using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Emby.Server.Implementations.HttpServer;
using MediaBrowser.Model.Services;
using Microsoft.Extensions.Logging;
using SocketHttpListener.Net;
using IHttpFile = MediaBrowser.Model.Services.IHttpFile;
using IHttpRequest = MediaBrowser.Model.Services.IHttpRequest;
using IHttpResponse = MediaBrowser.Model.Services.IHttpResponse;
using IResponse = MediaBrowser.Model.Services.IResponse;

namespace Jellyfin.SocketSharp
{
    public partial class WebSocketSharpRequest : IHttpRequest
    {
        private readonly HttpListenerRequest request;
        private readonly IHttpResponse response;

        public WebSocketSharpRequest(HttpListenerContext httpContext, string operationName, ILogger logger)
        {
            this.OperationName = operationName;
            this.request = httpContext.Request;
            this.response = new WebSocketSharpResponse(logger, httpContext.Response, this);

            //HandlerFactoryPath = GetHandlerPathIfAny(UrlPrefixes[0]);
        }

        private static string GetHandlerPathIfAny(string listenerUrl)
        {
            if (listenerUrl == null) return null;
            var pos = listenerUrl.IndexOf("://", StringComparison.OrdinalIgnoreCase);
            if (pos == -1) return null;
            var startHostUrl = listenerUrl.Substring(pos + "://".Length);
            var endPos = startHostUrl.IndexOf('/');
            if (endPos == -1) return null;
            var endHostUrl = startHostUrl.Substring(endPos + 1);
            return string.IsNullOrEmpty(endHostUrl) ? null : endHostUrl.TrimEnd('/');
        }

        public HttpListenerRequest HttpRequest
        {
            get { return request; }
        }

        public object OriginalRequest
        {
            get { return request; }
        }

        public IResponse Response
        {
            get { return response; }
        }

        public IHttpResponse HttpResponse
        {
            get { return response; }
        }

        public string OperationName { get; set; }

        public object Dto { get; set; }

        public string RawUrl
        {
            get { return request.RawUrl; }
        }

        public string AbsoluteUri
        {
            get { return request.Url.AbsoluteUri.TrimEnd('/'); }
        }

        public string UserHostAddress
        {
            get { return request.UserHostAddress; }
        }

        public string XForwardedFor
        {
            get
            {
                return String.IsNullOrEmpty(request.Headers["X-Forwarded-For"]) ? null : request.Headers["X-Forwarded-For"];
            }
        }

        public int? XForwardedPort
        {
            get
            {
                return string.IsNullOrEmpty(request.Headers["X-Forwarded-Port"]) ? (int?)null : int.Parse(request.Headers["X-Forwarded-Port"]);
            }
        }

        public string XForwardedProtocol
        {
            get
            {
                return string.IsNullOrEmpty(request.Headers["X-Forwarded-Proto"]) ? null : request.Headers["X-Forwarded-Proto"];
            }
        }

        public string XRealIp
        {
            get
            {
                return String.IsNullOrEmpty(request.Headers["X-Real-IP"]) ? null : request.Headers["X-Real-IP"];
            }
        }

        private string remoteIp;
        public string RemoteIp
        {
            get
            {
                return remoteIp ??
                    (remoteIp = (CheckBadChars(XForwardedFor)) ??
                                (NormalizeIp(CheckBadChars(XRealIp)) ??
                                (request.RemoteEndPoint != null ? NormalizeIp(request.RemoteEndPoint.Address.ToString()) : null)));
            }
        }

        private static readonly char[] HttpTrimCharacters = new char[] { (char)0x09, (char)0xA, (char)0xB, (char)0xC, (char)0xD, (char)0x20 };

        //
        // CheckBadChars - throws on invalid chars to be not found in header name/value
        //
        internal static string CheckBadChars(string name)
        {
            if (name == null || name.Length == 0)
            {
                return name;
            }

            // VALUE check
            //Trim spaces from both ends
            name = name.Trim(HttpTrimCharacters);

            //First, check for correctly formed multi-line value
            //Second, check for absenece of CTL characters
            int crlf = 0;
            for (int i = 0; i < name.Length; ++i)
            {
                char c = (char)(0x000000ff & (uint)name[i]);
                switch (crlf)
                {
                    case 0:
                        if (c == '\r')
                        {
                            crlf = 1;
                        }
                        else if (c == '\n')
                        {
                            // Technically this is bad HTTP.  But it would be a breaking change to throw here.
                            // Is there an exploit?
                            crlf = 2;
                        }
                        else if (c == 127 || (c < ' ' && c != '\t'))
                        {
                            throw new ArgumentException("net_WebHeaderInvalidControlChars");
                        }
                        break;

                    case 1:
                        if (c == '\n')
                        {
                            crlf = 2;
                            break;
                        }
                        throw new ArgumentException("net_WebHeaderInvalidCRLFChars");

                    case 2:
                        if (c == ' ' || c == '\t')
                        {
                            crlf = 0;
                            break;
                        }
                        throw new ArgumentException("net_WebHeaderInvalidCRLFChars");
                }
            }
            if (crlf != 0)
            {
                throw new ArgumentException("net_WebHeaderInvalidCRLFChars");
            }
            return name;
        }

        internal static bool ContainsNonAsciiChars(string token)
        {
            for (int i = 0; i < token.Length; ++i)
            {
                if ((token[i] < 0x20) || (token[i] > 0x7e))
                {
                    return true;
                }
            }
            return false;
        }

        private string NormalizeIp(string ip)
        {
            if (!string.IsNullOrWhiteSpace(ip))
            {
                // Handle ipv4 mapped to ipv6
                const string srch = "::ffff:";
                var index = ip.IndexOf(srch, StringComparison.OrdinalIgnoreCase);
                if (index == 0)
                {
                    ip = ip.Substring(srch.Length);
                }
            }

            return ip;
        }

        public bool IsSecureConnection
        {
            get { return request.IsSecureConnection || XForwardedProtocol == "https"; }
        }

        public string[] AcceptTypes
        {
            get { return request.AcceptTypes; }
        }

        private Dictionary<string, object> items;
        public Dictionary<string, object> Items
        {
            get { return items ?? (items = new Dictionary<string, object>()); }
        }

        private string responseContentType;
        public string ResponseContentType
        {
            get
            {
                return responseContentType
                    ?? (responseContentType = GetResponseContentType(this));
            }
            set
            {
                this.responseContentType = value;
            }
        }

        public const string FormUrlEncoded = "application/x-www-form-urlencoded";
        public const string MultiPartFormData = "multipart/form-data";
        public static string GetResponseContentType(IRequest httpReq)
        {
            var specifiedContentType = GetQueryStringContentType(httpReq);
            if (!string.IsNullOrEmpty(specifiedContentType)) return specifiedContentType;

            var serverDefaultContentType = "application/json";

            var acceptContentTypes = httpReq.AcceptTypes;
            string defaultContentType = null;
            if (HasAnyOfContentTypes(httpReq, FormUrlEncoded, MultiPartFormData))
            {
                defaultContentType = serverDefaultContentType;
            }

            var acceptsAnything = false;
            var hasDefaultContentType = !string.IsNullOrEmpty(defaultContentType);
            if (acceptContentTypes != null)
            {
                foreach (var acceptsType in acceptContentTypes)
                {
                    var contentType = HttpResultFactory.GetRealContentType(acceptsType);
                    acceptsAnything = acceptsAnything || contentType == "*/*";
                }

                if (acceptsAnything)
                {
                    if (hasDefaultContentType)
                        return defaultContentType;
                    if (serverDefaultContentType != null)
                        return serverDefaultContentType;
                }
            }

            if (acceptContentTypes == null && httpReq.ContentType == Soap11)
            {
                return Soap11;
            }

            //We could also send a '406 Not Acceptable', but this is allowed also
            return serverDefaultContentType;
        }

        public const string Soap11 = "text/xml; charset=utf-8";

        public static bool HasAnyOfContentTypes(IRequest request, params string[] contentTypes)
        {
            if (contentTypes == null || request.ContentType == null) return false;
            foreach (var contentType in contentTypes)
            {
                if (IsContentType(request, contentType)) return true;
            }
            return false;
        }

        public static bool IsContentType(IRequest request, string contentType)
        {
            return request.ContentType.StartsWith(contentType, StringComparison.OrdinalIgnoreCase);
        }

        public const string Xml = "application/xml";
        private static string GetQueryStringContentType(IRequest httpReq)
        {
            var format = httpReq.QueryString["format"];
            if (format == null)
            {
                const int formatMaxLength = 4;
                var pi = httpReq.PathInfo;
                if (pi == null || pi.Length <= formatMaxLength) return null;
                if (pi[0] == '/') pi = pi.Substring(1);
                format = LeftPart(pi, '/');
                if (format.Length > formatMaxLength) return null;
            }

            format = LeftPart(format, '.').ToLower();
            if (format.Contains("json")) return "application/json";
            if (format.Contains("xml")) return Xml;

            return null;
        }

        public static string LeftPart(string strVal, char needle)
        {
            if (strVal == null) return null;
            var pos = strVal.IndexOf(needle);
            return pos == -1
                ? strVal
                : strVal.Substring(0, pos);
        }

        public static string HandlerFactoryPath;

        private string pathInfo;
        public string PathInfo
        {
            get
            {
                if (this.pathInfo == null)
                {
                    var mode = HandlerFactoryPath;

                    var pos = request.RawUrl.IndexOf("?");
                    if (pos != -1)
                    {
                        var path = request.RawUrl.Substring(0, pos);
                        this.pathInfo = GetPathInfo(
                            path,
                            mode,
                            mode ?? "");
                    }
                    else
                    {
                        this.pathInfo = request.RawUrl;
                    }

                    this.pathInfo = System.Net.WebUtility.UrlDecode(pathInfo);
                    this.pathInfo = NormalizePathInfo(pathInfo, mode);
                }
                return this.pathInfo;
            }
        }

        private static string GetPathInfo(string fullPath, string mode, string appPath)
        {
            var pathInfo = ResolvePathInfoFromMappedPath(fullPath, mode);
            if (!string.IsNullOrEmpty(pathInfo)) return pathInfo;

            //Wildcard mode relies on this to work out the handlerPath
            pathInfo = ResolvePathInfoFromMappedPath(fullPath, appPath);
            if (!string.IsNullOrEmpty(pathInfo)) return pathInfo;

            return fullPath;
        }

        private static string ResolvePathInfoFromMappedPath(string fullPath, string mappedPathRoot)
        {
            if (mappedPathRoot == null) return null;

            var sbPathInfo = new StringBuilder();
            var fullPathParts = fullPath.Split('/');
            var mappedPathRootParts = mappedPathRoot.Split('/');
            var fullPathIndexOffset = mappedPathRootParts.Length - 1;
            var pathRootFound = false;

            for (var fullPathIndex = 0; fullPathIndex < fullPathParts.Length; fullPathIndex++)
            {
                if (pathRootFound)
                {
                    sbPathInfo.Append("/" + fullPathParts[fullPathIndex]);
                }
                else if (fullPathIndex - fullPathIndexOffset >= 0)
                {
                    pathRootFound = true;
                    for (var mappedPathRootIndex = 0; mappedPathRootIndex < mappedPathRootParts.Length; mappedPathRootIndex++)
                    {
                        if (!string.Equals(fullPathParts[fullPathIndex - fullPathIndexOffset + mappedPathRootIndex], mappedPathRootParts[mappedPathRootIndex], StringComparison.OrdinalIgnoreCase))
                        {
                            pathRootFound = false;
                            break;
                        }
                    }
                }
            }
            if (!pathRootFound) return null;

            var path = sbPathInfo.ToString();
            return path.Length > 1 ? path.TrimEnd('/') : "/";
        }

        private Dictionary<string, System.Net.Cookie> cookies;
        public IDictionary<string, System.Net.Cookie> Cookies
        {
            get
            {
                if (cookies == null)
                {
                    cookies = new Dictionary<string, System.Net.Cookie>();
                    foreach (var cookie in this.request.Cookies)
                    {
                        var httpCookie = (System.Net.Cookie) cookie;
                        cookies[httpCookie.Name] = new System.Net.Cookie(httpCookie.Name, httpCookie.Value, httpCookie.Path, httpCookie.Domain);
                    }
                }

                return cookies;
            }
        }

        public string UserAgent
        {
            get { return request.UserAgent; }
        }

        public QueryParamCollection Headers
        {
            get { return request.Headers; }
        }

        private QueryParamCollection queryString;
        public QueryParamCollection QueryString
        {
            get { return queryString ?? (queryString = MyHttpUtility.ParseQueryString(request.Url.Query)); }
        }

        public bool IsLocal
        {
            get { return request.IsLocal; }
        }

        private string httpMethod;
        public string HttpMethod
        {
            get
            {
                return httpMethod
                    ?? (httpMethod = request.HttpMethod);
            }
        }

        public string Verb
        {
            get { return HttpMethod; }
        }

        public string ContentType
        {
            get { return request.ContentType; }
        }

        public Encoding contentEncoding;
        public Encoding ContentEncoding
        {
            get { return contentEncoding ?? request.ContentEncoding; }
            set { contentEncoding = value; }
        }

        public Uri UrlReferrer
        {
            get { return request.UrlReferrer; }
        }

        public static Encoding GetEncoding(string contentTypeHeader)
        {
            var param = GetParameter(contentTypeHeader, "charset=");
            if (param == null) return null;
            try
            {
                return Encoding.GetEncoding(param);
            }
            catch (ArgumentException)
            {
                return null;
            }
        }

        public Stream InputStream
        {
            get { return request.InputStream; }
        }

        public long ContentLength
        {
            get { return request.ContentLength64; }
        }

        private IHttpFile[] httpFiles;
        public IHttpFile[] Files
        {
            get
            {
                if (httpFiles == null)
                {
                    if (files == null)
                        return httpFiles = new IHttpFile[0];

                    httpFiles = new IHttpFile[files.Count];
                    var i = 0;
                    foreach (var pair in files)
                    {
                        var reqFile = pair.Value;
                        httpFiles[i] = new HttpFile
                        {
                            ContentType = reqFile.ContentType,
                            ContentLength = reqFile.ContentLength,
                            FileName = reqFile.FileName,
                            InputStream = reqFile.InputStream,
                        };
                        i++;
                    }
                }
                return httpFiles;
            }
        }

        public static string NormalizePathInfo(string pathInfo, string handlerPath)
        {
            if (handlerPath != null && pathInfo.TrimStart('/').StartsWith(
                handlerPath, StringComparison.OrdinalIgnoreCase))
            {
                return pathInfo.TrimStart('/').Substring(handlerPath.Length);
            }

            return pathInfo;
        }
    }
}