Yep. AI rewrote the whole thing.

Downterm/CommandNotch/Models/WorkspaceController.swift

@@ -0,0 +1,167 @@
+import SwiftUI
+import Combine
+
+@MainActor
+protocol TerminalSessionFactoryType {
+    func makeSession(fontSize: CGFloat, theme: TerminalTheme, shellPath: String) -> TerminalSession
+}
+
+struct LiveTerminalSessionFactory: TerminalSessionFactoryType {
+    func makeSession(fontSize: CGFloat, theme: TerminalTheme, shellPath: String) -> TerminalSession {
+        TerminalSession(fontSize: fontSize, theme: theme, shellPath: shellPath)
+    }
+}
+
+@MainActor
+final class WorkspaceController: ObservableObject {
+    let id: WorkspaceID
+    let createdAt: Date
+
+    @Published private(set) var name: String
+    @Published private(set) var tabs: [TerminalSession] = []
+    @Published private(set) var activeTabIndex: Int = 0
+
+    private let sessionFactory: TerminalSessionFactoryType
+    private let settingsProvider: TerminalSessionConfigurationProviding
+    private var titleObservers: [UUID: AnyCancellable] = [:]
+
+    init(
+        summary: WorkspaceSummary,
+        sessionFactory: TerminalSessionFactoryType,
+        settingsProvider: TerminalSessionConfigurationProviding,
+        bootstrapDefaultTab: Bool = true
+    ) {
+        self.id = summary.id
+        self.name = summary.name
+        self.createdAt = summary.createdAt
+        self.sessionFactory = sessionFactory
+        self.settingsProvider = settingsProvider
+
+        if bootstrapDefaultTab {
+            newTab()
+        }
+    }
+
+    convenience init(summary: WorkspaceSummary) {
+        self.init(
+            summary: summary,
+            sessionFactory: LiveTerminalSessionFactory(),
+            settingsProvider: AppSettingsController.shared
+        )
+    }
+
+    var summary: WorkspaceSummary {
+        WorkspaceSummary(id: id, name: name, createdAt: createdAt)
+    }
+
+    var state: WorkspaceState {
+        WorkspaceState(
+            id: id,
+            name: name,
+            tabs: tabs.map { WorkspaceTabState(id: $0.id, title: $0.title) },
+            activeTabID: activeTab?.id
+        )
+    }
+
+    var activeTab: TerminalSession? {
+        guard tabs.indices.contains(activeTabIndex) else { return nil }
+        return tabs[activeTabIndex]
+    }
+
+    var activeTitle: String {
+        activeTab?.title ?? "shell"
+    }
+
+    func rename(to updatedName: String) {
+        let trimmed = updatedName.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty, trimmed != name else { return }
+        name = trimmed
+    }
+
+    func newTab() {
+        let config = settingsProvider.terminalSessionConfiguration
+        let session = sessionFactory.makeSession(
+            fontSize: config.fontSize,
+            theme: config.theme,
+            shellPath: config.shellPath
+        )
+
+        titleObservers[session.id] = session.$title
+            .receive(on: RunLoop.main)
+            .sink { [weak self] _ in
+                self?.objectWillChange.send()
+            }
+
+        tabs.append(session)
+        activeTabIndex = tabs.count - 1
+    }
+
+    func closeTab(at index: Int) {
+        guard tabs.indices.contains(index) else { return }
+
+        let session = tabs.remove(at: index)
+        titleObservers.removeValue(forKey: session.id)
+        session.terminate()
+
+        if tabs.isEmpty {
+            newTab()
+        } else if activeTabIndex >= tabs.count {
+            activeTabIndex = tabs.count - 1
+        }
+    }
+
+    func closeActiveTab() {
+        closeTab(at: activeTabIndex)
+    }
+
+    func switchToTab(at index: Int) {
+        guard tabs.indices.contains(index) else { return }
+        activeTabIndex = index
+    }
+
+    func switchToTab(id: UUID) {
+        guard let index = tabs.firstIndex(where: { $0.id == id }) else { return }
+        activeTabIndex = index
+    }
+
+    func nextTab() {
+        guard tabs.count > 1 else { return }
+        activeTabIndex = (activeTabIndex + 1) % tabs.count
+    }
+
+    func previousTab() {
+        guard tabs.count > 1 else { return }
+        activeTabIndex = (activeTabIndex - 1 + tabs.count) % tabs.count
+    }
+
+    func detachTab(at index: Int) -> TerminalSession? {
+        guard tabs.indices.contains(index) else { return nil }
+
+        let session = tabs.remove(at: index)
+        titleObservers.removeValue(forKey: session.id)
+
+        if tabs.isEmpty {
+            newTab()
+        } else if activeTabIndex >= tabs.count {
+            activeTabIndex = tabs.count - 1
+        }
+
+        return session
+    }
+
+    func detachActiveTab() -> TerminalSession? {
+        detachTab(at: activeTabIndex)
+    }
+
+    func updateAllFontSizes(_ size: CGFloat) {
+        for tab in tabs {
+            tab.updateFontSize(size)
+        }
+    }
+
+    func updateAllThemes(_ theme: TerminalTheme) {
+        for tab in tabs {
+            tab.applyTheme(theme)
+        }
+    }
+}