mastodon-ios/Mastodon/Scene/Discovery/News/DiscoveryNewsViewModel+Stat...

207 lines
7.1 KiB
Swift

//
// DiscoveryNewsViewModel+State.swift
// Mastodon
//
// Created by MainasuK on 2022-4-13.
//
import os.log
import Foundation
import GameplayKit
import MastodonSDK
extension DiscoveryNewsViewModel {
class State: GKState {
let logger = Logger(subsystem: "DiscoveryNewsViewModel.State", category: "StateMachine")
let id = UUID()
weak var viewModel: DiscoveryNewsViewModel?
init(viewModel: DiscoveryNewsViewModel) {
self.viewModel = viewModel
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
let from = previousState.flatMap { String(describing: $0) } ?? "nil"
let to = String(describing: self)
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): \(from) -> \(to)")
}
@MainActor
func enter(state: State.Type) {
stateMachine?.enter(state)
}
deinit {
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): [\(self.id.uuidString)] \(String(describing: self))")
}
}
}
extension DiscoveryNewsViewModel.State {
class Initial: DiscoveryNewsViewModel.State {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
switch stateClass {
case is Reloading.Type:
return true
default:
return false
}
}
}
class Reloading: DiscoveryNewsViewModel.State {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
switch stateClass {
case is Loading.Type:
return true
default:
return false
}
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
guard let _ = viewModel, let stateMachine = stateMachine else { return }
stateMachine.enter(Loading.self)
}
}
class Fail: DiscoveryNewsViewModel.State {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
switch stateClass {
case is Loading.Type:
return true
default:
return false
}
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
guard let _ = viewModel, let stateMachine = stateMachine else { return }
os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: retry loading 3s later…", ((#file as NSString).lastPathComponent), #line, #function)
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: retry loading", ((#file as NSString).lastPathComponent), #line, #function)
stateMachine.enter(Loading.self)
}
}
}
class Idle: DiscoveryNewsViewModel.State {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
switch stateClass {
case is Reloading.Type, is Loading.Type:
return true
default:
return false
}
}
}
class Loading: DiscoveryNewsViewModel.State {
var offset: Int?
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
switch stateClass {
case is Fail.Type:
return true
case is Idle.Type:
return true
case is NoMore.Type:
return true
default:
return false
}
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
guard let viewModel = viewModel, let stateMachine = stateMachine else { return }
switch previousState {
case is Reloading:
offset = nil
default:
break
}
let offset = self.offset
let isReloading = offset == nil
Task {
do {
let response = try await viewModel.context.apiService.trendLinks(
domain: viewModel.authContext.mastodonAuthenticationBox.domain,
query: Mastodon.API.Trends.StatusQuery(
offset: offset,
limit: nil
)
)
let newOffset: Int? = {
guard let offset = response.link?.offset else { return nil }
return self.offset.flatMap { max($0, offset) } ?? offset
}()
let hasMore: Bool = {
guard let newOffset = newOffset else { return false }
return newOffset != self.offset // not the same one
}()
self.offset = newOffset
var hasNewItemsAppend = false
var links = isReloading ? [] : viewModel.links
for link in response.value {
guard !links.contains(link) else { continue }
links.append(link)
hasNewItemsAppend = true
}
if hasNewItemsAppend, hasMore {
await enter(state: Idle.self)
} else {
await enter(state: NoMore.self)
}
viewModel.links = links
viewModel.didLoadLatest.send()
} catch {
logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): fetch news fail: \(error.localizedDescription)")
if let error = error as? Mastodon.API.Error, error.httpResponseStatus.code == 404 {
viewModel.isServerSupportEndpoint = false
await enter(state: NoMore.self)
} else {
await enter(state: Fail.self)
}
viewModel.didLoadLatest.send()
}
} // end Task
} // end func
}
class NoMore: DiscoveryNewsViewModel.State {
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
switch stateClass {
case is Reloading.Type:
return true
default:
return false
}
}
override func didEnter(from previousState: GKState?) {
super.didEnter(from: previousState)
}
}
}