using System;
using System.Collections;
using System.Text;
using System.Diagnostics;
using log4net;

namespace bsmd.AIS2Service
{
    /// <summary>
    /// Diese Nachricht wird normalerweise von Class B Geräten nicht verschickt.
    /// Sie wird nur als Antwort auf einen sog. "Base station poll" gesendet.
    /// Wir lesen sie trotzdem ;)
    /// </summary>
    // Todo
    internal class AIS_ClassBExt : AISClass
    {
        #region private members

        private int repeatIndicator;        
        private int spare1;
        private int sog;
        private int accuracy;
        private int longitude;
        private int latitude;
        private int cog;
        private int trueHeading;
        private int utcTimestampSecond;
        private DateTime timestamp;
        private int spare2;
        private string name;
        private int shipType;
        private int dimension;
        private int typeofDevice;
        private int raimFlag;
        private int dte;
        private int assignedMode;
        private int spare3;

        private static ILog _log = LogManager.GetLogger(typeof(AIS_ClassBExt));

        #endregion

        #region Properties

        public string Name
        {
            get { return this.name; }
        }

        public DateTime Timestamp
        {
            get { return this.timestamp; }
        }

        public double Latitude
        {
            get { return this.latitude / 600000.0f; }
        }

        public double Longitude
        {
            get { return this.longitude / 600000.0f; }
        }

        public int TrueHeading
        {
            get { return this.trueHeading; }
        }

        public double Cog
        {
            get { return (double)this.cog / 10.0f; }
        }

        #endregion

        protected override Status Decode()
        {
            BitArray bits = DecodeBinary(_data);
            Status result = Status.OK;

            try
            {
                int type = GetInt(bits, 0, 5);
                if (type != 19)
                {
                    result = Status.ILLEGAL_ARGUMENT;
                }
                else
                {
                    this.repeatIndicator = GetInt(bits, 6, 7);
                    _mmsi = GetInt(bits, 8, 37);
                    this.spare1 = GetInt(bits, 38, 45);
                    this.sog = GetInt(bits, 46, 55);
                    this.accuracy = GetInt(bits, 56, 56);
                    this.longitude = GetInt(bits, 57, 84);
                    this.latitude = GetInt(bits, 85, 111);
                    this.cog = GetInt(bits, 112, 123);
                    this.trueHeading = GetInt(bits, 124, 132);
                    this.utcTimestampSecond = GetInt(bits, 133, 138);
                    this.timestamp = DateTime.Now;
                    this.spare2 = GetInt(bits, 139, 142);

                    StringBuilder sb_name = new StringBuilder(20);
                    for (int i = 0; i < 20; i++)
                    {
                        int cval = GetInt(bits, 143 + (6 * i), 148 + (6 * i));
                        char ch = GetAISChar(cval);
                        if (ch == '@') ch = ' ';
                        sb_name.Append(ch);
                    }
                    this.name = sb_name.ToString().Trim();

                    this.shipType = GetInt(bits, 263, 270);
                    this.dimension = GetInt(bits, 271, 300);
                    this.typeofDevice = GetInt(bits, 301, 304);
                    this.raimFlag = GetInt(bits, 305, 305);
                    this.dte = GetInt(bits, 306, 306);
                    this.assignedMode = GetInt(bits, 307, 307);
                    this.spare3 = GetInt(bits, 308, 311);
                }
            }

            catch (Exception e)
            {
                _log.WarnFormat("Error decoding AIS class B Ext posreport: {0}", e.Message);
                result = Status.PARSE_ERROR;
            }

            return result;
        }
    }
}