Files
yattee/Yattee/Services/SubscriptionFeedCache.swift
2026-02-08 18:33:56 +01:00

678 lines
25 KiB
Swift

//
// SubscriptionFeedCache.swift
// Yattee
//
// Subscription feed cache with disk persistence.
// Routes feed fetching based on subscription account type.
//
import Foundation
#if os(iOS) || os(tvOS)
import UIKit
#elseif os(macOS)
import AppKit
#endif
/// State of feed loading.
enum FeedLoadState: Equatable {
case idle
case loading
case loadingMore
case ready
case partiallyLoaded(readyCount: Int, pendingCount: Int, errorCount: Int)
case error(FeedLoadError)
/// Specific error types for feed loading.
enum FeedLoadError: Equatable {
case yatteeServerRequired
case notAuthenticated
case networkError(String)
}
}
/// Subscription feed cache with disk persistence.
/// Routes feed fetching based on the selected subscription account type:
/// - Local accounts: Use Yattee Server (required)
/// - Invidious accounts: Use Invidious /api/v1/auth/feed endpoint
@MainActor
@Observable
final class SubscriptionFeedCache {
static let shared = SubscriptionFeedCache()
var videos: [Video] = []
var lastUpdated: Date?
var isLoading = false
var loadingProgress: (loaded: Int, total: Int)?
var hasLoadedOnce = false
/// State of feed loading.
var feedLoadState: FeedLoadState = .idle
/// Whether more pages are available from Invidious feed (for infinite scroll).
var hasMorePages = false
/// Whether the disk cache has been loaded.
private var diskCacheLoaded = false
/// Current page for Invidious feed pagination (1-based).
private var currentPage = 1
/// Active polling task for feed status (can be cancelled).
private var pollingTask: Task<Void, Never>?
/// Whether app is in foreground (polling only allowed in foreground).
private var isAppInForeground = true
private init() {
setupLifecycleObservers()
}
// MARK: - Lifecycle
/// Sets up observers to detect when app goes to background.
private func setupLifecycleObservers() {
#if os(iOS) || os(tvOS)
NotificationCenter.default.addObserver(
forName: UIApplication.willResignActiveNotification,
object: nil,
queue: .main
) { [weak self] _ in
guard let self else { return }
Task { @MainActor [self] in
self.handleAppBackgrounded()
}
}
#elseif os(macOS)
NotificationCenter.default.addObserver(
forName: NSApplication.willResignActiveNotification,
object: nil,
queue: .main
) { [weak self] _ in
guard let self else { return }
Task { @MainActor [self] in
self.handleAppBackgrounded()
}
}
#endif
}
/// Handles app going to background - cancels any active polling.
private func handleAppBackgrounded() {
isAppInForeground = false
cancelPolling()
}
/// Cancels any active feed status polling.
func cancelPolling() {
pollingTask?.cancel()
pollingTask = nil
}
// MARK: - Cache Validity
/// Returns true if the cache is valid based on the configured validity duration.
/// Uses the setting from SettingsManager (default 30 minutes).
func isCacheValid(using settingsManager: SettingsManager?) -> Bool {
guard let lastUpdated, !videos.isEmpty else { return false }
let validitySeconds = settingsManager?.feedCacheValiditySeconds
?? TimeInterval(SettingsManager.defaultFeedCacheValidityMinutes * 60)
return Date().timeIntervalSince(lastUpdated) < validitySeconds
}
// MARK: - Disk Cache
/// Loads cached data from disk if not already loaded.
/// Call this early (e.g., on app launch) to populate the feed quickly.
func loadFromDiskIfNeeded() async {
guard !diskCacheLoaded else {
LoggingService.shared.debug("Feed cache already loaded from disk, skipping", category: .general)
return
}
diskCacheLoaded = true
if let cacheData = await FeedCache.shared.load() {
videos = cacheData.videos
lastUpdated = cacheData.lastUpdated
hasLoadedOnce = true
let videoCount = videos.count
let oldestVideoDate = videos.compactMap { $0.publishedAt }.min()
let age = Date().timeIntervalSince(cacheData.lastUpdated)
LoggingService.shared.debug(
"Loaded feed cache from disk: \(videoCount) videos, lastUpdated: \(cacheData.lastUpdated) (\(Int(age))s ago), oldest video: \(oldestVideoDate?.description ?? "none")",
category: .general
)
} else {
LoggingService.shared.debug("No feed cache found on disk", category: .general)
}
}
func clear() {
cancelPolling()
videos = []
lastUpdated = nil
hasMorePages = false
currentPage = 1
Task {
await FeedCache.shared.clear()
}
}
func invalidate() {
lastUpdated = nil
Task {
await FeedCache.shared.invalidate()
}
}
/// Saves the current feed state to disk.
private func saveToDisk() {
guard let lastUpdated else {
LoggingService.shared.warning("saveToDisk called but lastUpdated is nil", category: .general)
return
}
LoggingService.shared.debug("Saving feed cache to disk: \(videos.count) videos, lastUpdated: \(lastUpdated)", category: .general)
Task {
await FeedCache.shared.save(videos: videos, lastUpdated: lastUpdated)
}
}
/// Updates the cache with new videos and persists to disk.
func update(videos: [Video]) {
let oldCount = self.videos.count
let oldDate = self.lastUpdated
self.videos = videos
self.lastUpdated = Date()
self.hasLoadedOnce = true
LoggingService.shared.info(
"Feed cache updated: \(oldCount) -> \(videos.count) videos, lastUpdated changed from \(oldDate?.description ?? "nil") to \(Date())",
category: .general
)
saveToDisk()
}
/// Appends videos to the existing cache (for pagination).
private func appendVideos(_ newVideos: [Video]) {
let existingIDs = Set(videos.map { $0.id })
let uniqueNewVideos = newVideos.filter { !existingIDs.contains($0.id) }
videos.append(contentsOf: uniqueNewVideos)
lastUpdated = Date()
LoggingService.shared.debug(
"Appended \(uniqueNewVideos.count) videos to feed cache (total: \(videos.count))",
category: .general
)
saveToDisk()
}
// MARK: - Account Change Handling
/// Clears cache when subscription account changes.
/// Call this when the user switches between local and Invidious accounts.
func handleAccountChange() {
LoggingService.shared.info("Subscription account changed, clearing feed cache", category: .general)
clear()
feedLoadState = .idle
}
// MARK: - Refresh
/// Refreshes the feed from network.
/// Routes based on subscription account type:
/// - Local: Requires Yattee Server
/// - Invidious: Uses authenticated feed endpoint
///
/// Note: This method uses a detached task internally to prevent SwiftUI from
/// cancelling the network request when view state changes during refresh.
func refresh(using appEnvironment: AppEnvironment) async {
guard !isLoading else {
LoggingService.shared.debug("Feed refresh called but already loading, skipping", category: .general)
return
}
let accountType = appEnvironment.settingsManager.subscriptionAccount.type
LoggingService.shared.debug("Starting feed refresh for account type: \(accountType)", category: .general)
// Use a detached task to prevent SwiftUI from cancelling the request
// when @State properties change during the refresh operation.
// This is necessary because loadSubscriptionsAsync() updates @State
// before feedCache.refresh() completes, which can cause SwiftUI to
// cancel the parent task.
await Task.detached { @MainActor in
switch accountType {
case .local:
await self.refreshLocalAccount(using: appEnvironment)
case .invidious:
await self.refreshInvidiousAccount(using: appEnvironment)
case .piped:
await self.refreshPipedAccount(using: appEnvironment)
}
}.value
}
/// Refreshes feed for local account using Yattee Server.
private func refreshLocalAccount(using appEnvironment: AppEnvironment) async {
// Require Yattee Server for local accounts
guard let serverInstance = appEnvironment.instancesManager.instances.first(where: {
$0.type == .yatteeServer && $0.isEnabled
}) else {
LoggingService.shared.warning("Local subscriptions require Yattee Server, but none is configured", category: .general)
feedLoadState = .error(.yatteeServerRequired)
isLoading = false
return
}
LoggingService.shared.info("Refreshing feed using Yattee Server: \(serverInstance.url.absoluteString)", category: .general)
await refreshFromStatelessServer(instance: serverInstance, using: appEnvironment)
}
/// Refreshes feed for Invidious account using authenticated feed endpoint.
private func refreshInvidiousAccount(using appEnvironment: AppEnvironment) async {
guard let (instance, sid) = getInvidiousAuth(using: appEnvironment) else {
LoggingService.shared.warning("Invidious account not authenticated", category: .general)
feedLoadState = .error(.notAuthenticated)
isLoading = false
return
}
LoggingService.shared.info("Refreshing feed using Invidious account: \(instance.url.absoluteString)", category: .general)
// Reset pagination for fresh refresh
currentPage = 1
await refreshFromInvidiousFeed(instance: instance, sid: sid, using: appEnvironment)
}
/// Gets the authenticated Invidious instance and session ID.
private func getInvidiousAuth(using appEnvironment: AppEnvironment) -> (Instance, String)? {
// Get the instance ID from subscription account settings
let account = appEnvironment.settingsManager.subscriptionAccount
let instance: Instance?
if let instanceID = account.instanceID {
// Use the specific instance from account settings
instance = appEnvironment.instancesManager.instances.first { $0.id == instanceID }
} else {
// Fall back to first enabled Invidious instance
instance = appEnvironment.instancesManager.instances.first {
$0.type == .invidious && $0.isEnabled
}
}
guard let instance else {
LoggingService.shared.debug("No Invidious instance found for subscription account", category: .general)
return nil
}
guard let sid = appEnvironment.invidiousCredentialsManager.sid(for: instance) else {
LoggingService.shared.debug("No session ID found for Invidious instance: \(instance.id)", category: .general)
return nil
}
return (instance, sid)
}
// MARK: - Piped Account
/// Refreshes feed for Piped account using authenticated feed endpoint.
private func refreshPipedAccount(using appEnvironment: AppEnvironment) async {
guard let (instance, authToken) = getPipedAuth(using: appEnvironment) else {
LoggingService.shared.warning("Piped account not authenticated", category: .general)
feedLoadState = .error(.notAuthenticated)
isLoading = false
return
}
LoggingService.shared.info("Refreshing feed using Piped account: \(instance.url.absoluteString)", category: .general)
isLoading = true
feedLoadState = .loading
loadingProgress = nil
hasMorePages = false // Piped doesn't support pagination
do {
let pipedAPI = PipedAPI(httpClient: appEnvironment.httpClient)
let feedVideos = try await pipedAPI.feed(instance: instance, authToken: authToken)
LoggingService.shared.info("Piped feed: Received \(feedVideos.count) videos", category: .general)
update(videos: feedVideos)
appEnvironment.dataManager.updateLastVideoPublishedDates(from: feedVideos)
prefetchDeArrow(for: feedVideos, using: appEnvironment)
feedLoadState = .ready
} catch {
LoggingService.shared.error("Failed to fetch Piped feed: \(error.localizedDescription)", category: .general)
feedLoadState = .error(.networkError(error.localizedDescription))
}
isLoading = false
}
/// Gets the authenticated Piped instance and auth token.
private func getPipedAuth(using appEnvironment: AppEnvironment) -> (Instance, String)? {
let account = appEnvironment.settingsManager.subscriptionAccount
guard let instanceID = account.instanceID,
let instance = appEnvironment.instancesManager.instances.first(where: { $0.id == instanceID }),
let authToken = appEnvironment.pipedCredentialsManager.credential(for: instance) else {
LoggingService.shared.debug("No authenticated Piped instance found for subscription account", category: .general)
return nil
}
return (instance, authToken)
}
// MARK: - Invidious Feed
/// Refreshes feed from authenticated Invidious feed API.
private func refreshFromInvidiousFeed(
instance: Instance,
sid: String,
using appEnvironment: AppEnvironment
) async {
isLoading = true
feedLoadState = .loading
loadingProgress = nil
do {
let response = try await appEnvironment.invidiousAPI.feed(
instance: instance,
sid: sid,
page: currentPage,
maxResults: 50
)
let feedVideos = response.videos
LoggingService.shared.info(
"Invidious feed: Received \(feedVideos.count) videos (page \(currentPage))",
category: .general
)
// For first page, replace all videos. For subsequent pages, this shouldn't be called.
update(videos: feedVideos)
appEnvironment.dataManager.updateLastVideoPublishedDates(from: feedVideos)
// Update pagination state
hasMorePages = response.hasMore
currentPage = 1
// Prefetch DeArrow branding for YouTube videos
prefetchDeArrow(for: feedVideos, using: appEnvironment)
feedLoadState = .ready
} catch {
LoggingService.shared.error(
"Failed to fetch Invidious feed: \(error.localizedDescription)",
category: .general
)
feedLoadState = .error(.networkError(error.localizedDescription))
}
isLoading = false
}
/// Loads the next page of Invidious feed (for infinite scroll).
func loadMoreInvidiousFeed(using appEnvironment: AppEnvironment) async {
guard !isLoading else { return }
guard hasMorePages else { return }
guard appEnvironment.settingsManager.subscriptionAccount.type == .invidious else { return }
guard let (instance, sid) = getInvidiousAuth(using: appEnvironment) else {
return
}
isLoading = true
feedLoadState = .loadingMore
let nextPage = currentPage + 1
do {
let response = try await appEnvironment.invidiousAPI.feed(
instance: instance,
sid: sid,
page: nextPage,
maxResults: 50
)
let feedVideos = response.videos
LoggingService.shared.info(
"Invidious feed: Loaded page \(nextPage), received \(feedVideos.count) videos",
category: .general
)
// Append new videos to existing cache
appendVideos(feedVideos)
// Update pagination state
hasMorePages = response.hasMore
currentPage = nextPage
// Prefetch DeArrow branding for new videos
prefetchDeArrow(for: feedVideos, using: appEnvironment)
feedLoadState = .ready
} catch {
LoggingService.shared.error(
"Failed to load more Invidious feed: \(error.localizedDescription)",
category: .general
)
// Don't show error state for pagination failures, just stop loading
feedLoadState = .ready
}
isLoading = false
}
// MARK: - Yattee Server Feed
/// Refreshes feed from Yattee Server's stateless POST feed API.
private func refreshFromStatelessServer(instance: Instance, using appEnvironment: AppEnvironment) async {
let subscriptions = appEnvironment.dataManager.subscriptions()
LoggingService.shared.debug("refreshFromStatelessServer: Found \(subscriptions.count) subscriptions", category: .general)
guard !subscriptions.isEmpty else {
videos = []
isLoading = false
hasLoadedOnce = true
feedLoadState = .ready
LoggingService.shared.debug("refreshFromStatelessServer: No subscriptions, clearing feed", category: .general)
return
}
isLoading = true
feedLoadState = .loading
loadingProgress = nil
let channelRequests = subscriptions.map { subscription in
StatelessChannelRequest(
channelId: subscription.channelID,
site: subscription.site,
channelName: subscription.name,
channelUrl: subscription.channelURLString,
avatarUrl: subscription.avatarURLString
)
}
do {
let yatteeServerAPI = YatteeServerAPI(httpClient: HTTPClient())
let authHeader = appEnvironment.yatteeServerCredentialsManager.basicAuthHeader(for: instance)
await yatteeServerAPI.setAuthHeader(authHeader)
LoggingService.shared.debug("refreshFromStatelessServer: Calling postFeed for \(channelRequests.count) channels", category: .general)
let response = try await yatteeServerAPI.postFeed(
channels: channelRequests,
limit: 100,
offset: 0,
instance: instance
)
let serverVideos = response.toVideos()
LoggingService.shared.info(
"refreshFromStatelessServer: Received \(serverVideos.count) videos from server, status: \(response.status), ready: \(response.isReady)",
category: .general
)
update(videos: serverVideos)
appEnvironment.dataManager.updateLastVideoPublishedDates(from: serverVideos)
// Prefetch DeArrow branding
prefetchDeArrow(for: serverVideos, using: appEnvironment)
if response.isReady {
feedLoadState = .ready
isLoading = false
} else {
// Show partial results and poll for completion
feedLoadState = .partiallyLoaded(
readyCount: response.readyCount ?? 0,
pendingCount: response.pendingCount ?? 0,
errorCount: response.errorCount ?? 0
)
// Reset foreground flag since this is a user-initiated action
isAppInForeground = true
pollingTask = Task {
await pollUntilReady(
channels: channelRequests,
instance: instance,
appEnvironment: appEnvironment
)
}
await pollingTask?.value
pollingTask = nil
}
} catch {
LoggingService.shared.error(
"Yattee Server feed failed: \(error.localizedDescription)",
category: .general
)
feedLoadState = .error(.networkError(error.localizedDescription))
isLoading = false
}
}
/// Polls server until all channels are cached, then refreshes.
/// Stops polling after max retries, consecutive errors, or when app is backgrounded.
private func pollUntilReady(
channels: [StatelessChannelRequest],
instance: Instance,
appEnvironment: AppEnvironment
) async {
let statusChannels = channels.map {
StatelessChannelStatusRequest(channelId: $0.channelId, site: $0.site)
}
let yatteeServerAPI = YatteeServerAPI(httpClient: HTTPClient())
let authHeader = appEnvironment.yatteeServerCredentialsManager.basicAuthHeader(for: instance)
await yatteeServerAPI.setAuthHeader(authHeader)
let maxRetries = 5
var retryCount = 0
let maxConsecutiveErrors = 3
var consecutiveErrors = 0
while retryCount < maxRetries {
// Check for cancellation before sleep
guard !Task.isCancelled else {
LoggingService.shared.debug("Feed status polling cancelled", category: .general)
break
}
// Check if app is still in foreground
guard isAppInForeground else {
LoggingService.shared.debug("Feed status polling stopped - app backgrounded", category: .general)
break
}
try? await Task.sleep(for: .seconds(5))
// Check again after sleep
guard !Task.isCancelled, isAppInForeground else {
LoggingService.shared.debug("Feed status polling cancelled during sleep", category: .general)
break
}
retryCount += 1
do {
let status = try await yatteeServerAPI.postFeedStatus(
channels: statusChannels,
instance: instance
)
consecutiveErrors = 0 // Reset on success
if status.isReady {
// Fetch full feed now that all channels are cached
if let response = try? await yatteeServerAPI.postFeed(
channels: channels,
limit: 100,
offset: 0,
instance: instance
) {
let serverVideos = response.toVideos()
update(videos: serverVideos)
appEnvironment.dataManager.updateLastVideoPublishedDates(from: serverVideos)
prefetchDeArrow(for: serverVideos, using: appEnvironment)
}
feedLoadState = .ready
isLoading = false
return
}
// Update progress UI
feedLoadState = .partiallyLoaded(
readyCount: status.readyCount,
pendingCount: status.pendingCount,
errorCount: status.errorCount
)
} catch {
consecutiveErrors += 1
LoggingService.shared.debug(
"Feed status poll error (\(consecutiveErrors)/\(maxConsecutiveErrors)): \(error.localizedDescription)",
category: .general
)
if consecutiveErrors >= maxConsecutiveErrors {
LoggingService.shared.warning(
"Feed status polling stopped after \(maxConsecutiveErrors) consecutive errors",
category: .general
)
break
}
}
}
if retryCount >= maxRetries {
LoggingService.shared.warning(
"Feed status polling timed out after \(retryCount) attempts",
category: .general
)
}
// Show whatever we have
feedLoadState = .ready
isLoading = false
}
// MARK: - Cache Warming
/// Warms the cache if expired.
func warmIfNeeded(using appEnvironment: AppEnvironment) {
guard !isLoading else { return }
Task { @MainActor in
// Load disk cache first to get accurate lastUpdated timestamp
await loadFromDiskIfNeeded()
guard !isCacheValid(using: appEnvironment.settingsManager) else { return }
// Use the same routing logic as refresh()
await refresh(using: appEnvironment)
}
}
// MARK: - Helpers
/// Prefetches DeArrow branding for YouTube videos.
private func prefetchDeArrow(for videos: [Video], using appEnvironment: AppEnvironment) {
let youtubeIDs = videos.compactMap { video -> String? in
if case .global = video.id.source { return video.id.videoID }
return nil
}
appEnvironment.deArrowBrandingProvider.prefetch(videoIDs: youtubeIDs)
}
}