{
			platform.Message(HOST_MESSAGE, "Network disabled.\n");
		}
	}
}

void Network::Exit()
{
	Stop();
}

// Get the network state into the reply buffer, returning true if there is some sort of error
bool Network::GetNetworkState(StringRef& reply)
{
	switch (state)
	{
	case NetworkState::disabled:
		reply.copy("WiFi module is disabled");
		break;
	case NetworkState::starting1:
	case NetworkState::starting2:
		reply.copy("WiFi module is being started");
		break;
	case NetworkState::changingMode:
		reply.copy("WiFi module is changing mode");
		break;
	case NetworkState::active:
		reply.copy("WiFi module is ");
		reply.cat(TranslateWiFiState(currentMode));
		if (currentMode == WiFiState::connected || currentMode == WiFiState::runningAsAccessPoint)
		{
			reply.catf("%s, IP address %u.%u.%u.%u", ssid, ipAddress[0], ipAddress[1], ipAddress[2], ipAddress[3]);
		}
		break;
	default:
		reply.copy("Unknown network state");
		return true;
		break;
	}
	return false;
}

// Start up the ESP. We assume it is not already started.
// ESP8266 boot modes:
// GPIO0	GPIO2	GPIO15
// 0		1		0		Firmware download from UART
// 1		1		0		Normal boot from flash memory
// 0		0		1		SD card boot (not used on Duet)
void Network::Start()
{
	// The ESP8266 is held in a reset state by a pulldown resistor until we enable it.
	// Make sure the ESP8266 is in the reset state
	pinMode(EspResetPin, OUTPUT_LOW);

	// Take the ESP8266 out of power down
	pinMode(EspEnablePin, OUTPUT_HIGH);

	// Set up our transfer request pin (GPIO4) as an output and set it low
	pinMode(SamTfrReadyPin, OUTPUT_LOW);

	// Set up our data ready pin (ESP GPIO0) as an output and set it high ready to boot the ESP from flash
	pinMode(EspTransferRequestPin, OUTPUT_HIGH);

	// GPIO2 also needs to be high to boot. It's connected to MISO on the SAM, so set the pullup resistor on that pin
	pinMode(APIN_SPI_MISO, INPUT_PULLUP);

	// Set our CS input (ESP GPIO15) low ready for booting the ESP. This also clears the transfer ready latch.
	pinMode(SamCsPin, OUTPUT_LOW);

	// Make sure it has time to reset - no idea how long it needs, but 20ms should be plenty
	delay(50);

	// Release the reset on the ESP8266
	digitalWrite(EspResetPin, HIGH);

	// Give it time to sample GPIO0 and GPIO15
	// GPIO0 has to be held high for sufficient time:
	// - 10ms is not enough
	// - 18ms after reset is released, an oscillating signal appears on GPIO0 for 55ms
	// - so 18ms is probably long enough. Use 50ms for safety.
	delay(50);

	// Relinquish control of our CS pin so that the ESP can take it over
	pinMode(SamCsPin, INPUT);

	// Set the data request pin to be an input
	pinMode(EspTransferRequestPin, INPUT_PULLUP);

	// The ESP takes about 300ms before it starts talking to us, so don't wait for it here, do that in Spin()
	spiTxUnderruns = spiRxOverruns = 0;

	lastTickMillis = millis();
	state = NetworkState::starting1;
}

// Stop the ESP
void Network::Stop()
{
	if (state != NetworkState::disabled)
	{
		digitalWrite(SamTfrReadyPin, LOW);			// tell the ESP we can't receive
		digitalWrite(EspResetPin, LOW);				// put the ESP back into reset
		DisableEspInterrupt();						// ignore IRQs from the transfer request pin

		NVIC_DisableIRQ(SPI_IRQn);
		spi_disable(SPI);
		spi_dma_check_rx_complete();
		spi_dma_disable();

		state = NetworkState::disabled;
		currentMode = WiFiState::disabled;
	}
}

void Network::Spin(bool full)
{
	// Main state machine.
	switch (state)
	{
	case NetworkState::starting1:
		if (full)
		{
			// The ESP toggles CS before it has finished starting up, so don't look at the CS signal too soon
			const uint32_t now = millis();
			if (now - lastTickMillis >= WiFiStartupMillis)
			{
				lastTickMillis = now;
				state = NetworkState::starting2;
			}
		}
		break;

	case NetworkState::starting2:
		if (full)
		{
			// See if the ESP8266 has kept its pins at their stable values for long enough
			const uint32_t now = millis();
			if (digitalRead(SamCsPin) && digitalRead(EspTransferRequestPin) && !digitalRead(APIN_SPI_SCK))
			{
				if (now - lastTickMillis >= WiFiStableMillis)
				{
					// Setup the SPI controller in slave mode and assign the CS pin to it
					platform.Message(NETWORK_INFO_MESSAGE, "WiFi module started\n");
					SetupSpi();									// set up the SPI subsystem

					// Read the status to get the WiFi server version
					Receiver<NetworkStatusResponse> status;
					const int32_t rc = SendCommand(NetworkCommand::networkGetStatus, 0, 0, nullptr, 0, status);
					if (rc > 0)
					{
						SafeStrncpy(wiFiServerVersion, status.Value().versionText, ARRAY_SIZE(wiFiServerVersion));

						// Set the hostname before anything else is done
						if (SendCommand(NetworkCommand::networkSetHostName, 0, 0, hostname, HostNameLength, nullptr, 0) != ResponseEmpty)
						{
							reprap.GetPlatform().Message(NETWORK_INFO_MESSAGE, "Error: Could not set WiFi hostname\n");
						}

						state = NetworkState::active;
						espStatusChanged = true;				// make sure we fetch the current state and enable the ESP interrupt
					}
					else
					{
						// Something went wrong, maybe a bad firmware image was flashed
						// Disable the WiFi chip again in this case
						platform.MessageF(NETWORK_INFO_MESSAGE, "Error: Failed to initialise WiFi module, code %d\n", rc);
						Stop();
					}
				}
			}
			else
			{
				lastTickMillis = now;
			}
		}
		break;

	case NetworkState::disabled:
		if (full)
		{
			uploader->Spin();
		}
		break;

	case NetworkState::active:
		if (full)
		{
			if (espStatusChanged && digitalRead(EspTransferRequestPin))
			{
				if (reprap.Debug(moduleNetwork))
				{
					debugPrintf("ESP reported status change\n");
				}
				GetNewStatus();
			}
			else if (currentMode != requestedMode && currentMode != WiFiState::connecting)
			{
				// Tell the wifi module to change mode
				int32_t rslt = ResponseUnknownError;
				if (currentMode != WiFiState::idle)
				{
					// We must set WiFi module back to idle before changing to the new state
					rslt = SendCommand(NetworkCommand::networkStop, 0, 0, nullptr, 0, nullptr, 0);
				}
				else if (requestedMode == WiFiState::connected)
				{
					rslt = SendCommand(NetworkCommand::networkStartClient, 0, 0, nullptr, 0, nullptr, 0);
				}
				else if (requestedMode == WiFiState::runningAsAccessPoint)
				{
					rslt = SendCommand(NetworkCommand::networkStartAccessPoint, 0, 0, nullptr, 0, nullptr, 0);
				}

				if (rslt >= 0)
				{
					state = NetworkState::changingMode;
				}
				else
				{
					Stop();
					platform.MessageF(NETWORK_INFO_MESSAGE, "Failed to change WiFi mode (code %d)\n", rslt);
				}
			}
			else if (currentMode == WiFiState::connected || currentMode == WiFiState::runningAsAccessPoint)
			{
				// Find the next socket to poll
				const size_t startingSocket = currentSocket;
				do
				{
					if (sockets[currentSocket].NeedsPolling())
					{
						break;
					}
					++currentSocket;
					if (currentSocket == NumTcpSockets)
					{
						currentSocket = 0;
					}
				} while (currentSocket != startingSocket);

				// Either the current socket needs polling, or no sockets do but we must still poll one of them to get notified of any new connections
				sockets[currentSocket].Poll(full);
				++currentSocket;
				if (currentSocket == NumTcpSockets)
				{
					currentSocket = 0;
				}

				// Poll the responders
				if (full)
				{
					NetworkResponder *nr = nextResponderToPoll;
					bool doneSomething = false;
					do
					{
						if (nr == nullptr)
						{
							nr = responders;		// 'responders' can't be null at this point
						}
						doneSomething = nr->Spin();
						nr = nr->GetNext();
					} while (!doneSomething && nr != nextResponderToPoll);
					nextResponderToPoll = nr;
				}
			}
		}
		else if (currentMode == requestedMode && (currentMode == WiFiState::connected || currentMode == WiFiState::runningAsAccessPoint))
		{
			sockets[currentSocket].Poll(full);
			++currentSocket;
			if (currentSocket == NumTcpSockets)
			{
				currentSocket = 0;
			}
		}
		break;

	case NetworkState::changingMode:
		if (full && espStatusChanged && digitalRead(EspTransferRequestPin))
		{
			GetNewStatus();
			if (currentMode != WiFiState::connecting)
			{
				requestedMode = currentMode;				// don't keep repeating the request if it failed
				state = NetworkState::active;
				if (currentMode == WiFiState::connected || currentMode == WiFiState::runningAsAccessPoint)
				{
					// Get our IP address, this needs to be correct for FTP to work
					Receiver<NetworkStatusResponse> status;
					if (SendCommand(NetworkCommand::networkGetStatus, 0, 0, nullptr, 0, status) > 0)
					{
						uint32_t ip = status.Value().ipAddress;
						for (size_t i = 0; i < 4; ++i)
						{
							ipAddress[i] = (uint8_t)(ip & 255);
							ip >>= 8;
						}
						SafeStrncpy(ssid, status.Value().ssid, SsidLength);
					}
					InitSockets();
					platform.MessageF(NETWORK_INFO_MESSAGE, "Wifi module is %s%s, IP address %u.%u.%u.%u\n",
						TranslateWiFiState(currentMode),
						ssid,
						ipAddress[0], ipAddress[1], ipAddress[2], ipAddress[3]);
				}
				else
				{
					platform.MessageF(NETWORK_INFO_MESSAGE, "Wifi module is %s\n", TranslateWiFiState(currentMode));
				}
			}
		}
		break;

	default:
		break;
	}

	if (full)
	{
		platform.ClassReport(longWait);
	}
}

// Translate a ESP8266 reset reason to text
const char* Network::TranslateEspResetReason(uint32_t reason)
{
	// Mapping from known ESP reset codes to reasons
	static const char * const resetReasonTexts[] =
	{
		"Power on",
		"Hardware watchdog",
		"Exception",
		"Software watchdog",
		"Software restart",
		"Deep-sleep wakeup",
		"Turned on by main processor"
	};

	return (reason < sizeof(resetReasonTexts)/sizeof(resetReasonTexts[0]))
			? resetReasonTexts[reason]
			: "Unknown";
}

const char* Network::TranslateNetworkState() const
{
	switch (state)
	{
	case NetworkState::disabled:		return "disabled";
	case NetworkState::starting1:
	case NetworkState::starting2:		return "starting";
	case NetworkState::active:			return "running";
	case NetworkState::changingMode:	return "changing mode";
	default:							return "unknown";
	}
}

void Network::Diagnostics(MessageType mtype)
{
	platform.MessageF(mtype, "Network state is %s\n", TranslateNetworkState());
	platform.MessageF(mtype, "WiFi module is %s\n", TranslateWiFiState(currentMode));
#if 0
	// The underrun/overrun counters don't work at present
	platform.MessageF(mtype, "SPI underruns %u, overruns %u\n", spiTxUnderruns, spiRxOverruns);
#endif
	if (state != NetworkState::disabled && state != NetworkState::starting1 && state != NetworkState::starting2)
	{
		Receiver<NetworkStatusResponse> status;
		if (SendCommand(NetworkCommand::networkGetStatus, 0, 0, nullptr, 0, status) > 0)
		{
			NetworkStatusResponse& r = status.Value();
			r.versionText[ARRAY_UPB(r.versionText)] = 0;
			platform.MessageF(mtype, "WiFi firmware version %s\n", r.versionText);
			platform.MessageF(mtype, "WiFi MAC address %02x:%02x:%02x:%02x:%02x:%02x\n",
								r.macAddress[0], r.macAddress[1], r.macAddress[2], r.macAddress[3], r.macAddress[4], r.macAddress[5]);
			platform.MessageF(mtype, "WiFi Vcc %.2f, reset reason %s\n", (float)r.vcc/1024, TranslateEspResetReason(r.resetReason));
			platform.MessageF(mtype, "WiFi flash size %u, free heap %u\n", r.flashSize, r.freeHeap);
			if (currentMode == WiFiState::connected)
			{
				platform.MessageF(mtype, "WiFi IP address %d.%d.%d.%d\n",
					r.ipAddress & 255, (r.ipAddress >> 8) & 255, (r.ipAddress >> 16) & 255, (r.ipAddress >> 24) & 255);
				platform.MessageF(mtype, "WiFi signal strength %ddb\n", r.rssi);
			}
			// status, ssid and hostName not displayed

			// Print LwIP stats and other values over the ESP's UART line
			if (SendCommand(NetworkCommand::diagnostics, 0, 0, nullptr, 0, nullptr, 0) != ResponseEmpty)
			{
				platform.Message(mtype, "Failed to request ESP stats\n");
			}
		}
		else
		{
			platform.Message(mtype, "Failed to get WiFi status\n");
		}
	}
	HttpResponder::CommonDiagnostics(mtype);
	platform.Message(mtype, "Socket states: ");
	for (size_t i = 0; i < NumTcpSockets; i++)
	{
		platform.MessageF(mtype, " %d", sockets[i].State());
	}
	platform.Message(mtype, "\nResponder states:");
	for (NetworkResponder *r = responders; r != nullptr; r = r->GetNext())
	{
		r->Diagnostics(mtype);
	}
	platform.Message(mtype, "\n");
}

void Network::Enable(int mode, StringRef& reply)
{
	// Translate enable mode to desired WiFi mode
	const WiFiState modeRequested = (mode == 0) ? WiFiState::idle
									: (mode == 1) ? WiFiState::connected
										: (mode == 2) ? WiFiState::runningAsAccessPoint
											: WiFiState::disabled;
	if (activated)
	{
		if (modeRequested == WiFiState::disabled)
		{
			// Shut down WiFi module completely
			requestedMode = modeRequested;
			if (state != NetworkState::disabled)
			{
				Stop();
				platform.Message(GENERIC_MESSAGE, "WiFi module stopped\n");
			}
		}
		else
		{
			if (state == NetworkState::disabled)
			{
				requestedMode = modeRequested;
				Start();
			}
			else if (modeRequested == currentMode || (modeRequested == WiFiState::connected && currentMode == WiFiState::connecting))
			{
				// Nothing to do, but make sure the requested mode is correct
				requestedMode = modeRequested;
			}
			else if (currentMode != WiFiState::idle && modeRequested != WiFiState::idle)
			{
				reply.copy("Turn off the current WiFi mode before selecting a new one");
			}
			else
			{
				requestedMode = modeRequested;
			}
		}
	}
	else
	{
		requestedMode = modeRequested;
	}
}

int Network::EnableState() const
{
	return (requestedMode == WiFiState::idle) ? 0
			: (requestedMode == WiFiState::connected) ? 1
				: (requestedMode == WiFiState::runningAsAccessPoint) ? 2
						: -1;
}

// Translate the wifi state to text.
// The 'connected' and 'runningAsAccessPoint' states include a space at the end because the caller is expected to append the access point name.
/*static*/ const char* Network::TranslateWiFiState(WiFiState w)
{
	switch (w)
	{
	case WiFiState::disabled:				return "disabled";
	case WiFiState::idle:					return "idle";
	case WiFiState::connecting:				return "trying to connect";
	case WiFiState::connected:				return "connected to access point ";
	case WiFiState::runningAsAccessPoint:	return "providing access point ";
	default:								return "in an unknown state";
	}
}

void Network::EspRequestsTransfer()
{
	espStatusChanged = true;
	DisableEspInterrupt();				// don't allow more interrupts until we have acknowledged this one
}

void Network::SetIPAddress(const uint8_t p_ipAddress[], const uint8_t p_netmask[], const uint8_t p_gateway[])
{
	memcpy(ipAddress, p_ipAddress, sizeof(ipAddress));
	memcpy(netmask, p_netmask, sizeof(netmask));
	memcpy(gateway, p_gateway, sizeof(gateway));
}

// Set the DHCP hostname. Removes all whitespaces and converts the name to lower-case.
void Network::SetHostname(const char *name)
{
	// Filter out illegal characters
	size_t i = 0;
	while (*name && i < ARRAY_UPB(hostname))
	{
		char c = *name++;
		if (c >= 'A' && c <= 'Z')
		{
			c += 'a' - 'A';
		}

		if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || (c == '-') || (c == '_'))
		{
			hostname[i++] = c;
		}
	}

	if (i != 0)
	{
		hostname[i] = 0;
	}
	else
	{
		strcpy(hostname, HOSTNAME);
	}

	// Update the hostname if possible
	if (state == NetworkState::active)
	{
		if (SendCommand(NetworkCommand::networkSetHostName, 0, 0, hostname, HostNameLength, nullptr, 0) != ResponseEmpty)
		{
			platform.Message(GENERIC_MESSAGE, "Error: Could not set WiFi hostname\n");
		}
	}
}

void Network::InitSockets()
{
	for (size_t i = 0; i < NumProtocols; ++i)
	{
		if (protocolEnabled[i])
		{
			StartProtocol(i);
		}
	}
	currentSocket = 0;
}

void Network::TerminateSockets()
{
	for (SocketNumber skt = 0; skt < NumTcpSockets; ++skt)
	{
		sockets[skt].Terminate();
	}
}

void Network::TerminateSockets(Port port)
{
	for (SocketNumber skt = 0; skt < NumTcpSockets; ++skt)
	{
		if (sockets[skt].GetLocalPort() == port)
		{
			sockets[skt].Terminate();
		}
	}
}

// This is called to tell the network which sockets are active
void Network::UpdateSocketStatus(uint16_t connectedSockets, uint16_t otherEndClosedSockets)
{
	for (size_t i = 0; i < NumTcpSockets; ++i)
	{
		if (((connectedSockets | otherEndClosedSockets) & (1u << i)) != 0)
		{
			sockets[i].SetNeedsPolling();
		}
	}
}

// Find a responder to process a new connection
bool Network::FindResponder(Socket *skt, Port localPort)
{
	// Get the right protocol
	Protocol protocol;
	if (localPort == ftpDataPort)
	{
		protocol = FtpDataProtocol;
	}
	else
	{
		bool protocolFound = false;
		for (size_t i = 0; i < NumProtocols; ++i)
		{
			if (protocolEnabled[i] && portNumbers[i] == localPort)
			{
				protocol = i;
				protocolFound = true;
				break;
			}
		}

		if (!protocolFound)
		{
			// Protocol is disabled
			return false;
		}
	}

	// Try to find a responder to deal with this connection
	for (NetworkResponder *r = responders; r != nullptr; r = r->GetNext())
	{
		if (r->Accept(skt, protocol))
		{
			return true;
		}
	}
	return false;
}

// Open the FTP data port
void Network::OpenDataPort(Port port)
{
	ftpDataPort = port;
	SendListenCommand(ftpDataPort, FtpDataProtocol, 1);
}

// Close FTP data port and purge associated resources
void Network::CloseDataPort()
{
	if (ftpDataPort != 0)
	{
		SendListenCommand(ftpDataPort, FtpDataProtocol, 0);
		for (SocketNumber skt = 0; skt < NumTcpSockets; ++skt)
		{
			if (sockets[skt].GetLocalPort() == ftpDataPort)
			{
				sockets[skt].TerminatePolitely();
			}
		}
		ftpDataPort = 0;
	}
}

void Network::HandleHttpGCodeReply(const char *msg)
{
	HttpResponder::HandleGCodeReply(msg);
}

void Network::HandleTelnetGCodeReply(const char *msg)
{
	telnetResponder->HandleGCodeReply(msg);
}

void Network::HandleHttpGCodeReply(OutputBuffer *buf)
{
	HttpResponder::HandleGCodeReply(buf);
}

void Network::HandleTelnetGCodeReply(OutputBuffer *buf)
{
	telnetResponder->HandleGCodeReply(buf);
}

uint32_t Network::GetHttpReplySeq()
{
	return HttpResponder::GetReplySeq();
}

#if USE_PDC
static Pdc *spi_pdc;
#endif

#if USE_DMAC

// Our choice of DMA channels to use
const uint32_t CONF_SPI_DMAC_TX_CH = 1;
const uint32_t CONF_SPI_DMAC_RX_CH = 2;

// Hardware IDs of the SPI transmit and receive DMA interfaces. See atsam datasheet.
const uint32_t DMA_HW_ID_SPI_TX = 1;
const uint32_t DMA_HW_ID_SPI_RX = 2;

#endif

static inline void spi_rx_dma_enable()
{
#if USE_PDC
	pdc_enable_transfer(spi_pdc, PERIPH_PTCR_RXTEN);
#endif

#if USE_DMAC
	dmac_channel_enable(DMAC, CONF_SPI_DMAC_RX_CH);
#endif
}

static inline void spi_tx_dma_enable()
{
#if USE_PDC
	pdc_enable_transfer(spi_pdc, PERIPH_PTCR_TXTEN);
#endif

#if USE_DMAC
	dmac_channel_enable(DMAC, CONF_SPI_DMAC_TX_CH);
#endif
}

static inline void spi_rx_dma_disable()
{
#if USE_PDC
	pdc_disable_transfer(spi_pdc, PERIPH_PTCR_RXTDIS);
#endif

#if USE_DMAC
	dmac_channel_disable(DMAC, CONF_SPI_DMAC_RX_CH);
#endif
}

static inline void spi_tx_dma_disable()
{
#if USE_PDC
	pdc_disable_transfer(spi_pdc, PERIPH_PTCR_TXTDIS);
#endif

#if USE_DMAC
	dmac_channel_disable(DMAC, CONF_SPI_DMAC_TX_CH);
#endif
}

static void spi_dma_disable()
{
	spi_tx_dma_disable();
	spi_rx_dma_disable();
}

static bool spi_dma_check_rx_complete()
{
#if USE_PDC
	return true;
#endif

#if USE_DMAC
	const uint32_t status = DMAC->DMAC_CHSR;
	if (   ((status & (DMAC_CHSR_ENA0 << CONF_SPI_DMAC_RX_CH)) == 0)	// controller is not enabled, perhaps because it finished a full buffer transfer
		|| ((status & (DMAC_CHSR_EMPT0 << CONF_SPI_DMAC_RX_CH)) != 0)	// controller is enabled, probably suspended, and the FIFO is empty
	   )
	{
		// Disable the channel.
		// We also need to set the resume bit, otherwise it remains suspended when we re-enable it.
		DMAC->DMAC_CHDR = (DMAC_CHDR_DIS0 << CONF_SPI_DMAC_RX_CH) | (DMAC_CHDR_RES0 << CONF_SPI_DMAC_RX_CH);
		return true;
	}
	return false;
#endif
}

static void spi_tx_dma_setup(const void *buf, uint32_t transferLength)
{
#if USE_PDC
	pdc_packet_t pdc_spi_packet;
	pdc_spi_packet.ul_addr = reinterpret_cast<uint32_t>(buf);
	pdc_spi_packet.ul_size = transferLength;
	pdc_tx_init(spi_pdc, &pdc_spi_packet, NULL);
#endif

#if USE_DMAC
	DMAC->DMAC_EBCISR;		// clear any pending interrupts

	dmac_channel_set_source_addr(DMAC, CONF_SPI_DMAC_TX_CH, reinterpret_cast<uint32_t>(buf));
	dmac_channel_set_destination_addr(DMAC, CONF_SPI_DMAC_TX_CH, reinterpret_cast<uint32_t>(& SPI->SPI_TDR));
	dmac_channel_set_descriptor_addr(DMAC, CONF_SPI_DMAC_TX_CH, 0);
	dmac_channel_set_ctrlA(DMAC, CONF_SPI_DMAC_TX_CH, transferLength | DMAC_CTRLA_SRC_WIDTH_WORD | DMAC_CTRLA_DST_WIDTH_BYTE);
	dmac_channel_set_ctrlB(DMAC, CONF_SPI_DMAC_TX_CH,
		DMAC_CTRLB_SRC_DSCR | DMAC_CTRLB_DST_DSCR | DMAC_CTRLB_FC_MEM2PER_DMA_FC | DMAC_CTRLB_SRC_INCR_INCREMENTING | DMAC_CTRLB_DST_INCR_FIXED);
#endif
}

static void spi_rx_dma_setup(const void *buf, uint32_t transferLength)
{
#if USE_PDC
	pdc_packet_t pdc_spi_packet;
	pdc_spi_packet.ul_addr = reinterpret_cast<uint32_t>(buf);
	pdc_spi_packet.ul_size = transferLength;
	pdc_rx_init(spi_pdc, &pdc_spi_packet, NULL);
#endif

#if USE_DMAC
	DMAC->DMAC_EBCISR;		// clear any pending interrupts

	dmac_channel_set_source_addr(DMAC, CONF_SPI_DMAC_RX_CH, reinterpret_cast<uint32_t>(& SPI->SPI_RDR));
	dmac_channel_set_destination_addr(DMAC, CONF_SPI_DMAC_RX_CH, reinterpret_cast<uint32_t>(buf));
	dmac_channel_set_descriptor_addr(DMAC, CONF_SPI_DMAC_RX_CH, 0);
	dmac_channel_set_ctrlA(DMAC, CONF_SPI_DMAC_RX_CH, transferLength | DMAC_CTRLA_SRC_WIDTH_BYTE | DMAC_CTRLA_DST_WIDTH_WORD);
	dmac_channel_set_ctrlB(DMAC, CONF_SPI_DMAC_RX_CH,
		DMAC_CTRLB_SRC_DSCR | DMAC_CTRLB_DST_DSCR | DMAC_CTRLB_FC_PER2MEM_DMA_FC | DMAC_CTRLB_SRC_INCR_FIXED | DMAC_CTRLB_DST_INCR_INCREMENTING);
#endif
}

/**
 * \brief Set SPI slave transfer.
 */
static void spi_slave_dma_setup(uint32_t dataOutSize, uint32_t dataInSize)
{
#if USE_PDC
	pdc_disable_transfer(spi_pdc, PERIPH_PTCR_TXTDIS | PERIPH_PTCR_RXTDIS);
	spi_rx_dma_setup(&bufferIn, dataInSize + sizeof(MessageHeaderEspToSam));
	spi_tx_dma_setup(&bufferOut, dataOutSize + sizeof(MessageHeaderSamToEsp));
	pdc_enable_transfer(spi_pdc, PERIPH_PTCR_TXTEN | PERIPH_PTCR_RXTEN);
#endif

#if USE_DMAC
	spi_dma_disable();

	spi_rx_dma_setup(&bufferIn, dataInSize + sizeof(MessageHeaderEspToSam));
	spi_rx_dma_enable();
	spi_tx_dma_setup(&bufferOut, dataOutSize + sizeof(MessageHeaderSamToEsp));
	spi_tx_dma_enable();
#endif
}

// Set up the SPI system
void Network::SetupSpi()
{
#if USE_PDC
	spi_pdc = spi_get_pdc_base(SPI);
	// The PDCs are masters 2 and 3 and the SRAM is slave 0. Give the PDCs the highest priority.
	matrix_set_master_burst_type(0, MATRIX_ULBT_8_BEAT_BURST);
	matrix_set_slave_default_master_type(0, MATRIX_DEFMSTR_LAST_DEFAULT_MASTER);
	matrix_set_slave_priority(0, (3 << MATRIX_PRAS0_M2PR_Pos) | (3 << MATRIX_PRAS0_M3PR_Pos));
	matrix_set_slave_slot_cycle(0, 8);
#endif

#if USE_DMAC
	pmc_enable_periph_clk(ID_DMAC);
	dmac_init(DMAC);
	dmac_set_priority_mode(DMAC, DMAC_PRIORITY_ROUND_ROBIN);
	dmac_enable(DMAC);
	// The DMAC is master 4 and the SRAM is slave 0. Give the DMAC the highest priority.
	matrix_set_slave_default_master_type(0, MATRIX_DEFMSTR_LAST_DEFAULT_MASTER);
	matrix_set_slave_priority(0, (3 << MATRIX_PRAS0_M4PR_Pos));
	// Set the slave slot cycle limit.
	// If we leave it at the default value of 511 clock cycles, we get transmit underruns due to the HSMCI using the bus for too long.
	// A value of 8 seems to work. I haven't tried other values yet.
	matrix_set_slave_slot_cycle(0, 8);
#endif

	// Set up the SPI pins
	ConfigurePin(g_APinDescription[APIN_SPI_SCK]);
	ConfigurePin(g_APinDescription[APIN_SPI_MOSI]);
	ConfigurePin(g_APinDescription[APIN_SPI_MISO]);
	ConfigurePin(g_APinDescription[APIN_SPI_SS0]);

	pmc_enable_periph_clk(ID_SPI);
	spi_dma_disable();
	spi_reset(SPI);					// this clears the transmit and receive registers and puts the SPI into slave mode

#if USE_DMAC
	// Configure DMA RX channel
	dmac_channel_set_configuration(DMAC, CONF_SPI_DMAC_RX_CH,
			DMAC_CFG_SRC_PER(DMA_HW_ID_SPI_RX) | DMAC_CFG_SRC_H2SEL | DMAC_CFG_SOD | DMAC_CFG_FIFOCFG_ASAP_CFG);

	// Configure DMA TX channel
	dmac_channel_set_configuration(DMAC, CONF_SPI_DMAC_TX_CH,
			DMAC_CFG_DST_PER(DMA_HW_ID_SPI_TX) | DMAC_CFG_DST_H2SEL | DMAC_CFG_SOD | DMAC_CFG_FIFOCFG_ASAP_CFG);
#endif

	(void)SPI->SPI_SR;				// clear any pending interrupt
	SPI->SPI_IDR = SPI_IER_NSSR;	// disable the interrupt

	NVIC_SetPriority(SPI_IRQn, NvicPrioritySpi);
	NVIC_EnableIRQ(SPI_IRQn);
}

// Send a command to the ESP and get the result
int32_t Network::SendCommand(NetworkCommand cmd, SocketNumber socketNum, uint8_t flags, const void *dataOut, size_t dataOutLength, void* dataIn, size_t dataInLength)
{
	if (state == NetworkState::disabled)
	{
		if (reprap.Debug(moduleNetwork))
		{
			debugPrintf("ResponseNetworkDisabled\n");
		}
		return ResponseNetworkDisabled;
	}

	if (!digitalRead(EspTransferRequestPin) || transferPending || !spi_dma_check_rx_complete())
	{
		if (reprap.Debug(moduleNetwork))
		{
			debugPrintf("ResponseBusy\n");
		}
		return ResponseBusy;
	}

	bufferOut.hdr.formatVersion = MyFormatVersion;
	bufferOut.hdr.command = cmd;
	bufferOut.hdr.socketNumber = socketNum;
	bufferOut.hdr.flags = flags;
	bufferOut.hdr.param32 = 0;
	bufferOut.hdr.dataLength = (uint16_t)dataOutLength;
	bufferOut.hdr.dataBufferAvailable = (uint16_t)dataInLength;
	if (dataOut != nullptr)
	{
		memcpy(bufferOut.data, dataOut, dataOutLength);
	}
	bufferIn.hdr.formatVersion = InvalidFormatVersion;
	transferPending = true;

	// DMA may have transferred an extra word to the SPI transmit data register. We need to clear this.
	// The only way I can find to do this is to issue a software reset to the SPI system.
	// Fortunately, this leaves the SPI system in slave mode.
	spi_reset(SPI);
	spi_set_bits_per_transfer(SPI, 0, SPI_CSR_BITS_8_BIT);

	// Set up the DMA controller
	spi_slave_dma_setup(dataOutLength, dataInLength);
	spi_enable(SPI);

	// Enable the end-of transfer interrupt
	(void)SPI->SPI_SR;						// clear any pending interrupt
	SPI->SPI_IER = SPI_IER_NSSR;			// enable the NSS rising interrupt

	// Tell the ESP that we are ready to accept data
	digitalWrite(SamTfrReadyPin, HIGH);

	// Wait for the DMA complete interrupt, with timeout
	const uint32_t now = millis();
	while (transferPending || !spi_dma_check_rx_complete())
	{
		if (millis() - now > WifiResponseTimeoutMillis)
		{
			if (reprap.Debug(moduleNetwork))
			{
				debugPrintf("ResponseTimeout, pending=%d\n", (int)transferPending);
			}
			return ResponseTimeout;
		}
	}

	// Look at the response
	int32_t response;
	if (bufferIn.hdr.formatVersion != MyFormatVersion)
	{
		response = ResponseBadReplyFormatVersion;
	}
	else
	{
		currentMode = bufferIn.hdr.state;
		response = bufferIn.hdr.response;
		if (response > 0 && dataIn != nullptr)
		{
			memcpy(dataIn, bufferIn.data, min<size_t>(dataInLength, (size_t)response));
		}
	}

	if (response < 0 && reprap.Debug(moduleNetwork))
	{
		debugPrintf("Network command %d socket %u returned error %d\n", (int)cmd, socketNum, response);
	}

#if 0
	//***TEMP debug
	if (cmd != NetworkCommand::connGetStatus)
	{
		debugPrintBuffer("Recv", &bufferIn, (dataIn == nullptr) ? 0 : (size_t)max<int>(0, response));
	}
#endif

	return response;
}

void Network::SendListenCommand(Port port, Protocol protocol, unsigned int maxConnections)
{
	ListenOrConnectData lcb;
	lcb.port = port;
	lcb.protocol = protocol;
	lcb.remoteIp = AnyIp;
	lcb.maxConnections = maxConnections;
	SendCommand(NetworkCommand::networkListen, 0, 0, &lcb, sizeof(lcb), nullptr, 0);
}

// This is called when ESP is signalling to us that an error occurred or there was a state change
void Network::GetNewStatus()
{
	struct MessageResponse
	{
		char messageBuffer[100];
	};
	Receiver<MessageResponse> rcvr;

	espStatusChanged = false;
	EnableEspInterrupt();

	const int32_t rslt = SendCommand(NetworkCommand::networkGetLastError, 0, 0, nullptr, 0, rcvr);
	rcvr.Value().messageBuffer[ARRAY_UPB(rcvr.Value().messageBuffer)] = 0;
	if (rslt < 0)
	{
		platform.Message(NETWORK_INFO_MESSAGE, "Error retrieving WiFi status message\n");
	}
	else if (rslt > 0 && rcvr.Value().messageBuffer[0] != 0)
	{
		platform.MessageF(NETWORK_INFO_MESSAGE, "WiFi reported error: %s\n", rcvr.Value().messageBuffer);
	}
}

// SPI interrupt handler, called when NSS goes high
void SPI_Handler()
{
	reprap.GetNetwork().SpiInterrupt();
}

void Network::SpiInterrupt()
{
	const uint32_t status = SPI->SPI_SR;					// read status and clear interrupt
	SPI->SPI_IDR = SPI_IER_NSSR;							// disable the interrupt
	if ((status & SPI_SR_NSSR) != 0)
	{
#if USE_PDC
		pdc_disable_transfer(spi_pdc, PERIPH_PTCR_TXTDIS | PERIPH_PTCR_RXTDIS);
#endif

#if USE_DMAC
		spi_tx_dma_disable();
		dmac_channel_suspend(DMAC, CONF_SPI_DMAC_RX_CH);	// suspend the receive channel, don't disable it because the FIFO needs to empty first
#endif
		spi_disable(SPI);
		digitalWrite(SamTfrReadyPin, LOW);
		if ((status & SPI_SR_OVRES) != 0)
		{
			++spiRxOverruns;
		}
		if ((status & SPI_SR_UNDES) != 0)
		{
			++spiTxUnderruns;
		}
		transferPending = false;
	}
}

// Reset the ESP8266 and leave held in reset
void Network::ResetWiFi()
{
	pinMode(EspResetPin, OUTPUT_LOW);							// assert ESP8266 /RESET
	pinMode(APIN_UART1_TXD, INPUT_PULLUP);						// just enable pullups on TxD and RxD pins for now to avoid floating pins
	pinMode(APIN_UART1_RXD, INPUT_PULLUP);
	currentMode = WiFiState::disabled;
}

// Reset the ESP8266 to take commands from the UART or from external input. The caller must wait for the reset to complete after calling this.
// ESP8266 boot modes:
// GPIO0	GPIO2	GPIO15
// 0		1		0		Firmware download from UART
// 1		1		0		Normal boot from flash memory
// 0		0		1		SD card boot (not used in on Duet)
void Network::ResetWiFiForUpload(bool external)
{
	// Make sure the ESP8266 is in the reset state
	pinMode(EspResetPin, OUTPUT_LOW);

	// Take the ESP8266 out of power down
	pinMode(EspEnablePin, OUTPUT_HIGH);

	// Set up our transfer request pin (GPIO4) as an output and set it low
	pinMode(SamTfrReadyPin, OUTPUT_LOW);

	// Set up our data ready pin (ESP GPIO0) as an output and set it low ready to boot the ESP from UART
	pinMode(EspTransferRequestPin, OUTPUT_LOW);

	// GPIO2 also needs to be high to boot up. It's connected to MISO on the SAM, so set the pullup resistor on that pin
	pinMode(APIN_SPI_MISO, INPUT_PULLUP);

	// Set our CS input (ESP GPIO15) low ready for booting the ESP. This also clears the transfer ready latch.
	pinMode(SamCsPin, OUTPUT_LOW);

	// Make sure it has time to reset - no idea how long it needs, but 50ms should be plenty
	delay(50);

	if (external)
	{
		pinMode(APIN_UART1_TXD, INPUT_PULLUP);					// just enable pullups on TxD and RxD pins
		pinMode(APIN_UART1_RXD, INPUT_PULLUP);
	}
	else
	{
		ConfigurePin(g_APinDescription[APINS_UART1]);			// connect the pins to UART1
	}

	// Release the reset on the ESP8266
	digitalWrite(EspResetPin, HIGH);
}

// End