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;
using System.Xml.Linq;

namespace HospitalDatabaseImplement.Models
{
    public class Procedure : IProcedureModel
    {
        public int Id { get; private set; }

        [Required]
        [MaxLength(50)]
        public string Name { get; private set; } = string.Empty;

        private Dictionary<int, IMedicineModel>? _procedureMedicines = null;

        [NotMapped]
        public Dictionary<int, IMedicineModel> ProcedureMedicines { get
            {
                if (_procedureMedicines == null)
                {
                    _procedureMedicines = Medicines.ToDictionary(rec => rec.MedicineId, rec =>
                   rec.Medicine as IMedicineModel);
                }
                return _procedureMedicines;
            }
        }

        [ForeignKey("ProcedureId")]
        public virtual List<ProcedureMedicine> Medicines { get; set; } = new();

        [ForeignKey("ProcedureId")]
        public virtual List<TreatmentProcedure> Treatments { get; set; } = new();

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

        public static Procedure? Create(XElement element)
        {
            if (element == null)
            {
                return null;
            }
            return new Procedure()
            {
                Name = element.Element("Name")!.Value, 
                // при чтении из файла мы не можем загрузить сведения о лекарствах в процедуре (Medicines),
                // так как на данном этапе нет созданных записей о лекарствах
                // привязка будет осуществляться позднее - на клиенте будет данная возможность на дополнительной формочке
                // Medicines = new()
            };
        }

        public void Update(ProcedureBindingModel model)
        {
            Name = model.Name;
        }

        public ProcedureViewModel GetViewModel => new()
        {
            Id = Id,
            Name = Name,
            ProcedureMedicines = ProcedureMedicines
        };

        public void UpdateMedicines(HospitalDatabase context, ProcedureBindingModel model)
        {
            var procedureMedicines = context.ProcedureMedicines.Where(rec => rec.ProcedureId == model.Id).ToList();
            if (procedureMedicines != null && procedureMedicines.Count > 0)
            { 
                context.ProcedureMedicines.RemoveRange(procedureMedicines.Where(rec
               => !model.ProcedureMedicines.ContainsKey(rec.MedicineId)));
                context.SaveChanges();
            }
            var procedure = context.Procedures.First(x => x.Id == Id);
            var existingMedicineIds = procedureMedicines?.Select(x => x.MedicineId).ToList();
            foreach (var pm in model.ProcedureMedicines)
            {
                if (existingMedicineIds != null && !existingMedicineIds.Contains(pm.Key))
                {
                    context.ProcedureMedicines.Add(new ProcedureMedicine
                    {
                        Procedure = procedure,
                        Medicine = context.Medicines.First(x => x.Id == pm.Key),
                    });
                }             
            }
            context.SaveChanges();
            _procedureMedicines = null;
        }
    }
}