using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TravelAgencyContracts.BindingModels;
using TravelAgencyContracts.ViewModels;
using TravelAgencyDataModels.Models;

namespace TravelAgencyDatabaseImplement.Models
{
    public class Trip : ITripModel
    {
        public int Id { get; set; }

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

        [Required]
        public DateTime TripDate { get; set; }

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

        public virtual Guide Guide { get; set; }

        private Dictionary<int, IPlaceModel>? _tripPlaces = null;

        [NotMapped]
        public Dictionary<int, IPlaceModel> TripPlaces
        {
            get
            {
                if (_tripPlaces == null)
                {
                    _tripPlaces = Places
                            .ToDictionary(recPC => recPC.PlaceId, recPC => recPC.Place as IPlaceModel);
                }
                return _tripPlaces;
            }
        }

        [ForeignKey("TripId")]
        public virtual List<TripPlace> Places { get; set; } = new();

        public static Trip? Create(TravelAgencyDatabase context, TripBindingModel? model)
        {
            if (model == null)
            {
                return null;
            }
            return new Trip()
            {
                Id = model.Id,
                TripName = model.TripName,
                TripDate = model.TripDate,
                GuideId = model.GuideId,
                Places = model.TripPlaces.Select(x => new TripPlace
                {
                    Place = context.Places.First(y => y.Id == x.Key)
                }).ToList()
            };
        }
        public void Update(TripBindingModel? model)
        {
            if (model == null)
            {
                return;
            }
            TripName = model.TripName;
            TripDate = model.TripDate;
        }

        public TripViewModel GetViewModel => new()
        {
            Id = Id,
            TripName = TripName,
            TripDate = TripDate,
            GuideId = GuideId,
            TripPlaces = TripPlaces
        };

        public void UpdatePlaces(TravelAgencyDatabase context, TripBindingModel model)
        {
            var tripPlaces = context.TripPlaces.Where(rec => rec.TripId == model.Id).ToList();
            if (tripPlaces != null && tripPlaces.Count > 0)
            {   // удалили те, которых нет в модели
                context.TripPlaces.RemoveRange(tripPlaces.Where(rec => !model.TripPlaces.ContainsKey(rec.PlaceId)));
                context.SaveChanges();
            }
            var trip = context.Trips.First(x => x.Id == Id);
            foreach (var et in model.TripPlaces)
            {
                context.TripPlaces.Add(new TripPlace
                {
                    Trip = trip,
                    Place = context.Places.First(x => x.Id == et.Key)
                });
                context.SaveChanges();
            }
            _tripPlaces = null;
        }
    }
}