using HotelContracts.BindingModels;
using HotelContracts.ViewModels;
using HotelDataModels.Models;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace HotelDataBaseImplement.Models
{
	public class Conference : IConferenceModel
	{
		public int Id { get; private set; }

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

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

        [Required]
        public DateTime StartDate { get; set; } = DateTime.Now;

        public int OrganiserId { get; private set; }

		public virtual Organiser Organiser { get; set; }

		private Dictionary<int, IParticipantModel> _conferenceParticipents = null;

		[ForeignKey("ConferenceId")]
		public virtual List<ConferenceBooking> Bookings { get; set; } = new();

		[ForeignKey("ConferenceId")]
		public virtual List<ConferenceParticipant> Participants { get; set; } = new();

		[NotMapped]
		public Dictionary<int, IParticipantModel> ConferenceParticipants
		{
			get
			{
				if (_conferenceParticipents == null)
				{
					using var context = new HotelDataBase();
					_conferenceParticipents = Participants.ToDictionary(x => x.ParticipantId, x => (context.Participants
														.FirstOrDefault(y => y.Id == x.ParticipantId)! as IParticipantModel));
				}
				return _conferenceParticipents;
			}
		}

		public static Conference Create(HotelDataBase context, ConferenceBindingModel model)
		{
			return new Conference()
			{
				Id = model.Id,
				ConferenceName = model.ConferenceName,
				Subject = model.Subject,
				StartDate = model.StartDate,
				OrganiserId = model.OrganiserId,
				Participants = model.ConferenceParticipants.Select(x => new ConferenceParticipant
				{
					Participant = context.Participants.First(y => y.Id == x.Key),
				}).ToList()
			};
		}

		public void Update(ConferenceBindingModel model)
		{
			ConferenceName = model.ConferenceName;
			Subject = model.Subject;
			StartDate = model.StartDate;
			OrganiserId = model.OrganiserId;
		}

		public ConferenceViewModel GetViewModel => new()
		{
			Id = Id,
			ConferenceName = ConferenceName,
			Subject = Subject,
			StartDate= StartDate,
			OrganiserId = OrganiserId,
			ConferenceParticipants = ConferenceParticipants
		};

		public void UpdateMembers(HotelDataBase context, ConferenceBindingModel model)
		{
			var сonferenceParticipants = context.ConferenceParticipants.Where(rec => rec.ConferenceId == model.Id).ToList();

			if (сonferenceParticipants != null && сonferenceParticipants.Count > 0)
			{
				context.ConferenceParticipants.RemoveRange(сonferenceParticipants.Where(rec => !model.ConferenceParticipants.ContainsKey(rec.ParticipantId)));
				context.SaveChanges();

				foreach (var updateParticipant in сonferenceParticipants)
				{
					model.ConferenceParticipants.Remove(updateParticipant.ParticipantId);
				}
				context.SaveChanges();
			}

			var conference = context.Conferences.First(x => x.Id == Id);
			foreach (var cm in model.ConferenceParticipants)
			{
				context.ConferenceParticipants.Add(new ConferenceParticipant
				{
					Conference = conference,
					Participant = context.Participants.First(x => x.Id == cm.Key),
				});
				context.SaveChanges(); 
			}
			_conferenceParticipents = null;
		}
	}
}