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 "Рецепт"
    /// </summary>
    public class Recipe : IRecipeModel
    {
        /// <summary>
        /// Идентификатор
        /// </summary>
        public int Id { get; private set; }

        /// <summary>
        /// Дата выписки рецепта
        /// </summary>
        [Required]
        public DateTime IssueDate { get; private set; } = DateTime.Now;

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

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

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

        /// <summary>
        /// Список лекарств в рецепте
        /// </summary>
        private Dictionary<int, IMedicineModel>? _recipeMedicines = null;

        /// <summary>
        /// Список лекарств в рецепте
        /// </summary>
        [NotMapped]
        public Dictionary<int, IMedicineModel> RecipeMedicines
        {
            get
            {
                if (_recipeMedicines == null)
                {
                    _recipeMedicines = Medicines
                        .ToDictionary(recRM => recRM.MedicineId, recRM => (recRM.Medicine as IMedicineModel));
                }
                return _recipeMedicines;
            }
        }

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

            return new Recipe()
            {
                Id = model.Id,
                IssueDate = model.IssueDate,
                DoctorId = model.DoctorId,
                Doctor = context.Doctors
                    .First(x =>  x.Id == model.DoctorId),
                Medicines = model.RecipeMedicines.Select(x => new RecipeMedicine
                {
                    Medicine = context.Medicines.First(y => y.Id == x.Key)
                }).ToList()
            };
        }

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

            IssueDate = model.IssueDate;
        }

        /// <summary>
        /// Получить модель представления
        /// </summary>
        public RecipeViewModel GetViewModel => new()
        {
            Id = Id,
            IssueDate = IssueDate,
            DoctorId = DoctorId,
            DoctorFullName = Doctor.FullName,
            RecipeMedicines = RecipeMedicines
        };

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

            var recipe = context.Recipes.First(x => x.Id == Id);
            foreach (var rm in model.RecipeMedicines)
            {
                context.RecipeMedicines.Add(new RecipeMedicine
                {
                    Recipe = recipe,
                    Medicine = context.Medicines.First(x => x.Id == rm.Key)
                });
                context.SaveChanges();
            }
            _recipeMedicines = null;
        }
    }
}