/// <summary>
/// Applies update
/// </summary>
/// <param name="updateId"></param>
public void Apply(Guid updateId)
{
IUpdate update = GetUpdate(updateId);
if (update is null)
{
throw new Exception($"Update {updateId} is not a valid update");
}
if (IsApplied(updateId))
{
return;
}
var missingUpdateIds = GetMissingDependentUpdates(update);
if (missingUpdateIds.Count > 0)
{
throw new Exception($"Update cannot be applied because it depends on update {missingUpdateIds[0]}");
}
try
{
update.Apply();
var updateDetails = new UpdateDetails()
{
Id = update.Id,
Name = update.Name,
TimeApplied = DateTime.UtcNow
};
_updateDetailsRepository.Add(updateDetails);
_updateDetailsRepository.SaveChanges();
}
catch (Exception exception)
{
try
{
if (update.SupportsRollback)
{
update.RollBack();
}
}
catch (Exception rollBackException)
{
throw new Exception($"Error applying update {update.Name}, roll back failed", rollBackException);
}
throw new Exception($"Error applying update {update.Name} - {exception.InnerException?.Message}", exception);
}
}
/// <summary>
/// Rolls back the update.
/// </summary>
/// <param name="updateId"></param>
public void RollBack(Guid updateId)
{
IUpdate update = GetUpdate(updateId);
if (update is null)
{
throw new Exception($"Update {updateId} is not a valid update");
}
if (IsApplied(updateId))
{
try
{
update.RollBack();
_updateDetailsRepository.Remove(updateId);
_updateDetailsRepository.SaveChanges();
}
catch (Exception exception)
{
throw new Exception($"Error rolling back update {update.Name}", exception);
}
}
}