mastodon-ios/Mastodon/Scene/Notification/NotificationTimeline/NotificationTimelineViewMod...

147 lines
5.7 KiB
Swift

//
// NotificationTimelineViewModel+LoadOldestState.swift
// Mastodon
//
// Created by MainasuK on 2022-1-21.
//
import CoreDataStack
import Foundation
import GameplayKit
import MastodonSDK
import os.log
extension NotificationTimelineViewModel {
class LoadOldestState: GKState, NamingState {
let logger = Logger(subsystem: "NotificationTimelineViewModel.LoadOldestState", category: "StateMachine")
let id = UUID()
var name: String {
String(describing: Self.self)
}
weak var viewModel: NotificationTimelineViewModel?
init(viewModel: NotificationTimelineViewModel) {
self.viewModel = viewModel
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
let previousState = previousState as? NotificationTimelineViewModel.LoadOldestState
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): [\(self.id.uuidString)] enter \(self.name), previous: \(previousState?.name ?? "<nil>")")
}
@MainActor
func enter(state: LoadOldestState.Type) {
stateMachine?.enter(state)
}
deinit {
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): [\(self.id.uuidString)] \(self.name)")
}
}
}
extension NotificationTimelineViewModel.LoadOldestState {
class Initial: NotificationTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
guard let viewModel = viewModel else { return false }
guard !viewModel.feedFetchedResultsController.records.isEmpty else { return false }
return stateClass == Loading.self
}
}
class Loading: NotificationTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
stateClass == Fail.self || stateClass == Idle.self || stateClass == NoMore.self
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
guard let viewModel = viewModel, let stateMachine = stateMachine else { return }
guard let authenticationBox = viewModel.context.authenticationService.activeMastodonAuthenticationBox.value else {
assertionFailure()
stateMachine.enter(Fail.self)
return
}
guard let lastFeedRecord = viewModel.feedFetchedResultsController.records.last else {
stateMachine.enter(Fail.self)
return
}
let scope = viewModel.scope
Task {
let managedObjectContext = viewModel.context.managedObjectContext
let _maxID: Mastodon.Entity.Notification.ID? = try await managedObjectContext.perform {
guard let feed = lastFeedRecord.object(in: managedObjectContext),
let notification = feed.notification
else { return nil }
return notification.id
}
guard let maxID = _maxID else {
await self.enter(state: Fail.self)
return
}
do {
let response = try await viewModel.context.apiService.notifications(
maxID: maxID,
scope: scope,
authenticationBox: authenticationBox
)
let notifications = response.value
// enter no more state when no new statuses
if notifications.isEmpty || (notifications.count == 1 && notifications[0].id == maxID) {
await self.enter(state: NoMore.self)
} else {
await self.enter(state: Idle.self)
}
} catch {
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): fetch statues failed: \(error.localizedDescription)")
await self.enter(state: Fail.self)
}
} // Task
}
}
class Fail: NotificationTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
stateClass == Loading.self || stateClass == Idle.self
}
}
class Idle: NotificationTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
stateClass == Loading.self
}
}
class NoMore: NotificationTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
// reset state if needs
stateClass == Idle.self
}
override func didEnter(from previousState: GKState?) {
guard let viewModel = viewModel else { return }
guard let diffableDataSource = viewModel.diffableDataSource else {
assertionFailure()
return
}
DispatchQueue.main.async {
var snapshot = diffableDataSource.snapshot()
snapshot.deleteItems([.bottomLoader])
diffableDataSource.apply(snapshot)
}
}
}
}