mastodon-ios/Mastodon/Scene/HomeTimeline/HomeTimelineViewModel+LoadL...

126 lines
5.4 KiB
Swift

//
// HomeTimelineViewModel+LoadLatestState.swift
// Mastodon
//
// Created by sxiaojian on 2021/2/5.
//
import os.log
import func QuartzCore.CACurrentMediaTime
import Foundation
import CoreData
import CoreDataStack
import GameplayKit
import MastodonCore
extension HomeTimelineViewModel {
class LoadLatestState: GKState {
let logger = Logger(subsystem: "HomeTimelineViewModel.LoadLatestState", category: "StateMachine")
let id = UUID()
var name: String {
String(describing: Self.self)
}
weak var viewModel: HomeTimelineViewModel?
init(viewModel: HomeTimelineViewModel) {
self.viewModel = viewModel
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
let previousState = previousState as? HomeTimelineViewModel.LoadLatestState
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>")")
viewModel?.loadLatestStateMachinePublisher.send(self)
}
@MainActor
func enter(state: LoadLatestState.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 HomeTimelineViewModel.LoadLatestState {
class Initial: HomeTimelineViewModel.LoadLatestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass == Loading.self
}
}
class Loading: HomeTimelineViewModel.LoadLatestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass == Fail.self || stateClass == Idle.self
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
guard let viewModel = viewModel, let stateMachine = stateMachine else { return }
let latestFeedRecords = viewModel.fetchedResultsController.records.prefix(APIService.onceRequestStatusMaxCount)
let parentManagedObjectContext = viewModel.fetchedResultsController.fetchedResultsController.managedObjectContext
let managedObjectContext = NSManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)
managedObjectContext.parent = parentManagedObjectContext
Task {
let start = CACurrentMediaTime()
let latestStatusIDs: [Status.ID] = latestFeedRecords.compactMap { record in
guard let feed = record.object(in: managedObjectContext) else { return nil }
return feed.status?.id
}
let end = CACurrentMediaTime()
os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: collect statuses id cost: %.2fs", ((#file as NSString).lastPathComponent), #line, #function, end - start)
do {
let response = try await viewModel.context.apiService.homeTimeline(
authenticationBox: viewModel.authContext.mastodonAuthenticationBox
)
await enter(state: Idle.self)
viewModel.homeTimelineNavigationBarTitleViewModel.receiveLoadingStateCompletion(.finished)
// stop refresher if no new statuses
let statuses = response.value
let newStatuses = statuses.filter { !latestStatusIDs.contains($0.id) }
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): load \(newStatuses.count) new statuses")
if newStatuses.isEmpty {
viewModel.didLoadLatest.send()
} else {
if !latestStatusIDs.isEmpty {
viewModel.homeTimelineNavigationBarTitleViewModel.newPostsIncoming()
}
}
viewModel.timelineIsEmpty.value = latestStatusIDs.isEmpty && statuses.isEmpty
} catch {
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): fetch statuses failed: \(error.localizedDescription)")
await enter(state: Idle.self)
viewModel.didLoadLatest.send()
viewModel.homeTimelineNavigationBarTitleViewModel.receiveLoadingStateCompletion(.failure(error))
}
} // end Task
}
}
class Fail: HomeTimelineViewModel.LoadLatestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass == Loading.self || stateClass == Idle.self
}
}
class Idle: HomeTimelineViewModel.LoadLatestState {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass == Loading.self
}
}
}