using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Runtime.Caching;
using System.Threading.Tasks;
using HtmlAgilityPack;
using Kreta.Client.Kir.Interfaces;
using Kreta.Client.Kir.Models;
using Kreta.Client.Kir2Service;
using Kreta.Core;
using Kreta.Resources;

namespace Kreta.Client.Kir
{
    public class KirAuthentication : IKirAuthentication
    {
        private static HttpClient HttpClient = new HttpClient();

        #region Privát osztály változók

        private string FelhasznaloNevCacheKey { get; set; }

        private string JelszoCacheKey { get; set; }

        private string IntezmenyAzonosito { get; }

        private string FelhasznaloNev
        {
            get => Cache.Get(FelhasznaloNevCacheKey)?.ToString();
            set
            {
                if (FelhasznaloNev == null)
                {
                    Cache.Add(FelhasznaloNevCacheKey, value, new CacheItemPolicy { AbsoluteExpiration = new DateTimeOffset(DateTime.Now.AddMinutes(5)) });
                }
            }
        }

        private string Jelszo
        {
            get => Cache.Get(JelszoCacheKey)?.ToString();
            set
            {
                if (Jelszo == null)
                {
                    Cache.Add(JelszoCacheKey, value, new CacheItemPolicy { AbsoluteExpiration = new DateTimeOffset(DateTime.Now.AddMinutes(5)) });
                }
            }
        }

        private string LoginUrl { get; }

        #endregion Privát osztály változók

        public KirAuthentication(KirLogin loginModel, string felhasznaloNevCacheKey, string jelszoCacheKey)
        {
            LoginUrl = loginModel.LoginUrl;
            IntezmenyAzonosito = loginModel.IntezmenyAzonosito;

            FelhasznaloNevCacheKey = felhasznaloNevCacheKey;
            JelszoCacheKey = jelszoCacheKey;

            if (string.IsNullOrWhiteSpace(FelhasznaloNev) && string.IsNullOrWhiteSpace(Jelszo))
            {
                FelhasznaloNev = loginModel.FelhasznaloNev;
                Jelszo = loginModel.Jelszo;
            }

            if (string.IsNullOrWhiteSpace(LoginUrl))
            {
                throw new ArgumentException(ErrorResource.KirLoginUrlNincsMegadvaAzAppSettingsben);
            }
        }

        public KIR2AuthHeaderType GetAuthHeader(string kirToken)
        {
            return new KIR2AuthHeaderType
            {
                Intezmeny = IntezmenyAzonosito,
                Felhasznalo = new FelhasznaloType
                {
                    Item = new IntezmenyiFelhasznaloType
                    {
                        FelhasznaloNev = FelhasznaloNev,
                        KIRToken = kirToken
                    }
                }
            };
        }

        #region Get KIR token

        public string GetKirToken()
        {
            try
            {
                string requestVerificationToken = GetRequestVerificationToken();

                string loginResponse = AsyncUtil.RunSync(() => GetLoginResponse(requestVerificationToken, IntezmenyAzonosito, FelhasznaloNev, Jelszo));

                return GetToken(loginResponse);
            }
            catch (WebException ex)
            {
                if (ex.Status == WebExceptionStatus.ProtocolError)
                {
                    if (ex.Response is HttpWebResponse response)
                    {
                        var statusCode = (int)response.StatusCode;
                        if (statusCode != (int)HttpStatusCode.OK)
                        {
                            throw new Exception(ErrorResource.ASzolgaltatasNemElerhetoProbaljaKesobbEsetlegHaAHibaHuzamosabbIdeigFennallJelezzeAzIlletekeseknek, ex);
                        }
                    }
                }
                else
                {
                    throw new Exception(ErrorResource.IsmeretlenHibaTortentAKirOldalanKerjukKisereljeMegAzImportalastKesobb, ex);
                }
            }

            return null;
        }

        private string GetRequestVerificationToken()
        {
            string loginPage = AsyncUtil.RunSync(() => HttpClient.GetStringAsync(LoginUrl));

            var htmlDocument = new HtmlDocument();
            htmlDocument.LoadHtml(loginPage);

            HtmlNode requestVerificationTokenNode = htmlDocument.DocumentNode.SelectSingleNode("//input[@name='__RequestVerificationToken']");

            return requestVerificationTokenNode?.Attributes["value"].Value;
        }

        private async Task<string> GetLoginResponse(string requestVerificationToken, string intezmenyAzonosito, string felhasznaloNev, string jelszo)
        {
            HttpResponseMessage result = await HttpClient.PostAsync(LoginUrl,
                new FormUrlEncodedContent(
                    new Dictionary<string, string>
                    {
                        { "__RequestVerificationToken", requestVerificationToken },
                        { "UserDto.UserType", "3" },
                        { "UserDto.FenntId", string.Empty },
                        { "UserDto.TKAzonosito", string.Empty },
                        { "UserDto.OMAzonosito", intezmenyAzonosito },
                        { "UserDto.UserName", felhasznaloNev },
                        { "UserDto.Password", jelszo },
                        { "ContinueUrl", string.Empty },
                        { "RedirectPartnerId", string.Empty }
                    }
                    ));

            return await result.Content.ReadAsStringAsync();
        }

        private string GetToken(string loginResponse)
        {
            var htmlDocument = new HtmlDocument();
            htmlDocument.LoadHtml(loginResponse);

            HtmlNode tokenNode = htmlDocument.GetElementbyId("token");

            return tokenNode?.InnerText.Trim();
        }

        #endregion Get KIR token
    }
}