using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using InABox.Core;
using PRSClasses;

namespace Comal.Classes
{
    
    // public class StockHoldingUnitAggregate : CoreAggregate<StockHolding, StockMovement, double>
    // {
    //     public override Expression<Func<StockMovement, double>> Aggregate => x => x.Units;
    //
    //     public override Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>> Links =>
    //         new Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>>()
    //         {
    //             { StockMovement => StockMovement.Product.ID, StockHolding => StockHolding.Product.ID },
    //             { StockMovement => StockMovement.Job.ID, StockHolding => StockHolding.Job.ID },
    //             { StockMovement => StockMovement.Location.ID, StockHolding => StockHolding.Location.ID },
    //             { StockMovement => StockMovement.Style.ID, StockHolding => StockHolding.Style.ID },
    //             { StockMovement => StockMovement.Dimensions.Unit.ID, StockHolding => StockHolding.Dimensions.Unit.ID },
    //             { StockMovement => StockMovement.Dimensions.Quantity, StockHolding => StockHolding.Dimensions.Quantity },
    //             { StockMovement => StockMovement.Dimensions.Length, StockHolding => StockHolding.Dimensions.Length },
    //             { StockMovement => StockMovement.Dimensions.Width, StockHolding => StockHolding.Dimensions.Width },
    //             { StockMovement => StockMovement.Dimensions.Height, StockHolding => StockHolding.Dimensions.Height },
    //             { StockMovement => StockMovement.Dimensions.Weight, StockHolding => StockHolding.Dimensions.Weight },
    //         };
    //
    //     public override AggregateCalculation Calculation => AggregateCalculation.Sum;
    // }
    //
    // public class StockHoldingValueAggregate : CoreAggregate<StockHolding, StockMovement, double>
    // {
    //     public override Expression<Func<StockMovement, double>> Aggregate => x => x.Value;
    //
    //     public override Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>> Links =>
    //         new Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>>()
    //         {
    //             { StockMovement => StockMovement.Product.ID, StockHolding => StockHolding.Product.ID },
    //             { StockMovement => StockMovement.Job.ID, StockHolding => StockHolding.Job.ID },
    //             { StockMovement => StockMovement.Location.ID, StockHolding => StockHolding.Location.ID },
    //             { StockMovement => StockMovement.Style.ID, StockHolding => StockHolding.Style.ID },
    //             { StockMovement => StockMovement.Dimensions.Unit.ID, StockHolding => StockHolding.Dimensions.Unit.ID },
    //             { StockMovement => StockMovement.Dimensions.Quantity, StockHolding => StockHolding.Dimensions.Quantity },
    //             { StockMovement => StockMovement.Dimensions.Length, StockHolding => StockHolding.Dimensions.Length },
    //             { StockMovement => StockMovement.Dimensions.Width, StockHolding => StockHolding.Dimensions.Width },
    //             { StockMovement => StockMovement.Dimensions.Height, StockHolding => StockHolding.Dimensions.Height },
    //             { StockMovement => StockMovement.Dimensions.Weight, StockHolding => StockHolding.Dimensions.Weight },
    //         };
    //
    //     public override AggregateCalculation Calculation => AggregateCalculation.Sum;
    // }
    //
    // public class StockHoldingAverageValueFormula : IFormula<StockHolding, double>
    // {
    //     public Expression<Func<StockHolding, double>> Value => x => x.Value;
    //
    //     public Expression<Func<StockHolding, double>>[] Modifiers => new Expression<Func<StockHolding, double>>[] { x => x.Units };
    //
    //     public FormulaOperator Operator => FormulaOperator.Divide;
    //     
    //     public FormulaType Type => FormulaType.Virtual;
    // }
    //
    // public class StockHoldingQuantityAggregate : CoreAggregate<StockHolding, StockMovement, double>
    // {
    //     public override Expression<Func<StockMovement, double>> Aggregate => x => x.Qty;
    //
    //     public override Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>> Links =>
    //         new Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>>()
    //         {
    //             { StockMovement => StockMovement.Product.ID, StockHolding => StockHolding.Product.ID },
    //             { StockMovement => StockMovement.Job.ID, StockHolding => StockHolding.Job.ID },
    //             { StockMovement => StockMovement.Location.ID, StockHolding => StockHolding.Location.ID },
    //             { StockMovement => StockMovement.Style.ID, StockHolding => StockHolding.Style.ID },
    //             { StockMovement => StockMovement.Dimensions.Unit.ID, StockHolding => StockHolding.Dimensions.Unit.ID },
    //             { StockMovement => StockMovement.Dimensions.Quantity, StockHolding => StockHolding.Dimensions.Quantity },
    //             { StockMovement => StockMovement.Dimensions.Length, StockHolding => StockHolding.Dimensions.Length },
    //             { StockMovement => StockMovement.Dimensions.Width, StockHolding => StockHolding.Dimensions.Width },
    //             { StockMovement => StockMovement.Dimensions.Height, StockHolding => StockHolding.Dimensions.Height },
    //             { StockMovement => StockMovement.Dimensions.Weight, StockHolding => StockHolding.Dimensions.Weight },
    //         };
    //
    //     public override AggregateCalculation Calculation => AggregateCalculation.Sum;
    // }


    // public class StockHoldingAvailableAggregate : CoreAggregate<StockHolding, StockMovement, double>
    // {
    //     public override Expression<Func<StockMovement, double>> Aggregate => x => x.Units;
    //
    //     public override Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>> Links =>
    //         new Dictionary<Expression<Func<StockMovement, object>>, Expression<Func<StockHolding, object>>>()
    //         {
    //             { StockMovement => StockMovement.Product.ID, StockHolding => StockHolding.Product.ID },
    //             { StockMovement => StockMovement.Job.ID, StockHolding => StockHolding.Job.ID },
    //             { StockMovement => StockMovement.Location.ID, StockHolding => StockHolding.Location.ID },
    //             { StockMovement => StockMovement.Style.ID, StockHolding => StockHolding.Style.ID },
    //             { StockMovement => StockMovement.Dimensions.Unit.ID, StockHolding => StockHolding.Dimensions.Unit.ID },
    //             { StockMovement => StockMovement.Dimensions.Quantity, StockHolding => StockHolding.Dimensions.Quantity },
    //             { StockMovement => StockMovement.Dimensions.Length, StockHolding => StockHolding.Dimensions.Length },
    //             { StockMovement => StockMovement.Dimensions.Width, StockHolding => StockHolding.Dimensions.Width },
    //             { StockMovement => StockMovement.Dimensions.Height, StockHolding => StockHolding.Dimensions.Height },
    //             { StockMovement => StockMovement.Dimensions.Weight, StockHolding => StockHolding.Dimensions.Weight },
    //         };
    //
    //     public override AggregateCalculation Calculation => AggregateCalculation.Sum;
    //
    //     public override Filter<StockMovement>? Filter => new Filter<StockMovement>(x => x.JobRequisitionItem.ID).IsEqualTo(Guid.Empty);
    // }
    
    // public class StockHoldingWeightFormula : IFormula<StockHolding, double>
    // {
    //     public Expression<Func<StockHolding, double>> Value => x => x.Qty;
    //
    //     public Expression<Func<StockHolding, double>>[] Modifiers => new Expression<Func<StockHolding, double>>[] { x => x.Dimensions.Weight };
    //
    //     public FormulaOperator Operator => FormulaOperator.Multiply;
    //     
    //     public FormulaType Type => FormulaType.Virtual;
    // }
    //
    // public class StockHoldingIsRemnantCondition : ICondition<StockHolding, double, object>
    // {
    //     public Expression<Func<StockHolding, double>> Left => x => x.Dimensions.Value;
    //
    //     public Condition Condition => Condition.LessThan;
    //
    //     public Expression<Func<StockHolding, double>> Right => x => x.Product.DefaultInstance.Dimensions.Value;
    //
    //     public Expression<Func<StockHolding, object>> True => x => true;
    //
    //     public Expression<Func<StockHolding, object>> False => x => null;
    //     
    //     public ConditionType Type => ConditionType.Virtual;
    // }
    
    // public class StockHoldingUnionGenerator : AutoEntityUnionGenerator<IStockHolding>
    // {
    //     protected override void Configure()
    //     {
    //         AddTable<StockMovement>();
    //     }
    //
    //     public override bool Distinct => true;
    //
    //     public override Column<IStockHolding>[] IDColumns => Columns;
    //
    //     public static Column<IStockHolding>[] Columns => new Column<IStockHolding>[]
    //     {
    //         new Column<IStockHolding>(x => x.Job.ID),
    //         new Column<IStockHolding>(x => x.Location.ID),
    //         new Column<IStockHolding>(x => x.Product.ID),
    //         new Column<IStockHolding>(x => x.Style.ID),
    //         new Column<IStockHolding>(x => x.Dimensions.Unit.ID),
    //         new Column<IStockHolding>(x => x.Dimensions.Quantity),
    //         new Column<IStockHolding>(x => x.Dimensions.Length),
    //         new Column<IStockHolding>(x => x.Dimensions.Width),
    //         new Column<IStockHolding>(x => x.Dimensions.Height),
    //         new Column<IStockHolding>(x => x.Dimensions.Weight),
    //     };
    //
    //     public static Filter<StockMovement>? GetFilter(IStockHolding holding)
    //     {
    //         var filter = new Filters<StockMovement>();
    //
    //         foreach(var column in Columns)
    //         {
    //             filter.Add(new Filter<StockMovement>(column.Cast<StockMovement>()).IsEqualTo(CoreUtils.GetPropertyValue(holding, column.Property)));
    //         }
    //
    //         return filter.Combine();
    //     }
    // }
    //
    // [UserTracking(typeof(StockMovement))]
    // [AutoEntity(typeof(StockHoldingUnionGenerator))]
    // public class StockHoldingView : StockEntity, IRemotable, IPersistent, IOneToMany<StockLocation>, IOneToMany<Product>, 
    //     IStockHolding, ILicense<WarehouseLicense>
    // {
    //     
    //     public override ProductLink Product { get; set; }
    //
    //     public ProductStyleLink Style { get; set; }
    //
    //     public StockLocationLink Location { get; set; }
    //
    //     public JobLink Job { get; set; }
    //
    //     [RequiredColumn]
    //     [DimensionsEditor(typeof(StockDimensions), AllowEditingUnit = false)]
    //     public override StockDimensions Dimensions { get; set; }
    //
    //     [Condition(typeof(StockHoldingIsRemnantCondition))]
    //     [NullEditor]
    //     public bool IsRemnant { get; set; }
    //     
    //     [Aggregate(typeof(StockHoldingUnitAggregate))]
    //     [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
    //     public double Units { get; set; }
    //     
    //     [Aggregate(typeof(StockHoldingQuantityAggregate))]
    //     [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
    //     public double Qty { get; set; }
    //     
    //     [Formula(typeof(StockHoldingWeightFormula))]
    //     [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
    //     public double Weight { get; set; }
    //     
    //     [Aggregate(typeof(StockHoldingValueAggregate))]
    //     [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
    //     public double Value { get; set; }
    //     
    //     [Formula(typeof(StockHoldingAverageValueFormula))]
    //     [DoubleEditor(Editable = Editable.Disabled)]
    //     public double AverageValue { get; set; }
    // }
    
    // FV 6/2/24: This used to be a view (see above), but we were running into performance issues trying to
    // get aggregates fof stock locations (ie show me how many holdings in a given location was taking upwrds of
    // 20 seconds.  Have moved update logic to StockHoldingStore / StockMovementStore so updates are a bit slower,
    // but reads are now much faster.
    [UserTracking(typeof(StockMovement))]
    [Unrecoverable]
    public class StockHolding : StockEntity, IRemotable, IPersistent, IOneToMany<StockLocation>, IOneToMany<Product>, 
        IStockHolding, ILicense<WarehouseLicense>
    {
        
        [Editable(Editable.Disabled)]
        [EditorSequence(1)]
        public StockLocationLink Location { get; set; }
        
        private class ProductLookupGenerator : LookupDefinitionGenerator<Product, StockHolding>
        {
            public override Filter<Product>? DefineFilter(StockHolding[] items)
                => LookupFactory.DefineFilter<Product>().And(x => x.NonStock).IsEqualTo(false);
        }
        [Editable(Editable.Disabled)]
        [EditorSequence(2)]
        [LookupDefinition(typeof(ProductLookupGenerator))]
        public override ProductLink Product { get; set; }
        
        [DimensionsEditor(typeof(StockDimensions), AllowEditingUnit = false)]
        [Editable(Editable.Disabled)]
        [EditorSequence(3)]
        public override StockDimensions Dimensions { get; set; }

        [Editable(Editable.Disabled)]
        [EditorSequence(4)]
        public ProductStyleLink Style { get; set; }
        
        [Editable(Editable.Disabled)]
        [EditorSequence(4)]
        public JobLink Job { get; set; }
        
        [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
        [EditorSequence(5)]
        public double Units { get; set; }
        
        [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
        [EditorSequence(6)]
        public double Qty { get; set; }
        
        [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
        [EditorSequence(7)]
        public double Weight { get; set; }
        
        [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
        [EditorSequence(8)]
        public double Value { get; set; }
        
        [DoubleEditor(Editable = Editable.Disabled)]
        [EditorSequence(9)]
        public double AverageValue { get; set; }
        
        [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
        [EditorSequence(10)]
        public double Available { get; set; }
        
        public static Column<IStockHolding>[] Columns => new Column<IStockHolding>[]
        {
            new Column<IStockHolding>(x => x.Job.ID),
            new Column<IStockHolding>(x => x.Location.ID),
            new Column<IStockHolding>(x => x.Product.ID),
            new Column<IStockHolding>(x => x.Style.ID),
            new Column<IStockHolding>(x => x.Dimensions.Unit.ID),
            new Column<IStockHolding>(x => x.Dimensions.Quantity),
            new Column<IStockHolding>(x => x.Dimensions.Length),
            new Column<IStockHolding>(x => x.Dimensions.Width),
            new Column<IStockHolding>(x => x.Dimensions.Height),
            new Column<IStockHolding>(x => x.Dimensions.Weight),
        };
        
        public static Filter<StockMovement>? GetFilter(IStockHolding holding)
        {
            var filter = new Filters<StockMovement>();
        
            foreach(var column in Columns)
            {
                filter.Add(new Filter<StockMovement>(column.Cast<StockMovement>()).IsEqualTo(CoreUtils.GetPropertyValue(holding, column.Property)));
            }
        
            return filter.Combine();
        }
    }

    public static class StockHoldingExtensions
    {
        /// <summary>
        /// Create a new stock movement from an <see cref="IStockHolding"/>, copying across the "key" properties;
        /// that is, the job, product, style, location and dimensions.
        /// </summary>
        /// <param name="holding"></param>
        /// <returns></returns>
        public static StockMovement CreateMovement(this IStockHolding holding)
        {
            var movement = new StockMovement();
            movement.Job.ID = holding.Job.ID;
            movement.Job.Synchronise(holding.Job);
            movement.Product.ID = holding.Product.ID;
            movement.Product.Synchronise(holding.Product);
            movement.Style.ID = holding.Style.ID;
            movement.Style.Synchronise(holding.Style);
            movement.Location.ID = holding.Location.ID;
            movement.Location.Synchronise(holding.Location);
            movement.Dimensions.CopyFrom(holding.Dimensions);
            return movement;
        }

        public static IEnumerable<StockHolding> GroupMovements(IEnumerable<StockMovement> movements)
        {
            var grouped = new List<StockHolding>();

            var toGroup = movements.AsList();
            while (toGroup.Count > 0)
            {
                var first = toGroup.First();
                var selected = toGroup.Where(x => x.IsEqualTo(first)).ToList();

                var holding = grouped.FirstOrDefault(x => x.IsEqualTo(first));
                if (holding == null)
                {
                    holding = new StockHolding();
                    holding.Location.ID = first.Location.ID;
                    holding.Product.ID = first.Product.ID;
                    holding.Style.ID = first.Style.ID;
                    holding.Job.ID = first.Job.ID;
                    holding.Dimensions.CopyFrom(first.Dimensions);
                }
                holding.Recalculate(selected);

                toGroup.RemoveAll(x => selected.Any(s => s.ID == x.ID));
            }
            return grouped;
        }

        public static bool IsEqualTo(this IStockHolding h1, IStockHolding h2)
        {
            return h1.Product.ID == h2.Product.ID
                && h1.Location.ID == h2.Location.ID
                && h1.Job.ID == h2.Job.ID
                && h1.Style.ID == h2.Style.ID
                && h1.Dimensions.Unit.ID == h2.Dimensions.Unit.ID
                && h1.Dimensions.Length.IsEffectivelyEqual(h2.Dimensions.Length)
                && h1.Dimensions.Width.IsEffectivelyEqual(h2.Dimensions.Width)
                && h1.Dimensions.Height.IsEffectivelyEqual(h2.Dimensions.Height)
                && h1.Dimensions.Quantity.IsEffectivelyEqual(h2.Dimensions.Quantity)
                && h1.Dimensions.Weight.IsEffectivelyEqual(h2.Dimensions.Weight);
        }

        public static void Recalculate(this StockHolding holding, IEnumerable<StockMovement> movements)
        {
            movements = movements.AsIList();
            var units = movements.Sum(x => x.Units);
            var cost = movements.Select(x => x.Units * x.Cost).Sum();
            var available = movements.Where(x => x.JobRequisitionItem.ID == Guid.Empty).Sum(x => x.Units);
            holding.Units = units;
            holding.Available = available;
            holding.Qty = movements.Sum(x => x.Units * x.Dimensions.Value);
            holding.Value = cost;

            holding.AverageValue = units.IsEffectivelyEqual(0.0F) ? 0.0d : cost / units;
            holding.Weight = holding.Qty * holding.Dimensions.Weight;
        }
    }
    
}