using Contracts.BindingModels;
using Contracts.SearchModels;
using Contracts.StorageContracts;
using Contracts.ViewModels;
using DataBaseImplements.Models;

namespace DataBaseImplements.Implements
{
    public class CityStorage : ICityStorage
    {
        public CityViewModel? Delete(CityBindingModel model)
        {
            using var context = new DataBase();
            var element = context.Cities.FirstOrDefault(x => x.Id == model.Id);
            if (element == null)
            {
                return null;
            }
            context.Cities.Remove(element);
            context.SaveChanges();
            return element.GetViewModel;
        }

        public CityViewModel? GetElement(CitySearchModel model)
        {
            using var context = new DataBase();
            if(model.Id == null)
            {
                return null;
            }
            return context.Cities.FirstOrDefault(x => x.Id != model.Id)?.GetViewModel;
        }

        public List<CityViewModel> GetFilteredList(CitySearchModel model)
        {
            var list = GetFullList();
            if(list == null)
            {
                return null;
            }
            if (model.Id.HasValue)
            {
                list = list.Where(x => x.Id == model.Id).ToList();
            }
            return list;
        }

        public List<CityViewModel> GetFullList()
        {
            using var context = new DataBase();
            return context.Cities.Select(x => x.GetViewModel).ToList();
        }

        public CityViewModel? Insert(CityBindingModel model)
        {
            using var context = new DataBase();
            var element = City.Create(model);
            if(element == null)
            {
                return null;
            }
            context.Cities.Add(element);
            context.SaveChanges();
            return element.GetViewModel;
        }

        public CityViewModel? Update(CityBindingModel model)
        {
            using var context = new DataBase();
            using var transaction = context.Database.BeginTransaction();
            try
            {
                var element = context.Cities.FirstOrDefault(x => x.Id == model.Id);
                if (element == null)
                {
                    return null;
                }
                element.Update(model);
                context.SaveChanges();
                transaction.Commit();
                return element.GetViewModel;
            }
            catch (Exception)
            {
                transaction.Rollback();
                throw;
            }
        }
    }
}