public class BookEntity : IModelIdentifiable<int>
{
    public int Id {get; set;}
    public string Title {get; set;}
    public string Authors {get; set;} // for simplicity
    public DateTimeOffset Created {get; set;}
    public DateTimeOffset Updated {get; set;}
}

public class BookDto
{
    public int Id {get; set;}
    public string Title {get; set;}
    public string Authors {get; set;} 
}

public static class BookFactory
{
    public static BookDto Create(BookEntity entity)
    {
        return new BookDto
        {
            Id = entity.Id,
            Title = entity.Title,
            Authors = entity.Authors;
        };
    }
}

public interface IModelContext
{
    DbSet<BookEntity> Books {get;set;}
}

public MoidelContext: DbContext<ModelContext>, IModelContext
{
    // todo: not mrntioned here constructor, entity mapping and so on
    public DbSet<BookEntity> Books {get; set;}
}

[ApiController]
public class BookController : BasicCrudController<BookDto, BookEntity, int>
{
    public BookController(BookManager manager)
    {
        Manager = manager;  // this is for basic operations
        _manager = manager; // this for extended operations
    }
    
    private BookManager _manager;
}

public class BookManager : EfModelManager<BookEntity, BookDto, int>
{
    public BookManager(ModelContext modelContext, ILoggerFactory loggerFactory) : base(modelContext, BookFactory.Create, loggerFactory)
    {
        _modelContext = modelContext;
    }
    
    public override async Task<OperationResultDto<StationDto>> CreateAsync(StationDto data)
    {
        // todo: implement
    }
    
    public override async Task<OperationResultDto<StationDto>> UpdateAsync(int id, StationDto data)
    {
        // todo: implement
    }
    
    private readonly ModelContext _modelContext;
}

[ApiController]
public class StationController : BasicCrudController<StationDto, StationEntity, int>
{
    public StationController(StationManager manager)
    {
        Manager = manager;  // this is for basic operations
        _manager = manager; // this for extended operations
    }
    
    private StationManager _manager;
}

public class StationManager : EfModelManager<StationEntity, StationDto, int>
{
    public StationManager(ModelContext modelContext, ILoggerFactory loggerFactory) : base(modelContext, StationFactory.Create, loggerFactory)
    {
        _modelContext = modelContext;
    }

    public override async Task<OperationResultDto<StationDto>> CreateAsync(StationDto data)
    {
        try
        {
            StationEntity entity = StationFactory.Create(data);
            await _modelContext.Stations.AddAsync(entity);
            int result = await _modelContext.SaveChangesAsync();
            if (result >= 0)
            {
                return new OperationResultDto<StationDto>(true, (int)HttpStatusCode.Created, null, StationFactory.Create(entity));
            }
            return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, "An unknown error occurred during station creation", null);

            }
        catch (Exception e)
        {
            return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, $"An error occurred during station creation: {e.Message}", null);
        }
    }

    public override async Task<OperationResultDto<StationDto>> UpdateAsync(int id, StationDto data)
    {
        try
        {
            StationEntity entity = StationFactory.Create(data);
            StationEntity existingEntity = await _modelContext.Stations.FirstOrDefaultAsync(s => s.Id == id);
            if (existingEntity == null)
            {
                return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.NotFound, $"Station with id: {id} does not exists", null);
            }

            // Copy only name, description and positions, create measurements if necessary from MeasurementsManager
            existingEntity.Name = entity.Name;
            existingEntity.Description = existingEntity.Description;
            existingEntity.Latitude = existingEntity.Latitude;
            existingEntity.Longitude = existingEntity.Longitude;
            int result = await _modelContext.SaveChangesAsync();
            if (result >= 0)
            {
                return new OperationResultDto<StationDto>(true, (int)HttpStatusCode.OK, null, StationFactory.Create(entity));
            }
            return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, "An unknown error occurred during station update", null);

        }
        catch (Exception e)
        {
             return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, $"An error occurred during station update: {e.Message}", null);
        }
            
    }

    private readonly ModelContext _modelContext;
}

[HttpGet]
[Route("api/[controller]/search")]
public async Task<PagedDataDto<BookDto>>> SearchAsync([FromQuery]string query, [FromQuery]int page, [FromQuery]int size)
{ 
    OperationResultDto<Tuple<IList<BookDto>, long>> result = await Manager.GetAsync(page, size, query);
    if (result == null)
    {
        HttpContext.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
    }

    HttpContext.Response.StatusCode = result.Status;
    return new PagedDataDto<TRes>(pageNumber, result.Data.Item2, GetTotalPages(result.Data.Item2, pageSize), result.Data.Item1);
}