mastodon-ios/Mastodon/Scene/HomeTimeline/AsyncHomeTimeline/AsyncHomeTimelineViewModel+...

118 lines
4.7 KiB
Swift

//
// AsyncHomeTimelineViewModel+LoadOldestState.swift
// Mastodon
//
// Created by MainasuK Cirno on 2021-6-21.
//
#if ASDK
import os.log
import Foundation
import GameplayKit
extension AsyncHomeTimelineViewModel {
class LoadOldestState: GKState {
weak var viewModel: AsyncHomeTimelineViewModel?
init(viewModel: AsyncHomeTimelineViewModel) {
self.viewModel = viewModel
}
override func didEnter(from previousState: GKState?) {
os_log("%{public}s[%{public}ld], %{public}s: enter %s, previous: %s", ((#file as NSString).lastPathComponent), #line, #function, self.debugDescription, previousState.debugDescription)
viewModel?.loadOldestStateMachinePublisher.send(self)
}
}
}
extension AsyncHomeTimelineViewModel.LoadOldestState {
class Initial: AsyncHomeTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
guard let viewModel = viewModel else { return false }
guard !(viewModel.fetchedResultsController.fetchedObjects ?? []).isEmpty else { return false }
return stateClass == Loading.self
}
}
class Loading: AsyncHomeTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return 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 activeMastodonAuthenticationBox = viewModel.context.authenticationService.activeMastodonAuthenticationBox.value else {
assertionFailure()
stateMachine.enter(Fail.self)
return
}
guard let last = viewModel.fetchedResultsController.fetchedObjects?.last else {
stateMachine.enter(Idle.self)
return
}
// TODO: only set large count when using Wi-Fi
let maxID = last.status.id
viewModel.context.apiService.homeTimeline(domain: activeMastodonAuthenticationBox.domain, maxID: maxID, authorizationBox: activeMastodonAuthenticationBox)
.delay(for: .seconds(1), scheduler: DispatchQueue.main)
.receive(on: DispatchQueue.main)
.sink { completion in
viewModel.homeTimelineNavigationBarTitleViewModel.receiveLoadingStateCompletion(completion)
switch completion {
case .failure(let error):
os_log("%{public}s[%{public}ld], %{public}s: fetch statuses failed. %s", ((#file as NSString).lastPathComponent), #line, #function, error.localizedDescription)
case .finished:
// handle isFetchingLatestTimeline in fetch controller delegate
break
}
} receiveValue: { response in
let statuses = response.value
// enter no more state when no new statuses
if statuses.isEmpty || (statuses.count == 1 && statuses[0].id == maxID) {
stateMachine.enter(NoMore.self)
} else {
stateMachine.enter(Idle.self)
}
}
.store(in: &viewModel.disposeBag)
}
}
class Fail: AsyncHomeTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass == Loading.self || stateClass == Idle.self
}
}
class Idle: AsyncHomeTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass == Loading.self
}
}
class NoMore: AsyncHomeTimelineViewModel.LoadOldestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
// reset state if needs
return 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)
}
}
}
}
#endif