Settings Feature Enhancement

Nucleic-Session: 89BFAB13-D559-43FC-BE28-0B2639BECF0F
Co-authored-by: Nucleic <[email protected]>

NucleicRemote/NucleicRemote/Views/SettingsView.swift

@@ -370,3 +370,118 @@ struct ManualPairingView: View {
         dismiss()
     }
 }
+
+/// "Add a device to this mesh": the phone can't mint a join code itself (it runs no listener), so
+/// it asks a connected Mac to open a pairing window and relays back that Mac's code — shown here as
+/// a QR to scan from a new iPhone/iPad, or a copyable link to send to a new Mac. Scanning/pasting it
+/// joins the new device to the whole group. Dismissing the sheet closes the Mac's pairing window
+/// (`RemoteStore.cancelPairingCode`, wired to the sheet's `onDismiss`).
+struct AddDeviceView: View {
+    @EnvironmentObject var store: RemoteStore
+    @Environment(\.dismiss) private var dismiss
+    @State private var copied = false
+    @State private var copyResetTask: Task<Void, Never>?
+
+    var body: some View {
+        NavigationStack {
+            Form {
+                switch store.addDevice {
+                case .idle, .requesting:
+                    Section {
+                        HStack {
+                            ProgressView()
+                            Text("Asking a Mac in your mesh for a join code…")
+                                .foregroundStyle(.secondary)
+                        }
+                    }
+                case .unavailable:
+                    Section {
+                        Label("Couldn't get a join code", systemImage: "exclamationmark.triangle.fill")
+                            .foregroundStyle(.orange)
+                        Text("This needs a Mac in your mesh that's connected right now. Make sure "
+                             + "one is reachable with its meshing service on, then try again.")
+                            .font(.callout).foregroundStyle(.secondary)
+                        Button("Try again") { store.requestPairingCode() }
+                    }
+                case .ready(let code):
+                    codeSection(code)
+                }
+            }
+            .navigationTitle("Add a device")
+            .navigationBarTitleDisplayMode(.inline)
+            .toolbar {
+                ToolbarItem(placement: .confirmationAction) { Button("Done") { dismiss() } }
+            }
+        }
+        // Fire the request as the sheet appears; `onDismiss` (on the presenter) tells the Mac to
+        // close its pairing window.
+        .onAppear { if case .ready = store.addDevice {} else { store.requestPairingCode() } }
+        .onDisappear { copyResetTask?.cancel() }
+    }
+
+    @ViewBuilder
+    private func codeSection(_ code: String) -> some View {
+        Section {
+            if let image = Self.qrImage(code) {
+                HStack {
+                    Spacer()
+                    Image(uiImage: image)
+                        .interpolation(.none)
+                        .resizable()
+                        .frame(width: 220, height: 220)
+                        .padding(10)
+                        .background(.white, in: RoundedRectangle(cornerRadius: 12))
+                    Spacer()
+                }
+                .listRowBackground(Color.clear)
+            }
+        } header: {
+            Text("Scan to join")
+        } footer: {
+            Text("On a new iPhone or iPad, open Nucleic Remote ▸ Join an Orbital mesh and scan this. "
+                 + "It joins the whole group — every Mac and device here.")
+        }
+
+        Section {
+            Text(code)
+                .font(.system(.caption, design: .monospaced))
+                .lineLimit(2)
+                .truncationMode(.middle)
+                .textSelection(.enabled)
+            Button {
+                copyCode(code)
+            } label: {
+                Label(copied ? "Copied" : "Copy join code",
+                      systemImage: copied ? "checkmark" : "doc.on.doc")
+            }
+        } header: {
+            Text("Or send a code")
+        } footer: {
+            Text("Paste into “Join mesh…” on another Mac, or “Enter code manually” on an iPhone or "
+                 + "iPad. A Mac joining is confirmed on the Mac that shared the code.")
+        }
+    }
+
+    private func copyCode(_ code: String) {
+        UIPasteboard.general.string = code
+        withAnimation(.easeOut(duration: 0.12)) { copied = true }
+        copyResetTask?.cancel()
+        copyResetTask = Task {
+            try? await Task.sleep(for: .seconds(1.4))
+            guard !Task.isCancelled else { return }
+            withAnimation(.easeIn(duration: 0.2)) { copied = false }
+        }
+    }
+
+    /// Render the join string as a QR code (CoreImage), mirroring the Mac's pairing sheet.
+    private static func qrImage(_ string: String) -> UIImage? {
+        let filter = CIFilter.qrCodeGenerator()
+        filter.message = Data(string.utf8)
+        filter.correctionLevel = "M"
+        guard let output = filter.outputImage else { return nil }
+        let scaled = output.transformed(by: CGAffineTransform(scaleX: 10, y: 10))
+        let context = CIContext()
+        guard let cg = context.createCGImage(scaled, from: scaled.extent) else { return nil }
+        return UIImage(cgImage: cg)
+    }
+}