using System;
using Microsoft.SPOT;

namespace CPF
{
    public static class Iridium
    {
        private static A3LA                     _modem;
        private static byte[]                   _message;
        private static byte[]                   _response;
        private static int                      _responseLength;
        private static int                      _originatedStatus;
        private static int                      _originatedSeqnum;
        private static int                      _terminatedStatus;
        private static int                      _terminatedSeqnum;
        private static int                      _lengthOfMobileTerminatedMessage;
        private static int                      _numberOfQueuedMessagesAwaitingReception;
        private static StructQueue.qStruct      _qe;
        private static Object                   _iridiumLock;
        private static ByteString               _bs;

        public static void PowerOn(string comPort)
        {
            _response = new byte[2048];
            _message = new byte[2048];
            _bs = new ByteString();
            _modem = new A3LA("COM2", 19200);
            _iridiumLock = new Object();
            _qe.byteArray = new Byte[StructQueue.qRecordWidth];
            _modem.PowerOn();
            _modem.ClearMobileOriginatedSequenceNumber();
            _modem.ClearBuffers(A3LA.BuffersToClear.BothOriginatedAndTerminated);
        }

        public static void ReportPosition()
        {

            Array.Clear(_qe.byteArray, 0, _qe.byteArray.Length);
                        Array.Clear(_response, 0, _response.Length);
            _modem.Position(_response, out _responseLength);
            _bs.Append(_response, _responseLength);
            _bs.Append(IridiumStrings.BVMSG, IridiumStrings.BVMSG.Length);
            _qe.errorCode = (int) _modem.SendTextMessage(_qe.byteArray, _responseLength);
            if (_qe.errorCode == (int)A3LA.Response.Match)
            {
                _modem.Status(out _originatedStatus, out _originatedSeqnum,
                              out _terminatedStatus, out _terminatedSeqnum,
                              out _lengthOfMobileTerminatedMessage,
                              out _numberOfQueuedMessagesAwaitingReception);
                _qe.errorCode = _originatedStatus;
                _modem.ClearBuffers(A3LA.BuffersToClear.MobileOriginated);
                if (_qe.errorCode == A3LA.MO_TransferredSuccessfully) 
                {
                    _qe.errorCode = _numberOfQueuedMessagesAwaitingReception + 1; 

                    QueueMessage(StructQueue.QRecordType.PositionReport);

                    if ((_terminatedStatus == 1) && (_lengthOfMobileTerminatedMessage > 0))
                    {
                        Array.Clear(_qe.byteArray, 0, _qe.byteArray.Length);
                        _modem.ReceiveTextMessage(_qe.byteArray,  out _responseLength);
                        QueueMessage(StructQueue.QRecordType.MT_MessageArrived);
                        do
                        {
                            _modem.Status(out _originatedStatus, out _originatedSeqnum,
                                          out _terminatedStatus, out _terminatedSeqnum,
                                          out _lengthOfMobileTerminatedMessage,
                                          out _numberOfQueuedMessagesAwaitingReception);
                            if ((_terminatedStatus == 1) && (_lengthOfMobileTerminatedMessage > 0))
                            {
                                Array.Clear(_qe.byteArray, 0, _qe.byteArray.Length);
                                _modem.ReceiveTextMessage(_qe.byteArray, out _responseLength);
                                QueueMessage(StructQueue.QRecordType.MT_MessageArrived);
                            }
                        } while (_numberOfQueuedMessagesAwaitingReception > 0);
                    }
                }
            }
        }

        public static void GetTimeAndDate()
        {
            _modem.SatelliteTimeAndDate(_response, out _responseLength);
            Debug.Print("Response from Time Request:\t\t" + Utils.StringFromBytes(_response, _responseLength));
        }

        private static void QueueMessage(StructQueue.QRecordType eventType)
        {
            Debug.Print("Queued Message:\t\t" + Utils.StringFromBytes(_qe.byteArray, _lengthOfMobileTerminatedMessage));
            _qe.timeStamp = DateTime.Now;
            _qe.state = Program.CPFState;
            _qe.qRecordType = eventType;
            _qe.errorCode = _terminatedStatus + A3LA.MT_Offset;
            lock (_iridiumLock) { Program.sQueue.Enqueue(_qe); }  
        }

        private static double BatteryVoltage()
        {
            return 1234.567;
        }

        public static void PowerOff()
        {
        }

    }
}