Add followers/following screen

Closes #323

Tusker.xcodeproj/project.pbxproj

@@ -17,6 +17,7 @@
 		04DACE8C212CB14B009840C4 /* MainTabBarViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04DACE8B212CB14B009840C4 /* MainTabBarViewController.swift */; };
 		04DACE8E212CC7CC009840C4 /* ImageCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04DACE8D212CC7CC009840C4 /* ImageCache.swift */; };
 		04ED00B121481ED800567C53 /* SteppedProgressView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04ED00B021481ED800567C53 /* SteppedProgressView.swift */; };
+		D601FA5B29787AB100A8E8B5 /* AccountFollowsListViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D601FA5A29787AB100A8E8B5 /* AccountFollowsListViewController.swift */; };
 		D6093F9B25BDD4B9004811E6 /* HashtagSearchResultsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6093F9A25BDD4B9004811E6 /* HashtagSearchResultsViewController.swift */; };
 		D6093FB725BE0CF3004811E6 /* TrendHistoryView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6093FB625BE0CF3004811E6 /* TrendHistoryView.swift */; };
 		D60CFFDB24A290BA00D00083 /* SwiftSoup in Frameworks */ = {isa = PBXBuildFile; productRef = D60CFFDA24A290BA00D00083 /* SwiftSoup */; };
@@ -155,6 +156,7 @@
 		D65B4B6629773AE600DABDFB /* DeleteStatusService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B6529773AE600DABDFB /* DeleteStatusService.swift */; };
 		D65B4B682977769E00DABDFB /* StatusActionAccountListViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B672977769E00DABDFB /* StatusActionAccountListViewController.swift */; };
 		D65B4B6A297777D900DABDFB /* StatusNotFoundView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B69297777D900DABDFB /* StatusNotFoundView.swift */; };
+		D65B4B8B297879E900DABDFB /* AccountFollowsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B8A297879E900DABDFB /* AccountFollowsViewController.swift */; };
 		D65C6BF525478A9C00A6E89C /* BackgroundableViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65C6BF425478A9C00A6E89C /* BackgroundableViewController.swift */; };
 		D65F613423AEAB6600F3CFD3 /* OnboardingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65F613323AEAB6600F3CFD3 /* OnboardingTests.swift */; };
 		D6620ACE2511A0ED00312CA0 /* StatusStateResolver.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6620ACD2511A0ED00312CA0 /* StatusStateResolver.swift */; };
@@ -413,6 +415,7 @@
 		04DACE8B212CB14B009840C4 /* MainTabBarViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainTabBarViewController.swift; sourceTree = "<group>"; };
 		04DACE8D212CC7CC009840C4 /* ImageCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ImageCache.swift; sourceTree = "<group>"; };
 		04ED00B021481ED800567C53 /* SteppedProgressView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SteppedProgressView.swift; sourceTree = "<group>"; };
+		D601FA5A29787AB100A8E8B5 /* AccountFollowsListViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AccountFollowsListViewController.swift; sourceTree = "<group>"; };
 		D6093F9A25BDD4B9004811E6 /* HashtagSearchResultsViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HashtagSearchResultsViewController.swift; sourceTree = "<group>"; };
 		D6093FB625BE0CF3004811E6 /* TrendHistoryView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TrendHistoryView.swift; sourceTree = "<group>"; };
 		D60D2B8123844C71001B87A3 /* BaseStatusTableViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BaseStatusTableViewCell.swift; sourceTree = "<group>"; };
@@ -547,6 +550,7 @@
 		D65B4B6529773AE600DABDFB /* DeleteStatusService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DeleteStatusService.swift; sourceTree = "<group>"; };
 		D65B4B672977769E00DABDFB /* StatusActionAccountListViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusActionAccountListViewController.swift; sourceTree = "<group>"; };
 		D65B4B69297777D900DABDFB /* StatusNotFoundView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusNotFoundView.swift; sourceTree = "<group>"; };
+		D65B4B8A297879E900DABDFB /* AccountFollowsViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AccountFollowsViewController.swift; sourceTree = "<group>"; };
 		D65C6BF425478A9C00A6E89C /* BackgroundableViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BackgroundableViewController.swift; sourceTree = "<group>"; };
 		D65F612D23AE990C00F3CFD3 /* Embassy.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = Embassy.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		D65F613023AE99E000F3CFD3 /* Ambassador.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = Ambassador.framework; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -966,6 +970,7 @@
 		D641C780213DD7C4004B4513 /* Screens */ = {
 			isa = PBXGroup;
 			children = (
+				D65B4B89297879DE00DABDFB /* Account Follows */,
 				D6A3BC822321F69400FD64D5 /* Account List */,
 				D6B053A023BD2BED00A066FA /* Asset Picker */,
 				0411610522B457290030A9B7 /* Attachment Gallery */,
@@ -1207,6 +1212,15 @@
 			path = Report;
 			sourceTree = "<group>";
 		};
+		D65B4B89297879DE00DABDFB /* Account Follows */ = {
+			isa = PBXGroup;
+			children = (
+				D65B4B8A297879E900DABDFB /* AccountFollowsViewController.swift */,
+				D601FA5A29787AB100A8E8B5 /* AccountFollowsListViewController.swift */,
+			);
+			path = "Account Follows";
+			sourceTree = "<group>";
+		};
 		D663626021360A9600C9CBA2 /* Preferences */ = {
 			isa = PBXGroup;
 			children = (
@@ -2024,6 +2038,7 @@
 				D627944A23A6AD6100D38C68 /* BookmarksTableViewController.swift in Sources */,
 				D63CC7102911F1E4000E19DE /* UIScrollView+Top.swift in Sources */,
 				D6F6A557291F4F1600F496A8 /* MuteAccountView.swift in Sources */,
+				D65B4B8B297879E900DABDFB /* AccountFollowsViewController.swift in Sources */,
 				D6945C3A23AC75E2005C403C /* FindInstanceViewController.swift in Sources */,
 				D65B4B6429771EFF00DABDFB /* ConversationViewController.swift in Sources */,
 				D68E6F59253C9969001A1B4C /* MultiSourceEmojiLabel.swift in Sources */,
@@ -2060,6 +2075,7 @@
 				D6969EA0240C8384002843CE /* EmojiLabel.swift in Sources */,
 				D64BC18623C1253A000D0238 /* AssetPreviewViewController.swift in Sources */,
 				D6F6A550291F058600F496A8 /* CreateListService.swift in Sources */,
+				D601FA5B29787AB100A8E8B5 /* AccountFollowsListViewController.swift in Sources */,
 				D6BEA24B291C6A2B002F4D01 /* AlertWithData.swift in Sources */,
 				D61ABEFE28F1C92600B29151 /* FavoriteService.swift in Sources */,
 				D61F75AB293AF11400C0B37F /* FilterKeywordMO.swift in Sources */,

Tusker/CoreData/MastodonCachePersistentStore.swift

@@ -348,6 +348,14 @@ class MastodonCachePersistentStore: NSPersistentCloudKitContainer {
             accounts.forEach { self.accountSubject.send($0.id) }
         }
     }
+    
+    func addAll(accounts: [Account], in context: NSManagedObjectContext? = nil) async {
+        await withCheckedContinuation { continuation in
+            addAll(accounts: accounts, in: context) {
+                continuation.resume()
+            }
+        }
+    }
 
     func addAll(notifications: [Pachyderm.Notification], completion: (() -> Void)? = nil) {
         backgroundContext.perform {

Tusker/Screens/Account Follows/AccountFollowsListViewController.swift

@@ -0,0 +1,277 @@
+//
+//  AccountFollowsListViewController.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 1/18/23.
+//  Copyright © 2023 Shadowfacts. All rights reserved.
+//
+
+import UIKit
+import Pachyderm
+
+class AccountFollowsListViewController: UIViewController, CollectionViewController {
+    
+    let accountID: String
+    let mastodonController: MastodonController
+    let mode: AccountFollowsViewController.Mode
+    
+    var collectionView: UICollectionView! {
+        view as? UICollectionView
+    }
+    private var dataSource: UICollectionViewDiffableDataSource<Section, Item>!
+    
+    private var state: State = .unloaded
+    private var newer: RequestRange?
+    private var older: RequestRange?
+    
+    init(accountID: String, mastodonController: MastodonController, mode: AccountFollowsViewController.Mode) {
+        self.accountID = accountID
+        self.mastodonController = mastodonController
+        self.mode = mode
+        
+        super.init(nibName: nil, bundle: nil)
+        
+        title = mode.title
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    override func loadView() {
+        var config = UICollectionLayoutListConfiguration(appearance: .grouped)
+        config.itemSeparatorHandler = { [unowned self] indexPath, sectionConfig in
+            guard let item = self.dataSource.itemIdentifier(for: indexPath) else {
+                return sectionConfig
+            }
+            var config = sectionConfig
+            if item.hideSeparators {
+                config.topSeparatorVisibility = .hidden
+                config.bottomSeparatorVisibility = .hidden
+            }
+            return config
+        }
+        let layout = UICollectionViewCompositionalLayout.list(using: config)
+        view = UICollectionView(frame: .zero, collectionViewLayout: layout)
+        collectionView.delegate = self
+        collectionView.dragDelegate = self
+        collectionView.allowsFocus = true
+        dataSource = createDataSource()
+    }
+    
+    private func createDataSource() -> UICollectionViewDiffableDataSource<Section, Item> {
+        let accountCell = UICollectionView.CellRegistration<AccountCollectionViewCell, String> { [unowned self] cell, indexPath, item in
+            cell.delegate = self
+            cell.updateUI(accountID: item)
+        }
+        let loadingCell = UICollectionView.CellRegistration<LoadingCollectionViewCell, Void> { cell, indexPath, item in
+            cell.indicator.startAnimating()
+        }
+        return UICollectionViewDiffableDataSource(collectionView: collectionView, cellProvider: { collectionView, indexPath, itemIdentifier in
+            switch itemIdentifier {
+            case .account(let id):
+                return collectionView.dequeueConfiguredReusableCell(using: accountCell, for: indexPath, item: id)
+            case .loadingIndicator:
+                return collectionView.dequeueConfiguredReusableCell(using: loadingCell, for: indexPath, item: ())
+            }
+        })
+    }
+    
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        
+        clearSelectionOnAppear(animated: animated)
+        
+        if case .unloaded = state {
+            Task {
+                await loadInitial()
+            }
+        }
+    }
+    
+    private func request(for range: RequestRange) -> Request<[Account]> {
+        switch mode {
+        case .following:
+            return Account.getFollowing(accountID, range: range)
+        case .followers:
+            return Account.getFollowers(accountID, range: range)
+        }
+    }
+    
+    private func apply(snapshot: NSDiffableDataSourceSnapshot<Section, Item>) async {
+        await Task { @MainActor in
+            self.dataSource.apply(snapshot)
+        }.value
+    }
+    
+    @MainActor
+    private func loadInitial() async {
+        guard case .unloaded = state else {
+            return
+        }
+        
+        self.state = .loadingInitial
+        var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
+        snapshot.appendSections([.accounts])
+        snapshot.appendItems([.loadingIndicator])
+        await apply(snapshot: snapshot)
+        
+        do {
+            let (accounts, pagination) = try await mastodonController.run(request(for: .default))
+            await mastodonController.persistentContainer.addAll(accounts: accounts)
+            
+            guard case .loadingInitial = self.state else {
+                return
+            }
+            self.state = .loaded
+            self.newer = pagination?.newer
+            self.older = pagination?.older
+            
+            var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
+            snapshot.appendSections([.accounts])
+            snapshot.appendItems(accounts.map { .account($0.id) })
+            await apply(snapshot: snapshot)
+            
+        } catch {
+            self.state = .unloaded
+            
+            let config = ToastConfiguration(from: error, with: "Error Loading Accounts", in: self) { [unowned self] toast in
+                toast.dismissToast(animated: true)
+                await self.loadInitial()
+            }
+            self.showToast(configuration: config, animated: true)
+        }
+    }
+    
+    @MainActor
+    private func loadOlder() async {
+        guard case .loaded = state,
+              let older else {
+            return
+        }
+        
+        self.state = .loadingOlder
+        var snapshot = dataSource.snapshot()
+        snapshot.appendItems([.loadingIndicator])
+        await apply(snapshot: snapshot)
+        
+        do {
+            let (accounts, pagination) = try await mastodonController.run(request(for: older))
+            await mastodonController.persistentContainer.addAll(accounts: accounts)
+            
+            guard case .loadingOlder = self.state else {
+                return
+            }
+            self.state = .loaded
+            self.older = pagination?.older
+            
+            var snapshot = dataSource.snapshot()
+            snapshot.deleteItems([.loadingIndicator])
+            snapshot.appendItems(accounts.map { .account($0.id) })
+            await apply(snapshot: snapshot)
+            
+        } catch {
+            self.state = .loaded
+            
+            let config = ToastConfiguration(from: error, with: "Error Loading More", in: self) { [unowned self] toast in
+                toast.dismissToast(animated: true)
+                await self.loadOlder()
+            }
+            self.showToast(configuration: config, animated: true)
+        }
+    }
+}
+
+extension AccountFollowsListViewController {
+    enum State {
+        case unloaded
+        case loadingInitial
+        case loaded
+        case loadingOlder
+    }
+}
+
+extension AccountFollowsListViewController {
+    enum Section {
+        case accounts
+    }
+    enum Item: Hashable {
+        case account(String)
+        case loadingIndicator
+        
+        var hideSeparators: Bool {
+            switch self {
+            case .account(_):
+                return false
+            case .loadingIndicator:
+                return true
+            }
+        }
+    }
+}
+
+extension AccountFollowsListViewController: UICollectionViewDelegate {
+    func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
+        if indexPath.section == collectionView.numberOfSections - 1,
+           indexPath.row == collectionView.numberOfItems(inSection: indexPath.section) - 1 {
+            Task {
+                await self.loadOlder()
+            }
+        }
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
+        guard case .account(let id) = dataSource.itemIdentifier(for: indexPath) else {
+            return
+        }
+        selected(account: id)
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, contextMenuConfigurationForItemAt indexPath: IndexPath, point: CGPoint) -> UIContextMenuConfiguration? {
+        guard case .account(let id) = dataSource.itemIdentifier(for: indexPath),
+              let cell = collectionView.cellForItem(at: indexPath) else {
+            return nil
+        }
+        return UIContextMenuConfiguration {
+            ProfileViewController(accountID: id, mastodonController: self.mastodonController)
+        } actionProvider: { _ in
+            UIMenu(children: self.actionsForProfile(accountID: id, source: .view(cell)))
+        }
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, willPerformPreviewActionForMenuWith configuration: UIContextMenuConfiguration, animator: UIContextMenuInteractionCommitAnimating) {
+        MenuPreviewHelper.willPerformPreviewAction(animator: animator, presenter: self)
+    }
+}
+
+extension AccountFollowsListViewController: UICollectionViewDragDelegate {
+    func collectionView(_ collectionView: UICollectionView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {
+        guard case .account(let id) = dataSource.itemIdentifier(for: indexPath),
+              let currentAccountID = mastodonController.accountInfo?.id,
+              let account = mastodonController.persistentContainer.account(for: id) else {
+            return []
+        }
+        let provider = NSItemProvider(object: account.url as NSURL)
+        let activity = UserActivityManager.showProfileActivity(id: id, accountID: currentAccountID)
+        activity.displaysAuxiliaryScene = true
+        provider.registerObject(activity, visibility: .all)
+        return [UIDragItem(itemProvider: provider)]
+    }
+}
+
+extension AccountFollowsListViewController: TuskerNavigationDelegate {
+    var apiController: MastodonController! { mastodonController }
+}
+
+extension AccountFollowsListViewController: MenuActionProvider {
+}
+
+extension AccountFollowsListViewController: ToastableViewController {
+}
+
+extension AccountFollowsListViewController: StatusBarTappableViewController {
+    func handleStatusBarTapped(xPosition: CGFloat) -> StatusBarTapActionResult {
+        collectionView.scrollToTop()
+        return .stop
+    }
+}

Tusker/Screens/Account Follows/AccountFollowsViewController.swift

@@ -0,0 +1,46 @@
+//
+//  AccountFollowsViewController.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 1/18/23.
+//  Copyright © 2023 Shadowfacts. All rights reserved.
+//
+
+import UIKit
+
+class AccountFollowsViewController: SegmentedPageViewController<AccountFollowsViewController.Mode> {
+    
+    let accountID: String
+    let mastodonController: MastodonController
+    
+    init(accountID: String, mastodonController: MastodonController) {
+        self.accountID = accountID
+        self.mastodonController = mastodonController
+        
+        super.init(pages: [.following, .followers]) { mode in
+            AccountFollowsListViewController(accountID: accountID, mastodonController: mastodonController, mode: mode)
+        }
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+}
+
+extension AccountFollowsViewController {
+    enum Mode: SegmentedPageViewControllerPage {
+        case following, followers
+        
+        var title: String {
+            switch self {
+            case .following:
+                return "Following"
+            case .followers:
+                return "Followers"
+            }
+        }
+        
+        var segmentedControlTitle: String { title }
+    }
+}

Tusker/Views/Profile Header/ProfileHeaderView.swift

@@ -351,6 +351,8 @@ class ProfileHeaderView: UIView {
     }
     
     @IBAction func followCountButtonPressed(_ sender: Any) {
+        guard let accountID else { return }
+        delegate?.show(AccountFollowsViewController(accountID: accountID, mastodonController: mastodonController))
     }
 }