using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TravelCompanyContracts.BindingModels;
using TravelCompanyContracts.SearchModels;
using TravelCompanyContracts.StoragesContracts;
using TravelCompanyContracts.ViewModels;
using TravelCompanyFileImplement.Models;

namespace TravelCompanyFileImplement.Implements
{
    public class TravelStorage : ITravelStorage
    {
        private readonly DataFileSingleton _source;
        public TravelStorage()
        {
            _source = DataFileSingleton.GetInstance();
        }
        public List<TravelViewModel> GetFullList()
        {
            return _source.Travels
            .Select(x => x.GetViewModel)
            .ToList();
        }
        public List<TravelViewModel> GetFilteredList(TravelSearchModel model)
        {
            if (string.IsNullOrEmpty(model.TravelName))
            {
                return new();
            }
            return _source.Travels
            .Where(x => x.TravelName.Contains(model.TravelName))
            .Select(x => x.GetViewModel)
            .ToList();
        }
        public TravelViewModel? GetElement(TravelSearchModel model)
        {
            if (string.IsNullOrEmpty(model.TravelName) && !model.Id.HasValue)
            {
                return null;
            }
            return _source.Travels
            .FirstOrDefault(x => (x.TravelName == model.TravelName && !string.IsNullOrEmpty(model.TravelName) ) ||
            (model.Id.HasValue && x.Id == model.Id))
            ?.GetViewModel;

        }
        public TravelViewModel? Insert(TravelBindingModel model)
        {
            model.Id = _source.Travels.Count > 0 ? _source.Travels.Max(x => x.Id) + 1 : 1;
            var newTravel = Travel.Create(model);
            if (newTravel == null)
            {
                return null;
            }
            _source.Travels.Add(newTravel);
            _source.SaveTravels();
            return newTravel.GetViewModel;
        }
        public TravelViewModel? Update(TravelBindingModel model)
        {
            var travel = _source.Travels.FirstOrDefault(x => x.Id == model.Id);
            if (travel == null)
            {
                return null;
            }
            travel.Update(model);
            _source.SaveTravels();
            return travel.GetViewModel;
        }
        public TravelViewModel? Delete(TravelBindingModel model)
        {
            var element = _source.Travels.FirstOrDefault(x => x.Id == model.Id);
            if (element != null)
            {
                _source.Travels.Remove(element);
                _source.SaveTravels();
                return element.GetViewModel;
            }
            return null;
        }
    }
}