using Comal.Classes;
using InABox.Core;
using InABox.Database;
using System;
using System.Linq;
namespace Comal.Stores;

public class StockHoldingStore : BaseStore<StockHolding>
{

    public enum Action
    {
        Increase,
        Decrease
    }

    /// <summary>
    /// Maintains the Stock Holding Table when manipulating Stock Movements
    /// We only accept an ID, because the rest of the movement is pulled from the database
    /// (slower, but more reliable)
    /// </summary>
    /// <param name="id">The id of the Stock Movement to query</param>
    /// <param name="action">The action to perform (increase / decrease)</param>
    public static void UpdateStockHolding(Guid id, Action action)
    {
        var movement = DbFactory.Provider.Query(
            new Filter<StockMovement>(x => x.ID).IsEqualTo(id),
            new Columns<StockMovement>(x => x.ID)
                .Add(x => x.Location.ID)
                .Add(x => x.Product.ID)
                .Add(x => x.Style.ID)
                .Add(x => x.Job.ID)
                .Add(x => x.Dimensions.Unit.ID)
                .Add(x => x.Dimensions.Quantity)
                .Add(x => x.Dimensions.Height)
                .Add(x => x.Dimensions.Width)
                .Add(x => x.Dimensions.Length)
                .Add(x => x.Dimensions.Weight)
                .Add(x => x.Dimensions.UnitSize)
                .Add(x => x.Dimensions.Value)
                .Add(x => x.JobRequisitionItem.ID)
                .Add(x => x.Units)
                .Add(x => x.Cost)
        ).Rows
            .FirstOrDefault()?
            .ToObject<StockMovement>();
        if (movement == null)
            return;
        
        var holding = DbFactory.Provider.Query(new Filter<StockHolding>(x => x.Product.ID).IsEqualTo(movement.Product.ID)
                .And(x => x.Location.ID).IsEqualTo(movement.Location.ID)
                .And(x => x.Style.ID).IsEqualTo(movement.Style.ID)
                .And(x => x.Job.ID).IsEqualTo(movement.Job.ID)
                .And(x => x.Dimensions.Unit.ID).IsEqualTo(movement.Dimensions.Unit.ID)
                .And(x => x.Dimensions.UnitSize).IsEqualTo(movement.Dimensions.UnitSize),
                new Columns<StockHolding>(x => x.ID)
                    .Add(x => x.Units)
                    .Add(x => x.Qty)
                    .Add(x => x.Value)
                    .Add(x => x.Available)
            ).Rows
            .FirstOrDefault()?
            .ToObject<StockHolding>();
        if (holding == null)
        {
            holding = new();
            holding.Location.ID = movement.Location.ID;
            holding.Product.ID = movement.Product.ID;
            holding.Style.ID = movement.Style.ID;
            holding.Job.ID = movement.Job.ID;
            holding.Dimensions.CopyFrom(movement.Dimensions);
        }

        double multiplier = action == Action.Increase ? 1F : -1F;
        holding.Units += (multiplier * movement.Units);
        holding.Qty += (multiplier * movement.Units * movement.Dimensions.Value);
        holding.Value += (multiplier * movement.Units * movement.Cost);
        holding.Available += (multiplier * (movement.JobRequisitionItem.ID == Guid.Empty ? movement.Units : 0.0));
        
        holding.Weight = holding.Qty * holding.Dimensions.Weight;
        holding.AverageValue = holding.Units != 0 ? holding.Value / holding.Units : 0.0F;

        // Automagically clean up empty holdings
        if (holding.Units.IsEffectivelyEqual(0.0F))
        {
            if (holding.ID != Guid.Empty)
                DbFactory.Provider.Delete(holding, "");
        }
        else
            DbFactory.Provider.Save(holding);
    }
    
}