//******************************************************************************************************//  FrameParser.cs - Gbtc////  Copyright © 2012, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), 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.opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  04/27/2009 - J. Ritchie Carroll//       Generated original version of source code.//  09/15/2009 - Stephen C. Wills//       Added new header and license agreement.//  12/17/2012 - Starlynn Danyelle Gilliam//       Modified Header.////****************************************************************************************************** using System;using System.Text;using GSF.IO;using GSF.Parsing; namespace GSF.PhasorProtocols.SelFastMessage{    /// <summary>    /// Represents a frame parser for a SEL Fast Message binary data stream that returns parsed data via events.    /// </summary>    /// <remarks>    /// Frame parser is implemented as a write-only stream - this way data can come from any source.    /// </remarks>    public class FrameParser : FrameParserBase<int>    {        #region [ Members ]         // Events         /// <summary>        /// Occurs when a SEL Fast Message <see cref="ConfigurationFrame"/> has been received.        /// </summary>        /// <remarks>        /// <see cref="EventArgs{T}.Argument"/> is the <see cref="ConfigurationFrame"/> that was received.        /// </remarks>        public new event EventHandler<EventArgs<ConfigurationFrame>> ReceivedConfigurationFrame;         /// <summary>        /// Occurs when a SEL Fast Message <see cref="DataFrame"/> has been received.        /// </summary>        /// <remarks>        /// <see cref="EventArgs{T}.Argument"/> is the <see cref="DataFrame"/> that was received.        /// </remarks>        public new event EventHandler<EventArgs<DataFrame>> ReceivedDataFrame;         // Fields        private ConfigurationFrame m_configurationFrame;         #endregion         #region [ Constructors ]         /// <summary>        /// Creates a new <see cref="FrameParser"/> from specified parameters.        /// </summary>        /// <param name="checkSumValidationFrameTypes">Frame types that should perform check-sum validation; default to <see cref="CheckSumValidationFrameTypes.AllFrames"/></param>        /// <param name="trustHeaderLength">Determines if header lengths should be trusted over parsed byte count.</param>        /// <param name="messagePeriod">The desired <see cref="SelFastMessage.MessagePeriod"/> for SEL device connection.</param>        public FrameParser(CheckSumValidationFrameTypes checkSumValidationFrameTypes = CheckSumValidationFrameTypes.AllFrames, bool trustHeaderLength = true, MessagePeriod messagePeriod = MessagePeriod.DefaultRate)            : base(checkSumValidationFrameTypes, trustHeaderLength)        {            // Initialize protocol synchronization bytes for this frame parser            base.ProtocolSyncBytes = new[] { Common.HeaderByte1, Common.HeaderByte2 };             MessagePeriod = messagePeriod;        }         #endregion         #region [ Properties ]         /// <summary>        /// Gets or sets current <see cref="IConfigurationFrame"/> used for parsing <see cref="IDataFrame"/>'s encountered in the data stream from a device.        /// </summary>        /// <remarks>        /// If a <see cref="IConfigurationFrame"/> has been parsed, this will return a reference to the parsed frame.  Consumer can manually assign a        /// <see cref="IConfigurationFrame"/> to start parsing data if one has not been encountered in the stream.        /// </remarks>        public override IConfigurationFrame ConfigurationFrame        {            get => m_configurationFrame;            set => m_configurationFrame = CastToDerivedConfigurationFrame(value, MessagePeriod);        }         /// <summary>        /// Gets flag that determines if SEL Fast Message protocol parsing implementation uses synchronization bytes.        /// </summary>        public override bool ProtocolUsesSyncBytes => true;         /// <summary>        /// Gets or sets the desired message period for the SEL device.        /// </summary>        public MessagePeriod MessagePeriod { get; set; }         /// <summary>        /// Gets current descriptive status of the <see cref="FrameParser"/>.        /// </summary>        public override string Status        {            get            {                StringBuilder status = new();                 status.Append("    Defined message period: ");                status.Append(MessagePeriod);                status.AppendLine();                status.Append(base.Status);                 return status.ToString();            }        }         /// <summary>        /// Gets or sets any connection specific <see cref="IConnectionParameters"/> that may be needed for parsing.        /// </summary>        public override IConnectionParameters ConnectionParameters        {            get => base.ConnectionParameters;            set            {                if (value is ConnectionParameters parameters)                {                    base.ConnectionParameters = parameters;                     // Assign new incoming connection parameter values                    MessagePeriod = parameters.MessagePeriod;                }            }        }         #endregion         #region [ Methods ]         /// <summary>        /// Start the data parser.        /// </summary>        public override void Start()        {            // We narrow down parsing types to just those needed...            base.Start(new[] { typeof(DataFrame) });        }         /// <summary>        /// Parses a common header instance that implements <see cref="ICommonHeader{TTypeIdentifier}"/> for the output type represented        /// in the binary image.        /// </summary>        /// <param name="buffer">Buffer containing data to parse.</param>        /// <param name="offset">Offset index into buffer that represents where to start parsing.</param>        /// <param name="length">Maximum length of valid data from offset.</param>        /// <returns>The <see cref="ICommonHeader{TTypeIdentifier}"/> which includes a type ID for the <see cref="Type"/> to be parsed.</returns>        /// <remarks>        /// <para>        /// Derived classes need to provide a common header instance (i.e., class that implements <see cref="ICommonHeader{TTypeIdentifier}"/>)        /// for the output types; this will primarily include an ID of the <see cref="Type"/> that the data image represents.  This parsing is        /// only for common header information, actual parsing will be handled by output type via its <see cref="ISupportBinaryImage.ParseBinaryImage"/>        /// method. This header image should also be used to add needed complex state information about the output type being parsed if needed.        /// </para>        /// <para>        /// If there is not enough buffer available to parse common header (as determined by <paramref name="length"/>), return null.  Also, if        /// the protocol allows frame length to be determined at the time common header is being parsed and there is not enough buffer to parse        /// the entire frame, it will be optimal to prevent further parsing by returning null.        /// </para>        /// </remarks>        protected override ICommonHeader<int> ParseCommonHeader(byte[] buffer, int offset, int length)        {            // See if there is enough data in the buffer to parse the common frame header.            if (length > CommonFrameHeader.FixedLength)            {                // Parse common frame header                CommonFrameHeader parsedFrameHeader = new(buffer, offset);                 // Derive frame length from common frame header                int frameLength = (int)parsedFrameHeader.FrameSize;                 // We also make sure entire frame buffer image is available to be parsed                if (length >= frameLength)                {                    // Create configuration frame if it doesn't exist or frame size has changed                    if (m_configurationFrame is null || m_configurationFrame.FrameSize != parsedFrameHeader.FrameSize)                    {                        // Create virtual configuration frame                        m_configurationFrame = new ConfigurationFrame(parsedFrameHeader.FrameSize, MessagePeriod, parsedFrameHeader.IDCode);                         // Notify clients of new configuration frame                        OnReceivedChannelFrame(m_configurationFrame);                    }                     if (m_configurationFrame is null)                        return null;                     // Assign common header and data frame parsing state                    parsedFrameHeader.State = new DataFrameParsingState(frameLength, m_configurationFrame, DataCell.CreateNewCell, TrustHeaderLength, ValidateDataFrameCheckSum);                     // Expose the frame buffer image in case client needs this data for any reason                    OnReceivedFrameBufferImage(FundamentalFrameType.DataFrame, buffer, offset, frameLength);                     return parsedFrameHeader;                }            }             return null;        }         /// <summary>        /// Queues a sequence of bytes, from the specified data source, onto the stream for parsing.        /// </summary>        /// <param name="source">Identifier of the data source.</param>        /// <param name="buffer">An array of bytes. This method copies count bytes from buffer to the queue.</param>        /// <param name="offset">The zero-based byte offset in buffer at which to begin copying bytes to the current stream.</param>        /// <param name="count">The number of bytes to be written to the current stream.</param>        public override void Parse(SourceChannel source, byte[] buffer, int offset, int count)        {            // When SEL Fast Message is transmitted over Ethernet it is embedded in a Telnet stream. As a result            // any 0xFF will be encoded for Telnet compliance as a duplicate, i.e., 0xFF 0xFF. We remove these            // duplications when encountered to make sure check-sums and parsing work as expected.            int doubleFFPosition = buffer.IndexOfSequence(new byte[] { 0xFF, 0xFF }, offset, count);             while (doubleFFPosition > -1)            {                using (BlockAllocatedMemoryStream newBuffer = new())                {                    // Write buffer before repeated byte                    newBuffer.Write(buffer, offset, doubleFFPosition - offset + 1);                     int nextByte = doubleFFPosition + 2;                     // Write buffer after repeated byte, if any                    if (nextByte < offset + count)                        newBuffer.Write(buffer, nextByte, offset + count - nextByte);                     buffer = newBuffer.ToArray();                }                 offset = 0;                count = buffer.Length;                 // Find next 0xFF 0xFF sequence                doubleFFPosition = buffer.IndexOfSequence(new byte[] { 0xFF, 0xFF }, offset, count);            }             base.Parse(source, buffer, offset, count);        }         /// <summary>        /// Casts the parsed <see cref="IChannelFrame"/> to its specific implementation (i.e., <see cref="DataFrame"/> or <see cref="ConfigurationFrame"/>).        /// </summary>        /// <param name="frame"><see cref="IChannelFrame"/> that was parsed by <see cref="FrameImageParserBase{TTypeIdentifier,TOutputType}"/> that implements protocol specific common frame header interface.</param>        protected override void OnReceivedChannelFrame(IChannelFrame frame)        {            // Raise abstract channel frame events as a priority (i.e., IDataFrame, IConfigurationFrame, etc.)            base.OnReceivedChannelFrame(frame);             // Raise SEL Fast Message specific channel frame events, if any have been subscribed            if (frame is null || ReceivedDataFrame is null && ReceivedConfigurationFrame is null)                return;                        switch (frame)            {                case DataFrame dataFrame:                {                    ReceivedDataFrame?.Invoke(this, new EventArgs<DataFrame>(dataFrame));                    break;                }                case ConfigurationFrame configFrame:                {                    ReceivedConfigurationFrame?.Invoke(this, new EventArgs<ConfigurationFrame>(configFrame));                    break;                }            }        }         #endregion         #region [ Static ]         // Attempts to cast given frame into a SEL Fast Message configuration frame - theoretically this will        // allow the same configuration frame to be used for any protocol implementation        internal static ConfigurationFrame CastToDerivedConfigurationFrame(IConfigurationFrame sourceFrame, MessagePeriod messagePeriod)        {            // See if frame is already a SEL Fast Message frame (if so, we don't need to do any work)            ConfigurationFrame derivedFrame = sourceFrame as ConfigurationFrame;             if (derivedFrame is null)            {                // Create a new SEL Fast Message configuration frame converted from equivalent configuration information; SEL Fast Message only supports one device                if (sourceFrame.Cells.Count > 0)                {                    IConfigurationCell sourceCell = sourceFrame.Cells[0];                     derivedFrame = sourceCell.PhasorDefinitions.Count switch                    {                        8 => new ConfigurationFrame(FrameSize.A, messagePeriod, sourceFrame.IDCode),                        4 => new ConfigurationFrame(FrameSize.V, messagePeriod, sourceFrame.IDCode),                        _ => new ConfigurationFrame(FrameSize.V1, messagePeriod, sourceFrame.IDCode),                    };                     // Create new derived configuration cell                    ConfigurationCell derivedCell = new(derivedFrame);                    IFrequencyDefinition sourceFrequency;                     // Create equivalent derived phasor definitions                    foreach (IPhasorDefinition sourcePhasor in sourceCell.PhasorDefinitions)                        derivedCell.PhasorDefinitions.Add(new PhasorDefinition(derivedCell, sourcePhasor.Label, sourcePhasor.PhasorType, null));                     // Create equivalent derived frequency definition                    sourceFrequency = sourceCell.FrequencyDefinition;                     if (sourceFrequency is not null)                        derivedCell.FrequencyDefinition = new FrequencyDefinition(derivedCell, sourceFrequency.Label);                     // Add cell to frame                    derivedFrame.Cells.Add(derivedCell);                }            }             return derivedFrame;        }         #endregion    }}