using System;
using System.Collections.Generic;
using System.Transactions;
using PizzaDAO;
using PizzaModel;
// stateless singleton object for student part of the service API
namespace PizzaService
{
    public class StudentService
    {
        public StudentService()
        {
        }

        public List<PizzaSize> AllPizzaSizes()
        {
            List<PizzaSize> all;
            using (PizzaEntities context = new PizzaEntities())
            {
                PizzaOrderDAO orderDAO = new PizzaOrderDAO(context);
                try
                {
                    using (TransactionScope tx = new TransactionScope())
                    {
                        all = orderDAO.FindAllPizzaSizes();
                        tx.Complete();
                    }
                }
                catch (Exception e)
                {
                    throw new ApplicationException("Error in accessing Pizza Sizes" 
                         + e.InnerException.Message, e);
                }
            }
            return all;
        }

        public List<Topping> AllToppings()
        {
            List<Topping> all;
            using (PizzaEntities context = new PizzaEntities())
            {
                PizzaOrderDAO orderDAO = new PizzaOrderDAO(context);
                try
                {
                    using (TransactionScope tx = new TransactionScope())
                    {
                        all = orderDAO.FindAllToppings();
                        tx.Complete();
                    }
                }
                catch (Exception e)
                {
                    throw new ApplicationException("Error in accessing Toppings"
                         + e.InnerException.Message, e);
                }
            }
            return all;
        }
        
 
        // returns order ID
        public int MakeOrder(int roomNumber, String sizeID, List<String> toppingIDs)
        {
            using (PizzaEntities context = new PizzaEntities())
            {
                PizzaOrderDAO orderDAO = new PizzaOrderDAO(context);
                AdminDAO adminDAO = new AdminDAO(context);
                try
                {
                    using (TransactionScope tx = new TransactionScope())
                    {
                        PizzaSize size = orderDAO.FindPizzaSizeByID(sizeID);
                        List<Topping> tops = new List<Topping>();
                        foreach (String t in toppingIDs)
                        {
                            Topping top = orderDAO.FindToppingByID(t);
                            tops.Add(top);
                        }
                        // here with all good toppings, good size
                        int day = adminDAO.FindCurrentDay();
                        int status = (int)PizzaOrder.OrderStatus.Preparing;
                        PizzaOrder o = orderDAO.InsertOrder(roomNumber, size, tops, day, status);
                        context.SaveChanges();
                        tx.Complete();
                        return o.ID;
                    } 
                }
                catch (Exception e)
                {
                    throw new ApplicationException(
                        "order insert failed" + e.Message, e);
                }
            }
        }

        // This provides PizzaOrder objects, with Topping and PizzaSize objects,
        // to the presentation layer, after the transaction is committed.
        // So any changes to them at that point have no effect on the DB.
        // The service API is set up so as not to accept domain objects
        // from the presentation layer, only ids specifying them.
        public List<PizzaOrder> OrderStatus(int roomNumber)
        {
            List<PizzaOrder> pizzaOrders = null;
            using (PizzaEntities context = new PizzaEntities())
            {
                PizzaOrderDAO orderDAO = new PizzaOrderDAO(context);
                AdminDAO adminDAO = new AdminDAO(context);
                try
                {
                    using (TransactionScope tx = new TransactionScope())
                    {
                        pizzaOrders = orderDAO.FindOrdersByRoom(roomNumber, adminDAO.FindCurrentDay());
                        foreach (PizzaOrder order in pizzaOrders)
                        {
                            if (order.Status == (int)PizzaOrder.OrderStatus.Baked)
                                // a student has seen it ready, so mark this pizza "finished"
                                order.Status = (int)PizzaOrder.OrderStatus.Finished;
                        }
                        context.SaveChanges();
                        tx.Complete();
                    }
                }
                catch (Exception e)
                {
                    throw new ApplicationException("Error in getting status"
                         + e.InnerException.Message, e);
                }
            }
            return pizzaOrders;
        }
    }
}