using System;
using System.Collections.Generic;
using System.Text;
using log4net;
using Quadarax.Foundation.Common.Object;
using StructureMap;

namespace Quadarax.Foundation.Infrastructure.Layers
{
    public abstract class Layer : DisposableObject
    {
        private IContainer _container;
        private IList<Layer> _childLayers = new List<Layer>();
        private Layer _parentLayer;

        protected ILog Log { get; }

        public string Name { get; }

        public int ChildLayersCount => _childLayers.Count;

        public LayerClassificationEnum LayerType { get; protected set; }

        protected Layer(string name, Layer parentLayer = null)
        {
            if (string.IsNullOrEmpty(name))
                throw new ArgumentNullException(nameof(name), "Infrastucture layer must have a name.");
            _parentLayer = parentLayer;

            Log = LogManager.GetLogger(GetType());
            Name = name;

            InitializeInternal();

            Log.Info($"Layer '{Name}' fully created.");
        }


        private void InitializeInternal()
        {
            _container = _parentLayer == null ? new Container() : _parentLayer._container.CreateChildContainer();
            OnModuleRegistry(_container);
            OnLayerRegistry();
            Log.Info($"Layer '{Name}' initialization done");
        }

        protected void AddChildLayer(Layer layer)
        {
            if (layer==null)
                throw new ArgumentNullException(nameof(layer));

            _childLayers.Add(layer);
            Log.Info($"Layer 'Name' append child layer '{layer.Name}'. Current child count on layer '{Name}' is {ChildLayersCount} childs.");
        }

        protected abstract void OnLayerRegistry();
        
        protected abstract void OnModuleRegistry(IContainer container);

        protected override void OnDisposing()
        {
            _parentLayer?.Dispose();
            _parentLayer = null;

            if (_childLayers != null)
            {
                foreach (var layer in _childLayers)
                {
                    layer.Dispose();
                }
            }

            Log.Info($"Layer '{Name}' disposed.");
        }

        public TModule Get<TModule>() where TModule : IModule
        {
            return _container.GetInstance<TModule>();
        }

        public string Dump()
        {
            var sb = new StringBuilder();
            sb.Append("*** Layer: ").Append(Name).Append(" [").Append(LayerType).Append("] * BEGIN ***").AppendLine();
            sb.Append("Parent:").AppendLine();
            sb.Append(_parentLayer == null ? "none" : _parentLayer.Name);
            sb.AppendLine();
            sb.Append("Childs:").AppendLine();
            foreach (var child in _childLayers)
                sb.Append(child.Dump()).AppendLine();
            sb.Append("*** Layer: ").Append(Name).Append(" [").Append(LayerType).Append("] * END ***").AppendLine();
            return sb.ToString();
        }
    }
}