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

namespace Comal.Stores
{
    public class ConsignmentStore : BaseStore<Consignment>
    {
        protected override void BeforeSave(Consignment entity)
        {
            base.BeforeSave(entity);
        }

        protected override void AfterSave(Consignment entity)
        {
            base.AfterSave(entity);

            //consignment has to be newly completed (usually done via receivals module) - checks further down as well to ensure no repeated saving of documents / batches
            if (entity.ActualWarehouseArrival == DateTime.MinValue)
                return;
            if (entity.HasOriginalValue(x => x.ActualWarehouseArrival) && entity.GetOriginalValue<Consignment, DateTime>("ActualWarehouseArrival") != DateTime.MinValue)
                return;

            //find previously saved PO Items attached to this consignment
            var purchaseOrderItemTable = Provider.Query<PurchaseOrderItem>(
                new Filter<PurchaseOrderItem>(x => x.Consignment.ID).IsEqualTo(entity.ID),
                Columns.None<PurchaseOrderItem>().Add(x => x.ID, x => x.PurchaseOrderLink.ID)
                );

            var firstPOItem = purchaseOrderItemTable.Rows.FirstOrDefault();
            if (firstPOItem is null) // i.e., there are no PO Items, return
                return;

            var consignmentDocIDs = new List<Guid>();

            var purchaseOrderID = firstPOItem.Get<PurchaseOrderItem, Guid>(x => x.PurchaseOrderLink.ID);

            var table = Provider.Query<ConsignmentDocument>
            (
                new Filter<ConsignmentDocument>(x => x.EntityLink.ID).IsEqualTo(entity.ID),
                Columns.None<ConsignmentDocument>().Add(x => x.DocumentLink.ID)
                );
            if (table.Rows.Any())
            {
                consignmentDocIDs = SavePurchaseOrderDocuments(table, purchaseOrderID);
            }

            //build filter for querying stock movements attached to PO Items on this consignment
            var filter =
                new Filter<StockMovement>(x => x.OrderItem.ID).InList(purchaseOrderItemTable.Rows.Select(x => x.Get<PurchaseOrderItem, Guid>(x => x.ID)).ToArray());
            
            var stockMovementTable = Provider.Query<StockMovement>(
                filter,
                Columns.None<StockMovement>().Add(
                    x => x.ID,
                    x => x.Notes,
                    x => x.Batch.ID
                    ));

            if (stockMovementTable.Rows.Any())
            {
                //check if movements already have a batch.id - means photos would have already been saved
                var batchID = stockMovementTable.Rows.First().Get<StockMovement, Guid>(x => x.Batch.ID);
                if (batchID != Guid.Empty)
                    return;

                //create new stockmovementbatch to attach new stockmovements to (movements created by server)
                var batch = new StockMovementBatch();
                batch.Type = StockMovementBatchType.Receipt;
                Provider.Save(batch);

                //add found stockmovements to batch, add stockmovements to save
                var movements = new List<StockMovement>();
                foreach (var movement in stockMovementTable.ToObjects<StockMovement>())
                {
                    movement.Batch.ID = batch.ID;
                    movement.Employee.ID = entity.Employee.ID;
                    movement.Notes = movement.Notes + " / Consignment " + entity.Number;
                    movements.Add(movement);
                }
                Provider.Save(movements);

                var stockMovementBatchDocuments = new List<StockMovementBatchDocument>();
                foreach (var id in consignmentDocIDs)
                {
                    var smd = new StockMovementBatchDocument();
                    smd.EntityLink.ID = batch.ID;
                    smd.DocumentLink.ID = id;
                    stockMovementBatchDocuments.Add(smd);
                }
                Provider.Save<StockMovementBatchDocument>(stockMovementBatchDocuments);
            }
        }

        private List<Guid> SavePurchaseOrderDocuments(CoreTable table, Guid purchaseOrderID)
        {
            var consignmentDocIDs = new List<Guid>();
            var purchaseOrderDocuments = new List<PurchaseOrderDocument>();
            foreach (var row in table.Rows)
            {
                var docID = row.Get<ConsignmentDocument, Guid>(x => x.DocumentLink.ID);
                consignmentDocIDs.Add(docID);
                var PODocument = new PurchaseOrderDocument();
                PODocument.DocumentLink.ID = docID;
                PODocument.EntityLink.ID = purchaseOrderID;
                var existingPODocs = Provider.Query<PurchaseOrderDocument>(
                    new Filter<PurchaseOrderDocument>(x => x.DocumentLink.ID).IsEqualTo(docID), //check that PO document doesn't already exist
                    Columns.None<PurchaseOrderDocument>().Add(x => x.ID));
                if (existingPODocs.Rows.Count == 0)
                    purchaseOrderDocuments.Add(PODocument);               
            }
            if (purchaseOrderDocuments.Any())
                Provider.Save<PurchaseOrderDocument>(purchaseOrderDocuments);
            return consignmentDocIDs;
        }       
    }
}