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

namespace Tesses.WebServer
{
    
internal class SizedStream : Stream
{
    Stream strm;
    long len;
    long pos=0;
    public SizedStream(Stream src,long len)
    {
        this.strm=src;
        this.len=len;
    }

    public override int ReadByte()
    {
        if(pos >= len) return -1;
        return strm.ReadByte();
    }
    public override bool CanRead => strm.CanRead;

    public override bool CanSeek => false;

    public override bool CanWrite => strm.CanWrite;

    public override long Length => len;

    public override long Position { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }

    public override void Flush()
    {
        strm.Flush();
    }

    public override int Read(byte[] buffer, int offset, int count)
    {
        int read=(int)Math.Min(count,len-pos);
        if(read == 0) return 0;
        
        read=strm.Read(buffer,offset,read);
       
        pos+=read;

        return read;
    }

    public override long Seek(long offset, SeekOrigin origin)
    {
        throw new NotImplementedException();
    }

    public override void SetLength(long value)
    {
        throw new NotImplementedException();
    }

    public override void Write(byte[] buffer, int offset, int count)
    {
         int read=(int)Math.Min(count,len-pos);
        pos+=read;
        strm.Write(buffer,offset,read);

       
    }
}
    public class ServerContext
    {
            static Mutex mtx=new Mutex();
        static long _unique=0;

        public static long UniqueNumber()
        {
            mtx.WaitOne();
            long u=_unique++;
            mtx.ReleaseMutex();
            return u;
        }

        const string bad_chars = "<>?/\\\"*|:";
        public static string FixFileName(string filename,bool requireAscii=false)
        {
            StringBuilder builder=new StringBuilder();
            foreach(var c in filename)
            {
                if(char.IsControl(c)) continue;
                if(requireAscii && c > 127) continue;
                if(bad_chars.Contains(c.ToString())) continue;
                builder.Append(c);
            }

            return builder.ToString();
        }
        /// <summary>
        /// Some user data
        /// </summary>
        
        public object Tag {get;set;}
        /// <summary>
        /// Method (ex GET, POST, HEAD)
        /// </summary>
        public string Method { get; set; }
        
        Func<bool> isConnected;

        public bool Connected {
            get{
                if(isConnected != null)
                {
                    return isConnected();
                }
                return true;
            }
        }
        public ServerContext(string method,Stream strm,string path,Dictionary<string,List<string>> headers,Func<bool> isConnected)
        {
                Method = method;
            NetworkStream = strm;
            RequestHeaders = headers;
            ResponseHeaders = new Dictionary<string, List<string>>();
            QueryParams = new Dictionary<string, List<string>>();
            ResponseHeaders.Add("Server","Tesses.WebServer");
            ResponseHeaders.Add("Connection","close");
            RawUrl=path;
            StatusCode = 200;

            // /joel/path/luigi?local=jim&john_surname=connor&demi_surname=lovato&local=tim

            string[] splitUrl = path.Split(new char[] { '?' }, 2);

            if (splitUrl.Length > 0)
            {
                UrlPath = splitUrl[0];
                OriginalUrlPath=splitUrl[0];
                if (splitUrl.Length == 2)
                {
                    //local=jim&john_surname=connor&demi_surname=lovato&local=tim
                    //we want to split on &
                    q_parm = splitUrl[1];
                }
                else
                {
                    q_parm = "";
                }
                ResetQueryParms();
            }
           
            this.isConnected=isConnected;
        }
        public ServerContext(string method,Stream strm,string path,Dictionary<string,List<string>> headers)
        {
            Method = method;
            NetworkStream = strm;
            RequestHeaders = headers;
            ResponseHeaders = new Dictionary<string, List<string>>();
            QueryParams = new Dictionary<string, List<string>>();
            ResponseHeaders.Add("Server","Tesses.WebServer");
            ResponseHeaders.Add("Connection","close");
            RawUrl=path;
            StatusCode = 200;

            // /joel/path/luigi?local=jim&john_surname=connor&demi_surname=lovato&local=tim

            string[] splitUrl = path.Split(new char[] { '?' }, 2);

            if (splitUrl.Length > 0)
            {
                UrlPath = splitUrl[0];
                OriginalUrlPath=splitUrl[0];
                if (splitUrl.Length == 2)
                {
                    //local=jim&john_surname=connor&demi_surname=lovato&local=tim
                    //we want to split on &
                    q_parm = splitUrl[1];
                }
                else
                {
                    q_parm = "";
                }
                ResetQueryParms();
            }
            isConnected=null;
        }
        /// <summary>
        /// Reset query parms (If api sets them)
        /// </summary>
        public void ResetQueryParms()
        {
            QueryParams.Clear();
            foreach (var item in q_parm.Split(new char[] { '&' }, StringSplitOptions.RemoveEmptyEntries))
            {
                //Console.WriteLine(item);
                var itemSplit = item.Split(new char[] { '=' }, 2);
                if (itemSplit.Length > 0)
                {
                    string key = itemSplit[0];
                    string value = "";
                    if (itemSplit.Length == 2)
                    {
                        value = WebUtility.UrlDecode( itemSplit[1]);
                    }
                    QueryParams.Add(key, value);
                }
            }

        }
        private string get_host()
        {
            if(RequestHeaders.ContainsKey("Host"))
            {
                return RequestHeaders.GetFirst("Host");
            }
            return Server.Address.ToString();
        }
        string q_parm;
        /// <summary>
        /// the /somepath/file?s=42&joel=file relative to Mount
        /// </summary>

        public string UrlAndQuery {get {
		if(!string.IsNullOrWhiteSpace(q_parm))
		{
			return UrlPath + "?" + q_parm;
		}
		return UrlPath;
        }}
        /// <summary>
        /// Original Url Path
        /// </summary>
        /// <value></value>
        public string OriginalUrlPath {get; private set;}
        /// <summary>
        /// Original Url path (includes query)
        /// </summary>
        /// <value></value>
        public string RawUrl {get;private set;}

        /// <summary>
        /// Query parms string only
        /// </summary>
        
        public string QueryParamsString {get {return q_parm;}}
        /// <summary>
        /// Server ip
        /// </summary>
        
        public IPEndPoint Server { get; set; }
        /// <summary>
        /// Client ip
        /// </summary>
    
        public IPEndPoint Client { get; set; }
        /// <summary>
        /// Host name
        /// </summary>
        /// <returns></returns>
        public string Host { get { return get_host(); } }
        /// <summary>
        /// Url path (can be eet by Moutable)
        /// </summary>
        
        public string UrlPath { get; set; }
        /// <summary>
        /// Query Params
        /// </summary>
     
        public Dictionary<string,List<string>> QueryParams { get; set; }
        /// <summary>
        /// Request headers
        /// </summary>
    
        public Dictionary<string,List<string>> RequestHeaders { get; set; }
        /// <summary>
        /// Response headers
        /// </summary>
        
        public Dictionary<string,List<string>> ResponseHeaders { get; set; }
        /// <summary>
        /// TCP Stream for http server
        /// </summary>
    
        public Stream NetworkStream { get; set; }
        /// <summary>
        /// Status code for resource
        /// </summary>
    
        public int StatusCode { get; set; }

        public Stream GetRequestStream()
        {
            string len_Str;
            long len;
            if(RequestHeaders.TryGetFirst("Content-Length",out len_Str))
            {
                if(long.TryParse(len_Str,out len))
                {
                    //DajuricSimpleHttpExtensions.Print($"Content-Length: {len}");
                     return new SizedStream(NetworkStream,len);
                }
            }
            else if(RequestHeaders.TryGetFirst("Transfer-Encoding",out var res) && res == "chunked")
            {
                return new ChunkedStream(NetworkStream,true);
            }
            //DajuricSimpleHttpExtensions.Print("Returns NetworkStream");
            return NetworkStream;
        }   
    }
}