aurora/aurora-sharp-desktop/Aurora/UserInterface/Views/Party/HostPartyViewModel.cs

using System;
using System.Threading.Tasks;
using System.Net;
using System.Net.Sockets;
using Grpc.Core;
using Xamarin.Forms;
using Aurora.Services.EventManager;
using Aurora.Services.Library;
using Aurora.Services.Settings;
using Aurora.Services;
using Aurora.Proto.Party;
using Aurora.Models.Media;
using Aurora.Services.Controllers;
using Aurora.Utils;


namespace Aurora.Design.Views.Party
{
    public class HostPartyViewModel : BasePartyViewModel
    {
        private IEventManager _eventManager;
        private ILibraryService _libraryService;

        private Grpc.Core.Server _server;
        private RemotePartyController _remotePartyController;
        private Channel _channel;
        private int _port = 8080;
        private bool _isServerStarted = false;

        public HostPartyViewModel(
            ISettingsService settingsService, 
            IEventManager eventManager,
            ILibraryService libraryService,
            Global global
        ): base(settingsService, global)
        {
            this._eventManager = eventManager;
            this._global.State = PartyState.Hosting;
            this._libraryService = libraryService;

            // Create and start grpc server
            string host = IpUtil.GetLocalIPAddress();
            if(string.IsNullOrWhiteSpace(host))
            {
                // TODO display error to screen
                throw new System.Exception("This device does not have a valid IP address");
            }
            this._hostname = IpUtil.GetLocalIPAddress();

            this.StartServer("test", "test description");

            // TODO assign members
            // TODO assign songList

            // Register commands
            PlayCommand = new Command(OnDoubleClickCommandExecute, CanDoubleClickCommandExecute);
            LeavePartyCommand = new Command(OnLeavePartyCommandExecute, CanLeavePartyCommandExecute);
            
        }

        #region Properties

        /// <summary>
        /// Public property for playing media command
        /// </summary>
        /// <value></value>
        public Command PlayCommand { get; private set; }

        /// <summary>
        /// Public property for leave party command
        /// </summary>
        /// <value></value>
        public Command LeavePartyCommand { get; private set; }

        #endregion Properties

        /// <summary>
        /// Called by framework when view becomes active
        /// </summary>
        /// <returns></returns>
        public override Task OnActive()
        {
            // Start server if not already started
            if(!this._isServerStarted)
            {
                this._hostname = IpUtil.GetLocalIPAddress();

                this.StartServer("test", "test description");
            }
            return Task.FromResult<object>(null);
        }

        /// <summary>
        /// Called by framework when view becomes inactive
        /// </summary>
        /// <returns></returns>
        public override Task OnInactive()
        {
            return Task.FromResult<object>(null);
        }

        private async void OnLeavePartyCommandExecute()
        {
            await this._channel.ShutdownAsync();
            await this._server.ShutdownAsync();
            this._global.State = PartyState.Idle;
            this.SetView(typeof(PartyView), typeof(PartyViewModel));
        }

        private bool CanLeavePartyCommandExecute()
        {
            return true;
        }

        public override void OnPlayButtonCommandExecute()
        {
            if (base.IsPlaying())
            {
                //Fire play stopped event
                AudioMetadata meta = SelectedMedia.Metadata as AudioMetadata;
                MediaPausedEvent mediaPaused = new MediaPausedEvent();

                _eventManager.FireEvent(new BaseEvent()
                {
                    MediaPausedEvent = mediaPaused
                });
            }
            else
            {
                //Fire play resume event
                AudioMetadata meta = SelectedMedia.Metadata as AudioMetadata;
                MediaResumedEvent mediaResumed = new MediaResumedEvent();

                _eventManager.FireEvent(new BaseEvent()
                {
                    MediaResumedEvent = mediaResumed
                });
            }
        }

        public override bool CanPlayButtonCommandExecute()
        {
            return true;
        }

        public override bool CanNextButtonCommandExecute()
        {
            return true;
        }

        public override bool CanPreviousButtonCommandExecute()
        {
            return true;
        }

        /// <summary>
        /// On double click execute, fire media playing event
        /// </summary>
        public void OnDoubleClickCommandExecute()
        {
            //Fire Playing event
            AudioMetadata meta = SelectedMedia.Metadata as AudioMetadata;
            NewMediaPlayingEvent mediaPlaying = new NewMediaPlayingEvent()
            {
                Media = new Media()
                {
                    //TODO need full resource name
                    Name = SelectedMedia.Id,
                    Title = meta.Title,
                    Artist = meta.Artist,
                    Album = meta.Album,
                }
            };

            _eventManager.FireEvent(new BaseEvent()
            {
                NewMediaPlayingEvent = mediaPlaying
            });
        }

        public bool CanDoubleClickCommandExecute()
        {
            return true;
        }

        #region Private Methods

        private void StartServer(string partyName, string description)
        {
            try
            {

                // TODO bmw replace with display in UI
                Console.WriteLine(string.Format("Starting gRPC server at hostname: {0}, port: {1}", _hostname, _port));

                _server = new Grpc.Core.Server
                {
                    Ports = { new ServerPort(_hostname, _port, ServerCredentials.Insecure) }
                };

                //Construct implementations
                this._remotePartyController = new RemotePartyController(
                    partyName,
                    description,
                    this._libraryService,
                    base._settingsService,
                    _eventManager);

                // Register grpc RemoteService with singleton server service
                RemotePartyService.BindService(this._remotePartyController);


                _server.Start();
                this._isServerStarted = true;
            }
            catch (Exception ex)
            {
                // TODO bmw replace with display in UI
                Console.WriteLine(string.Format("Error starting gRPC server: {0}", ex.Message));
            }
        }
        #endregion Private Methods

    }
}