using System;
using ln.http;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using ln.logging;
using ln.types;
using System.Net;
using ln.application.service;
using ln.http.resources;
using ln.types.btree;

namespace ln.application
{
    public class Application : IApplicationInterface
    {
        public ArgumentContainer Arguments { get; protected set; }
        public HTTPServer HttpServer { get; private set; }

        public ServiceContainer ServiceContainer { get; }
        public ResourceApplication HTTPApplication { get; private set; }

        public MemoryLogger MemoryLogger { get; }

		public int ApplicationContextTimeout { get; set; } = 1200;


		MappingBTree<Guid, ApplicationContext> applicationContexts = new MappingBTree<Guid, ApplicationContext>((x)=>x.ContextID);

        public Application()
        {
            MemoryLogger = new MemoryLogger(8192);
            Logger.Default.Backends.Add(MemoryLogger);

            Arguments = new ArgumentContainer()
                .Add((char)0, "log-level", "INFO")
                .Add('l', "http-listen","0.0.0.0")
                .Add('p', "http-port", "8080");

            ServiceContainer = new ServiceContainer(this);
        }

        public virtual void PrepareStart()
        {
        }

        public void Start(String[] arguments)
        {
            Arguments.Parse(arguments);
            Logger.ConsoleLogger.MaxLogLevel = (LogLevel)Enum.Parse(typeof(LogLevel), Arguments["log-level"].Value);

            /* Startup Sequence */

            Logging.Log(LogLevel.INFO, "Calling PrepareStart()");
            PrepareStart();

            /* HTTP Server */
            Logging.Log(LogLevel.INFO, "Start:    HTTPServer on {0}:{1}", Arguments['l'].Value, Arguments['p'].IntegerValue);
            HttpServer = new HTTPServer();
            HttpServer.AddEndpoint(new System.Net.IPEndPoint(
                IPAddress.Parse(Arguments['l'].Value),
                Arguments['p'].IntegerValue
            ));

            HttpServer.Start();
            HTTPApplication = new ResourceApplication();
            HttpServer.DefaultApplication = HTTPApplication;


            /* Application Services */
            foreach (ServiceDefinition serviceDefinition in ServiceContainer)
            {
                if (serviceDefinition.AutoStart && !serviceDefinition.IsAlive)
                    ServiceContainer.Start(serviceDefinition);
            }

        }
        public void Stop()
        {
            Logging.Log(LogLevel.INFO, "Application shutdown requested");

            /* Application Services */
            foreach (ServiceDefinition serviceDefinition in ServiceContainer)
            {
                if (serviceDefinition.IsAlive)
                {
                    ServiceContainer.Stop(serviceDefinition);
                    if (serviceDefinition.IsAlive)
                        throw new Exception("application service could not be stopped");
                }
            }

            /* HTTP Server */
            Logging.Log(LogLevel.INFO, "Stopping HTTP server");
            HttpServer.Stop();
        }

		public virtual ApplicationContext CreateApplicationContext() => new ApplicationContext(this);

		public ApplicationContext GetApplicationContext() => GetApplicationContext(Guid.Empty);
		public ApplicationContext GetApplicationContext(Guid contextID)
		{
			ApplicationContext applicationContext;
			if (Guid.Empty.Equals(contextID))
			{
				while (true)
				{
					applicationContext = CreateApplicationContext();
					if (!applicationContexts.ContainsKey(applicationContext.ContextID))
					{
						applicationContexts.Add(applicationContext);
						break;
					}
				}
			}
			else
			{
				if (!applicationContexts.ContainsKey(contextID))
					throw new KeyNotFoundException();

				applicationContext = applicationContexts[contextID];
			}
			return applicationContext;
		}

		public virtual AuthenticatedUser AuthenticateUser(string username,object prove)
		{
			return null;
		}

		public void CleanupApplicationContexts()
		{
			foreach (ApplicationContext applicationContext in applicationContexts.ToArray())
			{
				if (applicationContext.Untouched > TimeSpan.FromSeconds(ApplicationContextTimeout))
					applicationContexts.RemoveKey(applicationContext.ContextID);
			}
		}


		/*
         * Plugin Classes
         */
		Dictionary<Type, List<object>> pluginInstances = new Dictionary<Type, List<object>>();

        public void RegisterPluginInstance<PC>(PC pluginInstance) => RegisterPluginInstance(typeof(PC),pluginInstance);
        public void RegisterPluginInstance(Type type,object pluginInstance)
        {
            if (!pluginInstances.ContainsKey(type))
                pluginInstances.Add(type, new List<object>());

            if (!pluginInstances[type].Contains(pluginInstance))
                pluginInstances[type].Add(pluginInstance);
        }

        public IEnumerable<PC> GetPluginInstances<PC>()
        {
            Type pluginType = typeof(PC);
            if (!pluginInstances.ContainsKey(pluginType))
                return new PC[0];

            return pluginInstances[pluginType].Select((ut) => (PC)ut);
        }
        public IEnumerable GetPluginInstances(Type pluginType)
        {
            if (!pluginInstances.ContainsKey(pluginType))
                return new object[0];

            return pluginInstances[pluginType];
        }


    }
}