using Microsoft.EntityFrameworkCore;
using RouteGuideContracts.BindingModels;
using RouteGuideContracts.SearchModels;
using RouteGuideContracts.StoragesContracts;
using RouteGuideContracts.ViewModels;
using RouteGuideDatabaseImplement.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RouteGuideDatabaseImplement.Implements
{
    /// <summary>
    /// Хранилище для сущности "Маршрут"
    /// </summary>
    public class RouteStorage : IRouteStorage
    {
        /// <summary>
        /// Получение полного списка
        /// </summary>
        /// <returns></returns>
        public List<RouteViewModel> GetFullList()
        {
            using var context = new RouteGuideDatabase();
            return context.Routes
                .Include(x => x.Transport)
                .Include(x => x.Stops)
                .ThenInclude(x => x.Stop)
                .ToList()
                .Select(x => x.GetViewModel)
                .ToList();
        }

        /// <summary>
        /// Получение фильтрованного списка
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public List<RouteViewModel> GetFilteredList(RouteSearchModel model)
        {
            if (string.IsNullOrEmpty(model.Name))
            {
                return new();
            }

            using var context = new RouteGuideDatabase();
            return context.Routes
                .Include(x => x.Transport)
                .Include(x => x.Stops)
                .ThenInclude(x => x.Stop)
                .ToList()
                .Where(x => x.Name.Contains(model.Name))
                .Select(x => x.GetViewModel)
                .ToList();
        }

        /// <summary>
        /// Получить список из заданного количества элементов
        /// </summary>
        /// <param name="count"></param>
        /// <returns></returns>
        public List<RouteViewModel> GetList(int count)
        {
            if (count <= 0)
            {
                return new();
            }

            using var context = new RouteGuideDatabase();
            return context.Routes
                .Include(x => x.Transport)
                .Include(x => x.Stops)
                .ThenInclude(x => x.Stop)
                .ToList()
                .Take(count)
                .Select(x => x.GetViewModel)
                .ToList();
        }

        /// <summary>
        /// Получение элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public RouteViewModel? GetElement(RouteSearchModel model)
        {
            if (!model.Id.HasValue && string.IsNullOrEmpty(model.Name))
            {
                return null;
            }

            using var context = new RouteGuideDatabase();
            return context.Routes
                .Include(x => x.Transport)
                .Include(x => x.Stops)
                .ThenInclude(x => x.Stop)
                .FirstOrDefault(x => (!string.IsNullOrEmpty(model.Name) && x.Name.Contains(model.Name)) || (model.Id.HasValue && x.Id == model.Id))
                ?.GetViewModel;
        }

        /// <summary>
        /// Добавление элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public RouteViewModel? Insert(RouteBindingModel model)
        {
            using var context = new RouteGuideDatabase();
            var newRoute = Route.Create(context, model);
            if (newRoute == null)
            {
                return null;
            }

            context.Routes.Add(newRoute);
            context.SaveChanges();
            return newRoute.GetViewModel;
        }

        /// <summary>
        /// Редактирование элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public RouteViewModel? Update(RouteBindingModel model)
        {
            using var context = new RouteGuideDatabase();
            using var transaction = context.Database.BeginTransaction();
            try
            {
                var route = context.Routes.FirstOrDefault(x => x.Id == model.Id);
                if (route == null)
                {
                    return null;
                }

                route.Update(model);
                context.SaveChanges();
                route.UpdateStops(context, model);
                transaction.Commit();
                return route.GetViewModel;
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        /// <summary>
        /// Удаление элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public RouteViewModel? Delete(RouteBindingModel model)
        {
            using var context = new RouteGuideDatabase();
            var route = context.Routes
                .Include(x => x.Stops)
                .FirstOrDefault(rec => rec.Id == model.Id);
            if (route == null)
            {
                return null;
            }

            context.Routes.Remove(route);
            context.SaveChanges();
            return route.GetViewModel;
        }

        /// <summary>
        /// Удаление записи
        /// </summary>
        /// <returns></returns>
        public RouteViewModel? Delete()
        {
            using var context = new RouteGuideDatabase();
            if (!context.Routes.Any())
            {
                return null;
            }

            var element = context.Routes.First();
            context.Routes.Remove(element);
            context.SaveChanges();
            return element.GetViewModel;
        }

        /// <summary>
        /// Удаление всех элементов
        /// </summary>
        /// <returns></returns>
        public int Clear()
        {
            using var context = new RouteGuideDatabase();
            int count = context.Routes.Count();
            if (count <= 0)
            {
                return 0;
            }

            context.Routes.RemoveRange(context.Routes);
            context.SaveChanges();
            return count;
        }
    }
}