using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using JD.Adobe.Service.API;
using JD.Adobe.Service.ExecutableManagement;
using Microsoft.AspNet.SignalR;
using Plume.Core.Events;
using Plume.Core.Logging;
using Plume.Interfaces.Services;
using Shuttle.Api.ClientAPI;
using Shuttle.Servers;
using Shuttle.Servers.Hubs;
using Shuttle.Servers.Managers.AsyncProviders;
using Shuttle.Servers.Managers.Clients;
using Shuttle.Servers.Managers.Events;
using Shuttle.Servers.Managers.Items;
using Shuttle.Servers.Managers.Notifications;

namespace JD.Adobe.Service.Implementation
{
    public abstract class AdobeService : IAdobeService
    {
        private readonly object _lock = new object();
        private readonly HashSet<TargetAppInfo> _targets = new HashSet<TargetAppInfo>();
        private readonly ISignalrServer _signalrServer;
        private readonly EventInvoker _eventInvoker;
        private IAdobeEvents _adobeEvents;

        protected readonly AdobeExecutableManager _adobeExecutableManager;
        protected IAsyncProvider _asyncProvider;
        protected IClientManager _clientManager;
        protected bool _isInitialized = false;
        
        protected ILogger Logger { get; }

        public event Action<TargetAppInfo> OnTargetAdded;
        public event Action<TargetAppInfo> OnTargetRemoved;

        public event Action<TargetAppInfo, string> OnProjectFileChanged;
        public event Action<TargetAppInfo> OnTargetFocused;

        protected AdobeService(ILogger logger, string serverUrl)
        {
            if (serverUrl == null)
            {
                throw new ArgumentNullException(nameof(serverUrl));
            }

            Logger = logger ?? throw new ArgumentNullException(nameof(logger));
            _signalrServer = new SignalrServer(serverUrl);
            _eventInvoker = new EventInvoker(Logger);
            _adobeExecutableManager = new AdobeExecutableManager(Logger);
        }

        protected abstract void InitializeImpl(IServiceContext context);

        public void Initialize(IServiceContext context)
        {
            _asyncProvider = new AsyncProvider();
            var aeHubContext = GlobalHost.ConnectionManager.GetHubContext<ClientHub, IAfterEffectsClient>();
            var psHubContext = GlobalHost.ConnectionManager.GetHubContext<ClientHub, IPhotoshopClient>();
            _clientManager = new ClientManager(Logger, aeHubContext, psHubContext);

            _clientManager.OnTargetConnection += AddTarget;
            _clientManager.OnTargetDisconnection += RemoveTarget;

            var eventManager = new EventManager(Logger, _clientManager);
            eventManager.OnAppFocused += OnAppFocused;
            eventManager.OnProjectOpened += OnProjectOpened;
            eventManager.OnProjectClosed += OnProjectClosedEvent;
            _adobeEvents = eventManager;

            _signalrServer.Initialize(Logger, _clientManager,
                itemDepository: new ItemDepository(Logger, _asyncProvider), 
                operationNotificationListener: new OperationNotificationListener(Logger, _asyncProvider), 
                eventNotificationListener: eventManager);

            _signalrServer.Start();

            _adobeExecutableManager.Initialize();

            InitializeImpl(context);
        }

        public ICollection<TargetAppInfo> GetAvailableTargets()
        {
            ICollection<TargetAppInfo> results;
            lock (_lock)
            {
                results = new List<TargetAppInfo>(_targets);
            }

            return results;
        }

        public abstract Task<TargetAppInfo> StartNewInstance(AdobeApplicationType appType);

        public void Dispose()
        {
            _clientManager.OnTargetConnection -= AddTarget;
            _clientManager.OnTargetDisconnection -= RemoveTarget;

            _adobeEvents.OnAppFocused -= OnAppFocused;
            _adobeEvents.OnProjectOpened -= OnProjectOpened;
            _adobeEvents.OnProjectClosed -= OnProjectClosedEvent;

            _signalrServer.Dispose();
        }
        
        private void AddTarget(TargetAppInfo target)
        {
            if (target == null)
            {
                throw new ArgumentNullException(nameof(target));
            }

            if (TargetAppInfo.IsEmpty(target))
            {
                throw new ArgumentException($"{nameof(target)} cannot be the empty target.", nameof(target));
            }

            bool added;
            lock (_lock)
            {
                added = _targets.Add(target);
            }

            if (!added)
            {
                throw new ArgumentException($"Target '{target.ShuttleId}' ({target.ConnectionId}) was already known by {this.GetType().Name}.");
            }
            
            _eventInvoker.SafeInvokeEventAsync(OnTargetAdded, target);
        }

        private void RemoveTarget(TargetAppInfo target)
        {
            if (target == null)
            {
                throw new ArgumentNullException(nameof(target));
            }

            if (TargetAppInfo.IsEmpty(target))
            {
                throw new ArgumentException($"{nameof(target)} cannot be the empty target.", nameof(target));
            }

            bool removed;
            lock (_lock)
            {
                removed = _targets.Remove(target);
            }

            if (!removed)
            {
                throw new ArgumentException($"Target '{target.ShuttleId}' ({target.ConnectionId}) was not known by {this.GetType().Name} in the first place.");
            }
            
            _eventInvoker.SafeInvokeEventAsync(OnTargetRemoved, target);
        }

        protected void ThrowIfUnknown(TargetAppInfo target)
        {
            if (target == null)
            {
                throw new ArgumentNullException(nameof(target));
            }

            bool isKnown;
            lock (_lock)
            {
                isKnown = _targets.Contains(target);
            }

            if (isKnown)
            {
                return;
            }

            throw new ArgumentException($"Unknown target '{target.ShuttleId}' ({target.ConnectionId})");
        }

        private void OnProjectClosedEvent(TargetAppInfo target, string projectFile)
        {
            _eventInvoker.SafeInvokeEventAsync(OnProjectFileChanged, target, projectFile);
        }

        private void OnProjectOpened(TargetAppInfo target, string projectFile)
        {
            _eventInvoker.SafeInvokeEventAsync(OnProjectFileChanged, target, projectFile);
        }

        private void OnAppFocused(TargetAppInfo target)
        {
            _eventInvoker.SafeInvokeEventAsync(OnTargetFocused, target);
        }
    }
}