Kurdtvs-Live-Kurdish-TV-Kur.../Mastodon/Diffiable/FetchedResultsController/StatusFetchedResultsControl...

87 lines
3.0 KiB
Swift

//
// StatusFetchedResultsController.swift
// Mastodon
//
// Created by MainasuK Cirno on 2021-3-30.
//
import os.log
import UIKit
import Combine
import CoreData
import CoreDataStack
import MastodonSDK
final class StatusFetchedResultsController: NSObject {
var disposeBag = Set<AnyCancellable>()
let fetchedResultsController: NSFetchedResultsController<Status>
// input
let domain = CurrentValueSubject<String?, Never>(nil)
let statusIDs = CurrentValueSubject<[Mastodon.Entity.Status.ID], Never>([])
// output
let objectIDs = CurrentValueSubject<[NSManagedObjectID], Never>([])
init(managedObjectContext: NSManagedObjectContext, domain: String?, additionalTweetPredicate: NSPredicate) {
self.domain.value = domain ?? ""
self.fetchedResultsController = {
let fetchRequest = Status.sortedFetchRequest
fetchRequest.predicate = Status.predicate(domain: domain ?? "", ids: [])
fetchRequest.returnsObjectsAsFaults = false
fetchRequest.fetchBatchSize = 20
let controller = NSFetchedResultsController(
fetchRequest: fetchRequest,
managedObjectContext: managedObjectContext,
sectionNameKeyPath: nil,
cacheName: nil
)
return controller
}()
super.init()
fetchedResultsController.delegate = self
Publishers.CombineLatest(
self.domain.removeDuplicates().eraseToAnyPublisher(),
self.statusIDs.removeDuplicates().eraseToAnyPublisher()
)
.receive(on: DispatchQueue.main)
.sink { [weak self] domain, ids in
guard let self = self else { return }
self.fetchedResultsController.fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [
Status.predicate(domain: domain ?? "", ids: ids),
additionalTweetPredicate
])
do {
try self.fetchedResultsController.performFetch()
} catch {
assertionFailure(error.localizedDescription)
}
}
.store(in: &disposeBag)
}
}
// MARK: - NSFetchedResultsControllerDelegate
extension StatusFetchedResultsController: NSFetchedResultsControllerDelegate {
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChangeContentWith snapshot: NSDiffableDataSourceSnapshotReference) {
os_log("%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
let indexes = statusIDs.value
let objects = fetchedResultsController.fetchedObjects ?? []
let items: [NSManagedObjectID] = objects
.compactMap { object in
indexes.firstIndex(of: object.id).map { index in (index, object) }
}
.sorted { $0.0 < $1.0 }
.map { $0.1.objectID }
self.objectIDs.value = items
}
}