using HospitalContracts.BindingModels;
using HospitalContracts.ViewModels;
using HospitalDataModels.Models;
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 HospitalDatabaseImplement.Models
{
    /// <summary>
    /// Сущность "Процедура"
    /// </summary>
    public class Procedure : IProcedureModel
    {
        /// <summary>
        /// Идентификатор
        /// </summary>
        public int Id { get; private set; }

        /// <summary>
        /// Название процедуры
        /// </summary>
        [Required]
        [MaxLength(30)]
        public string Name { get; private set; } = string.Empty;

        /// <summary>
        /// Описание процедуры
        /// </summary>
        [MaxLength(100)]
        public string? Description { get; private set; }

        /// <summary>
        /// Связь с таблицей связи для сущностей "Процедура" и "Лекарство"
        /// </summary>
        [ForeignKey("ProcedureId")]
        public virtual List<ProcedureMedicine> Medicines { get; set; } = new();

        /// <summary>
        /// Список лекарств для процедуры
        /// </summary>
        private Dictionary<int, IMedicineModel>? _procedureMedicines = null;

        /// <summary>
        /// Список лекарств для процедуры
        /// </summary>
        [NotMapped]
        public Dictionary<int, IMedicineModel> ProcedureMedicines
        {
            get
            {
                if (_procedureMedicines == null)
                {
                    _procedureMedicines = Medicines
                        .ToDictionary(recPM => recPM.MedicineId, recPM => (recPM.Medicine as IMedicineModel));
                }
                return _procedureMedicines;
            }
        }

        /// <summary>
        /// Создать сущность
        /// </summary>
        /// <param name="context"></param>
        /// <param name="model"></param>
        /// <returns></returns>
        public static Procedure? Create(HospitalDatabase context, ProcedureBindingModel model)
        {
            if (model == null)
            {
                return null;
            }

            return new Procedure()
            {
                Id = model.Id,
                Name = model.Name,
                Description = model.Description,
                Medicines = model.ProcedureMedicines.Select(x => new ProcedureMedicine
                {
                    Medicine = context.Medicines.First(y => y.Id == x.Key)
                }).ToList()
            };
        }

        /// <summary>
        /// Изменить сущность
        /// </summary>
        /// <param name="model"></param>
        public void Update(ProcedureBindingModel model)
        {
            if (model == null)
            {
                return;
            }

            Name = model.Name;
            Description = model.Description;
        }

        /// <summary>
        /// Получить модель представления
        /// </summary>
        public ProcedureViewModel GetViewModel => new()
        {
            Id = Id,
            Name = Name,
            Description = Description,
            ProcedureMedicines = ProcedureMedicines
        };

        /// <summary>
        /// Обновить связи с лекарствами
        /// </summary>
        /// <param name="context"></param>
        /// <param name="model"></param>
        public void UpdateMedicines(HospitalDatabase context, ProcedureBindingModel model)
        {
            var procedureMedicines = context.ProcedureMedicines.Where(rec => rec.ProcedureId == model.Id).ToList();
            if (procedureMedicines != null && procedureMedicines.Count > 0)
            {
                // Удаление лекарств, не относящихся к процедуре
                context.ProcedureMedicines.RemoveRange(procedureMedicines.Where(rec => !model.ProcedureMedicines.ContainsKey(rec.MedicineId)));
                context.SaveChanges();
            }

            var procedure = context.Procedures.First(x => x.Id == Id);
            foreach (var pm in model.ProcedureMedicines)
            {
                context.ProcedureMedicines.Add(new ProcedureMedicine
                {
                    Procedure = procedure,
                    Medicine = context.Medicines.First(x => x.Id == pm.Key)
                });
                context.SaveChanges();
            }
            _procedureMedicines = null;
        }
    }
}