using System;
using System.Linq;
using System.Net;
using System.Security;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Dispatcher;
using System.Xml;

using BeWo.Data;
using BeWo.Data.Access;
using BeWo.Data.Entities;
using BeWo.Service.Core;

using BS.Shared.Extensions;

namespace BeWo.Service.Security
{
    public class SecurityContextInitializer : ICallContextInitializer
    {
        public void AfterInvoke(object pCorrelationState)
        {
            if (pCorrelationState is LoggedInUserOperationContextExt)
            {
                OperationContext.Current.Extensions.Remove((LoggedInUserOperationContextExt)pCorrelationState);
            }
        }

        public object BeforeInvoke(InstanceContext pInstanceContext, IClientChannel pChannel, Message pMessage)
        {
            try
            {
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

                var lTemp = pMessage.Headers.Action.Split("/");
                string lMethodName = lTemp[lTemp.Count - 1];
                string lServiceInterface = lTemp[lTemp.Count - 2];

                // TODO Hier kann man jetzt etwas bauen wer sich für welchen service autorisieren muss...
                var skip = new string[] { "Download", "Download2", "DownloadInfo", "GetUpdatePlan", "GetUpdateFile" };
                if (lMethodName == "IsUserValid" || lMethodName == "IsUserValidTwoFactor" || lMethodName == "ResetTenant" || lMethodName == "ResetAllTenant" || lMethodName == "GetEmailForUserName")
                {
                    return null;
                }
                else if (skip.Contains(lMethodName))
                {
                    return null;
                }
                else
                {
                    // Vergessen neue Methode einzutragen?
                }

                string lUserName = null, lPassword = null;

                int lSecurityHeaderIndex = pMessage.Headers.FindHeader("Security", "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd");

                if (lSecurityHeaderIndex > -1)
                {
                    XmlReader lReader = pMessage.Headers.GetReaderAtHeader(lSecurityHeaderIndex);

                    if (lReader.ReadToFollowing("Username"))
                    {
                        lUserName = lReader.ReadString();
                    }

                    if (lReader.ReadToFollowing("Password"))
                    {
                        lPassword = lReader.ReadString();
                    }

                    ApplicationUser lUser = DAOFactory.UserDAO.FindUserByLoginName(lUserName);

                    if (lUser != null && DAOFactory.UserDAO.CheckPassword(lUser, lPassword))
                    {
                        if (!HasMethodAuthorization(lUser, lMethodName))
                        {
                            throw new SecurityException("Methode nicht autorisiert: " + lMethodName);
                        }
                        

                        var lExt = new LoggedInUserOperationContextExt { User = lUser, LoginName = lUserName, UnhashedPassword = lPassword };
                        OperationContext.Current.Extensions.Add(lExt);
                        return lExt;
                    }
                }

                throw new SecurityException("Nicht autorisiert");
            }
            catch (Exception e)
            {
                throw Utils.CreateBeWoFaultException(e);
            }
        }

        private bool HasMethodAuthorization(ApplicationUser lUser, string methodName)
        {
            var alwaysAllowed = new string[]
            {
                "LoadUserByNameAndPassword", "LoadUserByLoginName", "GetMandator", "LoadEmployee",
                "GetPersonsHavingBirthday",
                "GetLastLogins",
                "GetSupportConceptsWithConferenceDate",
                "GetExpiringSupportConcepts",
                "GetPublishedNewsItemsForEmployee",
                "GetAllActiveEmployeesCompact",
                "GetHomeViewPanels",
                "LoadCompactEmployee",
                "GetTranslationDictionary",
                "ConvertToNewSubstitutionType"
            };

            if (alwaysAllowed.Contains(methodName))
            {
                return true;
            }

            var rights = Utils.GetGrantedRights(lUser);
            var dict = Method2Rights.GetAuthorizedMethodDictionary();

            if (dict.ContainsKey(methodName))
            {
                bool allowed = false;
                var minimumRechte = dict[methodName];

                foreach (var right in minimumRechte)
                {
                    if (rights.Contains(right))
                    {
                        allowed = true;
                    }
                }

                return allowed;
            }
            //var dict = Right2Methods.GetAuthorizedMethodDictionary();

            //foreach (var right in rights)
            //{

            //    if (dict.ContainsKey(right))
            //    {
            //        var names = dict[right];
            //        if (names.Contains(methodName))
            //        {
            //            return true;
            //        }

            //        return true;
            //    }
            //}

            return true;
        }

    }
}