using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Independentsoft.Sip;
using Independentsoft.Sip.Methods;
using SipComponent.Excera;

namespace SipComponent
{
    /// <summary>
    /// An implementation of the abstract class SipClientClass, used for Excera
    /// </summary>
    public class SipClientClassExcera : SipClientClassSimoco
    {

        #region Fields

        private ExceraSipMessageGenerator _sipMessageGenerator = new ExceraSipMessageGenerator();

        #endregion

        /// <summary>
        /// Constructor for the SipClientClassExcera
        /// </summary>
        /// <param name="repeaterIP">domain name, name or IP address of sip server</param>
        /// <param name="repeaterSipPort">port number of the sip server</param>
        /// <param name="localSipPort">port number of the local computer used for sip protocol</param>
        /// <param name="userName">user name on the sip server</param>
        /// <param name="registrationInterval">interval to send sip registration requests. Value is in seconds</param>
        /// <param name="bufferMiliseconds">Miliseconds for the buffer that stores the received voice packets</param>
        /// <param name="requestTimeout">Number of ms to wait before the sip request times out</param>
        /// <param name="localIPAddress">Local Ip adress. If not specified, the class will search for a local ip on the same network with the repeater's ip</param>
        public SipClientClassExcera(string repeaterIP, int repeaterSipPort, int localSipPort,
            string userName, int registrationInterval, int bufferMiliseconds, int requestTimeout, string localIPAddress = null)
            :base(repeaterIP, repeaterSipPort, localSipPort, userName, registrationInterval, bufferMiliseconds, requestTimeout, localIPAddress)
        {

        }


        #region Public Members

        /// <summary>
        /// Method used to send a Ping command to an Excera radio
        /// </summary>
        /// <param name="idToSendPing">The Excera ID of the radio</param>
        public override void SendPing(string idToSendPing)
        {
            base.SendExceraPing(idToSendPing);
        }

        #endregion

        #region Non-Public Members Overrinding

        /// <summary>
        /// Function that processes all the received Sip Message requests
        /// </summary>
        /// <param name="sipMessageRequest">The Sip Message request</param>
        /// <param name="senderID">The ID of the sender</param>
        protected override void ProcessReceivedSipMessage(Request sipMessageRequest, string senderID)
        {
            if (sipMessageRequest.Header.Contains("Ais-Msg-id"))
            {
                string msgId = sipMessageRequest.Header["Ais-Msg-id"];
                if (msgId.Contains("emerg-alarm"))
                {
                    EmergencyReceived?.Invoke(this, new SipEventArgs(senderID));
                }
            }
            // Handle messages when working with Excera 
            // Get Ais-Msg-Options Header value - this is used for Gps periodically reports 
            if (sipMessageRequest.Header.Contains("Ais-Msg-Options"))
            {
                string ais_options = sipMessageRequest.Header["Ais-Msg-Options"];
                switch (ais_options)
                {
                    case "service-attributes;transmission-type=raw;coding=nmea;rate=half":
                        // GPS periodically report
                        double lat, lon, speed;
                        DateTime time;
                        // Get latitude, longitude, speed and time
                        Simoco.Utils.GPSInfo(Convert.FromBase64String(sipMessageRequest.Body), out lat, out lon, out speed, out time);
                        // Raise Event
                        OnGpsPeriodicallyReportReceived(new GpsDataEventArgs(
                            senderID, lat, lon, speed, time));
                        break;
                    case "service-attributes; coding=iso8":
                        // Management message report
                        // Get the Type and the command bytes
                        byte[] data = Convert.FromBase64String(sipMessageRequest.Body);
                        byte type = SipComponent.Simoco.SP6.GetType(data);
                        byte command = SipComponent.Simoco.SP6.GetCommand(data);
                        switch (type)
                        {
                            case 0:
                                // GPS position report
                                byte[] nmeaData = new byte[10];
                                Array.Copy(data, 5, nmeaData, 0, nmeaData.Length);
                                // Get latitude, longitude, speed and time from nmea data
                                Simoco.Utils.GPSInfo(nmeaData, out lat, out lon, out speed, out time);
                                // Raise event
                                OnSimocoGpsReportReceived(new GpsDataEventArgs(senderID, lat, lon, speed, time));
                                break;
                            case 1:
                                // Device status
                                switch (command)
                                {
                                    case 1:
                                        // Device status report
                                        // Sent on request or when alarm conditions change
                                        // Is sent to remote radio to acknowledge receipt of alarm conditions

                                        // Get GPS from status report
                                        Simoco.Utils.GetGPSFromStatusReport(data, out lat, out lon);
                                        Simoco.AlarmType alarmType = Simoco.SP6.GetAlarmType(data);
                                        if (alarmType != Simoco.AlarmType.NO_ALARM)
                                        {
                                            // Save the message in a dictionary
                                            // It have to be resent to the radio to confirm the receipt
                                            AddSimocoAlarmToDictionary(senderID, sipMessageRequest.Body);
                                        }
                                        // Raise event
                                        OnSimocoStatusReportReceived(new SimocoDeviceStatusReportEventArgs(
                                            senderID, lat, lon, alarmType));
                                        break;
                                }
                                break;
                            case 255:
                                // Ping
                                int nbOfReceivedBytes = data.Length - 5;
                                byte[] pingData = new byte[nbOfReceivedBytes];
                                Array.Copy(data, 5, pingData, 0, pingData.Length);
                                if (HandleSimocoPingResponse(senderID, pingData))
                                {
                                    // Fire Event
                                    OnSimocoPingResponseReceived(new SipEventArgs(senderID));
                                }
                                break;
                        }
                        break;
                    default:
                        // This is surelly incorect - TO DO
                        // Sms from Simoco
                        string text = sipMessageRequest.Body;
                        if (text != null) // body is null in case of status message - future implementation - TO DO
                        {
                            OnSmsReceived(new SmsReceivedEventsArgs(senderID,
                                Encoding.BigEndianUnicode.GetString(Convert.FromBase64String(text))
                                ));
                        }
                        break;
                }
            }
        }


        internal override SipMessageGenerator SipMessageGenerator
        {
            get
            {
                return _sipMessageGenerator;
            }
        }


        #endregion

        #region events

        public event EventHandler<SipEventArgs> EmergencyReceived;

        #endregion
    }
}