using System;
using Comal.Classes;
using Comal.Stores;
using InABox.Core;
using InABox.Database;
using System.Collections.Generic;
using System.Linq;

namespace PRSStores;

public enum JobRequisitionItemAction
{
    Created,
    Updated,
    Deleted,
    None
}

public class JobRequisitionItemStore : BaseStore<JobRequisitionItem>
{
     protected override void AfterSave(JobRequisitionItem entity)
    {
        base.AfterSave(entity);

        if(entity.HasOriginalValue(x => x.Cancelled))
        {
            CancelMovements(entity);
        }
    }

    private static IEnumerable<StockMovement> GetMovements(IStore store, Guid jriID, Filter<StockMovement>? filter, Columns<StockMovement> columns)
    {
        return store.Provider
            .Query(
                Filter<StockMovement>.And(
                    new Filter<StockMovement>(x => x.JobRequisitionItem.ID).IsEqualTo(jriID),
                    filter),
                columns)
                .ToObjects<StockMovement>();
    }
 
    private void CancelMovements(JobRequisitionItem entity)
    {
        // Here, we care about *all* movements into or out of this requi. If stuff has been issued, it must be included,
        // since we cannot return issued stock back to general stock for the job.
        var movements = GetMovements(this, entity.ID, null,
            Columns.None<StockMovement>().Add(
                x => x.Product.ID,
                x => x.Style.ID,
                x => x.Job.ID,
                x => x.Location.ID,
                x => x.Units,
                x => x.Cost,
                x => x.OrderItem.ID)
            .AddDimensionsColumns(x => x.Dimensions, Dimensions.ColumnsType.Local));

        var newMovements = new List<StockMovement>();
        foreach(var movement in movements)
        {
            var from = movement.CreateMovement();
            from.Date = entity.Cancelled;
            from.Cost = movement.Cost;
            from.System = true;
            from.JobRequisitionItem.ID = entity.ID;
            from.OrderItem.ID = movement.OrderItem.ID;
            from.Notes = "Requisition item cancelled";

            var to = movement.CreateMovement();
            to.Date = entity.Cancelled;
            to.Cost = movement.Cost;
            to.System = true;
            to.Notes = "Requisition item cancelled";
            to.OrderItem.ID = movement.OrderItem.ID;
            to.Transaction = from.Transaction;

            if(movement.Units > 0)
            {
                // If this movement was an increase to reservation allocation, we create a transfer out of the reservation.
                from.Issued = movement.Units;
                to.Received = movement.Units;

                from.Type = StockMovementType.TransferOut;
                to.Type = StockMovementType.TransferIn;
            }
            else if(movement.Units < 0)
            {
                // If this movement was a decrease to reservation allocation, we create a transfer into the reservation.
                from.Received = -movement.Units;
                to.Issued = -movement.Units;

                from.Type = StockMovementType.TransferIn;
                to.Type = StockMovementType.TransferOut;
            }

            newMovements.Add(from);
            newMovements.Add(to);
        }

        if(newMovements.Count > 0)
        {
            var batch = new StockMovementBatch
            {
                Notes = "Requisition item cancelled."
            };
            FindSubStore<StockMovementBatch>().Save(batch, "");

            foreach(var mvt in newMovements)
            {
                mvt.Batch.ID = batch.ID;
            }

            FindSubStore<StockMovement>().Save(newMovements, "Requisition item cancelled.");
        }
    }
    
}