using System;
using System.Linq;
using InABox.Core;

namespace Comal.Classes
{
    public class BillLineLink : EntityLink<BillLine>
    {
        [NullEditor]
        public override Guid ID { get; set; }
    }

    [UserTracking(typeof(Bill))]
    public class BillLine : Entity, IPersistent, IRemotable, IOneToMany<Bill>, ITaxable, ILicense<AccountsPayableLicense>, IPostableFragment<Bill>
    {
        [EntityRelationship(DeleteAction.Cascade)]
        [NullEditor]
        public BillLink BillLink { get; set; }

        private class PurchaseOrderItemLookup : LookupDefinitionGenerator<PurchaseOrderItem, BillLine>
        {
            public override Filter<PurchaseOrderItem> DefineFilter(BillLine[] items)
            {
                if (!items.Any())
                    return new Filter<PurchaseOrderItem>().None();
                
                var supplierID = items.Select(x => x.BillLink.SupplierLink.ID).Distinct().SingleOrDefault();
                if(supplierID == Guid.Empty)
                    return new Filter<PurchaseOrderItem>().None();
                
                return new Filter<PurchaseOrderItem>(x => x.PurchaseOrderLink.SupplierLink.ID).IsEqualTo(supplierID)
                    .And(x=>x.BillLine.ID).IsEqualTo(Guid.Empty);
            }

            public override Columns<BillLine> DefineFilterColumns()
            {
                return new Columns<BillLine>(x => x.BillLink.SupplierLink.ID);
            }
        }
        [LookupDefinition(typeof(PurchaseOrderItemLookup))]
        [EntityRelationship(DeleteAction.SetNull)]
        [EditorSequence(1)]
        public PurchaseOrderItemLink OrderItem { get; set; }

        private class ProductLookupGenerator : LookupDefinitionGenerator<Product, BillLine>
        {
            public override Filter<Product>? DefineFilter(BillLine[] items)
                => new Filter<Product>(x => x.NonStock);
        }
        [EditorSequence(2)]
        [LookupDefinition(typeof(ProductLookupGenerator))]
        public ProductLink Product { get; set; }

        [MemoEditor]
        [EditorSequence(2)]
        public string Description { get; set; }
        
        [EditorSequence(3)]
        public PurchaseGLCodeLink PurchaseGL { get; set; }
        
        [EditorSequence(4)]
        public CostCentreLink CostCentre { get; set; }

        [CurrencyEditor(Summary = Summary.Sum)]
        [EditorSequence(5)]
        public double ExTax { get; set; }

        [RequiredColumn]
        [EditorSequence(6)]
        public TaxCodeLink TaxCode { get; set; }

        [DoubleEditor(Editable = Editable.Hidden)]
        public double TaxRate { get; set; }

        [CurrencyEditor(Summary = Summary.Sum)]
        public double Tax { get; set; }

        [CurrencyEditor(Summary = Summary.Sum)]
        [EditorSequence(7)]
        public double IncTax { get; set; }

        [EditorSequence(8)]
        public JobLink Job { get; set; }

        [NullEditor]
        public string PostedReference { get; set; }

        static BillLine()
        {
            
            LinkedProperties.Register<BillLine, PurchaseOrderItemLink, double>(x => x.OrderItem, x => x.ExTax,
                x => x.ExTax);

            LinkedProperties.Register<BillLine, PurchaseGLCodeLink, Guid>(x => x.OrderItem.PurchaseGL, x => x.ID,
                x => x.PurchaseGL.ID);
            
            LinkedProperties.Register<BillLine, CostCentreLink, Guid>(x => x.OrderItem.CostCentre, x => x.ID,
                x => x.CostCentre.ID);
            
            LinkedProperties.Register<BillLine, TaxCodeLink, Guid>(x => x.OrderItem.TaxCode, x => x.ID,
                x => x.TaxCode.ID);            

            LinkedProperties.Register<BillLine, TaxCodeLink, String>(x => x.OrderItem.TaxCode, x => x.Code,
                x => x.TaxCode.Code);            

            LinkedProperties.Register<BillLine, TaxCodeLink, String>(x => x.OrderItem.TaxCode, x => x.Description,
                x => x.TaxCode.Description);            

            LinkedProperties.Register<BillLine, TaxCodeLink, double>(x => x.OrderItem.TaxCode, x => x.Rate,
                x => x.TaxCode.Rate);            
            
            LinkedProperties.Register<BillLine, PurchaseOrderItemLink, double>(x => x.OrderItem, x => x.Tax,
                x => x.Tax);
            
            LinkedProperties.Register<BillLine, PurchaseOrderItemLink, double>(x => x.OrderItem, x => x.IncTax,
                x => x.IncTax);

            LinkedProperties.Register<BillLine, TaxCodeLink, double>(x => x.TaxCode, x => x.Rate, x => x.TaxRate);

            LinkedProperties.Register<BillLine, PurchaseGLCodeLink, Guid>(x => x.Product.PurchaseGL, x => x.ID, x => x.PurchaseGL.ID);
            LinkedProperties.Register<BillLine, CostCentreLink, Guid>(x => x.Product.CostCentre, x => x.ID, x => x.CostCentre.ID);
            LinkedProperties.Register<BillLine, TaxCodeLink, Guid>(x => x.Product.TaxCode, x => x.ID, x => x.TaxCode.ID);
            LinkedProperties.Register<BillLine, TaxCodeLink, string>(x => x.Product.TaxCode, x => x.Code, x => x.TaxCode.Code);
            LinkedProperties.Register<BillLine, TaxCodeLink, string>(x => x.Product.TaxCode, x => x.Description, x => x.TaxCode.Description);
            LinkedProperties.Register<BillLine, TaxCodeLink, double>(x => x.Product.TaxCode, x => x.Rate, x => x.TaxCode.Rate);
        }

        private static readonly Column<BillLine> OrderItemColumn = new Column<BillLine>(x => x.OrderItem.ID);
        private static readonly Column<BillLine> ProductColumn = new Column<BillLine>(x => x.Product.ID);
        private static readonly Column<BillLine> JobColumn = new Column<BillLine>(x => x.Job.ID);

        protected override void DoPropertyChanged(string name, object? before, object? after)
        {
            base.DoPropertyChanged(name, before, after);
            if (OrderItemColumn.IsEqualTo(name) && after is Guid orderItemID && orderItemID != Guid.Empty)
            {
                Product.ID = Guid.Empty;
                Product.Clear();
                Job.ID = Guid.Empty;
                Job.Clear();
            }
            else if((ProductColumn.IsEqualTo(name) && after is Guid productID && productID != Guid.Empty)
                || (JobColumn.IsEqualTo(name) && after is Guid jobID && jobID != Guid.Empty))
            {
                OrderItem.ID = Guid.Empty;
                OrderItem.Clear();
            }
        }
    }
}