using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Threading.Tasks;
using JD.Interfaces.Remoting;
using Plume.Core.Logging;
using Plume.Interfaces.Services;

namespace JD.Remoting.Services
{
    public sealed class PluginService : IPluginService
    {
        private readonly List<IPlugin> _plugins = new List<IPlugin>();
        private IServiceContext _serviceContext;

        /// <inheritdoc />
        public void Dispose()
        {
            if (_plugins.Any())
            {
                foreach (IPlugin plugin in _plugins.ToArray())
                {
                    plugin.Dispose();
                    RemovePlugin(plugin);
                }
            }
        }

        private void RemovePlugin(IPlugin plugin)
        {
            _plugins.Remove(plugin);
            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, plugin));
        }

        /// <inheritdoc />
        public void Initialize(IServiceContext serviceContext)
        {
            _serviceContext = serviceContext;
        }

        /// <inheritdoc />
        public void Register(IPlugin plugin)
        {
            if (_plugins.Any() && _plugins.All(x => x.IsConnected))
            {
                plugin.Start(EndPointId);
            }
            _plugins.Add(plugin);
            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, plugin));
        }
        

        public EndPointId EndPointId { get; private set; } = default(EndPointId);

        /// <inheritdoc />
        public void Start(EndPointId endPointId = default(EndPointId))
        {
            EndPointId = endPointId;
            foreach (var plugin in _plugins)
            {
                plugin.Start(endPointId);
            }
        }

        /// <inheritdoc />
        public void Stop()
        {
            foreach (var plugin in _plugins.Where(p=>p.IsConnected))
            {
                plugin.Stop();
            }
        }

        /// <inheritdoc />
        public event NotifyCollectionChangedEventHandler CollectionChanged;

        private void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
        {
            CollectionChanged?.Invoke(this, e);
        }

        /// <inheritdoc />
        public IEnumerator<IPlugin> GetEnumerator()
        {
            return _plugins.GetEnumerator();
        }

        /// <inheritdoc />
        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }
}