frenzy-ios/Reader/Screens/Home/HomeViewController.swift

137 lines
5.7 KiB
Swift

//
// HomeViewController.swift
// Reader
//
// Created by Shadowfacts on 11/25/21.
//
import UIKit
import CoreData
class HomeViewController: UIViewController, UICollectionViewDelegate {
let fervorController: FervorController
private var collectionView: UICollectionView!
private var dataSource: UICollectionViewDiffableDataSource<Section, Item>!
private var groupResultsController: NSFetchedResultsController<Group>!
private var feedResultsController: NSFetchedResultsController<Feed>!
init(fervorController: FervorController) {
self.fervorController = fervorController
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemBackground
// let label = UILabel()
// label.translatesAutoresizingMaskIntoConstraints = false
// label.text = "Logged in to \(fervorController.instanceURL.host!)"
// view.addSubview(label)
// NSLayoutConstraint.activate([
// label.centerXAnchor.constraint(equalTo: view.centerXAnchor),
// label.centerYAnchor.constraint(equalTo: view.centerYAnchor),
// ])
let configuration = UICollectionLayoutListConfiguration(appearance: .insetGrouped)
let layout = UICollectionViewCompositionalLayout.list(using: configuration)
collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: layout)
collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
collectionView.delegate = self
view.addSubview(collectionView)
dataSource = createDataSource()
// todo: maybe NSFetchedResultsController to automatically update when the database changes?
// applyInitialSnapshot()
var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
snapshot.appendSections([.groups, .feeds])
dataSource.apply(snapshot, animatingDifferences: false)
let groupReq = Group.fetchRequest()
groupReq.sortDescriptors = [NSSortDescriptor(key: "title", ascending: true)]
groupResultsController = NSFetchedResultsController(fetchRequest: groupReq, managedObjectContext: fervorController.persistentContainer.viewContext, sectionNameKeyPath: nil, cacheName: nil)
groupResultsController.delegate = self
try! groupResultsController.performFetch()
let feedReq = Feed.fetchRequest()
feedReq.sortDescriptors = [NSSortDescriptor(key: "title", ascending: true)]
feedResultsController = NSFetchedResultsController(fetchRequest: feedReq, managedObjectContext: fervorController.persistentContainer.viewContext, sectionNameKeyPath: nil, cacheName: nil)
feedResultsController.delegate = self
try! feedResultsController.performFetch()
}
private func createDataSource() -> UICollectionViewDiffableDataSource<Section, Item> {
let listCell = UICollectionView.CellRegistration<UICollectionViewListCell, Item> { cell, indexPath, item in
var config = cell.defaultContentConfiguration()
config.text = item.title
cell.contentConfiguration = config
cell.accessories = [.disclosureIndicator()]
}
let dataSource = UICollectionViewDiffableDataSource<Section, Item>(collectionView: collectionView) { collectionView, indexPath, item in
return collectionView.dequeueConfiguredReusableCell(using: listCell, for: indexPath, item: item)
}
return dataSource
}
// private func applyInitialSnapshot() {
// let groups = try! fervorController.persistentContainer.viewContext.fetch(Group.fetchRequest())
// let feeds = try! fervorController.persistentContainer.viewContext.fetch(Feed.fetchRequest())
//
// var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
// snapshot.appendSections([.groups, .feeds])
// snapshot.appendItems(groups.map { .group($0) }, toSection: .groups)
// snapshot.appendItems(feeds.map { .feed($0) }, toSection: .feeds)
// dataSource.apply(snapshot, animatingDifferences: false)
// }
}
extension HomeViewController {
enum Section: Hashable {
case groups
case feeds
}
enum Item: Hashable {
case group(Group)
case feed(Feed)
var title: String {
switch self {
case let .group(group):
// todo: manual codegen for models so this force unwrap isn't necessary
return group.title!
case let .feed(feed):
return feed.title!
}
}
}
}
extension HomeViewController: NSFetchedResultsControllerDelegate {
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChangeContentWith snapshot: NSDiffableDataSourceSnapshotReference) {
var snapshot = dataSource.snapshot()
if controller == groupResultsController {
if snapshot.sectionIdentifiers.contains(.groups) {
snapshot.deleteItems(snapshot.itemIdentifiers(inSection: .groups))
}
snapshot.appendItems(controller.fetchedObjects!.map { .group($0 as! Group) }, toSection: .groups)
} else if controller == feedResultsController {
if snapshot.sectionIdentifiers.contains(.feeds) {
snapshot.deleteItems(snapshot.itemIdentifiers(inSection: .feeds))
}
snapshot.appendItems(controller.fetchedObjects!.map { .feed($0 as! Feed) }, toSection: .feeds)
}
dataSource.apply(snapshot, animatingDifferences: false)
}
}