Provides a qr view to scan for nsec. Completes: #1291

- Allow scanning of QR codes, and if detects a nsec, will provide it to the login prompt.
- If nsec is found, provides option to keep nsec in keychain; default is to not store
- User stays logged in until they logout, or app is force-quit if nsec is not stored.

damusApp.swift:
Obtains keypair from the notification generated to allow login.

LoginView.swift:
New views allowing for adding and logic handling the QR reader in QRScanNSECView.swift to enable QR scan for nsec.

QRScanNSECView.swift:
New view to scan for QR code. The sparkling magnifying glass is enable if the view calling the QR view changes the privKeyFound bound variable.

npub1el277q4kesp8vhs7rq6qkwnhpxfp345u7tnuxykwr67d9wg0wvyslam5n0

Signed-off-by: Jericho Hasselbush <[email protected]>
Signed-off-by: William Casarin <[email protected]>

damus/Views/LoginView.swift

@@ -6,6 +6,7 @@
 //
 
 import SwiftUI
+import AudioToolbox // For haptic feedback on scanning of nsec qr code
 
 enum ParsedKey {
     case pub(Pubkey)
@@ -30,13 +31,21 @@ enum ParsedKey {
         }
         return false
     }
+
+    var is_priv: Bool {
+        if case .priv = self {
+            return true
+        }
+        return false
+    }
 }
 
 struct LoginView: View {
     @State var key: String = ""
     @State var is_pubkey: Bool = false
     @State var error: String? = nil
     @State private var credential_handler = CredentialHandler()
+    @State private var shouldSaveKey: Bool = true
     var nav: NavigationCoordinator
 
     func get_error(parsed_key: ParsedKey?) -> String? {
@@ -57,7 +66,7 @@ struct LoginView: View {
                 SignInHeader()
                     .padding(.top, 100)
 
-                SignInEntry(key: $key)
+                SignInEntry(key: $key, shouldSaveKey: $shouldSaveKey)
 
                 let parsed = parse_key(key)
 
@@ -83,7 +92,7 @@ struct LoginView: View {
                     Button(action: {
                         Task {
                             do {
-                                try await process_login(p, is_pubkey: is_pubkey)
+                                try await process_login(p, is_pubkey: is_pubkey, shouldSaveKey: shouldSaveKey)
                             } catch {
                                 self.error = error.localizedDescription
                             }
@@ -168,37 +177,39 @@ enum LoginError: LocalizedError {
     }
 }
 
-func process_login(_ key: ParsedKey, is_pubkey: Bool) async throws {
-    switch key {
-    case .priv(let priv):
-        try handle_privkey(priv)
-    case .pub(let pub):
-        try clear_saved_privkey()
-        save_pubkey(pubkey: pub)
-
-    case .nip05(let id):
-        guard let nip05 = await get_nip05_pubkey(id: id) else {
-            throw LoginError.nip05_failed
-        }
-
-        // this is a weird way to login anyways
-        /*
-         var bootstrap_relays = load_bootstrap_relays(pubkey: nip05.pubkey)
-         for relay in nip05.relays {
-         if !(bootstrap_relays.contains { $0 == relay }) {
-         bootstrap_relays.append(relay)
-         }
-         }
-         */
-        save_pubkey(pubkey: nip05.pubkey)
-
-    case .hex(let hexstr):
-        if is_pubkey, let pubkey = hex_decode_pubkey(hexstr) {
+func process_login(_ key: ParsedKey, is_pubkey: Bool, shouldSaveKey: Bool = true) async throws {
+    if shouldSaveKey {
+        switch key {
+        case .priv(let priv):
+            try handle_privkey(priv)
+        case .pub(let pub):
             try clear_saved_privkey()
+            save_pubkey(pubkey: pub)
+
+        case .nip05(let id):
+            guard let nip05 = await get_nip05_pubkey(id: id) else {
+                throw LoginError.nip05_failed
+            }
 
-            save_pubkey(pubkey: pubkey)
-        } else if let privkey = hex_decode_privkey(hexstr) {
-            try handle_privkey(privkey)
+            // this is a weird way to login anyways
+            /*
+             var bootstrap_relays = load_bootstrap_relays(pubkey: nip05.pubkey)
+             for relay in nip05.relays {
+             if !(bootstrap_relays.contains { $0 == relay }) {
+             bootstrap_relays.append(relay)
+             }
+             }
+             */
+            save_pubkey(pubkey: nip05.pubkey)
+
+        case .hex(let hexstr):
+            if is_pubkey, let pubkey = hex_decode_pubkey(hexstr) {
+                try clear_saved_privkey()
+
+                save_pubkey(pubkey: pubkey)
+            } else if let privkey = hex_decode_privkey(hexstr) {
+                try handle_privkey(privkey)
+            }
         }
     }
 
@@ -213,7 +224,16 @@ func process_login(_ key: ParsedKey, is_pubkey: Bool) async throws {
         save_pubkey(pubkey: pk)
     }
 
-    guard let keypair = get_saved_keypair() else {
+    func handle_transient_privkey(_ key: ParsedKey) -> Keypair? {
+        if case let .priv(priv) = key, let pubkey = privkey_to_pubkey(privkey: priv) {
+            return Keypair(pubkey: pubkey, privkey: priv)
+        }
+        return nil
+    }
+
+    let keypair = shouldSaveKey ? get_saved_keypair() : handle_transient_privkey(key)
+
+    guard let keypair = keypair else {
         return
     }
 
@@ -265,11 +285,15 @@ func get_nip05_pubkey(id: String) async -> NIP05User? {
 struct KeyInput: View {
     let title: String
     let key: Binding<String>
+    let shouldSaveKey: Binding<Bool>
+    var privKeyFound: Binding<Bool>
     @State private var is_secured: Bool = true
 
-    init(_ title: String, key: Binding<String>) {
+    init(_ title: String, key: Binding<String>, shouldSaveKey: Binding<Bool>, privKeyFound: Binding<Bool>) {
         self.title = title
         self.key = key
+        self.shouldSaveKey = shouldSaveKey
+        self.privKeyFound = privKeyFound
     }
 
     var body: some View {
@@ -281,6 +305,8 @@ struct KeyInput: View {
                         self.key.wrappedValue = pastedkey
                     }
                 }
+            SignInScan(shouldSaveKey: shouldSaveKey, loginKey: key, privKeyFound: privKeyFound)
+
             if is_secured  {
                      SecureField("", text: key)
                          .nsecLoginStyle(key: key.wrappedValue, title: title)
@@ -323,16 +349,69 @@ struct SignInHeader: View {
 
 struct SignInEntry: View {
     let key: Binding<String>
-
+    let shouldSaveKey: Binding<Bool>
+    @State private var privKeyFound: Bool = false
     var body: some View {
         VStack(alignment: .leading) {
             Text("Enter your account key", comment: "Prompt for user to enter an account key to login.")
                 .fontWeight(.medium)
                 .padding(.top, 30)
 
-            KeyInput(NSLocalizedString("nsec1...", comment: "Prompt for user to enter in an account key to login. This text shows the characters the key could start with if it was a private key."), key: key)
+            KeyInput(NSLocalizedString("nsec1...", comment: "Prompt for user to enter in an account key to login. This text shows the characters the key could start with if it was a private key."), 
+                     key: key,
+                     shouldSaveKey: shouldSaveKey,
+                     privKeyFound: $privKeyFound)
+            if privKeyFound {
+                Toggle("Save Key in Secure Keychain", isOn: shouldSaveKey)
+            }
+        }
+    }
+}
+
+struct SignInScan: View {
+    @State var showQR: Bool = false
+    @State var qrkey: ParsedKey?
+    @Binding var shouldSaveKey: Bool
+    @Binding var loginKey: String
+    @Binding var privKeyFound: Bool
+    var body: some View {
+        VStack {
+            Button(action: { showQR.toggle() }, label: {
+                Image(systemName: "qrcode.viewfinder")})
+            .foregroundColor(.gray)
+
+        }
+        .sheet(isPresented: $showQR, onDismiss: {
+            if qrkey == nil { resetView() }}
+        ) {
+            QRScanNSECView(showQR: $showQR,
+                          privKeyFound: $privKeyFound,
+                          scannedTextHandler: { handleQRString($0) })
+        }
+        .onChange(of: showQR) { show in
+            if showQR { resetView() }
+        }
+    }
+
+    func handleQRString(_ string: String) {
+        qrkey = parse_key(string)
+        if let key = qrkey, key.is_priv {
+            loginKey = string
+            privKeyFound = true
+            shouldSaveKey = false
+            AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
+            // TODO: Do we want to keep haptic feedback
+            // This should use the single tap or something instead of this crazy
+            // vibrating thing.
         }
     }
+
+    func resetView() {
+        loginKey = ""
+        qrkey = nil
+        privKeyFound = false
+        shouldSaveKey = true
+    }
 }
 
 struct CreateAccountPrompt: View {

damus/Views/QRScanNSECView.swift

@@ -0,0 +1,135 @@
+//
+//  QRScanNSECView.swift
+//  damus
+//
+//  Created by Jericho Hasselbush on 9/29/23.
+//
+
+import SwiftUI
+import VisionKit
+
+struct QRScanNSECView: View {
+    @Binding var showQR: Bool
+    @Binding var privKeyFound: Bool
+    var scannedTextHandler: (String) -> Void
+
+    var body: some View {
+        ZStack {
+            ZStack {
+                DamusGradient()
+            }
+            VStack {
+                Text("Scan Your Private Key QR", comment: "Text to prompt scanning a QR code of a user's privkey to login to their profile.")
+                    .padding(.top, 50)
+                    .font(.system(size: 24, weight: .heavy))
+
+                Spacer()
+
+                if QRViewController.scannerAvailable {
+                    QRViewController(scannedTextHandler)
+                        .scaledToFit()
+                        .frame(width: 300, height: 300)
+                        .cornerRadius(10)
+                        .overlay(RoundedRectangle(cornerRadius: 10).stroke(DamusColors.white, lineWidth: 5.0))
+                        .shadow(radius: 10)
+                } else {
+                    ScannerEmptyView()
+                }
+
+                Button(action: { withAnimation(.bouncy(duration: 2.5, extraBounce: 2.5)) { showQR = false  }}) {
+                    VStack {
+                        Image(systemName: privKeyFound ? "sparkle.magnifyingglass" : "magnifyingglass")
+                            .font(privKeyFound ? .title : .title3)
+                    }}
+                .padding(.top)
+                .buttonStyle(GradientButtonStyle())
+
+                Spacer()
+
+                Spacer()
+            }
+        }
+    }
+
+    func ScannerEmptyView() -> some View {
+        VStack {
+            if #available(iOS 17.0, macOS 14.0, *) {
+                ContentUnavailableView("No native support for QR Code Scanning", systemImage: "exclamationmark.triangle")
+            } else {
+                HStack {
+                    Spacer()
+                    VStack {
+                        Image(systemName: "exclamationmark.triangle")
+                        Text("No native support for QR Code Scanning", comment: "Device doesn't support scanning QR codes.")
+                            .multilineTextAlignment(.center)
+                    }
+                    .font(.largeTitle)
+                    .foregroundColor(.primary)
+                    Spacer()
+                }
+            }
+        }
+
+    }
+}
+
+#Preview {
+    @State var showQR  = true
+    @State var privKeyFound = false
+    @State var shouldSaveKey = true
+    return QRScanNSECView(showQR: $showQR,
+                         privKeyFound: $privKeyFound,
+                         scannedTextHandler: { _ in })
+}
+
+
+typealias RecognizedItemHandler = (String) -> Void
+
+@MainActor
+struct QRViewController: UIViewControllerRepresentable {
+    typealias UIViewControllerType = DataScannerViewController
+    var delegate: QRViewControllerDelegate
+
+    init(_ itemHandler: @escaping RecognizedItemHandler) {
+        self.delegate = QRViewControllerDelegate(itemHandler)
+    }
+
+    func makeUIViewController(context: Context) -> DataScannerViewController {
+        let controller = DataScannerViewController(recognizedDataTypes: [.barcode(symbologies: [.qr])],
+                                                   qualityLevel: .accurate,
+                                                   recognizesMultipleItems: false,
+                                                   isHighFrameRateTrackingEnabled: true,
+                                                   isPinchToZoomEnabled: true,
+                                                   isGuidanceEnabled: true,
+                                                   isHighlightingEnabled: true)
+        try? controller.startScanning()
+        controller.delegate = delegate
+        return controller
+    }
+
+    func updateUIViewController(_ uiViewController: DataScannerViewController, context: Context) {
+
+    }
+
+    static var scannerAvailable: Bool {
+        DataScannerViewController.isSupported &&
+        DataScannerViewController.isAvailable
+    }
+}
+
+class QRViewControllerDelegate: DataScannerViewControllerDelegate {
+    var handleItem: RecognizedItemHandler
+
+    init(_ handleItem: @escaping RecognizedItemHandler) {
+        self.handleItem = handleItem
+    }
+
+    func dataScanner(_ dataScanner: DataScannerViewController, didAdd addedItems: [RecognizedItem], allItems: [RecognizedItem]) {
+        guard let item = addedItems.first else { return }
+        if case let .barcode(barcode) = item {
+            let string = barcode.payloadStringValue ?? ""
+            self.handleItem(string)
+
+        }
+    }
+}

damus/damusApp.swift

@@ -32,6 +32,9 @@ struct MainView: View {
                     .onReceive(handle_notify(.login)) { notif in
                         needs_setup = false
                         keypair = get_saved_keypair()
+                        if keypair == nil, let tempkeypair = notif.to_full()?.to_keypair() {
+                            keypair = tempkeypair
+                        }
                     }
             }
         }