using System;
using System.Collections.Generic;
using Casestudy.ViewModels;
using Newtonsoft.Json;
using Casestudy.Models;
using System.Linq;

namespace Casestudy.Models
{
    public class OrderModel
    {
        private AppDbContext _db;
        public bool flag;
        public OrderModel(AppDbContext ctx)
        {
            _db = ctx;
        }
        public int AddOrder(Dictionary<string, object> items, string user)
        {
            int orderId = -1;
            using (_db)
            {
                // we need a transaction as multiple entities involved
                using (var _trans = _db.Database.BeginTransaction())
                {
                    try
                    {
                        Order order = new Order();
                        order.UserId = user;
                        order.OrderDate = System.DateTime.Now;
                        order.OrderAmount = 0.0M;
                        // calculate the totals and then add the tray row to the table
                        foreach (var key in items.Keys)
                        {
                            ProductViewModel item = JsonConvert.DeserializeObject<ProductViewModel>(Convert.ToString(items[key]));
                            if (item.Qty > 0)
                            {
                                order.OrderAmount += item.MSRP * item.Qty * 1.13M;
                            }
                        }
                        _db.Orders.Add(order);
                        _db.SaveChanges();
                        // then add each item to the orderproducts table
                        foreach (var key in items.Keys)
                        {
                            ProductViewModel item = JsonConvert.DeserializeObject<ProductViewModel>(Convert.ToString(items[key]));
                            if (item.Qty > 0)
                            {
                                OrderLineItem oli = new OrderLineItem();
                                oli.Product = _db.Products.FirstOrDefault(p => p.Id == item.Id);
                                oli.Order.Id = order.Id;
                                if (oli.Product.QtyOnHand > item.Qty)
                                {
                                    oli.Product.Id = item.Id;
                                    oli.Product.QtyOnHand -= item.Qty;
                                    oli.QtySold = item.Qty;
                                    oli.QtyOrdered = item.Qty;
                                    oli.QtyBackOrdered = 0;
                                    oli.SellingPrice = item.MSRP;
                                }
                                else
                                {
                                    oli.QtyBackOrdered = item.Qty - oli.Product.QtyOnHand;
                                    oli.Product.QtyOnBackOrder += (item.Qty - oli.Product.QtyOnHand);
                                    oli.Product.QtyOnHand = 0;
                                    oli.QtyOrdered = item.Qty;
                                    oli.QtySold = oli.QtyOrdered - oli.QtyBackOrdered;
                                    oli.SellingPrice = item.MSRP;
                                    flag = true;
                                }
                                _db.OrderLineItems.Add(oli);
                                _db.SaveChanges();

                            }
                        }
                        // test trans by uncommenting out these 3 lines
                        //int x = 1;
                        //int y = 0;
                        //x = x / y;
                        _trans.Commit();
                        orderId = order.Id;
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                        _trans.Rollback();
                    }
                }
            }
            return orderId;
        }
    }
}