mastodon-ios/Mastodon/Scene/Onboarding/PickServer/MastodonPickServerViewModel...

251 lines
11 KiB
Swift

//
// MastodonPickServerViewModel.swift
// Mastodon
//
// Created by BradGao on 2021/2/23.
//
import os.log
import UIKit
import Combine
import GameplayKit
import MastodonSDK
import CoreDataStack
class MastodonPickServerViewModel: NSObject {
enum PickServerMode {
case signUp
case signIn
}
enum EmptyStateViewState {
case none
case loading
case badNetwork
}
var disposeBag = Set<AnyCancellable>()
// input
let mode: PickServerMode
let context: AppContext
var categoryPickerItems: [CategoryPickerItem] = {
var items: [CategoryPickerItem] = []
items.append(.all)
items.append(contentsOf: APIService.stubCategories().map { CategoryPickerItem.category(category: $0) })
return items
}()
let selectCategoryItem = CurrentValueSubject<CategoryPickerItem, Never>(.all)
let searchText = CurrentValueSubject<String, Never>("")
let indexedServers = CurrentValueSubject<[Mastodon.Entity.Server], Never>([])
let unindexedServers = CurrentValueSubject<[Mastodon.Entity.Server]?, Never>([]) // set nil when loading
let viewWillAppear = PassthroughSubject<Void, Never>()
// output
var diffableDataSource: UITableViewDiffableDataSource<PickServerSection, PickServerItem>?
private(set) lazy var loadIndexedServerStateMachine: GKStateMachine = {
// exclude timeline middle fetcher state
let stateMachine = GKStateMachine(states: [
LoadIndexedServerState.Initial(viewModel: self),
LoadIndexedServerState.Loading(viewModel: self),
LoadIndexedServerState.Fail(viewModel: self),
LoadIndexedServerState.Idle(viewModel: self),
])
stateMachine.enter(LoadIndexedServerState.Initial.self)
return stateMachine
}()
let filteredIndexedServers = CurrentValueSubject<[Mastodon.Entity.Server], Never>([])
let servers = CurrentValueSubject<[Mastodon.Entity.Server], Error>([])
let selectedServer = CurrentValueSubject<Mastodon.Entity.Server?, Never>(nil)
let error = CurrentValueSubject<Error?, Never>(nil)
let isLoadingIndexedServers = CurrentValueSubject<Bool, Never>(false)
let emptyStateViewState = CurrentValueSubject<EmptyStateViewState, Never>(.none)
init(context: AppContext, mode: PickServerMode) {
self.context = context
self.mode = mode
super.init()
configure()
}
deinit {
os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
}
}
extension MastodonPickServerViewModel {
private func configure() {
Publishers.CombineLatest(
filteredIndexedServers,
unindexedServers
)
.receive(on: DispatchQueue.main)
.sink(receiveValue: { [weak self] indexedServers, unindexedServers in
guard let self = self else { return }
guard let diffableDataSource = self.diffableDataSource else { return }
let oldSnapshot = diffableDataSource.snapshot()
var oldSnapshotServerItemAttributeDict: [String : PickServerItem.ServerItemAttribute] = [:]
for item in oldSnapshot.itemIdentifiers {
guard case let .server(server, attribute) = item else { continue }
oldSnapshotServerItemAttributeDict[server.domain] = attribute
}
var snapshot = NSDiffableDataSourceSnapshot<PickServerSection, PickServerItem>()
snapshot.appendSections([.header, .category, .search, .servers])
snapshot.appendItems([.header], toSection: .header)
snapshot.appendItems([.categoryPicker(items: self.categoryPickerItems)], toSection: .category)
snapshot.appendItems([.search], toSection: .search)
// TODO: handle filter
var serverItems: [PickServerItem] = []
for server in indexedServers {
let attribute = oldSnapshotServerItemAttributeDict[server.domain] ?? PickServerItem.ServerItemAttribute(isLast: false, isExpand: false)
attribute.isLast.value = false
let item = PickServerItem.server(server: server, attribute: attribute)
guard !serverItems.contains(item) else { continue }
serverItems.append(item)
}
if let unindexedServers = unindexedServers {
if !unindexedServers.isEmpty {
for server in unindexedServers {
let attribute = oldSnapshotServerItemAttributeDict[server.domain] ?? PickServerItem.ServerItemAttribute(isLast: false, isExpand: false)
attribute.isLast.value = false
let item = PickServerItem.server(server: server, attribute: attribute)
guard !serverItems.contains(item) else { continue }
serverItems.append(item)
}
} else {
if indexedServers.isEmpty && !self.isLoadingIndexedServers.value {
serverItems.append(.loader(attribute: PickServerItem.LoaderItemAttribute(isLast: false, isEmptyResult: true)))
}
}
} else {
serverItems.append(.loader(attribute: PickServerItem.LoaderItemAttribute(isLast: false, isEmptyResult: false)))
}
if case let .server(_, attribute) = serverItems.last {
attribute.isLast.value = true
}
if case let .loader(attribute) = serverItems.last {
attribute.isLast = true
}
snapshot.appendItems(serverItems, toSection: .servers)
diffableDataSource.defaultRowAnimation = .fade
diffableDataSource.apply(snapshot, animatingDifferences: true, completion: nil)
})
.store(in: &disposeBag)
isLoadingIndexedServers
.map { isLoadingIndexedServers -> EmptyStateViewState in
if isLoadingIndexedServers {
return .loading
} else {
return .none
}
}
.assign(to: \.value, on: emptyStateViewState)
.store(in: &disposeBag)
Publishers.CombineLatest3(
indexedServers.eraseToAnyPublisher(),
selectCategoryItem.eraseToAnyPublisher(),
searchText.debounce(for: .milliseconds(300), scheduler: DispatchQueue.main).removeDuplicates()
)
.map { indexedServers, selectCategoryItem, searchText -> [Mastodon.Entity.Server] in
// Filter the indexed servers from joinmastodon.org
switch selectCategoryItem {
case .all:
return MastodonPickServerViewModel.filterServers(servers: indexedServers, category: nil, searchText: searchText)
case .category(let category):
return MastodonPickServerViewModel.filterServers(servers: indexedServers, category: category.category.rawValue, searchText: searchText)
}
}
.assign(to: \.value, on: filteredIndexedServers)
.store(in: &disposeBag)
searchText
.debounce(for: .milliseconds(300), scheduler: DispatchQueue.main)
.removeDuplicates()
.compactMap { [weak self] searchText -> AnyPublisher<Result<Mastodon.Response.Content<[Mastodon.Entity.Server]>, Error>, Never>? in
// Check if searchText is a valid mastodon server domain
guard let self = self else { return nil }
guard let domain = AuthenticationViewModel.parseDomain(from: searchText) else {
return Just(Result.failure(APIService.APIError.implicit(.badRequest))).eraseToAnyPublisher()
}
self.unindexedServers.value = nil
return self.context.apiService.instance(domain: domain)
.map { response -> Result<Mastodon.Response.Content<[Mastodon.Entity.Server]>, Error>in
let newResponse = response.map { [Mastodon.Entity.Server(instance: $0)] }
return Result.success(newResponse)
}
.catch { error in
return Just(Result.failure(error))
}
.eraseToAnyPublisher()
}
.switchToLatest()
.sink(receiveValue: { [weak self] result in
guard let self = self else { return }
switch result {
case .success(let response):
self.unindexedServers.send(response.value)
case .failure(let error):
if let error = error as? APIService.APIError,
case let .implicit(reason) = error,
case .badRequest = reason {
self.unindexedServers.send([])
} else {
self.unindexedServers.send(nil)
}
}
})
.store(in: &disposeBag)
}
}
extension MastodonPickServerViewModel {
private static func filterServers(servers: [Mastodon.Entity.Server], category: String?, searchText: String) -> [Mastodon.Entity.Server] {
return servers
// 1. Filter the category
.filter {
guard let category = category else { return true }
return $0.category.caseInsensitiveCompare(category) == .orderedSame
}
// 2. Filter the searchText
.filter {
let searchText = searchText.trimmingCharacters(in: .whitespacesAndNewlines)
guard !searchText.isEmpty else {
return true
}
return $0.domain.lowercased().contains(searchText.lowercased())
}
}
}
// MARK: - SignUp methods & structs
extension MastodonPickServerViewModel {
struct SignUpResponseFirst {
let instance: Mastodon.Response.Content<Mastodon.Entity.Instance>
let application: Mastodon.Response.Content<Mastodon.Entity.Application>
}
struct SignUpResponseSecond {
let instance: Mastodon.Response.Content<Mastodon.Entity.Instance>
let authenticateInfo: AuthenticationViewModel.AuthenticateInfo
}
struct SignUpResponseThird {
let instance: Mastodon.Response.Content<Mastodon.Entity.Instance>
let authenticateInfo: AuthenticationViewModel.AuthenticateInfo
let applicationToken: Mastodon.Response.Content<Mastodon.Entity.Token>
}
}