using Microsoft.EntityFrameworkCore;
using RestaurantContracts.BindingModels;
using RestaurantContracts.SearchModels;
using RestaurantContracts.StoragesContracts;
using RestaurantContracts.ViewModels;
using RestaurantDatabaseImplement.Models;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RestaurantDatabaseImplement.Implements
{
    public class OrderStorage : IOrderStorage
    {
        public List<OrderViewModel> GetFullList()
        {
            using var context = new RestaurantDatabase();
            return context.Orders
            .Include(x => x.Client)
            .Include(x => x.Products)
            .ThenInclude(x => x.Product)
            .ToList()
            .Select(x => x.GetViewModel)
            .ToList();
        }
        public List<OrderViewModel> GetFilteredList(OrderSearchModel model)
        {
            using var context = new RestaurantDatabase();
            if (model.Id.HasValue)
            {
                return context.Orders
                    .Include(x => x.Products)
                    .ThenInclude(x => x.Product)
                    .Include(x => x.Client)
                    .Where(x => x.Id == model.Id)
                    .Select(x => x.GetViewModel)
                    .ToList();
            }
            else if (model.ClientId.HasValue)
            {
                return context.Orders
                    .Include(x => x.Products)
                    .ThenInclude(x => x.Product)
                    .Include(x => x.Client)
                    .Where(x => x.ClientId == model.ClientId)
                    .Select(x => x.GetViewModel)
                    .ToList();
            }
            else if (model.Date.HasValue)
            {
                return context.Orders
                    .Include(x => x.Products)
                    .ThenInclude(x => x.Product)
                    .Include(x => x.Client)
                    .Where(x => x.Date == model.Date)
                    .Select(x => x.GetViewModel)
                    .ToList();
            }
            else
            {
                return new();
            }
        }
        public OrderViewModel? GetElement(OrderSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return null;
            }

            using var context = new RestaurantDatabase();
            return context.Orders
                .Include(x => x.Client)
             .Include(x => x.Products)
             .ThenInclude(x => x.Product)
             .FirstOrDefault(x => model.Id.HasValue && x.Id == model.Id)?.GetViewModel;
        }
        public OrderViewModel? Insert(OrderBindingModel model)
        {
            using var context = new RestaurantDatabase();
            var newOrder = Order.Create(context, model);
            if (newOrder == null)
            {
                return null;
            }
            context.Orders.Add(newOrder);
            context.SaveChanges();
            return newOrder.GetViewModel;
        }
        public OrderViewModel? Update(OrderBindingModel model)
        {
            using var context = new RestaurantDatabase();
            var element = context.Orders
                .Include(x => x.Client)
                .Include(x => x.Products)
                .ThenInclude(x => x.Product)
                .FirstOrDefault(x => x.Id == model.Id);
            if (element == null)
            {
                return null;
            }
            element.Update(model);
            context.SaveChanges();
            return GetElement(new OrderSearchModel { Id = element.Id });
        }
        public OrderViewModel? Delete(OrderBindingModel model)
        {
            using var context = new RestaurantDatabase();
            var element = context.Orders
            .Include(x => x.Client)
            .Include(x => x.Products)
            .ThenInclude(x => x.Product)
            .FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null)
            {
                context.Orders.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }

        public string DiffGetTest(int count)
        {
            using var context = new RestaurantDatabase();
            Stopwatch stopwatch = new();
            stopwatch.Start();
            var list = context.Orders
                .Include(x => x.Client)
                .Join(context.Clients,
                order => order.ClientId,
                client => client.Id,
                (order, client) => new { Order = order, Client = client })
                .Select(order => new
                {
                    Order = order.Order.GetViewModel,
                    Client = order.Client.GetViewModel,
                })
                .Take(count)
                .ToList();
            stopwatch.Stop();
            return stopwatch.ElapsedMilliseconds.ToString();
        }

        public string GetTest(int count)
        {
            using var context = new RestaurantDatabase();
            Stopwatch stopwatch = new();
            stopwatch.Start();
            var list = context.Orders
                .Include(x => x.Client)
                .Take(count)
                .Select(x => x.GetViewModel)
                .ToList();
            stopwatch.Stop();
            return stopwatch.ElapsedMilliseconds.ToString();
        }

        public string SetTest(int count)
        {
            Random rnd = new Random();
            using var context = new RestaurantDatabase();
            var listClients = context.Clients.Select(x => x.Id).ToList();
            if (listClients.Count < 1)
            {
                throw new Exception("Недостаточно для генерации!");
            }
            for (int i = 0; i < count; ++i)
            {
                context.Orders.Add(Order.Create(context, new OrderBindingModel
                {
                    Id = 0,
                    Date = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Utc),
                    Price = rnd.NextDouble(),
                    ClientId = listClients[rnd.Next(listClients.Count)],
                }));
            }
            Stopwatch stopwatch = new();
            stopwatch.Start();
            context.SaveChanges();
            stopwatch.Stop();
            return stopwatch.ElapsedMilliseconds.ToString();
        }

        public bool ClearList()
        {
            try
            {
                using var context = new RestaurantDatabase();
                var tableName = context.Model.FindEntityType(typeof(Order)).GetTableName();
                context.Database.ExecuteSqlRaw($"DELETE FROM \"{tableName}\"");
            }
            catch (Exception)
            {
                return false;
            }
            return true;
        }
    }
}