using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using VeterinaryClinicContracts.BindingModels;
using VeterinaryClinicContracts.BusinessLogicsContracts;
using VeterinaryClinicContracts.SearchModels;
using VeterinaryClinicContracts.StoragesContracts;
using VeterinaryClinicContracts.ViewModels;
using Microsoft.Extensions.Logging;

namespace VeterinaryClinicBusinessLogics.BusinessLogics
{
    public class MedicationLogic : IMedicationLogic
    {
        private readonly ILogger _logger;
        private readonly IMedicationStorage _medicationStorage;

        public MedicationLogic(ILogger<MedicationLogic> logger, IMedicationStorage medicationStorage)
        {
            _logger = logger;
            _medicationStorage = medicationStorage;
        }

        public bool Create(MedicationBindingModel model)
        {
            CheckModel(model);
            _logger.LogInformation("Create. Medication.Id: {Id}", model.Id);

            if (_medicationStorage.Insert(model) == null)
            {
                _logger.LogWarning("Insert operation failed");
                return false;
            }
            return true;
        }

        public bool Delete(MedicationBindingModel model)
        {
            CheckModel(model, false);
            _logger.LogInformation("Delete. Medication.Id: {Id}", model.Id);

            if (_medicationStorage.Delete(model) == null)
            {
                _logger.LogWarning("Delete operation failed");
                return false;
            }
            return true;
        }

        public MedicationViewModel? ReadElement(MedicationSearchModel model)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }

            _logger.LogInformation("ReadElement. Medication.Id: {Id}.", model?.Id);

            var element = _medicationStorage.GetElement(model!);
            if (element == null)
            {
                _logger.LogWarning("ReadElement. Element not found");
                return null;
            }

            _logger.LogInformation("ReadElement. Find Medication.Id: {Id}", element?.Id);
            return element;
        }

        public List<MedicationViewModel>? ReadList(MedicationSearchModel? model)
        {
            _logger.LogInformation("ReadList. Medication.Id: {Id}. Name: {Name}", model?.Id, model?.Name);

            var list = model == null ? _medicationStorage.GetFullList() : _medicationStorage.GetFilteredList(model);
            if (list == null)
            {
                _logger.LogWarning("ReadList. Returned null list");
                return null;
            }

            _logger.LogInformation("ReadList. Count: {Count}", list.Count);
            return list;
        }

        public bool Update(MedicationBindingModel model)
        {
            CheckModel(model);
            _logger.LogInformation("Update. Medication.Id: {Id}", model.Id);

            if (_medicationStorage.Update(model) == null)
            {
                _logger.LogWarning("Update operation failed");
                return false;
            }
            return true;
        }

        private void CheckModel(MedicationBindingModel model, bool withParams = true)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            if (!withParams)
            {
                return;
            }
            if (string.IsNullOrEmpty(model.Name))
            {
                throw new ArgumentNullException("Не указано название медикамента", nameof(model.Name));
            }
            if (string.IsNullOrEmpty(model.Description))
            {
                throw new ArgumentNullException("Не указано описание медикамента", nameof(model.Description));
            }

            _logger.LogInformation("CheckModel. Medication.Id: {Id}", model.Id);

            var element = _medicationStorage.GetElement(new MedicationSearchModel
            {
                Name = model.Name
            });
            if (element != null && !element.Id.Equals(model.Id))
            {
                throw new InvalidOperationException("Медикамент с данным названием уже есть");
            }
        }
    }
}