using System;
using System.Collections.Generic;
using System.Linq;
using System.Workflow.ComponentModel;
using Mediachase.Commerce.Orders;

namespace Mediachase.Commerce.Workflow.Activities
{
	public partial class CheckInventoryActivity : OrderGroupActivityBase
	{
		/// <summary>
		/// Initializes a new instance of the <see cref="CheckInventoryActivity"/> class.
		/// </summary>
		public CheckInventoryActivity()
		{
			InitializeComponent();
		}

		/// <summary>
		/// Called by the workflow runtime to execute an activity.
		/// </summary>
		/// <param name="executionContext">The <see cref="T:System.Workflow.ComponentModel.ActivityExecutionContext"/> to associate with this <see cref="T:System.Workflow.ComponentModel.Activity"/> and execution.</param>
		/// <returns>
		/// The <see cref="T:System.Workflow.ComponentModel.ActivityExecutionStatus"/> of the run task, which determines whether the activity remains in the executing state, or transitions to the closed state.
		/// </returns>
		protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
		{
			try
			{
				// Validate the properties at runtime
				this.ValidateRuntime();

				// Calculate order discounts
				this.ValidateItems();

				// Retun the closed status indicating that this activity is complete.
				return ActivityExecutionStatus.Closed;
			}
			catch
			{
				// An unhandled exception occured.  Throw it back to the WorkflowRuntime.
				throw;
			}
		}

		private void ValidateItems()
		{
			//We don't need to validate quantity in the wishlist
			var orderForms = OrderGroup.OrderForms.ToArray();
			var lineItems = orderForms.SelectMany(x => x.LineItems.ToArray());
			var validLineItems = lineItems.Where(x => x.Code != "0" && !String.IsNullOrEmpty(x.Code) && !x.Code.StartsWith("@"));
			foreach (LineItem lineItem in validLineItems)
			{
				List<string> changeQtyReason = new List<string>();
                
                decimal newQty;
                if (lineItem.IsInventoryAllocated)
                {
                    newQty = lineItem.Quantity;
                }
                else
                {
                    newQty = GetNewLineItemQty(lineItem, changeQtyReason, null);
                }

				var changeQtyReasonDisplay = String.Join(" and ", changeQtyReason.ToArray());
				if (newQty == 0)
				{
					// Remove item if it reached this stage
                    Warnings.Add("LineItemRemoved-" + lineItem.LineItemId.ToString(), String.Format("Item \"{0}\" has been removed from the cart because it is no longer available or there is not enough available quantity.", lineItem.DisplayName));
					DeleteLineItemFromShipments(lineItem);
					// Delete item
					lineItem.Delete();
				}
				else
				{
					var delta = lineItem.Quantity - newQty;
					if (delta != 0)
					{
						lineItem.Quantity -= delta;
						ChangeShipmentsLineItemQty(lineItem, delta);
                        Warnings.Add("LineItemQtyChanged-" + lineItem.LineItemId.ToString(),
									 String.Format("Item \"{0}\" quantity has been changed {1}", lineItem.DisplayName, changeQtyReasonDisplay));
					}
				}
			}

            //delete shipment if it has no item.
            var shipments = orderForms.SelectMany(of => of.Shipments.ToArray());
            foreach (Shipment shipment in shipments)
            {
                if (shipment.LineItemIndexes.Length == 0)
                {
                    CancelOperationKeys(shipment);
                    shipment.Delete();
                }
            }
         }

        private void DeleteLineItemFromShipments(LineItem lineItem)
		{
			var orderForm = OrderGroup.OrderForms.ToArray().FirstOrDefault();
			if (orderForm != null)
			{
                int lineItemIndex = orderForm.LineItems.IndexOf(lineItem);
                var allShipmentContainsLineItem = orderForm.Shipments.ToArray().Where(x => Shipment.GetShipmentLineItems(x).Contains(lineItem));
                foreach (var shipment in allShipmentContainsLineItem)
                {
                    shipment.RemoveLineItemIndex(lineItemIndex);
                }

                ReorderIndexes(orderForm, lineItem);
			}
		}
		private void ChangeShipmentsLineItemQty(LineItem lineItem, decimal delta)
		{
			var orderForm = OrderGroup.OrderForms.ToArray().FirstOrDefault();
			if (orderForm != null)
			{
				var lineItemIndex = orderForm.LineItems.IndexOf(lineItem);
				var allShipmentContainsLineItem = orderForm.Shipments.ToArray().Where(x => Shipment.GetShipmentLineItems(x).Contains(lineItem));
				foreach (var shipment in allShipmentContainsLineItem)
				{
					//Decrease qty in all shipment contains line item
					var shipmentQty = Shipment.GetLineItemQuantity(shipment, lineItem.LineItemId);
					var newShipmentQty = shipmentQty - delta;
					newShipmentQty = newShipmentQty > 0 ? newShipmentQty : 0;
					//Set new line item qty in shipment
					shipment.SetLineItemQuantity(lineItemIndex, newShipmentQty);
					delta -= Math.Min(delta, shipmentQty);

					if (delta == 0)
						break;
				}
			}
		}
	}
}