metatext/View Controllers/ExploreViewController.swift
2021-02-05 17:16:59 -08:00

173 lines
6 KiB
Swift

// Copyright © 2021 Metabolist. All rights reserved.
import Combine
import UIKit
import ViewModels
final class ExploreViewController: UICollectionViewController {
private let viewModel: ExploreViewModel
private let rootViewModel: RootViewModel
private var cancellables = Set<AnyCancellable>()
private lazy var dataSource: ExploreDataSource = {
.init(collectionView: collectionView, viewModel: viewModel)
}()
init(viewModel: ExploreViewModel, rootViewModel: RootViewModel) {
self.viewModel = viewModel
self.rootViewModel = rootViewModel
super.init(collectionViewLayout: Self.layout())
tabBarItem = UITabBarItem(
title: NSLocalizedString("main-navigation.explore", comment: ""),
image: UIImage(systemName: "magnifyingglass"),
selectedImage: nil)
}
@available(*, unavailable)
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
collectionView.dataSource = dataSource
collectionView.backgroundColor = .systemBackground
collectionView.contentInset.bottom = Self.bottomInset
collectionView.isAccessibilityElement = false
collectionView.shouldGroupAccessibilityChildren = true
clearsSelectionOnViewWillAppear = true
collectionView.refreshControl = UIRefreshControl()
collectionView.refreshControl?.addAction(
UIAction { [weak self] _ in
self?.viewModel.refresh() },
for: .valueChanged)
navigationItem.title = NSLocalizedString("main-navigation.explore", comment: "")
let searchResultsController = TableViewController(
viewModel: viewModel.searchViewModel,
rootViewModel: rootViewModel,
insetBottom: false,
parentNavigationController: navigationController)
let searchController = UISearchController(searchResultsController: searchResultsController)
searchController.searchResultsUpdater = self
navigationItem.searchController = searchController
viewModel.identityContext.$appPreferences.sink { appPreferences in
searchController.searchBar.scopeButtonTitles = SearchScope.allCases.map {
$0.title(statusWord: appPreferences.statusWord)
}
}
.store(in: &cancellables)
viewModel.events.sink { [weak self] in self?.handle(event: $0) }.store(in: &cancellables)
viewModel.$loading.sink { [weak self] in
guard let self = self else { return }
let refreshControlVisibile = self.collectionView.refreshControl?.isRefreshing ?? false
if !$0, refreshControlVisibile {
self.collectionView.refreshControl?.endRefreshing()
}
}
.store(in: &cancellables)
viewModel.searchViewModel.events.sink { [weak self] in
if case let .navigation(navigation) = $0,
case let .searchScope(scope) = navigation {
searchController.searchBar.selectedScopeButtonIndex = scope.rawValue
self?.updateSearchResults(for: searchController)
}
}
.store(in: &cancellables)
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
viewModel.refresh()
}
override func collectionView(_ collectionView: UICollectionView,
shouldHighlightItemAt indexPath: IndexPath) -> Bool {
dataSource.itemIdentifier(for: indexPath) != .instance
}
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
guard let item = dataSource.itemIdentifier(for: indexPath) else { return }
viewModel.select(item: item)
}
}
extension ExploreViewController: UISearchResultsUpdating {
func updateSearchResults(for searchController: UISearchController) {
if let scope = SearchScope(rawValue: searchController.searchBar.selectedScopeButtonIndex) {
if scope != viewModel.searchViewModel.scope,
let scrollView = searchController.searchResultsController?.view as? UIScrollView {
scrollView.setContentOffset(.init(x: 0, y: -scrollView.safeAreaInsets.top), animated: false)
}
viewModel.searchViewModel.scope = scope
}
viewModel.searchViewModel.query = searchController.searchBar.text ?? ""
}
}
extension ExploreViewController: ScrollableToTop {
func scrollToTop(animated: Bool) {
collectionView.scrollToTop(animated: animated)
}
}
private extension ExploreViewController {
static let bottomInset: CGFloat = .newStatusButtonDimension + .defaultSpacing * 4
static func layout() -> UICollectionViewLayout {
var listConfiguration = UICollectionLayoutListConfiguration(appearance: .plain)
listConfiguration.headerMode = .supplementary
return UICollectionViewCompositionalLayout(
sectionProvider: {
let section = NSCollectionLayoutSection.list(using: listConfiguration, layoutEnvironment: $1)
if UIDevice.current.userInterfaceIdiom == .pad {
section.contentInsetsReference = .readableContent
}
return section
})
}
func handle(event: ExploreViewModel.Event) {
switch event {
case let .navigation(navigation):
handle(navigation: navigation)
}
}
func handle(navigation: Navigation) {
switch navigation {
case let .collection(collectionService):
let vc = TableViewController(
viewModel: CollectionItemsViewModel(
collectionService: collectionService,
identityContext: viewModel.identityContext),
rootViewModel: rootViewModel,
parentNavigationController: nil)
show(vc, sender: self)
default:
break
}
}
}