/**
 * FreeRDP: A Remote Desktop Protocol Implementation
 * Redirected Parallel Port Device Service
 *
 * Copyright 2010 O.S. Systems Software Ltda.
 * Copyright 2010 Eduardo Fiss Beloni <beloni@ossystems.com.br>
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <fcntl.h>
#include <errno.h>

#ifndef _WIN32
#include <termios.h>
#include <strings.h>
#include <sys/ioctl.h>
#endif

#ifdef __LINUX__
#include <linux/ppdev.h>
#include <linux/parport.h>
#endif

#include <winpr/crt.h>
#include <winpr/synch.h>
#include <winpr/thread.h>
#include <winpr/interlocked.h>

#include <freerdp/types.h>
#include <freerdp/constants.h>
#include <freerdp/utils/list.h>
#include <freerdp/utils/thread.h>
#include <freerdp/utils/memory.h>
#include <freerdp/utils/stream.h>
#include <freerdp/utils/unicode.h>
#include <freerdp/utils/svc_plugin.h>
#include <freerdp/channels/rdpdr.h>

struct _PARALLEL_DEVICE
{
	DEVICE device;

	int file;
	char* path;
	UINT32 id;

	PSLIST_HEADER pIrpList;
	freerdp_thread* thread;
};
typedef struct _PARALLEL_DEVICE PARALLEL_DEVICE;

static void parallel_process_irp_create(PARALLEL_DEVICE* parallel, IRP* irp)
{
	char* path;
	UINT32 PathLength;

	stream_seek(irp->input, 28);
	/* DesiredAccess(4) AllocationSize(8), FileAttributes(4) */
	/* SharedAccess(4) CreateDisposition(4), CreateOptions(4) */
	stream_read_UINT32(irp->input, PathLength);

	freerdp_UnicodeToAsciiAlloc((WCHAR*) stream_get_tail(irp->input), &path, PathLength / 2);

	parallel->id = irp->devman->id_sequence++;
	parallel->file = open(parallel->path, O_RDWR);

	if (parallel->file < 0)
	{
		irp->IoStatus = STATUS_ACCESS_DENIED;
		parallel->id = 0;

		DEBUG_WARN("failed to create %s: %s", parallel->path, strerror(errno));
	}
	else
	{
		/* all read and write operations should be non-blocking */
		if (fcntl(parallel->file, F_SETFL, O_NONBLOCK) == -1)
			DEBUG_WARN("%s fcntl %s", path, strerror(errno));

		DEBUG_SVC("%s(%d) created", parallel->path, parallel->file);
	}

	stream_write_UINT32(irp->output, parallel->id);
	stream_write_BYTE(irp->output, 0);

	free(path);

	irp->Complete(irp);
}

static void parallel_process_irp_close(PARALLEL_DEVICE* parallel, IRP* irp)
{
	if (close(parallel->file) < 0)
		DEBUG_SVC("failed to close %s(%d)", parallel->path, parallel->id);
	else
		DEBUG_SVC("%s(%d) closed", parallel->path, parallel->id);

	stream_write_zero(irp->output, 5); /* Padding(5) */

	irp->Complete(irp);
}

static void parallel_process_irp_read(PARALLEL_DEVICE* parallel, IRP* irp)
{
	UINT32 Length;
	UINT64 Offset;
	ssize_t status;
	BYTE* buffer = NULL;

	stream_read_UINT32(irp->input, Length);
	stream_read_UINT64(irp->input, Offset);

	buffer = (BYTE*) malloc(Length);

	status = read(parallel->file, irp->output->p, Length);

	if (status < 0)
	{
		irp->IoStatus = STATUS_UNSUCCESSFUL;
		free(buffer);
		buffer = NULL;
		Length = 0;

		DEBUG_WARN("read %s(%d) failed", parallel->path, parallel->id);
	}
	else
	{
		DEBUG_SVC("read %llu-%llu from %d", Offset, Offset + Length, parallel->id);
	}

	stream_write_UINT32(irp->output, Length);
	if (Length > 0)
	{
		stream_check_size(irp->output, Length);
		stream_write(irp->output, buffer, Length);
	}
	free(buffer);

	irp->Complete(irp);
}

static void parallel_process_irp_write(PARALLEL_DEVICE* parallel, IRP* irp)
{
	UINT32 Length;
	UINT64 Offset;
	ssize_t status;
	UINT32 len;

	stream_read_UINT32(irp->input, Length);
	stream_read_UINT64(irp->input, Offset);
	stream_seek(irp->input, 20); /* Padding */

	DEBUG_SVC("Length %u Offset %llu", Length, Offset);

	len = Length;

	while (len > 0)
	{
		status = write(parallel->file, stream_get_tail(irp->input), len);

		if (status < 0)
		{
			irp->IoStatus = STATUS_UNSUCCESSFUL;
			Length = 0;

			DEBUG_WARN("write %s(%d) failed.", parallel->path, parallel->id);
			break;
		}

		stream_seek(irp->input, status);
		len -= status;
	}

	stream_write_UINT32(irp->output, Length);
	stream_write_BYTE(irp->output, 0); /* Padding */

	irp->Complete(irp);
}

static void parallel_process_irp_device_control(PARALLEL_DEVICE* parallel, IRP* irp)
{
	DEBUG_SVC("in");
	stream_write_UINT32(irp->output, 0); /* OutputBufferLength */
	irp->Complete(irp);
}

static void parallel_process_irp(PARALLEL_DEVICE* parallel, IRP* irp)
{
	DEBUG_SVC("MajorFunction %u", irp->MajorFunction);

	switch (irp->MajorFunction)
	{
		case IRP_MJ_CREATE:
			parallel_process_irp_create(parallel, irp);
			break;

		case IRP_MJ_CLOSE:
			parallel_process_irp_close(parallel, irp);
			break;

		case IRP_MJ_READ:
			parallel_process_irp_read(parallel, irp);
			break;

		case IRP_MJ_WRITE:
			parallel_process_irp_write(parallel, irp);
			break;

		case IRP_MJ_DEVICE_CONTROL:
			parallel_process_irp_device_control(parallel, irp);
			break;

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

static void parallel_process_irp_list(PARALLEL_DEVICE* parallel)
{
	IRP* irp;

	while (1)
	{
		if (freerdp_thread_is_stopped(parallel->thread))
			break;

		irp = (IRP*) InterlockedPopEntrySList(parallel->pIrpList);

		if (irp == NULL)
			break;

		parallel_process_irp(parallel, irp);
	}
}

static void* parallel_thread_func(void* arg)
{
	PARALLEL_DEVICE* parallel = (PARALLEL_DEVICE*) arg;

	while (1)
	{
		freerdp_thread_wait(parallel->thread);

		if (freerdp_thread_is_stopped(parallel->thread))
			break;

		freerdp_thread_reset(parallel->thread);

		parallel_process_irp_list(parallel);
	}

	freerdp_thread_quit(parallel->thread);

	return NULL;
}

static void parallel_irp_request(DEVICE* device, IRP* irp)
{
	PARALLEL_DEVICE* parallel = (PARALLEL_DEVICE*) device;

	InterlockedPushEntrySList(parallel->pIrpList, &(irp->ItemEntry));

	freerdp_thread_signal(parallel->thread);
}

static void parallel_free(DEVICE* device)
{
	IRP* irp;
	PARALLEL_DEVICE* parallel = (PARALLEL_DEVICE*) device;

	DEBUG_SVC("freeing device");

	freerdp_thread_stop(parallel->thread);
	freerdp_thread_free(parallel->thread);

	while ((irp = (IRP*) InterlockedPopEntrySList(parallel->pIrpList)) != NULL)
		irp->Discard(irp);

	_aligned_free(parallel->pIrpList);

	free(parallel);
}

#ifdef STATIC_CHANNELS
#define DeviceServiceEntry	parallel_DeviceServiceEntry
#endif

int DeviceServiceEntry(PDEVICE_SERVICE_ENTRY_POINTS pEntryPoints)
{
	char* name;
	char* path;
	int i, length;
	PARALLEL_DEVICE* parallel;

	name = (char*) pEntryPoints->plugin_data->data[1];
	path = (char*) pEntryPoints->plugin_data->data[2];

	if (name[0] && path[0])
	{
		parallel = xnew(PARALLEL_DEVICE);

		parallel->device.type = RDPDR_DTYP_PARALLEL;
		parallel->device.name = name;
		parallel->device.IRPRequest = parallel_irp_request;
		parallel->device.Free = parallel_free;

		length = strlen(name);
		parallel->device.data = stream_new(length + 1);

		for (i = 0; i <= length; i++)
			stream_write_BYTE(parallel->device.data, name[i] < 0 ? '_' : name[i]);

		parallel->path = path;

		parallel->pIrpList = (PSLIST_HEADER) _aligned_malloc(sizeof(SLIST_HEADER), MEMORY_ALLOCATION_ALIGNMENT);
		InitializeSListHead(parallel->pIrpList);

		parallel->thread = freerdp_thread_new();

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

		freerdp_thread_start(parallel->thread, parallel_thread_func, parallel);
	}

	return 0;
}