/**
 * FreeRDP: A Remote Desktop Protocol Implementation
 * Serial Port Device Service Virtual Channel
 *
 * Copyright 2011 O.S. Systems Software Ltda.
 * Copyright 2011 Eduardo Fiss Beloni <beloni@ossystems.com.br>
 * Copyright 2014 Hewlett-Packard Development Company, L.P.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#ifdef HAVE_SYS_MODEM_H
#include <sys/modem.h>
#endif
#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>
#endif
#ifdef HAVE_SYS_STRTIO_H
#include <sys/strtio.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <winpr/collections.h>
#include <winpr/comm.h>
#include <winpr/crt.h>
#include <winpr/stream.h>
#include <winpr/synch.h>
#include <winpr/thread.h>
#include <winpr/wlog.h>

#include <freerdp/freerdp.h>
#include <freerdp/utils/list.h>
#include <freerdp/channels/rdpdr.h>
#include <freerdp/utils/svc_plugin.h>

typedef struct _SERIAL_DEVICE SERIAL_DEVICE;

struct _SERIAL_DEVICE
{
	DEVICE device;
	HANDLE* hComm;

	// TMP: use of log
	wLog* log;
	HANDLE MainThread;
	wMessageQueue* MainIrpQueue;

	HANDLE ReadThread;
	wMessageQueue* ReadIrpQueue;
};

static void serial_process_irp_create(SERIAL_DEVICE* serial, IRP* irp)
{
	DWORD DesiredAccess;
	DWORD SharedAccess;
	DWORD CreateDisposition;
	UINT32 PathLength;

	Stream_Read_UINT32(irp->input, DesiredAccess);		/* DesiredAccess (4 bytes) */
	Stream_Seek_UINT64(irp->input);				/* AllocationSize (8 bytes) */
	Stream_Seek_UINT32(irp->input);				/* FileAttributes (4 bytes) */
	Stream_Read_UINT32(irp->input, SharedAccess);		/* SharedAccess (4 bytes) */
	Stream_Read_UINT32(irp->input, CreateDisposition);	/* CreateDisposition (4 bytes) */
	Stream_Seek_UINT32(irp->input); 			/* CreateOptions (4 bytes) */
	Stream_Read_UINT32(irp->input, PathLength);		/* PathLength (4 bytes) */
	Stream_Seek(irp->input, PathLength);			/* Path (variable) */

	assert(PathLength == 0); /* MS-RDPESP 2.2.2.2 */


#ifndef _WIN32
	/* Windows 2012 server sends on a first call : 
	 *     DesiredAccess     = 0x00100080: SYNCHRONIZE | FILE_READ_ATTRIBUTES
	 *     SharedAccess      = 0x00000007: FILE_SHARE_DELETE | FILE_SHARE_WRITE | FILE_SHARE_READ
	 *     CreateDisposition = 0x00000001: CREATE_NEW
	 *
	 * then Windows 2012 sends : 
	 *     DesiredAccess     = 0x00120089: SYNCHRONIZE | READ_CONTROL | FILE_READ_ATTRIBUTES | FILE_READ_EA | FILE_READ_DATA
	 *     SharedAccess      = 0x00000007: FILE_SHARE_DELETE | FILE_SHARE_WRITE | FILE_SHARE_READ
	 *     CreateDisposition = 0x00000001: CREATE_NEW
	 *
	 * assert(DesiredAccess == (GENERIC_READ | GENERIC_WRITE));
	 * assert(SharedAccess == 0);
	 * assert(CreateDisposition == OPEN_EXISTING);
	 *
	 */

	DEBUG_SVC("DesiredAccess: 0x%0.8x, SharedAccess: 0x%0.8x, CreateDisposition: 0x%0.8x", DesiredAccess, SharedAccess, CreateDisposition);

	/* FIXME: As of today only the flags below are supported by CommCreateFileA: */
	DesiredAccess     = GENERIC_READ | GENERIC_WRITE;
	SharedAccess      = 0;
	CreateDisposition = OPEN_EXISTING;
#endif

	serial->hComm = CreateFile(serial->device.name,
				   DesiredAccess,	
				   SharedAccess,	
				   NULL,		/* SecurityAttributes */
				   CreateDisposition,	
				   0,			/* FlagsAndAttributes */
				   NULL);		/* TemplateFile */

	if (!serial->hComm || (serial->hComm == INVALID_HANDLE_VALUE))
	{
		DEBUG_WARN("CreateFile failure: %s last-error: Ox%x\n", serial->device.name, GetLastError());

		irp->IoStatus = STATUS_UNSUCCESSFUL;
		goto error_handle;
	}

	/* NOTE: binary mode/raw mode required for the redirection. On
	 * Linux, CommCreateFileA forces this setting.
	 */
	/* ZeroMemory(&dcb, sizeof(DCB)); */
	/* dcb.DCBlength = sizeof(DCB); */
	/* GetCommState(serial->hComm, &dcb); */
	/* dcb.fBinary = TRUE; */
	/* SetCommState(serial->hComm, &dcb); */

	// TMP:
	COMMTIMEOUTS timeouts;
	timeouts.ReadIntervalTimeout = MAXULONG; /* ensures a non blocking state */
	timeouts.ReadTotalTimeoutMultiplier = 0;
	timeouts.ReadTotalTimeoutConstant = 0;
	timeouts.WriteTotalTimeoutMultiplier = 0;
	timeouts.WriteTotalTimeoutConstant = 0;
	SetCommTimeouts(serial->hComm, &timeouts);

	assert(irp->FileId == 0);
	irp->FileId = irp->devman->id_sequence++; /* FIXME: why not ((WINPR_COMM*)hComm)->fd? */

	irp->IoStatus = STATUS_SUCCESS;

	DEBUG_SVC("%s (DeviceId: %d, FileId: %d) created.", serial->device.name, irp->device->id, irp->FileId);

  error_handle:
	Stream_Write_UINT32(irp->output, irp->FileId);	/* FileId (4 bytes) */
	Stream_Write_UINT8(irp->output, 0);		/* Information (1 byte) */

	irp->Complete(irp);
}

static void serial_process_irp_close(SERIAL_DEVICE* serial, IRP* irp)
{
	Stream_Seek(irp->input, 32); /* Padding (32 bytes) */

	if (!CloseHandle(serial->hComm))
	{
		DEBUG_WARN("CloseHandle failure: %s (%d) closed.", serial->device.name, irp->device->id);
		irp->IoStatus = STATUS_UNSUCCESSFUL;
		goto error_handle;
	}

	DEBUG_SVC("%s (DeviceId: %d, FileId: %d) closed.", serial->device.name, irp->device->id, irp->FileId);

	serial->hComm = NULL;
	irp->IoStatus = STATUS_SUCCESS;

  error_handle:
	Stream_Zero(irp->output, 5); /* Padding (5 bytes) */

	irp->Complete(irp);
}

static void serial_process_irp_read(SERIAL_DEVICE* serial, IRP* irp)
{
	UINT32 Length;
	UINT64 Offset;
	BYTE* buffer = NULL;
	DWORD nbRead = 0;

	Stream_Read_UINT32(irp->input, Length); /* Length (4 bytes) */
	Stream_Read_UINT64(irp->input, Offset); /* Offset (8 bytes) */
	Stream_Seek(irp->input, 20); /* Padding (20 bytes) */


	buffer = (BYTE*)calloc(Length, sizeof(BYTE));
	if (buffer == NULL)
	{
		irp->IoStatus = STATUS_NO_MEMORY;
		goto error_handle;
	}

	
	/* MSRDPESP 3.2.5.1.4: If the Offset field is not set to 0, the value MUST be ignored
	 * assert(Offset == 0);
	 */
	

	DEBUG_SVC("reading %lu bytes from %s", Length, serial->device.name);

	/* FIXME: CommReadFile to be replaced by ReadFile */
	if (CommReadFile(serial->hComm, buffer, Length, &nbRead, NULL))
	{
		irp->IoStatus = STATUS_SUCCESS;
	}
	else
	{
		DEBUG_SVC("read failure to %s, nbRead=%d, last-error: 0x%0.8x", serial->device.name, nbRead, GetLastError());

		switch(GetLastError())
		{
			case ERROR_INVALID_HANDLE:
				irp->IoStatus = STATUS_INVALID_DEVICE_REQUEST;
				break;

			case ERROR_NOT_SUPPORTED:
				irp->IoStatus = STATUS_NOT_SUPPORTED;
				break;
				
			case ERROR_INVALID_PARAMETER:
				irp->IoStatus = STATUS_INVALID_PARAMETER;
				break;

			case ERROR_IO_DEVICE:
				irp->IoStatus = STATUS_IO_DEVICE_ERROR;
				break;

			case ERROR_TIMEOUT:
				irp->IoStatus = STATUS_TIMEOUT;
				break;

			case ERROR_BAD_DEVICE:
				irp->IoStatus = STATUS_INVALID_DEVICE_REQUEST;
				break;

			default:
				DEBUG_SVC("unexpected last-error: 0x%x", GetLastError());
				irp->IoStatus = STATUS_UNSUCCESSFUL;
				break;
		}
	}

	
  error_handle:

	Stream_Write_UINT32(irp->output, nbRead); /* Length (4 bytes) */

	if (nbRead > 0)
	{
		Stream_EnsureRemainingCapacity(irp->output, nbRead);
		Stream_Write(irp->output, buffer, nbRead); /* ReadData */
	}

	if (buffer)
		free(buffer);

	irp->Complete(irp);
}

static void serial_process_irp_write(SERIAL_DEVICE* serial, IRP* irp)
{
	UINT32 Length;
	UINT64 Offset;
	DWORD nbWritten = 0;

	Stream_Read_UINT32(irp->input, Length); /* Length (4 bytes) */
	Stream_Read_UINT64(irp->input, Offset); /* Offset (8 bytes) */
	Stream_Seek(irp->input, 20); /* Padding (20 bytes) */

	assert(Offset == 0); /* not implemented otherwise */

	DEBUG_SVC("writing %lu bytes to %s", Length, serial->device.name);

	/* FIXME: CommWriteFile to be replaced by WriteFile */
	if (CommWriteFile(serial->hComm, Stream_Pointer(irp->input), Length, &nbWritten, NULL))
	{
		irp->IoStatus = STATUS_SUCCESS;
	}
	else
	{
		DEBUG_SVC("write failure to %s, nbWritten=%d, last-error: 0x%0.8x", serial->device.name, nbWritten, GetLastError());

		switch(GetLastError())
		{
			case ERROR_INVALID_HANDLE:
				irp->IoStatus = STATUS_INVALID_DEVICE_REQUEST;
				break;

			case ERROR_NOT_SUPPORTED:
				irp->IoStatus = STATUS_NOT_SUPPORTED;
				break;
				
			case ERROR_INVALID_PARAMETER:
				irp->IoStatus = STATUS_INVALID_PARAMETER;
				break;

			case ERROR_IO_DEVICE:
				irp->IoStatus = STATUS_IO_DEVICE_ERROR;
				break;

			case ERROR_TIMEOUT:
				irp->IoStatus = STATUS_TIMEOUT;
				break;

			case ERROR_BAD_DEVICE:
				irp->IoStatus = STATUS_INVALID_DEVICE_REQUEST;
				break;

			default:
				DEBUG_SVC("unexpected last-error: 0x%x", GetLastError());
				irp->IoStatus = STATUS_UNSUCCESSFUL;
				break;
		}
	}

	DEBUG_SVC("%lu bytes written to %s", nbWritten, serial->device.name);

	Stream_Write_UINT32(irp->output, nbWritten); /* Length (4 bytes) */
	Stream_Write_UINT8(irp->output, 0); /* Padding (1 byte) */
	irp->Complete(irp);
}

static void serial_process_irp_device_control(SERIAL_DEVICE* serial, IRP* irp)
{
	UINT32 IoControlCode;
	UINT32 InputBufferLength;
	BYTE*  InputBuffer = NULL;
	UINT32 OutputBufferLength;
	BYTE*  OutputBuffer = NULL;
	DWORD  BytesReturned = 0;

	Stream_Read_UINT32(irp->input, OutputBufferLength); /* OutputBufferLength (4 bytes) */
	Stream_Read_UINT32(irp->input, InputBufferLength); /* InputBufferLength (4 bytes) */
	Stream_Read_UINT32(irp->input, IoControlCode); /* IoControlCode (4 bytes) */
	Stream_Seek(irp->input, 20); /* Padding (20 bytes) */

	OutputBuffer = (BYTE*)calloc(OutputBufferLength, sizeof(BYTE));
	if (OutputBuffer == NULL)
	{
		irp->IoStatus = STATUS_NO_MEMORY;
		goto error_handle;
	}

	InputBuffer = (BYTE*)calloc(InputBufferLength, sizeof(BYTE));
	if (InputBuffer == NULL)
	{
		irp->IoStatus = STATUS_NO_MEMORY;
		goto error_handle;
	}

	Stream_Read(irp->input, InputBuffer, InputBufferLength);

	DEBUG_SVC("CommDeviceIoControl: IoControlCode 0x%x", IoControlCode);
		
	/* FIXME: CommDeviceIoControl to be replaced by DeviceIoControl() */
	if (CommDeviceIoControl(serial->hComm, IoControlCode, InputBuffer, InputBufferLength, OutputBuffer, OutputBufferLength, &BytesReturned, NULL))
	{
		irp->IoStatus = STATUS_SUCCESS;
	}
	else
	{
		DEBUG_SVC("CommDeviceIoControl failure: IoControlCode 0x%0.8x last-error: 0x%x", IoControlCode, GetLastError());

		switch(GetLastError())
		{
			case ERROR_INVALID_HANDLE:
				irp->IoStatus = STATUS_INVALID_DEVICE_REQUEST;
				break;

			case ERROR_NOT_SUPPORTED:
				irp->IoStatus = STATUS_NOT_SUPPORTED;
				break;

			case ERROR_INSUFFICIENT_BUFFER:
				irp->IoStatus = STATUS_BUFFER_TOO_SMALL; /* TMP: better have STATUS_BUFFER_SIZE_TOO_SMALL? http://msdn.microsoft.com/en-us/library/windows/hardware/ff547466%28v=vs.85%29.aspx#generic_status_values_for_serial_device_control_requests */
				break;

			case ERROR_INVALID_PARAMETER:
				irp->IoStatus = STATUS_INVALID_PARAMETER;
				break;

			case ERROR_CALL_NOT_IMPLEMENTED:
				irp->IoStatus = STATUS_NOT_IMPLEMENTED;
				break;

			default:
				DEBUG_SVC("unexpected last-error: 0x%x", GetLastError());
				irp->IoStatus = STATUS_UNSUCCESSFUL;
				break;
		}
	}

  error_handle:

	Stream_Write_UINT32(irp->output, BytesReturned); /* OutputBufferLength (4 bytes) */

	if (BytesReturned > 0)
	{
		Stream_EnsureRemainingCapacity(irp->output, BytesReturned);
		Stream_Write(irp->output, OutputBuffer, BytesReturned); /* OutputBuffer */
	}
	/* TMP: FIXME: Why at least Windows 2008R2 gets lost with this
	 * extra byte and likely on a IOCTL_SERIAL_SET_BAUD_RATE? The
	 * extra byte is well required according MS-RDPEFS
	 * 2.2.1.5.5 */
	/* else */
	/* { */
	/* 	Stream_Write_UINT8(irp->output, 0); /\* Padding (1 byte) *\/ */
	/* } */

	if (InputBuffer != NULL)
		free(InputBuffer);

	if (OutputBuffer != NULL)
		free(OutputBuffer);

	irp->Complete(irp);
}

static void serial_process_irp(SERIAL_DEVICE* serial, IRP* irp)
{
	WLog_Print(serial->log, WLOG_DEBUG, "IRP MajorFunction: 0x%04X MinorFunction: 0x%04X\n",
			irp->MajorFunction, irp->MinorFunction);

	switch (irp->MajorFunction)
	{
		case IRP_MJ_CREATE:
			serial_process_irp_create(serial, irp);
			break;

		case IRP_MJ_CLOSE:
			serial_process_irp_close(serial, irp);
			break;

		case IRP_MJ_READ:
			serial_process_irp_read(serial, irp);
			break;

		case IRP_MJ_WRITE:
			serial_process_irp_write(serial, irp);
			break;

		case IRP_MJ_DEVICE_CONTROL:
			serial_process_irp_device_control(serial, irp);
			break;

		default:
			DEBUG_WARN("MajorFunction 0x%X not supported", irp->MajorFunction);
			irp->IoStatus = STATUS_NOT_SUPPORTED;
			irp->Complete(irp);
			break;
	}
}

static void* serial_read_thread_func(void* arg)
{
	IRP* irp;
	wMessage message;
	SERIAL_DEVICE* serial = (SERIAL_DEVICE*) arg;

	while (1)
	{
		if (!MessageQueue_Wait(serial->ReadIrpQueue))
			break;

		if (!MessageQueue_Peek(serial->ReadIrpQueue, &message, TRUE))
			break;

		if (message.id == WMQ_QUIT)
			break;

		irp = (IRP*) message.wParam;

		if (irp)
		{
			assert(irp->MajorFunction == IRP_MJ_READ);
			serial_process_irp(serial, irp);
		}
	}

	ExitThread(0);
	return NULL;
}

static void* serial_thread_func(void* arg)
{
	IRP* irp;
	wMessage message;
	SERIAL_DEVICE* serial = (SERIAL_DEVICE*) arg;

	while (1)
	{
		if (!MessageQueue_Wait(serial->MainIrpQueue))
			break;

		if (!MessageQueue_Peek(serial->MainIrpQueue, &message, TRUE))
			break;

		if (message.id == WMQ_QUIT)
			break;

		irp = (IRP*) message.wParam;

		if (irp)
			serial_process_irp(serial, irp);
	}

	ExitThread(0);
	return NULL;
}

static void serial_irp_request(DEVICE* device, IRP* irp)
{
	SERIAL_DEVICE* serial = (SERIAL_DEVICE*) device;

	assert(irp != NULL);

	if (irp == NULL)
		return;

	/* NB: ENABLE_ASYNCIO is set, (MS-RDPEFS 2.2.2.7.2) this
	 * allows the server to send multiple simultaneous read or
	 * write requests.
	 */

	switch(irp->MajorFunction)
	{
		case IRP_MJ_READ:
			MessageQueue_Post(serial->ReadIrpQueue, NULL, 0, (void*) irp, NULL);
			break;

		default:
			MessageQueue_Post(serial->MainIrpQueue, NULL, 0, (void*) irp, NULL);
	}
}

static void serial_free(DEVICE* device)
{
	SERIAL_DEVICE* serial = (SERIAL_DEVICE*) device;
	
	WLog_Print(serial->log, WLOG_DEBUG, "freeing");

	MessageQueue_PostQuit(serial->ReadIrpQueue, 0);
	WaitForSingleObject(serial->ReadThread, 100 /* ms */); /* INFINITE can block the process on a Read, FIXME: is a better signal possible? */ 
	CloseHandle(serial->ReadThread);

	MessageQueue_PostQuit(serial->MainIrpQueue, 0);
	WaitForSingleObject(serial->MainThread, INFINITE); /* FIXME: might likely block on a pending Write or ioctl */
	CloseHandle(serial->MainThread);

	if (serial->hComm)
		CloseHandle(serial->hComm);

	/* Clean up resources */
	Stream_Free(serial->device.data, TRUE);
	MessageQueue_Free(serial->ReadIrpQueue);
	MessageQueue_Free(serial->MainIrpQueue);

	free(serial);
}

#ifdef STATIC_CHANNELS
#define DeviceServiceEntry	serial_DeviceServiceEntry
#endif

int DeviceServiceEntry(PDEVICE_SERVICE_ENTRY_POINTS pEntryPoints)
{
	int i, len;
	char* name;
	char* path;
	RDPDR_SERIAL* device;
	SERIAL_DEVICE* serial;

	device = (RDPDR_SERIAL*) pEntryPoints->device;
	name = device->Name;
	path = device->Path;

	if (!name || (name[0] == '*'))
	{
		/* TODO: implement auto detection of parallel ports */
		return 0;
	}

	if ((name && name[0]) && (path && path[0]))
	{
		DEBUG_SVC("Defining %s as %s", name, path);
			
		if (!DefineCommDevice(name /* eg: COM1 */, path /* eg: /dev/ttyS0 */))
		{
			DEBUG_SVC("Could not define %s as %s", name, path);
			return -1;
		}

		serial = (SERIAL_DEVICE*) calloc(1, sizeof(SERIAL_DEVICE));
		if (!serial)
			return -1;

		serial->device.type = RDPDR_DTYP_SERIAL;
		serial->device.name = name;
		serial->device.IRPRequest = serial_irp_request;
		serial->device.Free = serial_free;

		len = strlen(name);
		serial->device.data = Stream_New(NULL, len + 1);

		for (i = 0; i <= len; i++)
			Stream_Write_UINT8(serial->device.data, name[i] < 0 ? '_' : name[i]);

		serial->ReadIrpQueue = MessageQueue_New(NULL);
		serial->MainIrpQueue = MessageQueue_New(NULL);

		WLog_Init();
		serial->log = WLog_Get("com.freerdp.channel.serial.client");
		WLog_Print(serial->log, WLOG_DEBUG, "initializing");

		pEntryPoints->RegisterDevice(pEntryPoints->devman, (DEVICE*) serial);

		serial->ReadThread = CreateThread(NULL, 
						  0, 
						  (LPTHREAD_START_ROUTINE) serial_read_thread_func, 
						  (void*) serial, 
						  0, 
						  NULL);

		serial->MainThread = CreateThread(NULL, 
						  0, 
						  (LPTHREAD_START_ROUTINE) serial_thread_func, 
						  (void*) serial, 
						  0, 
						  NULL);
	}

	return 0;
}