using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using BeWo.Data.Access;
using BeWo.Data.Entities;
using BeWo.Data.Security;
using BeWo.Service.Configuration;
using BeWo.Service.Core;
using BeWo.Service.DCEntityMapper;
using BeWo.Service.Invoicing;
using BS.Shared;
using BS.Shared.Core;
using BS.Shared.DataContracts;
using BS.Shared.DataContracts.Compact;
using BS.Shared.Extensions;
using BS.Shared.Models;

namespace BeWo.Service.Plugins
{
    public class AccountingService : AbstractIDSpecificDefaultClass<AccountingService>
    {
        public virtual List<ServiceInvoiceDC> GenerateInitialServiceInvoices(long costBearerOid, long? supportConceptOid, DateTimeSpan invoicePeriod)
        {
            var cs = PluginLoader.FindClass<CustomerService>();
            IEnumerable<CompactSupportConceptDC> supportConcepts;
            // GetAllActiveSupportConceptCostbearer returns a "Flat" SupportConcept List, one for each CostBearer2SupportConcept!
            if (!supportConceptOid.HasValue)
            {
                supportConcepts = cs.GetAllActiveSupportConceptCostbearer(false, true, 0)
                    .Where(i => i.CostBearerOids2CostBearerRelOids.ContainsKey(costBearerOid));
            }
            else
            {
                supportConcepts = cs.GetCompactSupportConcepts(supportConceptOid.Value, null)
                    .Where(i => i.CostBearerOids2CostBearerRelOids.ContainsKey(costBearerOid));
            }

            DateTimeSpan newSpan = null;
            if (invoicePeriod != null)
            {
                //invoicePeriod.StartDateTime = invoicePeriod.StartDateTime.Date;
                //invoicePeriod.EndDateTime = invoicePeriod.EndDateTime.Date;
                newSpan = new DateTimeSpan();
                newSpan.StartDateTime = invoicePeriod.StartDateTime.Date;
                newSpan.EndDateTime = invoicePeriod.EndDateTime.Date.AddDays(1).AddTicks(-1);
                if (!supportConceptOid.HasValue)
                {
                    supportConcepts =
                        supportConcepts.Where(sc => sc.StartDate < newSpan.EndDateTime && sc.EndDate >= newSpan.StartDate);
                }
            }
            var supportConcepts2ServiceRecords = supportConcepts.ToDictionary(
                                                        i => i,
                                                        i => MapperFactory.ServiceRecordDC_ServiceRecord.MapToNewDCs(
                                                                                                                    DAOFactory.SearchDAO.FindServiceRecordsInSpan(i.CostBearerRelOids[0], newSpan)));
            var cb = DAOFactory.GenericDAO.LoadByID<CostBearer>(costBearerOid);
            String tenant = PluginLoader.Tenant;
            var factory = PluginLoader.FindClass<InvoiceFactory>(cb.ID);
            if (factory == null)
            {
                factory = InvoiceFactory.GetInstance(cb.ID, tenant);
            }

            var creator = factory.CreateInvoiceCreator(cb.ID, tenant, supportConcepts2ServiceRecords);
            var newInvoices = creator.GenerateServiceInvoices(costBearerOid, invoicePeriod, supportConcepts2ServiceRecords);


            //Prüfe ob Rechnungen neu sind oder Diff vorhanden
            var differenzRechnungChecks = GetNewInvoices(newInvoices, invoicePeriod?.StartDate, invoicePeriod?.EndDate);
            var resultList = ErstelleNeueRechnungen(differenzRechnungChecks);


            return resultList;
        }

        protected virtual List<ServiceInvoiceDC> ErstelleNeueRechnungen(List<DifferenzRechnungCheck> differenzRechnungChecks)
        {
            var rechnungen = new List<ServiceInvoiceDC>();
            foreach (var item in differenzRechnungChecks)
            {
                if (item.VorhandeneRechungen.Count == 0 || !item.VorhandeneRechungen.Any(r => item.NeueRechnung.InvoiceBase.CustomerOid == r.InvoiceBase.CustomerOid))
                {
                    item.NeueRechnung.InvoiceBase.NeuErstellen = true;
                    rechnungen.Add(item.NeueRechnung);
                }
                else
                {
                    var diffRechnung = ErstelleDifferenzRechnung(item);
                    if (diffRechnung != null)
                    {
                        diffRechnung.InvoiceBase.NeuErstellen = false;
                        rechnungen.Add(diffRechnung);
                    }
                }
            }

            return rechnungen;
        }

        protected virtual ServiceInvoiceDC ErstelleDifferenzRechnung(DifferenzRechnungCheck item)
        {
            ServiceInvoiceDC diffRechnung = null;
            //var alterBetrag = item.VorhandeneRechungen.Sum(i => i.ClaimSum ?? 0);
            var letzteRg = item.VorhandeneRechungen.OrderByDescending(r => r.ServiceInvoiceOid).FirstOrDefault();

            letzteRg = item.VorhandeneRechungen.FirstOrDefault(r => item.NeueRechnung.InvoiceBase.CustomerOid == r.InvoiceBase.CustomerOid);
            if (letzteRg != null)
            {
                if (item.NeueRechnung.ClaimSum == letzteRg.ClaimSum)
                {
                    diffRechnung = item.NeueRechnung;
                    diffRechnung.InvoiceBase.NeuErstellen = false;
                    diffRechnung.InvoiceBase.Hinweise = String.Format("Rechnung wurde bereits erstellt");
                }
                else
                {
                    diffRechnung = new ServiceInvoiceDC();
                    diffRechnung.OriginalZurDifferenz = item.NeueRechnung;
                    diffRechnung.InvoiceBase = new InvoiceBaseDC();
                    CopyInvoiceBaseDC(item.NeueRechnung.InvoiceBase, diffRechnung);

                    ServiceInvoice counterInvoice = new ServiceInvoice();
                    var serviceInvoice = DAOFactory.SearchDAO.GetServiceInvoiceByInvoiceBaseOid(letzteRg.InvoiceBase.InvoiceBaseOid.Value);

                    CopyServiceInvoice(serviceInvoice, counterInvoice);
                    SetzeStornoInfos(counterInvoice);
                    SetzeRechnungspositionenServiceInvoice(diffRechnung, counterInvoice, item);

                    diffRechnung.InvoiceBase.NeuErstellen = true;
                    diffRechnung.InvoiceBase.Hinweise = String.Format("Rechnungsdifferenz zu Rechnung {0} in Höhe von {1:c}", letzteRg.InvoiceBase.InvoiceNumber, letzteRg.InvoiceBase.TotalAmount.Value);
                }
            }

            return diffRechnung;
        }

        protected virtual List<DifferenzRechnungCheck> GetNewInvoices(List<ServiceInvoiceDC> invoices, DateTime? start, DateTime? end)
        {
            List<DifferenzRechnungCheck> result = new List<DifferenzRechnungCheck>();
            var existingInvoices = DAOFactory.SearchDAO.GetInvoiceBases(start, end, false);

            foreach (var si in invoices)
            {
                var checkResult = new DifferenzRechnungCheck();
                result.Add(checkResult);
                checkResult.NeueRechnung = si;
                checkResult.VorhandeneRechungen = new List<ServiceInvoiceDC>();

                foreach (var i2 in existingInvoices.Where(i => i.Type == InvoiceType.Service))
                {
                    if (si.InvoiceBase.SupportConceptCostBearerRelDc != null && si.InvoiceBase.SupportConceptCostBearerRelDc.CostBearer2SupportConceptOid == i2.CostBearer2SupportConceptOid)
                    {
                        var siAlt = DAOFactory.SearchDAO.GetServiceInvoiceByInvoiceBaseOid(i2.Oid.Value);
                        var siDCAlt = MapperFactory.ServiceInvoiceDC_ServiceInvoice.MapToNewDC(siAlt);

                        checkResult.VorhandeneRechungen.Add(siDCAlt);
                    }
                    else // Sammelrechnung
                    {
                        if (i2.SupportConceptOid == invoices[0].InvoiceBase.SupportConceptOid)
                        {
                            var siAlt = DAOFactory.SearchDAO.GetServiceInvoiceByInvoiceBaseOid(i2.Oid.Value);
                            var siDCAlt = MapperFactory.ServiceInvoiceDC_ServiceInvoice.MapToNewDC(siAlt);
                            if (siAlt.ServiceInvoicePeriodList != null && siAlt.ServiceInvoicePeriodList.Count > 0)
                            {
                                foreach (var i in invoices)
                                {
                                    if (i.ServiceInvoicePeriods != null && i.ServiceInvoicePeriods.Count > 0)
                                    {
                                        foreach (var sip in siDCAlt.ServiceInvoicePeriods)
                                        {
                                            if (sip.Customer != null && i.ServiceInvoicePeriods.Any(s => s.Customer.CustomerOid == sip.Customer.CustomerOid))
                                            {
                                                checkResult.VorhandeneRechungen.Add(siDCAlt);
                                                break;
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
            return result;
        }

        public virtual List<long> UpdateServiceInvoices(List<ServiceInvoiceDC> invoices)
        {
            //if (!Data.Security.UserRightHelper.LoggedInUserHasRight(UserRightType.AccountingTransactionView_Create))
            //{
            //	throw new FaultException<BeWoFault>(new BeWoFault("Du kommst hier nicht rein!", BeWoFaultType.CustomWithoutDetails));
            //}
            var originals = DAOFactory.GenericDAO.LoadByIDs<ServiceInvoice>(invoices.Select(i => i.ServiceInvoiceOid.Value));
            MapperFactory.ServiceInvoiceDC_ServiceInvoice.MergeWithEntitys(invoices, originals);
            DAOFactory.GenericDAO.Update(originals);
            return originals.Select(e => e.Version.Value).ToList();
        }

        public virtual List<InvoiceBaseDC> GetInvoiceBases(DateTime? startDate, DateTime? endDate)
        {
            DateTime? end = endDate;
            if (end.HasValue)
            {
                end = end.Value.Date.AddDays(1).AddTicks(-1);
            }
            var list = DAOFactory.SearchDAO.GetInvoiceBases(startDate, end);

            return MapperFactory.InvoiceBaseDC_InvoiceBase.MapToNewDCs(list);
        }

        public virtual List<InvoiceBaseDC> GetInvoiceBases(DateTime? startDate, DateTime? endDate, bool filterByInvoiceDate)
        {
            DateTime? end = endDate;
            if (end.HasValue)
            {
                end = end.Value.Date.AddDays(1).AddTicks(-1);
            }
            var list = DAOFactory.SearchDAO.GetInvoiceBases(startDate, end, filterByInvoiceDate);

            return MapperFactory.InvoiceBaseDC_InvoiceBase.MapToNewDCs(list);
        }

        public virtual List<InvoiceBaseDC> GetInvoiceBases(DateTime? startDate, DateTime? endDate, long costBearerOid, String invoiceId)
        {
            DateTime? end = endDate;
            if (end.HasValue)
            {
                end = end.Value.Date.AddDays(1).AddTicks(-1);
            }
            var list = DAOFactory.SearchDAO.GetInvoiceBases(startDate, end, costBearerOid, invoiceId);

            return MapperFactory.InvoiceBaseDC_InvoiceBase.MapToNewDCs(list);
        }

        public virtual void DeactivateInvoiceBases(List<InvoiceBaseDC> invoices)
        {
            ServiceLogic.SetActivationType<InvoiceBase>(invoices.ToDictionary(i => i.InvoiceBaseOid.Value, i => i.InvoiceBaseVersion.Value), ActivationTypeId.Deleted);
        }

        public virtual void DeactivateServiceInvoices(List<ServiceInvoiceDC> invoices)
        {
            ServiceLogic.SetActivationType<ServiceInvoice>(invoices.ToDictionary(i => i.ServiceInvoiceOid.Value, i => i.ServiceInvoiceVersion.Value), ActivationTypeId.Deleted);
            ServiceLogic.SetActivationType<InvoiceBase>(invoices.ToDictionary(i => i.InvoiceBase.InvoiceBaseOid.Value, i => i.InvoiceBase.InvoiceBaseVersion.Value), ActivationTypeId.Deleted);
        }

        public virtual void StorniereInvoiceBases(List<InvoiceBaseDC> invoices)
        {
            foreach (var item in invoices)
            {
                if (item.Type == InvoiceType.Service)
                {
                    ErstelleStornoRechnung(item);
                }
                else if (item.Type == InvoiceType.Settlement)
                {
                    ErstelleStornoSpitzabrechnung(item);
                }
                else
                {
                    ErstelleStornoAllgemeineRechnung(item);
                }
            }
        }

        public virtual InvoiceBase ErstelleStornoAllgemeineRechnung(InvoiceBaseDC ibdc)
        {
            InvoiceBase newInvoice = new InvoiceBase();

            var oldInvoice = DAOFactory.GenericDAO.LoadByID<InvoiceBase>(ibdc.InvoiceBaseOid.Value);

            CopyInvoiceBase(oldInvoice, newInvoice);
            SetzeStornoInfos(newInvoice);

            return newInvoice;
        }

        public virtual ServiceInvoice ErstelleStornoRechnung(InvoiceBaseDC ibdc)
        {
            ServiceInvoice newInvoice = new ServiceInvoice();
            var serviceInvoice = DAOFactory.SearchDAO.GetServiceInvoiceByInvoiceBaseOid(ibdc.InvoiceBaseOid.Value);

            CopyServiceInvoice(serviceInvoice, newInvoice);
            SetzeStornoInfos(newInvoice);

            return newInvoice;
        }

        public virtual SettlementInvoice ErstelleStornoSpitzabrechnung(InvoiceBaseDC ibdc)
        {
            SettlementInvoice newInvoice = new SettlementInvoice();
            newInvoice.InvoiceBase = new InvoiceBase();

            var settlementInvoice = DAOFactory.SearchDAO.GetSettlementInvoiceByInvoiceBaseOid(ibdc.InvoiceBaseOid.Value);

            CopySettlementInvoice(settlementInvoice, newInvoice);
            SetzeStornoInfos(newInvoice);

            if (newInvoice.InvoiceBase.InvoiceItems.Count == 0 && newInvoice.Claim.HasValue)
            {
                newInvoice.InvoiceBase.InvoiceItems.Add(new InvoiceItem
                {
                    AmountTotal = newInvoice.Claim,
                    ItemPeriodStart = newInvoice.InvoiceBase.AccountingPeriodStart,
                    ItemPeriodEnd = newInvoice.InvoiceBase.AccountingPeriodEnd,
                    ItemDescription = "Spitzabrechnung"

                });
            }

            return newInvoice;
        }

        public virtual ServiceInvoice ErstelleStornoRechnung(ServiceInvoiceDC sidc)
        {
            ServiceInvoice newInvoice = new ServiceInvoice();

            var serviceInvoice = DAOFactory.GenericDAO.LoadByID<ServiceInvoice>(sidc.ServiceInvoiceOid.Value);

            CopyServiceInvoice(serviceInvoice, newInvoice);
            SetzeStornoInfos(newInvoice);

            return newInvoice;
        }

        public virtual void SaveStornoRechnung(InvoiceBase originalInvoice, ServiceInvoice stornoInvoice)
        {
            DAOFactory.GenericDAO.Insert(stornoInvoice);
            originalInvoice.StornoInvoiceBaseOid = stornoInvoice.Oid;
            DAOFactory.GenericDAO.Update(originalInvoice);

        }

        public virtual void SetzeStornoInfos(InvoiceBase newInvoice)
        {
            foreach (var ii in newInvoice.InvoiceItems)
            {
                if (ii.AmountTotal.HasValue)
                {
                    ii.AmountTotal *= -1;
                }

                if (ii.GrossAmountTotal.HasValue)
                {
                    ii.GrossAmountTotal *= -1;
                }
            }
        }

        public virtual void SetzeStornoInfos(SettlementInvoice newInvoice)
        {
            if (newInvoice.Claim.HasValue)
                newInvoice.Claim *= -1;
            if (newInvoice.AmountBillableTotal.HasValue)
                newInvoice.AmountBillableTotal *= -1;
            if (newInvoice.AmountTotalAdvancedPaidWithNewHourlyRate.HasValue)
                newInvoice.AmountTotalAdvancedPaidWithNewHourlyRate *= -1;
            if (newInvoice.AmountTotalAdvancedPaidWithOldHourlyRate.HasValue)
                newInvoice.AmountTotalAdvancedPaidWithOldHourlyRate *= -1;
            if (newInvoice.AmountWithRateFactor.HasValue)
                newInvoice.AmountWithRateFactor *= -1;
            if (newInvoice.AmountRateFactor.HasValue)
                newInvoice.AmountRateFactor *= -1;

            // FLS-Felder negieren, damit isDefaultSpitzabrechnung-Pfad negative Positionen berechnet
            if (newInvoice.ApprovedFLSWithActualHourlyRate.HasValue)
                newInvoice.ApprovedFLSWithActualHourlyRate *= -1;
            if (newInvoice.ApprovedFLSWithOldHourlyRate.HasValue)
                newInvoice.ApprovedFLSWithOldHourlyRate *= -1;

            // XMLData aktualisieren: Claim (wird vom Mapper als TotalAmount verwendet) und
            // ApprovedFLSWithHourlyRate3 (nur bei DifferentHourlyRateCount == 3 vorhanden) negieren
            if (newInvoice.InvoiceBase != null && !string.IsNullOrEmpty(newInvoice.InvoiceBase.XMLData))
            {
                var xmlDC = BS.Shared.Core.Utils.XMLDeserializeFromString<SettlementDC>(newInvoice.InvoiceBase.XMLData);
                if (xmlDC != null)
                {
                    bool xmlChanged = false;
                    if (xmlDC.Claim != 0)
                    {
                        xmlDC.Claim *= -1;
                        xmlChanged = true;
                    }
                    if (xmlDC.ApprovedFLSWithHourlyRate3 != 0)
                    {
                        xmlDC.ApprovedFLSWithHourlyRate3 *= -1;
                        xmlChanged = true;
                    }
                    if (xmlChanged)
                        newInvoice.InvoiceBase.XMLData = BS.Shared.Core.Utils.XMLSerializeToString(xmlDC);
                }
            }

            SetzeStornoInfos(newInvoice.InvoiceBase);
        }

        public virtual void SetzeStornoInfos(ServiceInvoice newInvoice)
        {
            foreach (var sip in newInvoice.ServiceInvoicePeriodList)
            {
                sip.HoursNotBillableAbsence = 0;
                sip.HoursNotBillableNotApproved = 0;
                if (sip.Claim.HasValue)
                {
                    sip.Claim *= -1;
                }

                foreach (var ii in sip.InvoiceItemList)
                {
                    if (ii.AmountTotal.HasValue)
                    {
                        ii.AmountTotal *= -1;
                    }

                    if (ii.GrossAmountTotal.HasValue)
                    {
                        ii.GrossAmountTotal *= -1;
                    }
                }
            }
        }

        public void CopyServiceInvoice(ServiceInvoice existingInvoice, ServiceInvoice copyInvoice)
        {
            copyInvoice.AmountAdvancePayments = existingInvoice.AmountAdvancePayments;
            copyInvoice.AmountEquityContribution = existingInvoice.AmountEquityContribution;
            copyInvoice.ServiceUnitOid = existingInvoice.ServiceUnitOid;

            CopyInvoiceBase(existingInvoice.InvoiceBase, copyInvoice.InvoiceBase);

            foreach (var sip in existingInvoice.ServiceInvoicePeriodList)
            {
                var copySip = new ServiceInvoicePeriod();
                copyInvoice.ServiceInvoicePeriodList.Add(copySip);

                CopyServiceInvoicePeriod(sip, copySip);
            }
        }

        public void CopySettlementInvoice(SettlementInvoice existing, SettlementInvoice copy)
        {
            copy.AmountAdvancedPayments = existing.AmountAdvancedPayments;
            copy.AmountBillableTotal = existing.AmountBillableTotal;
            copy.AmountRateFactor = existing.AmountRateFactor;
            copy.AmountTotalAdvancedPaidWithNewHourlyRate = existing.AmountTotalAdvancedPaidWithNewHourlyRate;
            copy.AmountTotalAdvancedPaidWithOldHourlyRate = existing.AmountTotalAdvancedPaidWithOldHourlyRate;
            copy.AmountWithRateFactor = existing.AmountWithRateFactor;
            copy.ApprovalNoticeDate = existing.ApprovalNoticeDate;
            copy.ApprovedFLS = existing.ApprovedFLS;
            copy.ApprovedFLSWithActualHourlyRate = existing.ApprovedFLSWithActualHourlyRate;
            copy.ApprovedFLSWithOldHourlyRate = existing.ApprovedFLSWithOldHourlyRate;
            copy.Claim = existing.Claim;
            copy.ErrorNotice = existing.ErrorNotice;
            copy.HourlyRateNew = existing.HourlyRateNew;
            copy.HourlyRateNewStartDate = existing.HourlyRateNewStartDate;
            copy.HourlyRateOld = existing.HourlyRateOld;
            copy.HourlyRateOldEndDate = existing.HourlyRateOldEndDate;
            copy.RecordedBillableFLSBrutto = existing.RecordedBillableFLSBrutto;
            copy.RecordedBillableFLSNetto = existing.RecordedBillableFLSNetto;
            copy.RecordedBillableFLSNotBillableCustomerAbsent = existing.RecordedBillableFLSNotBillableCustomerAbsent;
            copy.RecordedBillableFLSNotBillableOutOfApprovedSpan = existing.RecordedBillableFLSNotBillableOutOfApprovedSpan;

            CopyInvoiceBase(existing.InvoiceBase, copy.InvoiceBase);
        }

        public void CopyInvoiceBase(InvoiceBase existing, InvoiceBase copy)
        {
            copy.AccountingPeriodEnd = existing.AccountingPeriodEnd;
            copy.AccountingPeriodStart = existing.AccountingPeriodStart;
            copy.CostBearer2SupportConcept = existing.CostBearer2SupportConcept;
            copy.CreatorFirstName = existing.CreatorFirstName;
            copy.CreatorLastName = existing.CreatorLastName;
            copy.CustomerReferenceNumber = existing.CustomerReferenceNumber;
            copy.DueDate = existing.DueDate;
            copy.DunningLetterCount = existing.DunningLetterCount;
            copy.InvoiceDate = existing.InvoiceDate;
            copy.InvoiceId = existing.InvoiceId;
            copy.InvoiceNumber = existing.InvoiceNumber;
            copy.InvoiceTitle = existing.InvoiceTitle;
            copy.InvoiceTypeText = existing.InvoiceTypeText;
            copy.IsPaid = existing.IsPaid;
            copy.IsPrinted = existing.IsPrinted;
            copy.RecipientCostBearerOid = existing.RecipientCostBearerOid;
            copy.RecipientCustomerOid = existing.RecipientCustomerOid;
            copy.RecipientDivision = existing.RecipientDivision;
            copy.RecipientOrganisation = existing.RecipientOrganisation;
            copy.RecipientOrganisationOid = existing.RecipientOrganisationOid;
            copy.RecipientPersonFirstName = existing.RecipientPersonFirstName;
            copy.RecipientPersonLastName = existing.RecipientPersonLastName;
            copy.RecipientPersonOid = existing.RecipientPersonOid;
            copy.SenderDivision = existing.SenderDivision;
            copy.SenderFirstName = existing.SenderFirstName;
            copy.SenderLastName = existing.SenderLastName;
            copy.SenderOrganisation = existing.SenderOrganisation;
            copy.SupportConceptOid = existing.SupportConceptOid;
            copy.Type = existing.Type;
            copy.XMLData = existing.XMLData;

            foreach (var ii in existing.InvoiceItems)
            {
                var copyItem = new InvoiceItem();
                copy.InvoiceItems.Add(copyItem);

                CopyInvoiceItem(ii, copyItem);

            }

            if (existing.RecipientAddress != null)
            {
                copy.RecipientAddress = CreateCopyAddress(existing.RecipientAddress);
            }

            if (existing.RecipientContacts != null)
            {
                copy.RecipientContacts = new List<Contact>();
                foreach (var existingContact in existing.RecipientContacts)
                {
                    copy.RecipientContacts.Add(CreateCopyContact(existingContact));
                }
            }

            if (existing.SenderAddress != null)
            {
                copy.SenderAddress = existing.SenderAddress;
            }

            if (existing.SenderContacts != null)
            {
                copy.SenderContacts = new List<Contact>();
                foreach (var existingContact in existing.SenderContacts)
                {
                    copy.SenderContacts.Add(CreateCopyContact(existingContact));
                }
            }

        }

        public void CopyInvoiceBaseDC(InvoiceBaseDC orgRechnung, ServiceInvoiceDC diffRechnung)
        {
            diffRechnung.InvoiceBase.DiffErstellen = true;
            diffRechnung.InvoiceBase.AccountingPeriodStart = orgRechnung.AccountingPeriodStart;
            diffRechnung.InvoiceBase.AccountingPeriodEnd = orgRechnung.AccountingPeriodEnd;
            diffRechnung.InvoiceBase.CustomerLastName = orgRechnung.CustomerLastName;
            diffRechnung.InvoiceBase.CustomerFirstName = orgRechnung.CustomerFirstName;
            diffRechnung.InvoiceBase.CustomerReferenceNumber = orgRechnung.CustomerReferenceNumber;
            diffRechnung.InvoiceBase.InvoiceBaseOid = orgRechnung.InvoiceBaseOid;
            diffRechnung.InvoiceBase.InvoiceDate = orgRechnung.InvoiceDate;
            diffRechnung.InvoiceBase.InvoiceId = orgRechnung.InvoiceId;
            diffRechnung.InvoiceBase.InvoiceNumber = orgRechnung.InvoiceNumber;
            diffRechnung.InvoiceBase.InvoiceTitle = orgRechnung.InvoiceTitle;
            diffRechnung.InvoiceBase.InvoiceTypeText = orgRechnung.InvoiceTypeText;
            diffRechnung.InvoiceBase.RecipientAddressLine1 = orgRechnung.RecipientAddressLine1;
            diffRechnung.InvoiceBase.RecipientAddressOid = orgRechnung.RecipientAddressOid;
            diffRechnung.InvoiceBase.RecipientAddressVersion = orgRechnung.RecipientAddressVersion;
            diffRechnung.InvoiceBase.RecipientContactInformations = orgRechnung.RecipientContactInformations;
            diffRechnung.InvoiceBase.RecipientCostBearerOid = orgRechnung.RecipientCostBearerOid;
            diffRechnung.InvoiceBase.RecipientCustomerOid = orgRechnung.RecipientCustomerOid;
            diffRechnung.InvoiceBase.RecipientDivision = orgRechnung.RecipientDivision;
            diffRechnung.InvoiceBase.RecipientOrganisation = orgRechnung.RecipientOrganisation;
            diffRechnung.InvoiceBase.RecipientOrganisationOid = orgRechnung.RecipientOrganisationOid;
            diffRechnung.InvoiceBase.RecipientPersonFirstName = orgRechnung.RecipientPersonFirstName;
            diffRechnung.InvoiceBase.RecipientPersonLastName = orgRechnung.RecipientPersonLastName;
            diffRechnung.InvoiceBase.RecipientPersonOid = orgRechnung.RecipientPersonOid;
            diffRechnung.InvoiceBase.RecipientPostCode = orgRechnung.RecipientPostCode;
            diffRechnung.InvoiceBase.RecipientSalutationAddressField = orgRechnung.RecipientSalutationAddressField;
            diffRechnung.InvoiceBase.RecipientStreet = orgRechnung.RecipientStreet;
            diffRechnung.InvoiceBase.RecipientTown = orgRechnung.RecipientTown;
            diffRechnung.InvoiceBase.SenderAddressOid = orgRechnung.SenderAddressOid;
            diffRechnung.InvoiceBase.SenderAddressVersion = orgRechnung.SenderAddressVersion;
            diffRechnung.InvoiceBase.SenderContactInformations = orgRechnung.SenderContactInformations;
            diffRechnung.InvoiceBase.SenderDivision = orgRechnung.SenderDivision;
            diffRechnung.InvoiceBase.SenderFirstName = orgRechnung.SenderFirstName;
            diffRechnung.InvoiceBase.SenderLastName = orgRechnung.SenderLastName;
            diffRechnung.InvoiceBase.SenderOrganisation = orgRechnung.SenderOrganisation;
            diffRechnung.InvoiceBase.SenderPostCode = orgRechnung.SenderPostCode;
            diffRechnung.InvoiceBase.SenderStreet = orgRechnung.SenderStreet;
            diffRechnung.InvoiceBase.SenderTown = orgRechnung.SenderTown;
            diffRechnung.InvoiceBase.SupportConceptCostBearerRelDc = orgRechnung.SupportConceptCostBearerRelDc;
            diffRechnung.InvoiceBase.SupportConceptOid = orgRechnung.SupportConceptOid;
            diffRechnung.InvoiceBase.TotalAmount = orgRechnung.TotalAmount;
            diffRechnung.InvoiceBase.Type = orgRechnung.Type;
        }

        public Contact CreateCopyContact(Contact existingContact)
        {
            Contact newContact = new Contact();
            newContact.Value = existingContact.Value;
            newContact.Type = existingContact.Type;

            return newContact;
        }

        public Address CreateCopyAddress(Address address)
        {
            Address newAddress = new Address();
            newAddress.AddressLine1 = address.AddressLine1;
            newAddress.AddressLine2 = address.AddressLine2;
            newAddress.Country = address.Country;
            newAddress.PostalCode = address.PostalCode;
            newAddress.State = address.State;
            newAddress.Street = address.Street;
            newAddress.Town = address.Town;

            return newAddress;
        }

        public void CopyServiceInvoicePeriod(ServiceInvoicePeriod existingSip, ServiceInvoicePeriod copySip)
        {
            copySip.AccountingInterval = existingSip.AccountingInterval;
            copySip.ApprovedAmountDefaultHourlyRate = existingSip.ApprovedAmountDefaultHourlyRate;
            copySip.ApprovedBE = existingSip.ApprovedBE;
            copySip.ApprovedFixedAmount = existingSip.ApprovedFixedAmount;
            copySip.ApprovedHours = existingSip.ApprovedHours;
            copySip.Claim = existingSip.Claim;
            copySip.End = existingSip.End;
            copySip.HoursNotBillableAbsence = existingSip.HoursNotBillableAbsence;
            copySip.HoursNotBillableNotApproved = existingSip.HoursNotBillableNotApproved;
            copySip.ServiceUnitName = existingSip.ServiceUnitName;
            copySip.Start = existingSip.Start;
            copySip.Notice = existingSip.Notice;
            copySip.Customer = existingSip.Customer;
            copySip.SupportConceptApprovalPeriod = existingSip.SupportConceptApprovalPeriod;

            foreach (var ii in existingSip.InvoiceItemList)
            {
                var copyItem = new InvoiceItem();
                copySip.InvoiceItemList.Add(copyItem);

                CopyInvoiceItem(ii, copyItem);
            }

        }

        public void CopyInvoiceItem(InvoiceItem existingItem, InvoiceItem copyItem)
        {
            copyItem.AccountingInterval = existingItem.AccountingInterval;
            copyItem.AmountPerUnit = existingItem.AmountPerUnit;
            copyItem.AmountTotal = existingItem.AmountTotal;
            copyItem.ApprovalUnit = existingItem.AccountingInterval;
            copyItem.ApprovedPerUnit = existingItem.ApprovedPerUnit;
            copyItem.GrossAmountTotal = existingItem.GrossAmountTotal;
            copyItem.ItemDescription = existingItem.ItemDescription;
            copyItem.ItemPeriodEnd = existingItem.ItemPeriodEnd;
            copyItem.ItemPeriodStart = existingItem.ItemPeriodStart;
            copyItem.MaxApprovedAmount = existingItem.MaxApprovedAmount;
            copyItem.MaxApprovedUnitCount = existingItem.MaxApprovedUnitCount;
            copyItem.RateFactor = existingItem.RateFactor;
            copyItem.ReceivedAmount = existingItem.ReceivedAmount;
            copyItem.SupportConceptApprovalPeriodOid = existingItem.SupportConceptApprovalPeriodOid;
            copyItem.UnitCount = existingItem.UnitCount;
            copyItem.UnitDescription = existingItem.UnitDescription;
            copyItem.Notice = existingItem.Notice;
            copyItem.ServiceRecord = existingItem.ServiceRecord;
        }

        public virtual void SetzeRechnungspositionenServiceInvoice(ServiceInvoiceDC diffRechnung, ServiceInvoice counterInvoice, DifferenzRechnungCheck item)
        {
            var siDCAlt = MapperFactory.ServiceInvoiceDC_ServiceInvoice.MapToNewDC(counterInvoice);
            if (siDCAlt.ServiceInvoicePeriods != null && siDCAlt.ServiceInvoicePeriods.Count > 0)
            {
                diffRechnung.ServiceInvoicePeriods = siDCAlt.ServiceInvoicePeriods;
            }

            if (item.NeueRechnung.ServiceInvoicePeriods != null && item.NeueRechnung.ServiceInvoicePeriods.Count > 0)
            {
                if (diffRechnung.ServiceInvoicePeriods == null)
                {
                    diffRechnung.ServiceInvoicePeriods = item.NeueRechnung.ServiceInvoicePeriods;
                }
                else
                {
                    foreach (var NewSip in item.NeueRechnung.ServiceInvoicePeriods)
                    {
                        if (NewSip.InvoiceItems != null && NewSip.InvoiceItems.Count > 0)
                        {
                            if (NewSip.Customer != null && diffRechnung.ServiceInvoicePeriods.Any(s => s.Customer.CustomerOid == NewSip.Customer.CustomerOid) &&
                            NewSip.SupportConceptApprovalPeriod != null && NewSip.SupportConceptApprovalPeriod.SupportConceptApprovalPeriodOid.HasValue
                            && diffRechnung.ServiceInvoicePeriods.Any(s => s.SupportConceptApprovalPeriod != null && s.SupportConceptApprovalPeriod.SupportConceptApprovalPeriodOid.HasValue
                            && s.SupportConceptApprovalPeriod.SupportConceptApprovalPeriodOid.Value == NewSip.SupportConceptApprovalPeriod.SupportConceptApprovalPeriodOid.Value))
                            {
                                var ip = diffRechnung.ServiceInvoicePeriods.Where(s => s.SupportConceptApprovalPeriod != null && s.SupportConceptApprovalPeriod.SupportConceptApprovalPeriodOid.Value == NewSip.SupportConceptApprovalPeriod.SupportConceptApprovalPeriodOid.Value).First();
                                if (ip.InvoiceItems != null && ip.InvoiceItems.Count > 0)
                                {
                                    ip.Claim += NewSip.Claim;
                                    foreach (var ii in NewSip.InvoiceItems)
                                    {
                                        ip.InvoiceItems.Add(ii);
                                    }

                                    // Bei Rechnungspositionen mit negativem Betrag auf alte Rechnung verweisen
                                    foreach (var iitem in ip.InvoiceItems)
                                    {
                                        if (iitem.AmountTotal < 0)
                                        {
                                            var vorhandeneRechnung = item.VorhandeneRechungen.FirstOrDefault(r => r.InvoiceBase != null && r.InvoiceBase.CustomerOid == ip.Customer.CustomerOid);
                                            if (vorhandeneRechnung != null)
                                                iitem.ItemDescription += string.Format(" (am {0:dd.MM.yyyy} in Rechnung {1} berechnet)", vorhandeneRechnung.InvoiceBase.InvoiceDate, vorhandeneRechnung.InvoiceBase.InvoiceNumber);
                                        }
                                    }
                                }
                            }
                            else
                            {
                                diffRechnung.ServiceInvoicePeriods.Add(NewSip);
                            }
                        }
                    }
                }
            }
        }

        public virtual Settlement2DC ErstelleDifferenzSpitzabrechnung(Settlement2DC neueRechnung, Settlement2DC letzteRechnung)
        {
            neueRechnung.Claim = neueRechnung.Claim - letzteRechnung.Claim;

            var differenzItems = new List<InvoiceItemDC>();

            // Exaktieselbe Erkennung wie SettlementReport.cs für isDefaultSpitzabrechnung:
            // genau 1 Item mit Bezeichnung "Spitzabrechnung"/"Spitzabrechung", GrossAmountTotal==null, RateFactor==null
            bool letzteIstOldWay = letzteRechnung.InvoiceItems == null
                || (letzteRechnung.InvoiceItems.Count == 1 && (letzteRechnung.InvoiceItems[0].ItemDescription == "Spitzabrechnung" || letzteRechnung.InvoiceItems[0].ItemDescription == "Spitzabrechung")
                    && letzteRechnung.InvoiceItems[0].GrossAmountTotal == null && letzteRechnung.InvoiceItems[0].RateFactor == null);

            if (letzteIstOldWay)
            {
                // Storno der alten Gesamtsumme als einzelne explizite Position
                differenzItems.Add(new InvoiceItemDC
                {
                    AmountTotal = -(letzteRechnung.Claim ?? 0),
                    GrossAmountTotal = -(letzteRechnung.Claim ?? 0),
                    ItemPeriodStart = letzteRechnung.AccountingPeriodStart,
                    ItemPeriodEnd = letzteRechnung.AccountingPeriodEnd,
                    ItemDescription = "Storno"
                });

                // Neue Rechnung als Old-Way mit expliziten Items (isDefaultSpitzabrechnung = false im Report)
                bool neueHatExpliziteItems = neueRechnung.InvoiceItems != null && neueRechnung.InvoiceItems.Any(ii => ii.GrossAmountTotal != null);
                if (neueHatExpliziteItems)
                    differenzItems.AddRange(neueRechnung.InvoiceItems);
                else
                    differenzItems.AddRange(ErstelleExpliziteSpitzabrechnungsItems(neueRechnung));

                // Claim aus den tatsächlichen Items berechnen (Storno + neue Items),
                // da bei old-way Rechnungen neueRechnung.Claim null sein kann
                neueRechnung.Claim = differenzItems.Sum(i => i.AmountTotal ?? 0m);
            }
            else
            {
                // Normalfall: Items der alten Rechnung negieren (SettlementReport2 → SettlementReport2)
                if (letzteRechnung.InvoiceItems != null)
                {
                    foreach (var item in letzteRechnung.InvoiceItems)
                    {
                        differenzItems.Add(new InvoiceItemDC
                        {
                            AmountTotal = -(item.AmountTotal ?? 0),
                            GrossAmountTotal = item.GrossAmountTotal.HasValue ? -item.GrossAmountTotal : null,
                            AmountPerUnit = item.AmountPerUnit,
                            ApprovedPerUnit = item.ApprovedPerUnit,
                            ItemPeriodStart = item.ItemPeriodStart,
                            ItemPeriodEnd = item.ItemPeriodEnd,
                            UnitDescription = item.UnitDescription,
                            UnitCount = item.UnitCount,
                            RateFactor = item.RateFactor,
                            ItemDescription = item.ItemDescription + " (Storno)"
                        });
                    }
                }

                if (neueRechnung.InvoiceItems != null)
                    differenzItems.AddRange(neueRechnung.InvoiceItems);
            }

            neueRechnung.InvoiceItems = differenzItems;
            neueRechnung.Notice = string.Format("Differenzrechnung zu Rechnung {0} vom {1:dd.MM.yyyy}", letzteRechnung.InvoiceNumber, letzteRechnung.InvoiceDate);

            return neueRechnung;
        }

        private IList<InvoiceItemDC> ErstelleExpliziteSpitzabrechnungsItems(Settlement2DC dc)
        {
            decimal fact = 1;
            if (dc.RateFactor != null && dc.RateFactor.Value > 0)
            {
                fact = (100 + dc.RateFactor.Value) / 100;
            }
            decimal? rateFactor = fact != 1 ? fact : (decimal?)null;
            var items = new List<InvoiceItemDC>();

            // Periode mit drittem Stundensatz (nur bei DifferentHourlyRateCount >= 3)
            if (dc.DifferentHourlyRateCount >= 3)
            {
                items.Add(new InvoiceItemDC
                {
                    ItemPeriodStart = dc.AccountingPeriodStart,
                    ItemPeriodEnd = dc.HourlyRateEndDate3,
                    UnitCount = dc.ApprovedFLSWithHourlyRate3,
                    AmountPerUnit = dc.HourlyRate3,
                    RateFactor = rateFactor,
                    GrossAmountTotal = dc.ApprovedFLSWithHourlyRate3 * fact * dc.HourlyRate3,
                    AmountTotal = dc.ApprovedFLSWithHourlyRate3 * fact * dc.HourlyRate3
                });
            }

            // Periode mit altem Stundensatz (bei DifferentHourlyRateCount >= 2)
            if (dc.DifferentHourlyRateCount >= 2)
            {
                items.Add(new InvoiceItemDC
                {
                    ItemPeriodStart = dc.DifferentHourlyRateCount >= 3 ? dc.HourlyRateOldStartDate : dc.AccountingPeriodStart,
                    ItemPeriodEnd = dc.HourlyRateOldEndDate,
                    UnitCount = dc.ApprovedFLSWithOldHourlyRate,
                    AmountPerUnit = dc.HourlyRateOld,
                    RateFactor = rateFactor,
                    GrossAmountTotal = dc.ApprovedFLSWithOldHourlyRate * fact * (dc.HourlyRateOld ?? 0),
                    AmountTotal = dc.ApprovedFLSWithOldHourlyRate * fact * (dc.HourlyRateOld ?? 0)
                });
            }

            // Periode mit aktuellem Stundensatz (immer vorhanden)
            items.Add(new InvoiceItemDC
            {
                ItemPeriodStart = dc.DifferentHourlyRateCount >= 2 ? dc.HourlyRateNewStartDate : dc.AccountingPeriodStart,
                ItemPeriodEnd = dc.AccountingPeriodEnd,
                UnitCount = dc.ApprovedFLSWithActualHourlyRate,
                AmountPerUnit = dc.HourlyRateNew,
                RateFactor = rateFactor,
                GrossAmountTotal = dc.ApprovedFLSWithActualHourlyRate * fact * (dc.HourlyRateNew ?? 0),
                AmountTotal = dc.ApprovedFLSWithActualHourlyRate * fact * (dc.HourlyRateNew ?? 0)
            });

            return items;
        }

        public virtual AddressInformation GetAddressInformation(long? customer_oid = null)
        {
            var user = UserRightHelper.GetLoggedInUser().Employee;
            var mandator = AppSettings.GetMandatorEntity();

            return new AddressInformation()
            {
                IKLeistungserbringer = mandator.IKLeistungserbringer,
                Fax = user.Person.Contacts.FirstOrDefault(x => x.Type == ContactType.business_Fax)?.Value.ToNullIfEmpty(),
                Mail = user.Person.Contacts.FirstOrDefault(x => x.Type == ContactType.business_Mail)?.Value.ToNullIfEmpty(),
                Phone = user.Person.Contacts.FirstOrDefault(x => x.Type == ContactType.business_Phone)?.Value.ToNullIfEmpty(),
                OrganisationName = mandator.Name,
                PostCode = mandator.PostalCode,
                Street = mandator.Street,
                Town = mandator.Town,
                Website = mandator.Website
            };
        }
    }

    public class DifferenzRechnungCheck
    {
        public ServiceInvoiceDC NeueRechnung { get; set; }
        public IList<ServiceInvoiceDC> VorhandeneRechungen { get; set; }
    }
}