using Microsoft.EntityFrameworkCore;
using RouteGuideContracts.BindingModels;
using RouteGuideContracts.SearchModels;
using RouteGuideContracts.StoragesModels;
using RouteGuideContracts.ViewModels;
using RouteGuideDatabaseImplements.Models;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RouteGuideDatabaseImplements.Implements
{
    public class RouteStorage : IRouteStorage
    {
        public RouteViewModel? Delete(RouteBindingModel model)
        {
            using var context = new RouteGuideDatabase();

            var element = context.Routes.Include(x => x.Stops).FirstOrDefault(rec => rec.Id == model.Id);

            if (element != null)
            {
                context.Routes.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }

            return null;
        }

        public RouteViewModel? GetElement(RouteSearchModel model)
        {
            if (string.IsNullOrEmpty(model.Name) && !model.Id.HasValue)
            {
                return null;
            }

            using var context = new RouteGuideDatabase();

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

        public List<RouteViewModel> GetFilteredList(RouteSearchModel model)
        {
            if (string.IsNullOrEmpty(model.Name))
            {
                return new();
            }

            using var context = new RouteGuideDatabase();

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

        public List<RouteViewModel> GetFullList()
        {
            using var context = new RouteGuideDatabase();

            return context.Routes.Include(x => x.Stops).ThenInclude(x => x.Stop).ToList().Select(x => x.GetViewModel).ToList();
        }

        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;
        }

        public RouteViewModel? Update(RouteBindingModel model)
        {
            using var context = new RouteGuideDatabase();

            using var transaction = context.Database.BeginTransaction();

            try
            {
                var route = context.Routes.FirstOrDefault(rec => rec.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;
            }
        }
    }
}