Check/MagicCarpetProject/MagicCarpetDatabase/Implementations/AgencyStorageContract.cs

using AutoMapper;
using MagicCarpetContracts.DataModels;
using MagicCarpetContracts.Exceptions;
using MagicCarpetContracts.StoragesContracts;
using MagicCarpetDatabase.Models;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MagicCarpetDatabase.Implementations;

public class AgencyStorageContract : IAgencyStorageContract
{
    private readonly MagicCarpetDbContext _dbContext;
    private readonly Mapper _mapper;

    public AgencyStorageContract(MagicCarpetDbContext dbContext)
    {
        _dbContext = dbContext;
        var config = new MapperConfiguration(cfg =>
        {
            cfg.AddMaps(typeof(TourAgency));
            cfg.AddMaps(typeof(Agency));
        });
        _mapper = new Mapper(config);
    }

    public List<AgencyDataModel> GetList()
    {
        try
        {
            return [.. _dbContext.Agencies.Select(x => _mapper.Map<AgencyDataModel>(x))];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public AgencyDataModel GetElementById(string id)
    {
        try
        {
            return _mapper.Map<AgencyDataModel>(GetAgencyById(id));
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void AddElement(AgencyDataModel agencyDataModel)
    {
        try
        {
            _dbContext.Agencies.Add(_mapper.Map<Agency>(agencyDataModel));
            _dbContext.SaveChanges();
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void UpdElement(AgencyDataModel agencyDataModel)
    {
        try
        {
            var element = GetAgencyById(agencyDataModel.Id) ?? throw new ElementNotFoundException(agencyDataModel.Id);
            _dbContext.Agencies.Update(_mapper.Map(agencyDataModel, element));
            _dbContext.SaveChanges();
        }
        catch (ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void DelElement(string id)
    {
        try
        {
            var element = GetAgencyById(id) ?? throw new ElementNotFoundException(id);
            _dbContext.Agencies.Remove(element);
            _dbContext.SaveChanges();
        }
        catch (ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    //второе требование 
    public bool CheckComponents(SaleDataModel saleDataModel)
    {
        using (var transaction = _dbContext.Database.BeginTransaction())
        {
            var componentTasks = saleDataModel.Tours
                .AsParallel()
                .Select(async saleComponent =>
                {
                    var component = await _dbContext.Tours.FirstOrDefaultAsync(x => x.Id == saleComponent.TourId);
                    var agency = await _dbContext.Agencies.FirstOrDefaultAsync(x => x.TourType == component.TourType && x.Count >= saleComponent.Count);
                    if (agency == null)
                    {
                        transaction.Rollback();
                        return false;
                    }
                    if (agency.Count - saleComponent.Count == 0)
                    {
                        DelElement(agency.Id);
                    }
                    else
                    {
                        agency.Count -= saleComponent.Count;
                        _dbContext.Agencies.Update(agency);
                    }

                    return true;
                })
                .ToList();

            Task.WaitAll(componentTasks.ToArray());
            transaction.Commit();
            _dbContext.SaveChanges();
            return true;
        }
    }

    private Agency? GetAgencyById(string id) => _dbContext.Agencies.FirstOrDefault(x => x.Id == id);
}