using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;

namespace WindowsServiceClient
{
    public delegate void RequestReceivedEventHandler(HttpListenerContext context);
    public class HttpWebServer : IDisposable
    {
        protected HttpListener _listener;
        protected bool _isListenerOn;

        public event RequestReceivedEventHandler OnRequestReceived;


        public HttpWebServer(HttpWebServerResponsor responsor)
        {
            OnRequestReceived += responsor.Response;
        }
        public void StartListening(string[] urlCollection)
        {
            _isListenerOn = true;
            _listener = new HttpListener();
            foreach (var i in urlCollection) _listener.Prefixes.Add(i);
            _listener.Start();
            Action requestLoop = new Action(delegate
            {
                while (_isListenerOn)
                {
                    _listener.BeginGetContext(new AsyncCallback(delegate (IAsyncResult ar)
                    {
                        OnRequestReceived(_listener.EndGetContext(ar));
                    }), null).AsyncWaitHandle.WaitOne();
                }
            });
            requestLoop.BeginInvoke(null, null);
        }

        public void StopListening()
        {
            if (_isListenerOn)
            {
                _isListenerOn = false;
                if (_listener != null)
                {
                    _listener.Stop();
                    _listener.Close();
                    _listener = null;
                }
            }
        }

        public void Dispose()
        {
            StopListening();
        }
    }
    public class HttpWebServerResponsor
    {
        public RequestReceivedEventHandler errorResponseMethod;
        private ServerCommandNode _rootNode;
        public ServerCommandNode RootNode { get => _rootNode; }
        public HttpWebServerResponsor()
        {
            _rootNode = new ServerCommandNode("");
        }
        public void Response(HttpListenerContext context)
        {
            string[] urlGroup = context.Request.RawUrl.Split('?')[0].Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            ServerCommandNode node = _rootNode;
            RequestReceivedEventHandler responseMethod = null;
            foreach (var i in urlGroup)
            {
                node = node[i];
                if (node == null)
                {
                    responseMethod = errorResponseMethod;
                    break;
                }
            }
            if (node != null) responseMethod = node.RootResponseMethod;
            responseMethod?.Invoke(context);
            return;
        }
    }
    public class ServerCommandNode
    {
        string _name;
        Dictionary<string, ServerCommandNode> _serverNodes;
        public RequestReceivedEventHandler RootResponseMethod;
        public ServerCommandNode this[string nodeName] { get => _serverNodes[nodeName]; }
        public void AddNode(string name, RequestReceivedEventHandler requestReceived = null)
        {
            _serverNodes.Add(name, new ServerCommandNode(name, requestReceived));
        }
        public ServerCommandNode(string name, RequestReceivedEventHandler requestReceived = null)
        {
            _name = name;
            _serverNodes = new Dictionary<string, ServerCommandNode>();
            RootResponseMethod = requestReceived;
        }

    }
}