Refactor status lists

ServiceLayer/Sources/ServiceLayer/Extensions/URL+Extensions.swift

@@ -0,0 +1,42 @@
+// Copyright © 2020 Metabolist. All rights reserved.
+
+import Foundation
+
+extension URL {
+    var isAccountURL: Bool {
+        (pathComponents.count == 2 && pathComponents[1].starts(with: "@"))
+            || (pathComponents.count == 3 && pathComponents[0...1] == ["/", "users"])
+    }
+
+    var accountID: String? {
+        if let accountID = pathComponents.last, pathComponents == ["/", "web", "accounts", accountID] {
+            return accountID
+        }
+
+        return nil
+    }
+
+    var statusID: String? {
+        guard let statusID = pathComponents.last else { return nil }
+
+        if pathComponents.count == 3, pathComponents[1].starts(with: "@") {
+            return statusID
+        } else if pathComponents == ["/", "web", "statuses", statusID] {
+            return statusID
+        }
+
+        return nil
+    }
+
+    var tag: String? {
+        if let tag = pathComponents.last, pathComponents == ["/", "tags", tag] {
+            return tag
+        }
+
+        return nil
+    }
+
+    var shouldWebfinger: Bool {
+        isAccountURL || accountID != nil || statusID != nil || tag != nil
+    }
+}

ServiceLayer/Sources/ServiceLayer/IdentityService.swift

@@ -199,7 +199,7 @@ public extension IdentityService {
     }
 
     func service(timeline: Timeline) -> StatusListService {
-        TimelineService(timeline: timeline, networkClient: networkClient, contentDatabase: contentDatabase)
+        StatusListService(timeline: timeline, networkClient: networkClient, contentDatabase: contentDatabase)
     }
 }
 

ServiceLayer/Sources/ServiceLayer/Status List Services/ContextService.swift

@@ -1,84 +0,0 @@
-// Copyright © 2020 Metabolist. All rights reserved.
-
-import Foundation
-import Combine
-import Mastodon
-
-public struct ContextService {
-    public let statusSections: AnyPublisher<[[Status]], Error>
-    public let paginates = false
-
-    private let status: Status
-    private let context = CurrentValueSubject<Context, Never>(Context(ancestors: [], descendants: []))
-    private let networkClient: APIClient
-    private let contentDatabase: ContentDatabase
-
-    init(status: Status, networkClient: APIClient, contentDatabase: ContentDatabase) {
-        self.status = status
-        self.networkClient = networkClient
-        self.contentDatabase = contentDatabase
-        statusSections = contentDatabase.contextObservation(parentID: status.id)
-    }
-}
-
-extension ContextService: StatusListService {
-    public var filters: AnyPublisher<[Filter], Error> {
-        contentDatabase.activeFiltersObservation(date: Date(), context: .thread)
-    }
-
-    public var contextParentID: String? { status.id }
-
-    public func isReplyInContext(status: Status) -> Bool {
-        let flatContext = flattenedContext()
-
-        guard
-            let index = flatContext.firstIndex(where: { $0.id == status.id }),
-            index > 0
-        else { return false }
-
-        let previousStatus = flatContext[index - 1]
-
-        return previousStatus.id != contextParentID && status.inReplyToId == previousStatus.id
-    }
-
-    public func hasReplyFollowing(status: Status) -> Bool {
-        let flatContext = flattenedContext()
-
-        guard
-            let index = flatContext.firstIndex(where: { $0.id == status.id }),
-            flatContext.count > index + 1
-        else { return false }
-
-        let nextStatus = flatContext[index + 1]
-
-        return status.id != contextParentID && nextStatus.inReplyToId == status.id
-    }
-
-    public func request(maxID: String?, minID: String?) -> AnyPublisher<Never, Error> {
-        Publishers.Merge(
-            networkClient.request(StatusEndpoint.status(id: status.id))
-                .map { ([$0], nil) }
-                .flatMap(contentDatabase.insert(statuses:timeline:))
-                .eraseToAnyPublisher(),
-            networkClient.request(ContextEndpoint.context(id: status.id))
-                .handleEvents(receiveOutput: context.send)
-                .map { ($0, status.id) }
-                .flatMap(contentDatabase.insert(context:parentID:))
-                .eraseToAnyPublisher())
-            .eraseToAnyPublisher()
-    }
-
-    public func statusService(status: Status) -> StatusService {
-        StatusService(status: status, networkClient: networkClient, contentDatabase: contentDatabase)
-    }
-
-    public func contextService(status: Status) -> ContextService {
-        ContextService(status: status.displayStatus, networkClient: networkClient, contentDatabase: contentDatabase)
-    }
-}
-
-private extension ContextService {
-    func flattenedContext() -> [Status] {
-        context.value.ancestors + [status] + context.value.descendants
-    }
-}

ServiceLayer/Sources/ServiceLayer/Status List Services/StatusListService.swift

@@ -1,30 +0,0 @@
-// Copyright © 2020 Metabolist. All rights reserved.
-
-import Foundation
-import Combine
-import Mastodon
-
-public protocol StatusListService {
-    var statusSections: AnyPublisher<[[Status]], Error> { get }
-    var filters: AnyPublisher<[Filter], Error> { get }
-    var paginates: Bool { get }
-    var contextParentID: String? { get }
-    func isPinned(status: Status) -> Bool
-    func isReplyInContext(status: Status) -> Bool
-    func hasReplyFollowing(status: Status) -> Bool
-    func request(maxID: String?, minID: String?) -> AnyPublisher<Never, Error>
-    func statusService(status: Status) -> StatusService
-    func contextService(status: Status) -> ContextService
-}
-
-public extension StatusListService {
-    var paginates: Bool { true }
-
-    var contextParentID: String? { nil }
-
-    func isPinned(status: Status) -> Bool { false }
-
-    func isReplyInContext(status: Status) -> Bool { false }
-
-    func hasReplyFollowing(status: Status) -> Bool { false }
-}

ServiceLayer/Sources/ServiceLayer/Status List Services/TimelineService.swift

@@ -1,53 +0,0 @@
-// Copyright © 2020 Metabolist. All rights reserved.
-
-import Foundation
-import Combine
-import Mastodon
-
-struct TimelineService {
-    let statusSections: AnyPublisher<[[Status]], Error>
-
-    private let timeline: Timeline
-    private let networkClient: APIClient
-    private let contentDatabase: ContentDatabase
-
-    init(timeline: Timeline, networkClient: APIClient, contentDatabase: ContentDatabase) {
-        self.timeline = timeline
-        self.networkClient = networkClient
-        self.contentDatabase = contentDatabase
-        statusSections = contentDatabase.statusesObservation(timeline: timeline)
-            .eraseToAnyPublisher()
-    }
-}
-
-extension TimelineService: StatusListService {
-    var filters: AnyPublisher<[Filter], Error> {
-        contentDatabase.activeFiltersObservation(date: Date(), context: filterContext)
-    }
-
-    func request(maxID: String?, minID: String?) -> AnyPublisher<Never, Error> {
-        networkClient.request(Paged(timeline.endpoint, maxID: maxID, minID: minID))
-            .map { ($0, timeline) }
-            .flatMap(contentDatabase.insert(statuses:timeline:))
-            .eraseToAnyPublisher()
-    }
-
-    func statusService(status: Status) -> StatusService {
-        StatusService(status: status, networkClient: networkClient, contentDatabase: contentDatabase)
-    }
-
-    func contextService(status: Status) -> ContextService {
-        ContextService(status: status.displayStatus, networkClient: networkClient, contentDatabase: contentDatabase)
-    }
-}
-
-private extension TimelineService {
-    var filterContext: Filter.Context {
-        switch timeline {
-        case .home, .list:
-            return .home
-        case .local, .federated, .tag:
-            return .public
-        }
-    }
-}

ServiceLayer/Sources/ServiceLayer/StatusListService.swift

@@ -0,0 +1,75 @@
+// Copyright © 2020 Metabolist. All rights reserved.
+
+import Combine
+import Foundation
+import Mastodon
+
+public struct StatusListService {
+    public let statusSections: AnyPublisher<[[Status]], Error>
+    public let paginates: Bool
+    public let contextParentID: String?
+
+    private let filterContext: Filter.Context
+    private let networkClient: APIClient
+    private let contentDatabase: ContentDatabase
+    private let requestClosure: (_ maxID: String?, _ minID: String?) -> AnyPublisher<Never, Error>
+}
+
+extension StatusListService {
+    init(timeline: Timeline, networkClient: APIClient, contentDatabase: ContentDatabase) {
+        let filterContext: Filter.Context
+
+        switch timeline {
+        case .home, .list:
+            filterContext = .home
+        case .local, .federated, .tag:
+            filterContext = .public
+        }
+
+        self.init(statusSections: contentDatabase.statusesObservation(timeline: timeline),
+                  paginates: true,
+                  contextParentID: nil,
+                  filterContext: filterContext,
+                  networkClient: networkClient,
+                  contentDatabase: contentDatabase) { maxID, minID in
+            networkClient.request(Paged(timeline.endpoint, maxID: maxID, minID: minID))
+                .map { ($0, timeline) }
+                .flatMap(contentDatabase.insert(statuses:timeline:))
+                .eraseToAnyPublisher()
+        }
+    }
+}
+
+public extension StatusListService {
+    func request(maxID: String?, minID: String?) -> AnyPublisher<Never, Error> {
+        requestClosure(maxID, minID)
+    }
+
+    var filters: AnyPublisher<[Filter], Error> {
+        contentDatabase.activeFiltersObservation(date: Date(), context: filterContext)
+    }
+
+    func statusService(status: Status) -> StatusService {
+        StatusService(status: status, networkClient: networkClient, contentDatabase: contentDatabase)
+    }
+
+    func contextService(statusID: String) -> Self {
+        Self(statusSections: contentDatabase.contextObservation(parentID: statusID),
+             paginates: false,
+             contextParentID: statusID,
+             filterContext: .thread,
+             networkClient: networkClient,
+             contentDatabase: contentDatabase) { _, _ in
+            Publishers.Merge(
+                networkClient.request(StatusEndpoint.status(id: statusID))
+                    .map { ([$0], nil) }
+                    .flatMap(contentDatabase.insert(statuses:timeline:))
+                    .eraseToAnyPublisher(),
+                networkClient.request(ContextEndpoint.context(id: statusID))
+                    .map { ($0, statusID) }
+                    .flatMap(contentDatabase.insert(context:parentID:))
+                    .eraseToAnyPublisher())
+                .eraseToAnyPublisher()
+        }
+    }
+}

View Controllers/StatusListViewController.swift

@@ -9,6 +9,8 @@ class StatusListViewController: UITableViewController {
     private let loadingTableFooterView = LoadingTableFooterView()
     private var cancellables = Set<AnyCancellable>()
     private var cellHeightCaches = [CGFloat: [String: CGFloat]]()
+    private let dataSourceQueue =
+        DispatchQueue(label: "com.metabolist.metatext.status-list.data-source-queue")
 
     private lazy var dataSource: UITableViewDiffableDataSource<Int, String> = {
         UITableViewDiffableDataSource(tableView: tableView) { [weak self] tableView, indexPath, statusID in
@@ -54,7 +56,7 @@ class StatusListViewController: UITableViewController {
         tableView.tableFooterView = UIView()
 
         viewModel.$statusIDs
-            .sink { [weak self] in
+            .sink { [weak self] statusIDs in
                 guard let self = self else { return }
 
                 var offsetFromNavigationBar: CGFloat?
@@ -67,7 +69,8 @@ class StatusListViewController: UITableViewController {
                     offsetFromNavigationBar = self.tableView.rectForRow(at: indexPath).origin.y - navigationBarMaxY
                 }
 
-                self.dataSource.apply($0.snapshot(), animatingDifferences: false) {
+                self.dataSourceQueue.async {
+                    self.dataSource.apply(statusIDs.snapshot(), animatingDifferences: false) {
                         if
                             let id = self.viewModel.maintainScrollPositionOfStatusID,
                             let indexPath = self.dataSource.indexPath(for: id) {
@@ -79,6 +82,7 @@ class StatusListViewController: UITableViewController {
                         }
                     }
                 }
+            }
             .store(in: &cancellables)
 
         viewModel.$loading
@@ -122,13 +126,10 @@ class StatusListViewController: UITableViewController {
     }
 
     override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
-        guard
+        guard let id = dataSource.itemIdentifier(for: indexPath) else { return }
-            let id = dataSource.itemIdentifier(for: indexPath),
-            let contextViewModel = viewModel.contextViewModel(id: id)
-        else { return }
 
         navigationController?.pushViewController(
-            StatusListViewController(viewModel: contextViewModel),
+            StatusListViewController(viewModel: viewModel.contextViewModel(id: id)),
             animated: true)
     }
 

ViewModels/Sources/ViewModels/StatusListViewModel.swift

@@ -65,18 +65,16 @@ public extension StatusListViewModel {
                 .sink { _ in })
         }
 
-        statusViewModel.isContextParent = status.id == contextParentID
+        statusViewModel.isContextParent = status.id == statusListService.contextParentID
-        statusViewModel.isPinned = statusListService.isPinned(status: status)
+        statusViewModel.isPinned = status.displayStatus.pinned ?? false
-        statusViewModel.isReplyInContext = statusListService.isReplyInContext(status: status)
+        statusViewModel.isReplyInContext = isReplyInContext(status: status)
-        statusViewModel.hasReplyFollowing = statusListService.hasReplyFollowing(status: status)
+        statusViewModel.hasReplyFollowing = hasReplyFollowing(status: status)
 
         return statusViewModel
     }
 
-    func contextViewModel(id: String) -> StatusListViewModel? {
+    func contextViewModel(id: String) -> StatusListViewModel {
-        guard let status = statuses[id] else { return nil }
+        StatusListViewModel(statusListService: statusListService.contextService(statusID: id))
-
-        return StatusListViewModel(statusListService: statusListService.contextService(status: status))
     }
 }
 
@@ -105,4 +103,29 @@ private extension StatusListViewModel {
 
         statusViewModelCache = statusViewModelCache.filter { newStatuses.contains($0.key) }
     }
+
+    func isReplyInContext(status: Status) -> Bool {
+        let flatStatusIDs = statusIDs.reduce([], +)
+
+        guard
+            let index = flatStatusIDs.firstIndex(where: { $0 == status.id }),
+            index > 0
+        else { return false }
+
+        let previousStatusID = flatStatusIDs[index - 1]
+
+        return previousStatusID != contextParentID && status.inReplyToId == previousStatusID
+    }
+
+    func hasReplyFollowing(status: Status) -> Bool {
+        let flatStatusIDs = statusIDs.reduce([], +)
+
+        guard
+            let index = flatStatusIDs.firstIndex(where: { $0 == status.id }),
+            flatStatusIDs.count > index + 1,
+            let nextStatus = statuses[flatStatusIDs[index + 1]]
+        else { return false }
+
+        return status.id != contextParentID && nextStatus.inReplyToId == status.id
+    }
 }