using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Xml;

namespace Intel.Management.PSModule.Amt
{

    class MessageFormat : IFormatProvider
    {
        object _format;

        public MessageFormat() {}
        public object GetFormat(Type formatType)
        {
            if (formatType.Equals(typeof(AmtMessageLogEntry)))
            {
                if (_format == null)
                {
                    XmlDocument doc = new XmlDocument();
                    doc.LoadXml(
                        Intel.Management.PSModule.Properties.Resources.EventDataXML);

                    _format = doc;
                }
            }
            else
            {
                throw new FormatException();
            }

            return _format;
        }

    }


    public class AmtMessageLogEntry
    {

        [StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Ansi)]
        internal struct AMT_EVENT_RECORD
        {

            public UInt32 TimeStamp; // little endian 
            public byte DeviceAddress;
            public byte EventSensorType;
            public byte EventType;
            public byte EventOffset;
            public byte EventSourceType;
            public byte EventSeverity;
            public byte SensorNumber;
            public byte Entity;
            public byte EntityInstance;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public byte[] EventData;
        }

        AMT_EVENT_RECORD _interalRec;
        string _message;
        string _source;

        private AmtMessageLogEntry(AMT_EVENT_RECORD rec,string message,string source)
        {
            _interalRec = rec;
            _message = message;
            _source = source;
        }

        public string Severity
        {
            get
            {

                return _interalRec.EventSeverity.ToString();
            }
        }

        public DateTime TimeStamp
        {
            get
            {
                DateTime time = new DateTime(1970, 1, 1);
                //time.ToShortDateString
                //time.ToShortTimeString()
                return time.AddSeconds((double)_interalRec.TimeStamp);
            }
        }

        public string Source
        {
            get
            {
                return _source;
            }
        }

        public string Message
        {
            get
            {
                return _message;
            }
        }




        public static XmlDocument LoadMessageData()
        {
            XmlDocument doc = new XmlDocument();
            doc.LoadXml(
                Intel.Management.PSModule.Properties.Resources.EventDataXML);

            return doc;
        }

        public static AmtMessageLogEntry CreateFromPtr(IntPtr ptr,IFormatProvider provider )
        {
            AMT_EVENT_RECORD rec = (AMT_EVENT_RECORD)Marshal.PtrToStructure(ptr, typeof(AMT_EVENT_RECORD));
            string[] args = { rec.EventSensorType.ToString(),
                                rec.EventOffset.ToString(), 
                                rec.EventData[1].ToString(), };

            XmlDocument eventDoc = (XmlDocument)provider.GetFormat(typeof(AmtMessageLogEntry));

            XmlNode srcNode = eventDoc.DocumentElement.SelectSingleNode( string.Format(
                "EventSource[@Entity=\"{0}\"]",rec.Entity));
            
            XmlNode msgNode = eventDoc.DocumentElement.SelectSingleNode( string.Format(
                "EventData[@Type=\"{0}\" and @Offset=\"{1}\" and @Data2=\"{2}\"]",args));

            string source = rec.EventSourceType.ToString();
            string message = string.Empty;

            if (srcNode != null)
                source = srcNode.InnerText;
            if (msgNode != null)
                message = msgNode.InnerText;

            return new AmtMessageLogEntry(rec, message,source);
        }
    }
}