using RouteGuideContracts.BindingModels;
using RouteGuideContracts.ViewModels;
using RouteGuideDataModels.Models;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Threading.Tasks;

namespace RouteGuideDatabaseImplement.Models
{
    /// <summary>
    /// Сущность "Маршрут"
    /// </summary>
    public class Route : IRouteModel
    {
        /// <summary>
        /// Идентификатор
        /// </summary>
        public int Id { get; private set; }

        /// <summary>
        /// Название маршрута
        /// </summary>
        [Required]
        public string Name { get; private set; } = string.Empty;

        /// <summary>
        /// Идентификатор транспорта
        /// </summary>
        [ForeignKey("TransportId")]
        public int TransportId { get; private set; }

        /// <summary>
        /// Сущность "Транспорт"
        /// </summary>
        public virtual Transport Transport { get; private set; } = new();

        /// <summary>
        /// Коллекция остановок маршрута
        /// </summary>
        private Dictionary<int, (IStopModel, int)>? _routeStops = null;

        /// <summary>
        /// Коллекция остановок маршрута
        /// </summary>
        [NotMapped]
        public Dictionary<int, (IStopModel, int)> RouteStops
        {
            get
            {
                if (_routeStops == null)
                {
                    _routeStops = Stops
                        .ToDictionary(recRS => recRS.StopId, recRS => (recRS.Stop as IStopModel, recRS.Number));
                }
                return _routeStops;
            }
        }

        /// <summary>
        /// Связь с классом связи маршрутов и остановок
        /// </summary>
        [ForeignKey("RouteId")]
        public virtual List<RouteStop> Stops { get; set; } = new();

        /// <summary>
        /// Созданме модели
        /// </summary>
        /// <param name="context"></param>
        /// <param name="model"></param>
        /// <returns></returns>
        public static Route Create(RouteGuideDatabase context, RouteBindingModel model)
        {
            return new Route()
            {
                Id = model.Id,
                Name = model.Name,
                TransportId = model.TransportId,
                Transport = context.Transport
                    .FirstOrDefault(x => x.Id == model.TransportId),
                Stops = model.RouteStops.Select(x => new RouteStop
                {
                    Stop = context.Stops.First(y => y.Id == x.Key),
                    Number = x.Value.Item2
                }).ToList()
            };
        }

        /// <summary>
        /// Изменение модели
        /// </summary>
        /// <param name="model"></param>
        public void Update(RouteBindingModel model)
        {
            if (model == null)
            {
                return;
            }

            Name = model.Name;
        }

        /// <summary>
        /// Получение модели
        /// </summary>
        public RouteViewModel GetViewModel => new()
        {
            Id = Id,
            Name = Name,
            TransportId = TransportId,
            RouteStops = RouteStops
        };

        /// <summary>
        /// Обновление списка связей
        /// </summary>
        /// <param name="context"></param>
        /// <param name="model"></param>
        public void UpdateStops(RouteGuideDatabase context, RouteBindingModel model)
        {
            var routeStops = context.RouteStops.Where(rec => rec.RouteId == model.Id).ToList();
            if (routeStops != null && routeStops.Count > 0)
            {
                // Удаление остановок, которых нет в маршруте
                context.RouteStops.RemoveRange(routeStops.Where(rec => !model.RouteStops.ContainsKey(rec.StopId)));
                context.SaveChanges();
                // Обновление количества у существующих записей
                foreach (var updateStop in routeStops)
                {
                    updateStop.Number = model.RouteStops[updateStop.StopId].Item2;
                    model.RouteStops.Remove(updateStop.StopId);
                }
                context.SaveChanges();
            }

            var route = context.Routes.First(x => x.Id == Id);
            foreach (var rs in model.RouteStops)
            {
                context.RouteStops.Add(new RouteStop
                {
                    Route = route,
                    Stop = context.Stops.First(x => x.Id == rs.Key),
                    Number = rs.Value.Item2
                });
                context.SaveChanges();
            }
            _routeStops = null;
        }
    }
}