add three-column layout with sidebar, thread list, detail view

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

clients/macos/MagnumOpus/ViewModels/MailViewModel.swift

@@ -0,0 +1,67 @@
+import Foundation
+
+@Observable
+final class MailViewModel {
+	let apiClient: APIClient
+
+	var threads: [ThreadSummary] = []
+	var selectedThread: ThreadSummary?
+	var selectedMessages: [EmailMessage] = []
+	var selectedPerspective: Perspective = .inbox
+	var isLoading = false
+	var errorMessage: String?
+
+	enum Perspective: String, CaseIterable, Identifiable {
+		case inbox = "Inbox"
+		case today = "Today"
+		case archive = "Archive"
+
+		var id: String { rawValue }
+
+		var systemImage: String {
+			switch self {
+			case .inbox: "tray"
+			case .today: "sun.max"
+			case .archive: "archivebox"
+			}
+		}
+	}
+
+	init(apiClient: APIClient) {
+		self.apiClient = apiClient
+	}
+
+	func loadThreads(accountId: String) async {
+		isLoading = true
+		errorMessage = nil
+		do {
+			threads = try await apiClient.fetchThreads(accountId: accountId)
+		} catch {
+			errorMessage = error.localizedDescription
+		}
+		isLoading = false
+	}
+
+	func loadMessages(for thread: ThreadSummary) async {
+		selectedThread = thread
+		do {
+			selectedMessages = try await apiClient.fetchMessages(threadId: thread.threadId)
+		} catch {
+			errorMessage = error.localizedDescription
+		}
+	}
+
+	func connectToEvents(baseURL: URL, accountId: String) {
+		let sseURL = baseURL.appendingPathComponent("api/events")
+		let sseClient = SSEClient(url: sseURL)
+
+		sseClient.connect { [weak self] event in
+			guard let self else { return }
+			if event.event == "threads_updated" {
+				Task { @MainActor in
+					await self.loadThreads(accountId: accountId)
+				}
+			}
+		}
+	}
+}

clients/macos/MagnumOpus/Views/SidebarView.swift

@@ -0,0 +1,18 @@
+import SwiftUI
+
+struct SidebarView: View {
+	@Bindable var viewModel: MailViewModel
+
+	var body: some View {
+		List(selection: $viewModel.selectedPerspective) {
+			Section("Views") {
+				ForEach(MailViewModel.Perspective.allCases) { perspective in
+					Label(perspective.rawValue, systemImage: perspective.systemImage)
+						.tag(perspective)
+				}
+			}
+		}
+		.navigationTitle("Magnum Opus")
+		.listStyle(.sidebar)
+	}
+}

clients/macos/MagnumOpus/Views/ThreadDetailView.swift

@@ -0,0 +1,60 @@
+import SwiftUI
+
+struct ThreadDetailView: View {
+	let thread: ThreadSummary?
+	let messages: [EmailMessage]
+
+	var body: some View {
+		Group {
+			if let thread {
+				ScrollView {
+					VStack(alignment: .leading, spacing: 0) {
+						Text(thread.subject)
+							.font(.title2)
+							.fontWeight(.semibold)
+							.padding()
+
+						Divider()
+
+						ForEach(messages) { message in
+							MessageView(message: message)
+							Divider()
+						}
+					}
+				}
+			} else {
+				ContentUnavailableView(
+					"No Thread Selected",
+					systemImage: "envelope",
+					description: Text("Select a thread to read")
+				)
+			}
+		}
+	}
+}
+
+struct MessageView: View {
+	let message: EmailMessage
+
+	var body: some View {
+		VStack(alignment: .leading, spacing: 8) {
+			HStack {
+				Text(message.senderName)
+					.fontWeight(.semibold)
+				Spacer()
+				Text(message.date)
+					.font(.caption)
+					.foregroundStyle(.secondary)
+			}
+
+			Text("To: \(message.toHeader)")
+				.font(.caption)
+				.foregroundStyle(.secondary)
+
+			Text(message.body)
+				.font(.body)
+				.textSelection(.enabled)
+		}
+		.padding()
+	}
+}

clients/macos/MagnumOpus/Views/ThreadListView.swift

@@ -0,0 +1,59 @@
+import SwiftUI
+
+struct ThreadListView: View {
+	@Bindable var viewModel: MailViewModel
+
+	var body: some View {
+		List(viewModel.threads, selection: Binding(
+			get: { viewModel.selectedThread?.threadId },
+			set: { newId in
+				if let thread = viewModel.threads.first(where: { $0.threadId == newId }) {
+					Task { await viewModel.loadMessages(for: thread) }
+				}
+			}
+		)) { thread in
+			ThreadRow(thread: thread)
+				.tag(thread.threadId)
+		}
+		.listStyle(.inset)
+		.navigationTitle(viewModel.selectedPerspective.rawValue)
+		.overlay {
+			if viewModel.isLoading {
+				ProgressView()
+			} else if viewModel.threads.isEmpty {
+				ContentUnavailableView(
+					"No Messages",
+					systemImage: "tray",
+					description: Text("Inbox is empty")
+				)
+			}
+		}
+	}
+}
+
+struct ThreadRow: View {
+	let thread: ThreadSummary
+
+	var body: some View {
+		VStack(alignment: .leading, spacing: 4) {
+			HStack {
+				Text(thread.authors)
+					.fontWeight(thread.isUnread ? .bold : .regular)
+					.lineLimit(1)
+				Spacer()
+				Text(thread.date, style: .relative)
+					.font(.caption)
+					.foregroundStyle(.secondary)
+			}
+			Text(thread.subject)
+				.font(.subheadline)
+				.lineLimit(1)
+			if thread.totalMessages > 1 {
+				Text("\(thread.totalMessages) messages")
+					.font(.caption2)
+					.foregroundStyle(.tertiary)
+			}
+		}
+		.padding(.vertical, 2)
+	}
+}