Pibd-21_Semin_D.A._SmallSoftware/SmallSoftwareProject/SmallSoftwareDatabase/Implementations/ManufacturerStorageContract.cs

using AutoMapper;
using Microsoft.EntityFrameworkCore;
using Npgsql;
using SmallSoftwareContracts.DataModels;
using SmallSoftwareContracts.Exceptions;
using SmallSoftwareContracts.StoragesContracts;
using SmallSoftwareDatabase.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SmallSoftwareDatabase.Implementations;
internal class ManufacturerStorageContract : IManufacturerStorageContract
{
    private readonly SmallSoftwareDbContext _dbContext;
    private readonly Mapper _mapper; 
public ManufacturerStorageContract(SmallSoftwareDbContext dbContext)
    {
        _dbContext = dbContext;
        var config = new MapperConfiguration(cfg =>
        {
            cfg.AddMaps(typeof(Manufacturer));
        });
        _mapper = new Mapper(config);
    }
    public List<ManufacturerDataModel> GetList()
    {
        try
        {
            return [.. _dbContext.Manufacturers.Select(x => _mapper.Map<ManufacturerDataModel>(x))];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    public ManufacturerDataModel? GetElementById(string id)
    {
        try
        {
            return
            _mapper.Map<ManufacturerDataModel>(GetManufacturerById(id));
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    public ManufacturerDataModel? GetElementByName(string name)
    {
        try
        {
            return
            _mapper.Map<ManufacturerDataModel>(_dbContext.Manufacturers.FirstOrDefault(x => x.ManufacturerName == name));
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    public ManufacturerDataModel? GetElementByOldName(string name)
    {
        try
        {
            return
            _mapper.Map<ManufacturerDataModel>(_dbContext.Manufacturers.FirstOrDefault(x =>
            x.PrevManufacturerName == name ||
            x.PrevPrevManufacturerName == name));
        } 
        catch (Exception ex)
{
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    public void AddElement(ManufacturerDataModel manufacturerDataModel)
    {
        try
        {
            _dbContext.Manufacturers.Add(_mapper.Map<Manufacturer>(manufacturerDataModel));
            _dbContext.SaveChanges();
        }
        catch (InvalidOperationException ex) when (ex.TargetSite?.Name ==
        "ThrowIdentityConflict")
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("Id",
            manufacturerDataModel.Id);
        }
        catch (DbUpdateException ex) when (ex.InnerException is
        PostgresException { ConstraintName: "IX_Manufacturers_ManufacturerName" })
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("ManufacturerName",
            manufacturerDataModel.ManufacturerName);
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    public void UpdElement(ManufacturerDataModel manufacturerDataModel)
    {
        try
        {
            var element = GetManufacturerById(manufacturerDataModel.Id) ??
            throw new ElementNotFoundException(manufacturerDataModel.Id);
            if (element.ManufacturerName !=
            manufacturerDataModel.ManufacturerName)
            {
                element.PrevPrevManufacturerName =
                element.PrevManufacturerName;
                element.PrevManufacturerName = element.ManufacturerName;
                element.ManufacturerName =
                manufacturerDataModel.ManufacturerName;
            }
            _dbContext.Manufacturers.Update(element);
            _dbContext.SaveChanges();
        }
        catch (ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (DbUpdateException ex) when (ex.InnerException is
        PostgresException { ConstraintName: "IX_Manufacturers_ManufacturerName" })
        {
            _dbContext.ChangeTracker.Clear(); 
        throw new ElementExistsException("ManufacturerName",
        manufacturerDataModel.ManufacturerName);
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    public void DelElement(string id)
    {
        try
        {
            var element = GetManufacturerById(id) ?? throw new
            ElementNotFoundException(id);
            _dbContext.Manufacturers.Remove(element);
            _dbContext.SaveChanges();
        }
        catch (ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }
    private Manufacturer? GetManufacturerById(string id) =>
    _dbContext.Manufacturers.FirstOrDefault(x => x.Id == id);
}