using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using ln.http.exceptions;
using ln.types.net;
using System.Threading;
using ln.http.session;

namespace ln.http
{
	public class HttpRequest : IDisposable
	{
        static ThreadLocal<HttpRequest> current = new ThreadLocal<HttpRequest>();
        static public HttpRequest Current => current.Value;

        Dictionary<String, String> requestHeaders;
        Dictionary<String, String> requestCookies;
        Dictionary<string, String> requestParameters;

	    public HTTPServer HTTPServer { get; }

	    public Endpoint RemoteEndpoint { get; private set; }
        public Endpoint LocalEndpoint { get; private set; }

        public Uri BaseURI { get; set; }
        public Uri URI { get; private set; }

		public String Method { get; private set; }
		public String RequestURL { get; private set; }
		public String Protocol { get; private set; }

		public String Hostname { get; private set; }
		public int Port { get; private set; }

        public QueryStringParameters Query { get; private set; }

        public Session Session { get; set; }
        public HttpUser CurrentUser => Session.CurrentUser;


        public MemoryStream ContentStream { get; }
        public TextReader ContentReader
        {
            get
            {
                if (contentReader == null)
                    contentReader = new StreamReader(ContentStream);
                return contentReader;
            }
        }

        public Stream GetConnectionStream()
        {
            return connectionStream;
        }

        StreamReader contentReader;
        byte[] requestBody;
        Stream connectionStream;

        public HttpRequest(HTTPServer httpServer, HttpReader httpReader, Endpoint localEndpoint)
        {
            HTTPServer = httpServer;
            connectionStream = httpReader.Stream;

            LocalEndpoint = localEndpoint;
            RemoteEndpoint = httpReader.RemoteEndpoint;
            Method = httpReader.Method;
            Protocol = httpReader.Protocol;
            RequestURL = httpReader.URL;

            requestHeaders = new Dictionary<string, string>(httpReader.Headers);
            requestCookies = new Dictionary<string, string>();
            requestParameters = new Dictionary<string, string>();

            Setup();


            int clength = int.Parse(GetRequestHeader("content-length", "0"));
            requestBody = new byte[clength];

            if (clength > 0)
            {
                int nread = httpReader.ReadRequestBody(requestBody, 0, clength);
                if (nread != clength)
                    throw new HttpException(500, "failed to read request content");
            }

            ContentStream = new MemoryStream(requestBody);
        }

        public void MakeCurrent() => current.Value = this;
        public static void ClearCurrent() => current.Value = null;

        private void Setup()
        {
            SetupResourceURI();
            SetupCookies();
        }

        /*
         * SetupResourceURI()
         * 
         * Setup the following fields:
         * 
         *  - Hostname
         *  - Port
         *  - BaseURI        
         *  - URI
         *  - Query        
         *         
         */
        private void SetupResourceURI()
        {
            String host = GetRequestHeader("HOST");
            String[] hostTokens = host.Split(':');

            Hostname = hostTokens[0];
            Port = (hostTokens.Length > 1) ? int.Parse(hostTokens[1]) : LocalEndpoint.Port;
            BaseURI = new UriBuilder("http", Hostname, Port).Uri;
            URI = new Uri(BaseURI, RequestURL);
            Query = new QueryStringParameters(URI.Query);
        }

        private void SetupCookies()
        {
            string cookies = GetRequestHeader("COOKIE");
            foreach (String cookie in cookies.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries))
            {
                string[] c = cookie.Split(new char[] { '=' }, 2);
                string cn, cv;
                cn = c[0].Trim();
                if (c.Length > 1)
                    cv = c[1].Trim();
                else
                    cv = "";

                if (!this.requestCookies.ContainsKey(cn))
                    this.requestCookies.Add(cn, cv);
            }
        }

        public override string ToString()
		{
            //return string.Format("[HttpRequest: RemoteEndpoint={0}, Hostname={1} Port={2} URI={4}, Method={4}, RequestURL={5}, Protocol={6} Query={7}]", RemoteEndpoint, URI, Method, RequestURL, Protocol, Hostname, Port,Query);
            return base.ToString();
		}

        public String GetRequestHeader(String name)
        {
            return GetRequestHeader(name, "");
        }
        public String GetRequestHeader(String name, String def)
		{
			name = name.ToUpper();

			if (requestHeaders.ContainsKey(name))
				return requestHeaders[name];

			return def;
		}

        public String[] RequestHeaderNames => requestHeaders.Keys.ToArray();

        public String[] CookieNames => requestCookies.Keys.ToArray();
        public bool ContainsCookie(String name)
        {
            return this.requestCookies.ContainsKey(name);
        }
        public String GetCookie(String name)
        {
            return requestCookies[name];
        }

        public String GetParameter(String parameterName) => GetParameter(parameterName, null);
        public String GetParameter(String parameterName,String defaultValue)
        {
            if (!requestParameters.TryGetValue(parameterName, out string value))
                value = defaultValue;
            return value;
        }
        public void SetParameter(String parameterName,String parameterValue) => requestParameters[parameterName] = parameterValue;
        public IEnumerable<string> ParameterNames => requestParameters.Keys;


        public string self()
        {
            return BaseURI.ToString();
        }



        public HttpResponse Redirect(string location,int status = 307)
        {
            HttpResponse httpResponse = new HttpResponse(this);
            httpResponse.AddHeader("location", location);
            httpResponse.StatusCode = status;
            httpResponse.AddHeader("content-type", "text/plain");
            httpResponse.ContentWriter.WriteLine("Redirect: {0}", location);
            return httpResponse;
        }

        public void Dispose()
        {
            contentReader?.Dispose();
            ContentStream?.Dispose();
        }

    }
}