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 "Пациент"
    /// </summary>
    public class Patient : IPatientModel
    {
        /// <summary>
        /// Идентификатор
        /// </summary>
        public int Id { get; private set; }

        /// <summary>
        /// ФИО пациента
        /// </summary>
        [Required]
        [MaxLength(100)]
        public string FullName { get; private set; } = string.Empty;

        /// <summary>
        /// Дата рождения пациента
        /// </summary>
        [Required]
        public DateTime BirthDate { get; private set; }

        /// <summary>
        /// Номер телефона пациента
        /// </summary>
        [Required]
        [MaxLength(16)]
        public string Phone { get; private set; } = string.Empty;

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

        /// <summary>
        /// Лечащий врач
        /// </summary>
        public virtual Doctor Doctor { get; private set; } = new();

        /// <summary>
        /// Связь с таблицей связи для сущностей "Пациент" и "Рецепт"
        /// </summary>
        [ForeignKey("PatientId")]
        public virtual List<PatientRecipe> Recipes { get; set; } = new();

        /// <summary>
        /// Список рецептов пациента
        /// </summary>
        private Dictionary<int, IRecipeModel>? _patientRecipes = null;

        /// <summary>
        /// Список рецептов пациента
        /// </summary>
        [NotMapped]
        public Dictionary<int, IRecipeModel> PatientRecipes
        {
            get
            {
                if (_patientRecipes == null)
                {
                    _patientRecipes = Recipes
                        .ToDictionary(recPR => recPR.RecipeId, recPR => (recPR.Recipe as IRecipeModel));
                }
                return _patientRecipes;
            }
        }

        /// <summary>
        /// Связь с таблицей связи для сущностей "Пациент" и "Процедура"
        /// </summary>
        [ForeignKey("PatientId")]
        public virtual List<PatientProcedure> Procedures { get; set; } = new();

        /// <summary>
        /// Список процедур пациента
        /// </summary>
        private Dictionary<int, IProcedureModel>? _patientProcedures = null;

        /// <summary>
        /// Список процедур пациента
        /// </summary>
        [NotMapped]
        public Dictionary<int, IProcedureModel> PatientProcedures
        {
            get
            {
                if (_patientProcedures == null)
                {
                    _patientProcedures = Procedures
                        .ToDictionary(recPP => recPP.ProcedureId, recPP => (recPP.Procedure as IProcedureModel));
                }
                return _patientProcedures;
            }
        }

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

            return new Patient()
            {
                Id = model.Id,
                FullName = model.FullName,
                BirthDate = model.BirthDate,
                Phone = model.Phone,
                DoctorId = model.DoctorId,
                Doctor = context.Doctors
                    .First(x => x.Id == model.DoctorId),
                Recipes = model.PatientRecipes.Select(x => new PatientRecipe
                {
                    Recipe = context.Recipes.First(y => y.Id == x.Key)
                }).ToList(),
                Procedures = model.PatientProcedures.Select(x => new PatientProcedure
                {
                    Procedure = context.Procedures.First(y => y.Id == x.Key)
                }).ToList()
            };
        }

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

            FullName = model.FullName;
            BirthDate = model.BirthDate;
            Phone = model.Phone;
        }

        /// <summary>
        /// Получить модель представления
        /// </summary>
        public PatientViewModel GetViewModel => new()
        {
            Id = Id,
            FullName = FullName,
            BirthDate = BirthDate,
            Phone = Phone,
            DoctorId = DoctorId,
            DoctorFullName = Doctor.FullName,
            PatientRecipes = PatientRecipes,
            PatientProcedures = PatientProcedures
        };

        /// <summary>
        /// Обновить связи с рецептами
        /// </summary>
        /// <param name="context"></param>
        /// <param name="model"></param>
        public void UpdateRecipes(HospitalDatabase context, PatientBindingModel model)
        {
            var patientRecipes = context.PatientRecipes.Where(rec => rec.PatientId == model.Id).ToList();
            if (patientRecipes != null && patientRecipes.Count > 0)
            {
                // Удаление рецептов, не относящихся к пациенту
                context.PatientRecipes.RemoveRange(patientRecipes.Where(rec => !model.PatientRecipes.ContainsKey(rec.RecipeId)));
                context.SaveChanges();          
            }

            var patient = context.Patients.First(x => x.Id == Id);
            foreach (var pr in model.PatientRecipes)
            {
                context.PatientRecipes.Add(new PatientRecipe
                {
                    Patient = patient,
                    Recipe = context.Recipes.First(x => x.Id == pr.Key)
                });
                context.SaveChanges();
            }
            _patientRecipes = null;
        }

        /// <summary>
        /// Обновить связи с процедурами
        /// </summary>
        /// <param name="context"></param>
        /// <param name="model"></param>
        public void UpdateProcedures(HospitalDatabase context, PatientBindingModel model)
        {
            var patientProcedures = context.PatientProcedures.Where(rec => rec.PatientId == model.Id).ToList();
            if (patientProcedures != null && patientProcedures.Count > 0)
            {
                // Удаление процедур, не относящихся к пациенту
                context.PatientProcedures.RemoveRange(patientProcedures.Where(rec => !model.PatientProcedures.ContainsKey(rec.ProcedureId)));
                context.SaveChanges();
            }

            var patient = context.Patients.First(x => x.Id == Id);
            foreach (var pp in model.PatientProcedures)
            {
                context.PatientProcedures.Add(new PatientProcedure
                {
                    Patient = patient,
                    Procedure = context.Procedures.First(x => x.Id == pp.Key)
                });
                context.SaveChanges();
            }
            _patientProcedures = null;
        }
    }
}