/// <summary>
/// The add.
/// </summary>
/// <param name="item">
/// The item.
/// </param>
public bool Add(SyncHelperItem item)
{
throw new NotImplementedException();
if (item == null)
{
throw new ArgumentNullException("item");
}
lock (this.items)
{
this.AddWithoutLock(item);
}
}
/// <summary>
/// The add without lock.
/// </summary>
/// <param name="item">
/// The item.
/// </param>
/// <exception cref="ArgumentNullException">
/// </exception>
/// <exception cref="InvalidOperationException">
/// </exception>
/// <exception cref="InvalidOperationException">
/// </exception>
/// <exception cref="InvalidOperationException">
/// </exception>
/// <exception cref="InvalidOperationException">
/// </exception>
/// <exception cref="InvalidOperationException">
/// </exception>
private void AddWithoutLock(SyncHelperItem item)
{
if (item == null)
{
throw new ArgumentNullException("item");
}
var existingItem = this.items.SingleOrDefault(x => x.Entity == item.Entity);
if (existingItem != null)
{
const int DeleteAction = 2;
const int CreateAction = 0;
const int EditAction = 1;
var oldAction = existingItem.Delete
? DeleteAction
: existingItem.Entity.StoreId == default(int) ? CreateAction : EditAction;
var newAction = item.Delete
? DeleteAction
: item.Entity.StoreId == default(int) ? CreateAction : EditAction;
// Delete, Edit
if (oldAction == DeleteAction && newAction == EditAction)
{
throw new InvalidOperationException("Cannot edit an entity that is pending deletion.");
}
// Delete, Create
if (oldAction == DeleteAction && newAction == CreateAction)
{
throw new InvalidOperationException("Cannot create an entity that is pending creation.");
}
// Delete, Delete
if (oldAction == DeleteAction && newAction == DeleteAction)
{
throw new InvalidOperationException("Cannot delete an entity that is pending deletion.");
}
// Edit, Create
if (oldAction == EditAction && newAction == CreateAction)
{
throw new InvalidOperationException("Cannot create an entity that is pending creation.");
}
// Edit, Edit
// No action is required as the entity is already queued.
if (oldAction == EditAction && newAction == EditAction)
{
return;
}
// Edit, Delete
if (oldAction == EditAction && newAction == DeleteAction)
{
Debug.WriteLine("An entity that is marked for edit will now be marked for deletion instead.");
existingItem.Delete = true;
}
// Create, Create
if (oldAction == CreateAction && newAction == CreateAction)
{
// The case is where the user edits an item that is newly created. It just means that the entity
// has not yet received a store id.
Debug.WriteLine("An edit was performed on an entity that is marked for creation.");
return;
}
// Create, Edit
if (oldAction == CreateAction && newAction == EditAction)
{
throw new InvalidOperationException(
"An entity marked for creation was edited. This should not happen.");
}
// Create, Delete
if (oldAction == CreateAction && newAction == DeleteAction)
{
Debug.WriteLine("An entity that is queued for creation was deleted.");
this.items.Remove(existingItem);
return;
}
}
else
{
this.items.Add(item);
}
}