This should teach folks how and why to add decks. Bonus points if it has some sort of icon or illustration 🙂

We need some way to tie new cards created in a deck with the Leitner boxes that the user (hopefully) installed or created. This could be a table view listing different "chains" of Leitner boxes and letting the user pick each one.

See DeckStudyViewModel.handle(.didSwipeCard(...)). That's called when a user swipes left or right on a card but right now it does nothing. We'll likely need to implement #13 or #14 first to make this work right.

This can probably just be a static function that takes in inputs and gives a tuple of outputs.

See here, here, or here for various descriptions of the algorithm.

Essentially this would "bucket" cards into different categories, with a different amount of time between each category and cards going up the categories as users correctly answer them. It would be nice if this was customizable (even per-deck?) but start with a "recommended" set of categories.

Here's a description of WaniKani's system and here's the Wikipedia page for the Leitner system in general.

Right now you can tap "edit" to start the table view editing mode but it doesn't do anything. We should have everything in place to implement deletion now. That would involve:

1. Adding a delete(_ deckModel: DeckModel) function to DeckRepository.

That would look something like:

let fetchRequest = NSFetchRequest<Deck>(entityName: DeckModel.entityName)
fetchRequest.predicate = NSPredicate(format: "uuid == $@", deckModel.uuid)
fetchRequest.fetchLimit = 1

let deck = (try? persistentContainer.viewContext.fetch(fetchRequest))?.first
persistentContainer.viewContext.delete(deck!)

2. Hooking up the table view's deletion state to the view model and from there to the repository.
3. Adding a confirmation dialog before committing the delete.
4. [optional] Most iOS apps implement slide-to-delete for individual rows in a table view (even if you're not in edit mode). We might be able to get that "for free" using some random table view delegate.
5. Adding some unit tests 🙂

In #16 I set this to default to the UUID that's passed in to DeckStudyViewController. It would be nice to show the actual name of the deck from the data model instead.

That's actually going to be more difficult than it looks, hence why this isn't necessarily a good task for new folks.

1. Add a fetchDeck() method to DeckRepository that returns an AnyPublisher<DeckModel, Never> with the updates for just one deck. (I suppose in theory we could use fetchDeckList() and just filter the resulting [DeckModel], but that feels icky.
2. That will likely require some cleverness in DeckCoreDataRepository to ensure having multiple fetch controllers etc will work as expected.
3. Subscribe to fetchDeck() in DeckStudyViewModel.handle(.viewDidLoad).
4. In the subscription, set state.title.

This is probably a good place to use UserDefaults - just store a boolean for installed / uninstalled

Basically a copy of #18 🙂

1. Stub out a CreateDeckViewController (and view model, etc), which for now might be nothing more than a text field to enter a title and a save button. The text field should of course show some sort of error state or alert if you try to enter an empty name.
2. The save button should add the card via repos.deckRepo.updateOrCreate.
3. When pressing the add button in DeckListViewController, navigate to CreateDeckViewController (via MainCoordinator of course).
4. Add unit tests 🙂

Right now decks are always sorted by name ascending (thanks to fetchRequest.sortDescriptors = [NSSortDescriptor(key: "title", ascending: true)] in DeckCoreDateRepository). It would be nice to add a UI to customize this, or even add enough details to the data model to be able to support reordering.

Right now once you've swiped all your cards, you're just presented with an empty screen. We should change that!

This might be something like "badge count of all unreviewed cards" or perhaps customizable to "unreviewed cards from a certain deck".

See AddCardViewModel.handle(.cancelTapped). We should probably add a function to Coordinator to present an alert.

This could be as simple as an alert that shows up on first launch prompting the user to install. This should be coordinated with #58.

I really need to sit down and figure out how Core Data Really Works™️ so that I can move the logic in the various createOrUpdate calls to a background queue for performance reasons.

We're committing something in pre-push which isn't really good form. We can move the linting to post-commit instead.

In #16, tapping the add button in DeckStudyViewController just adds a random card to the deck. It would be nice to start building out the actual UI for a quick-add-card modal.

1. Stub out a CreateCardViewController (and view model, etc), which for now might be nothing more than a text field showing the autogenerated UUID and a save button 😅
2. The save button should add the card via repos.cardRepo.updateOrCreate.
3. When pressing the add button in DeckStudyViewController, navigate to CreateCardViewController (via MainCoordinator of course).
4. Add unit tests 🙂

The deck data model has a rank field, which is how the decks are sorted. We should be able to support drag-and-drop by updating the rank fields appropriately after the table view drag-and-drop delegates are called.

See AddCardViewModel.handle(.saveTapped). We could maybe show some red text below the empty text field when this happens.

This should be pretty straightforward by adding a UISearchController to DeckListViewController and hooking it up to do some filtering on DeckModel.title. We might consider refactoring by doing the diffable data source snapshot in the view controller and just storing "current visible deck models" on the state in that case, though.