Files
omnivore/apple/OmnivoreKit/Sources/App/Views/Home/HomeFeedViewModel.swift
2023-02-27 08:45:28 -07:00

346 lines
11 KiB
Swift

import CoreData
import Models
import Services
import SwiftUI
import Utils
import Views
@MainActor final class HomeFeedViewModel: NSObject, ObservableObject {
var currentDetailViewModel: LinkItemDetailViewModel?
private var fetchedResultsController: NSFetchedResultsController<LinkedItem>?
@Published var items = [LinkedItem]()
@Published var isLoading = false
@Published var showPushNotificationPrimer = false
@Published var itemUnderLabelEdit: LinkedItem?
@Published var itemUnderTitleEdit: LinkedItem?
@Published var itemForHighlightsView: LinkedItem?
@Published var searchTerm = ""
@Published var scopeSelection = 0
@Published var selectedLabels = [LinkedItemLabel]()
@Published var negatedLabels = [LinkedItemLabel]()
@Published var snoozePresented = false
@Published var itemToSnoozeID: String?
@Published var linkRequest: LinkRequest?
@Published var showLoadingBar = false
@Published var appliedSort = LinkedItemSort.newest.rawValue
@Published var selectedLinkItem: NSManagedObjectID? // used by mac app only
@Published var selectedItem: LinkedItem?
@Published var linkIsActive = false
@Published var showLabelsSheet = false
@Published var showCommunityModal = false
var cursor: String?
// These are used to make sure we handle search result
// responses in the right order
var searchIdx = 0
var receivedIdx = 0
var syncCursor: String?
@AppStorage(UserDefaultKey.lastSelectedLinkedItemFilter.rawValue) var appliedFilter = LinkedItemFilter.inbox.rawValue
func handleReaderItemNotification(objectID: NSManagedObjectID, dataService: DataService) {
// Pop the current selected item if needed
if selectedItem != nil, selectedItem?.objectID != objectID {
// Temporarily disable animation to avoid excessive animations
#if os(iOS)
UIView.setAnimationsEnabled(false)
#endif
linkIsActive = false
selectedItem = nil
DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(100)) {
self.selectedLinkItem = objectID
self.selectedItem = dataService.viewContext.object(with: objectID) as? LinkedItem
self.linkIsActive = true
}
DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(200)) {
#if os(iOS)
UIView.setAnimationsEnabled(true)
#endif
}
} else {
selectedLinkItem = objectID
selectedItem = dataService.viewContext.object(with: objectID) as? LinkedItem
linkIsActive = true
}
}
func itemAppeared(item: LinkedItem, dataService: DataService) async {
if isLoading { return }
let itemIndex = items.firstIndex(where: { $0.id == item.id })
let thresholdIndex = items.index(items.endIndex, offsetBy: -5)
// Check if user has scrolled to the last five items in the list
// Make sure we aren't currently loading though, as this would get triggered when the first set
// of items are presented to the user.
if let itemIndex = itemIndex, itemIndex > thresholdIndex {
await loadMoreItems(dataService: dataService, isRefresh: false)
}
}
func pushFeedItem(item: LinkedItem) {
items.insert(item, at: 0)
}
func loadCurrentViewer(dataService: DataService) async {
// Cache the viewer
if dataService.currentViewer == nil {
_ = try? await dataService.fetchViewer()
}
}
func loadLabels(dataService: DataService) async {
let fetchRequest: NSFetchRequest<Models.LinkedItemLabel> = LinkedItemLabel.fetchRequest()
fetchRequest.fetchLimit = 1
if (try? dataService.viewContext.count(for: fetchRequest)) == 0 {
_ = try? await dataService.labels()
}
}
func syncItems(dataService: DataService) async {
let syncStart = Date.now
let lastSyncDate = dataService.lastItemSyncTime
try? await dataService.syncOfflineItemsWithServerIfNeeded()
let syncResult = try? await dataService.syncLinkedItems(since: lastSyncDate,
cursor: nil)
syncCursor = syncResult?.cursor
if let syncResult = syncResult, syncResult.hasMore {
dataService.syncLinkedItemsInBackground(since: lastSyncDate) {
// Set isLoading to false here
self.isLoading = false
}
} else {
dataService.lastItemSyncTime = syncStart
}
// If possible start prefetching new pages in the background
if
let itemIDs = syncResult?.updatedItemIDs,
let username = dataService.currentViewer?.username,
!itemIDs.isEmpty
{
Task.detached(priority: .background) {
await dataService.prefetchPages(itemIDs: itemIDs, username: username)
}
}
}
func loadSearchQuery(dataService: DataService, isRefresh: Bool) async {
let thisSearchIdx = searchIdx
searchIdx += 1
if thisSearchIdx > 0, thisSearchIdx <= receivedIdx {
return
}
let queryResult = try? await dataService.loadLinkedItems(
limit: 10,
searchQuery: searchQuery,
cursor: isRefresh ? nil : cursor
)
if let queryResult = queryResult {
let newItems: [LinkedItem] = {
var itemObjects = [LinkedItem]()
dataService.viewContext.performAndWait {
itemObjects = queryResult.itemIDs.compactMap { dataService.viewContext.object(with: $0) as? LinkedItem }
}
return itemObjects
}()
if searchTerm.replacingOccurrences(of: " ", with: "").isEmpty {
updateFetchController(dataService: dataService)
} else {
// Don't use FRC for searching. Use server results directly.
if fetchedResultsController != nil {
fetchedResultsController = nil
items = []
}
items = isRefresh ? newItems : items + newItems
}
isLoading = false
receivedIdx = thisSearchIdx
cursor = queryResult.cursor
if let username = dataService.currentViewer?.username {
await dataService.prefetchPages(itemIDs: newItems.map(\.unwrappedID), username: username)
}
} else {
updateFetchController(dataService: dataService)
}
}
func loadItems(dataService: DataService, isRefresh: Bool) async {
isLoading = true
showLoadingBar = true
await withTaskGroup(of: Void.self) { group in
group.addTask { await self.loadCurrentViewer(dataService: dataService) }
group.addTask { await self.loadLabels(dataService: dataService) }
group.addTask { await self.syncItems(dataService: dataService) }
group.addTask { await self.updateFetchController(dataService: dataService) }
await group.waitForAll()
}
let shouldSearch = items.count < 1 || isRefresh
if shouldSearch {
await loadSearchQuery(dataService: dataService, isRefresh: isRefresh)
} else {
updateFetchController(dataService: dataService)
}
isLoading = false
showLoadingBar = false
}
func loadMoreItems(dataService: DataService, isRefresh: Bool) async {
isLoading = true
showLoadingBar = true
await loadSearchQuery(dataService: dataService, isRefresh: isRefresh)
isLoading = false
showLoadingBar = false
}
private var fetchRequest: NSFetchRequest<Models.LinkedItem> {
let fetchRequest: NSFetchRequest<Models.LinkedItem> = LinkedItem.fetchRequest()
var subPredicates = [NSPredicate]()
subPredicates.append((LinkedItemFilter(rawValue: appliedFilter) ?? .inbox).predicate)
if !selectedLabels.isEmpty {
var labelSubPredicates = [NSPredicate]()
for label in selectedLabels {
labelSubPredicates.append(
NSPredicate(format: "SUBQUERY(labels, $label, $label.id == \"\(label.unwrappedID)\").@count > 0")
)
}
subPredicates.append(NSCompoundPredicate(orPredicateWithSubpredicates: labelSubPredicates))
}
if !negatedLabels.isEmpty {
var labelSubPredicates = [NSPredicate]()
for label in negatedLabels {
labelSubPredicates.append(
NSPredicate(format: "SUBQUERY(labels, $label, $label.id == \"\(label.unwrappedID)\").@count == 0")
)
}
subPredicates.append(NSCompoundPredicate(orPredicateWithSubpredicates: labelSubPredicates))
}
fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: subPredicates)
fetchRequest.sortDescriptors = (LinkedItemSort(rawValue: appliedSort) ?? .newest).sortDescriptors
return fetchRequest
}
private func updateFetchController(dataService: DataService) {
fetchedResultsController = NSFetchedResultsController(
fetchRequest: fetchRequest,
managedObjectContext: dataService.viewContext,
sectionNameKeyPath: nil,
cacheName: nil
)
guard let fetchedResultsController = fetchedResultsController else {
return
}
fetchedResultsController.delegate = self
try? fetchedResultsController.performFetch()
items = fetchedResultsController.fetchedObjects ?? []
}
func setLinkArchived(dataService: DataService, objectID: NSManagedObjectID, archived: Bool) {
dataService.archiveLink(objectID: objectID, archived: archived)
Snackbar.show(message: archived ? "Link archived" : "Link moved to Inbox")
}
func removeLink(dataService: DataService, objectID: NSManagedObjectID) {
Snackbar.show(message: "Link removed")
dataService.removeLink(objectID: objectID)
}
func snoozeUntil(dataService: DataService, linkId: String, until: Date, successMessage: String?) async {
isLoading = true
if let itemIndex = items.firstIndex(where: { $0.id == linkId }) {
items.remove(at: itemIndex)
}
do {
try await dataService.createReminder(
reminderItemId: .link(id: linkId),
remindAt: until
)
if let message = successMessage {
Snackbar.show(message: message)
}
} catch {
NSNotification.operationFailed(message: "Failed to snooze")
}
isLoading = false
}
private var queryContainsFilter: Bool {
if searchTerm.contains("in:inbox") || searchTerm.contains("in:all") || searchTerm.contains("in:archive") {
return true
}
return false
}
private var searchQuery: String {
let sort = LinkedItemSort(rawValue: appliedSort) ?? .newest
var query = sort.queryString
if !queryContainsFilter, let filter = LinkedItemFilter(rawValue: appliedFilter) {
query = "\(filter.queryString) \(sort.queryString)"
}
if !searchTerm.isEmpty {
query.append(" \(searchTerm)")
}
if !selectedLabels.isEmpty {
query.append(" label:")
query.append(selectedLabels.map { $0.name ?? "" }.joined(separator: ","))
}
if !negatedLabels.isEmpty {
query.append(" !label:")
query.append(negatedLabels.map { $0.name ?? "" }.joined(separator: ","))
}
print("QUERY: `\(query)`")
return query
}
}
extension HomeFeedViewModel: NSFetchedResultsControllerDelegate {
func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
items = controller.fetchedObjects as? [LinkedItem] ?? []
}
}