using Microsoft.EntityFrameworkCore;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using TravelAgencyContracts.BindingModels;
using TravelAgencyContracts.ViewModels;
using TravelAgencyDataModels.Models;

namespace TravelAgencyDatabaseImplement.Models
{
    public class Excursion : IExcursionModel
    {
        public int Id { get; set; }

        [Required]
        public string ExcursionName { get; set; } = string.Empty;

        public string ExcursionDescription { get; set; } = string.Empty;

        [Required]
        public double Price { get; set; }

        [Required]
        public int UserId { get; set; }

        [DeleteBehavior(DeleteBehavior.Restrict)]
        public virtual User User { get; set; }

        [Required]
        public int PlaceId { get; set; }

        public virtual Place Place { get; set; }

        private Dictionary<int, ITourModel>? _excursionTours = null;

        [NotMapped]
        public Dictionary<int, ITourModel> ExcursionTours
        {
            get
            {
                if (_excursionTours == null)
                {
                    _excursionTours = Tours
                            .ToDictionary(recPC => recPC.TourId, recPC => recPC.Tour as ITourModel);
                }
                return _excursionTours;
            }
        }

        [ForeignKey("ExcursionId")]
        public virtual List<ExcursionTour> Tours { get; set; } = new();

        public static Excursion? Create(TravelAgencyDatabase context, ExcursionBindingModel? model)
        {
            if (model == null)
            {
                return null;
            }
            return new Excursion()
            {
                Id = model.Id,
                ExcursionName = model.ExcursionName,
                ExcursionDescription = model.ExcursionDescription,
                Price = model.Price,
                UserId = model.UserId,
                PlaceId = model.PlaceId,
                Place = context.Places
                    .First(x => x.Id == model.PlaceId),
                Tours = model.ExcursionTours.Select(x => new ExcursionTour
                {
                    Tour = context.Tours.First(y => y.Id == x.Key)
                }).ToList()
            };
        }
        public void Update(ExcursionBindingModel? model)
        {
            if (model == null)
            {
                return;
            }
            using var context = new TravelAgencyDatabase();
            ExcursionName = model.ExcursionName;
            ExcursionDescription = model.ExcursionDescription;
            Price = model.Price;
            PlaceId = model.PlaceId;
            Place = context.Places
                    .First(x => x.Id == model.PlaceId);
        }

        public ExcursionViewModel GetViewModel => new()
        {
            Id = Id,
            ExcursionName = ExcursionName,
            ExcursionDescription = ExcursionDescription,
            Price = Price,
            UserId = UserId,
            PlaceId = PlaceId,
            PlaceName = Place?.PlaceName,
            ExcursionTours = ExcursionTours
        };

        public void UpdateTours(TravelAgencyDatabase context, ExcursionBindingModel model)
        {
            var excursionTours = context.ExcursionTours.Where(rec => rec.ExcursionId == model.Id).ToList();
            if (excursionTours != null && excursionTours.Count > 0)
            {   // удалили те, которых нет в модели
                context.ExcursionTours.RemoveRange(excursionTours.Where(rec => !model.ExcursionTours.ContainsKey(rec.TourId)));
                context.SaveChanges();
            }
            var excursion = context.Excursions.First(x => x.Id == Id);
            foreach (var et in model.ExcursionTours)
            {
                if (excursionTours!.Any(x => x.TourId == et.Key))
                {
                    continue;
                }
                context.ExcursionTours.Add(new ExcursionTour
                {
                    Excursion = excursion,
                    Tour = context.Tours.First(x => x.Id == et.Key)
                });
                context.SaveChanges();
            }
            _excursionTours = null;
        }
    }
}