Add issue label and milestone filters

ios/Sources/ContentScreens.swift

@@ -6,6 +6,8 @@ final class IssuesViewController: RefreshingTableViewController {
     private let owner: String
     private let repository: String
     private var rows: [IssueRow] = []
+    private var filterOptions: IssueFilterOptions?
+    private var filterTask: Task<Void, Never>?
 
     init(context: AppContext, owner: String, repository: String) {
         self.context = context
@@ -18,6 +20,8 @@ final class IssuesViewController: RefreshingTableViewController {
     @available(*, unavailable)
     required init?(coder: NSCoder) { fatalError("init(coder:) is not supported") }
 
+    deinit { filterTask?.cancel() }
+
     override func viewDidLoad() {
         super.viewDidLoad()
         tableView.register(IssueCell.self, forCellReuseIdentifier: "issue")
@@ -26,19 +30,18 @@ final class IssuesViewController: RefreshingTableViewController {
     }
 
     override func loadContent(refreshing: Bool) {
+        loadFilterOptions()
+        loadIssues(refreshing: refreshing)
+    }
+
+    private func loadIssues(refreshing: Bool) {
         beginLoading(refreshing: refreshing)
         loadingTask?.cancel()
         loadingTask = Task {
             do {
                 rows = try await context.core.issues(owner: owner, repository: repository)
                 tableView.reloadData()
-                let status = context.core.settings().issueStatus
-                tableView.backgroundView = rows.isEmpty
-                    ? EmptyBackgroundView(
-                        title: "No \(status) issues",
-                        detail: "No issues match the selected status."
-                    )
-                    : nil
+                updateEmptyState()
             } catch {
                 if !Task.isCancelled { show(error: error) }
             }
@@ -46,6 +49,24 @@ final class IssuesViewController: RefreshingTableViewController {
         }
     }
 
+    private func loadFilterOptions() {
+        filterTask?.cancel()
+        filterTask = Task {
+            do {
+                let options = try await context.core.issueFilters(
+                    owner: owner,
+                    repository: repository
+                )
+                guard !Task.isCancelled else { return }
+                filterOptions = options
+                updateFilterMenu()
+                updateEmptyState()
+            } catch {
+                if !Task.isCancelled { show(error: error) }
+            }
+        }
+    }
+
     override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
         rows.count
     }
@@ -74,9 +95,11 @@ final class IssuesViewController: RefreshingTableViewController {
 
     private func updateFilterMenu() {
         let current = context.core.settings().issueStatus
-        navigationItem.rightBarButtonItem = UIBarButtonItem(
-            image: context.symbol("line.3.horizontal.decrease.circle"),
-            menu: UIMenu(children: ["open", "closed"].map { status in
+        let status = UIMenu(
+            title: "Status",
+            image: context.symbol("circle.lefthalf.filled"),
+            options: .singleSelection,
+            children: ["open", "closed"].map { status in
                 UIAction(
                     title: status.capitalized,
                     state: current == status ? .on : .off
@@ -85,12 +108,134 @@ final class IssuesViewController: RefreshingTableViewController {
                     do {
                         try self.context.core.setIssueStatus(status: status)
                         self.updateFilterMenu()
-                        self.loadContent(refreshing: false)
+                        self.loadIssues(refreshing: false)
                     } catch {
                         self.show(error: error)
                     }
                 }
-            })
+            }
+        )
+        var children: [UIMenuElement] = [status]
+        if let filterOptions {
+            children.append(milestoneMenu(filterOptions))
+            children.append(labelMenu(filterOptions))
+        } else {
+            children.append(UIAction(title: "Loading filters…", attributes: .disabled) { _ in })
+        }
+        let item = navigationItem.rightBarButtonItem ?? UIBarButtonItem(
+            image: context.symbol("line.3.horizontal.decrease.circle")
+        )
+        item.menu = UIMenu(children: children)
+        item.accessibilityLabel = "Filter issues"
+        if navigationItem.rightBarButtonItem == nil {
+            navigationItem.rightBarButtonItem = item
+        }
+        updateFilterTint()
+    }
+
+    private func milestoneMenu(_ options: IssueFilterOptions) -> UIMenu {
+        let selected = options.selectedMilestone
+        var milestones = options.milestones
+        if !selected.isEmpty, !milestones.contains(selected) { milestones.append(selected) }
+        let all = UIAction(title: "All Milestones", state: selected.isEmpty ? .on : .off) {
+            [weak self] _ in self?.selectMilestone("")
+        }
+        let actions = milestones.sorted { $0.localizedCaseInsensitiveCompare($1) == .orderedAscending }
+            .map { milestone in
+                UIAction(
+                    title: milestone,
+                    state: selected == milestone ? .on : .off
+                ) { [weak self] _ in self?.selectMilestone(milestone) }
+            }
+        return UIMenu(
+            title: "Milestone",
+            image: context.symbol("flag"),
+            options: .singleSelection,
+            children: [all] + actions
+        )
+    }
+
+    private func labelMenu(_ options: IssueFilterOptions) -> UIMenu {
+        let available = Set(options.labels)
+        let selected = Set(options.selectedLabels)
+        let labels = available.union(selected)
+            .sorted { $0.localizedCaseInsensitiveCompare($1) == .orderedAscending }
+        let actions = labels.map { label in
+            UIAction(
+                title: available.contains(label) ? label : "\(label) (Unavailable)",
+                attributes: .keepsMenuPresented,
+                state: selected.contains(label) ? .on : .off
+            ) { [weak self] action in
+                guard let self, let options = self.filterOptions else { return }
+                self.filterTask?.cancel()
+                var labels = Set(options.selectedLabels)
+                if labels.remove(label) == nil { labels.insert(label) }
+                do {
+                    try self.saveFilters(milestone: options.selectedMilestone, labels: labels)
+                    self.filterOptions?.selectedLabels = labels.sorted()
+                    action.state = labels.contains(label) ? .on : .off
+                    self.updateFilterMenu()
+                    self.loadIssues(refreshing: false)
+                } catch {
+                    self.show(error: error)
+                }
+            }
+        }
+        return UIMenu(
+            title: "Labels",
+            image: context.symbol("tag"),
+            children: actions.isEmpty
+                ? [UIAction(title: "No labels", attributes: .disabled) { _ in }]
+                : actions
+        )
+    }
+
+    private func selectMilestone(_ milestone: String) {
+        guard let options = filterOptions else { return }
+        filterTask?.cancel()
+        do {
+            try saveFilters(milestone: milestone, labels: Set(options.selectedLabels))
+            filterOptions?.selectedMilestone = milestone
+            updateFilterMenu()
+            loadIssues(refreshing: false)
+        } catch {
+            show(error: error)
+        }
+    }
+
+    private func saveFilters(milestone: String, labels: Set<String>) throws {
+        try context.core.setIssueFilters(
+            owner: owner,
+            repository: repository,
+            milestone: milestone,
+            labels: labels.sorted()
+        )
+    }
+
+    private var filtersActive: Bool {
+        context.core.settings().issueStatus != "open"
+            || filterOptions?.selectedMilestone.isEmpty == false
+            || filterOptions?.selectedLabels.isEmpty == false
+    }
+
+    private func updateFilterTint() {
+        navigationItem.rightBarButtonItem?.tintColor = filtersActive ? .tintColor : .secondaryLabel
+        navigationItem.rightBarButtonItem?.accessibilityValue = filtersActive
+            ? "Filters active"
+            : "Default filters"
+    }
+
+    private func updateEmptyState() {
+        guard rows.isEmpty else {
+            tableView.backgroundView = nil
+            return
+        }
+        let status = context.core.settings().issueStatus
+        tableView.backgroundView = EmptyBackgroundView(
+            title: "No \(status) issues",
+            detail: filtersActive
+                ? "No issues match the selected filters."
+                : "This repository has no \(status) issues."
         )
     }
 }