Add qr code scanner

Changelog-Added: Add qr code scanner
Closes: #733

damus/Views/QRCodeView.swift

@@ -14,6 +14,20 @@ struct QRCodeView: View {
     
     @Environment(\.presentationMode) var presentationMode
     
+    @State private var selectedTab = 0
+    
+    @State var scanResult: Search? = nil
+    
+    @State var showProfileView: Bool = false
+    @State var profile: Profile? = nil
+    
+    @State private var scannedCode = ""
+    
+    @State private var outerTrimEnd: CGFloat = 0
+    var animationDuration: Double = 0.5
+    
+    let generator = UIImpactFeedbackGenerator(style: .light)
+
     var maybe_key: String? {
         guard let key = bech32_pubkey(pubkey) else {
             return nil
@@ -22,87 +36,235 @@ struct QRCodeView: View {
         return key
     }
     
-    var body: some View {
+    @ViewBuilder
-        ZStack(alignment: .center) {
+    func navImage(systemImage: String) -> some View {
+        Image(systemName: systemImage)
+            .frame(width: 33, height: 33)
+            .background(Color.black.opacity(0.6))
+            .clipShape(Circle())
+    }
     
-            ZStack(alignment: .topLeading) {
+    var navBackButton: some View {
-                DamusGradient()
+        Button {
-                Button {
-                    presentationMode.wrappedValue.dismiss()
-                } label: {
-                    Image("close")
-                        .foregroundColor(.white)
-                        .font(.subheadline)
-                        .padding(.leading, 20)
-                }
-                .zIndex(1)
-            }
-        
-            VStack(alignment: .center) {
-                
-                let profile = damus_state.profiles.lookup(id: pubkey)
-                
-                if (damus_state.profiles.lookup(id: pubkey)?.picture) != nil {
-                    ProfilePicView(pubkey: pubkey, size: 90.0, highlight: .custom(DamusColors.white, 4.0), profiles: damus_state.profiles, disable_animation: damus_state.settings.disable_animation)
-                        .padding(.top, 50)
-                } else {
-                    Image(systemName: "person.fill")
-                        .font(.system(size: 60))
-                        .foregroundColor(DamusColors.white)
-                        .padding(.top, 50)
-                }
-                
-                if let display_name = profile?.display_name {
-                    Text(display_name)
-                        .foregroundColor(DamusColors.white)
-                        .font(.system(size: 24, weight: .heavy))
-                }
-                if let name = profile?.name {
-                    Text("@" + name)
-                        .foregroundColor(DamusColors.white)
-                        .font(.body)
-                }
-                
-                Spacer()
-                
-                if let key = maybe_key {
-                    Image(uiImage: generateQRCode(pubkey: "nostr:" + key))
-                        .interpolation(.none)
-                        .resizable()
-                        .scaledToFit()
-                        .frame(width: 200, height: 200)
-                        .padding()
-                        .cornerRadius(10)
-                        .overlay(RoundedRectangle(cornerRadius: 10)
-                            .stroke(DamusColors.white, lineWidth: 1))
-                        .shadow(radius: 10)
-                }
-                
-                Spacer()
-                
-                if (pubkey == damus_state.pubkey) {
-                    Text("Follow me on nostr", comment: "Text on QR code view to prompt viewer looking at screen to follow the user.")
-                        .foregroundColor(DamusColors.white)
-                        .font(.system(size: 24, weight: .heavy))
-                        .padding(.top)
-                } else {
-                    Text("Follow them on nostr", comment: "Text on QR code view to prompt viewer looking at screen to follow the user (someone else).")
-                        .foregroundColor(DamusColors.white)
-                        .font(.system(size: 24, weight: .heavy))
-                        .padding(.top)
-                }
-                
-                Text("Scan the code", comment: "Text on QR code view to prompt viewer to scan the QR code on screen with their device camera.")
-                    .foregroundColor(DamusColors.white)
-                    .font(.system(size: 18, weight: .ultraLight))
-                
-                Spacer()
-            }
-            
-        }
-        .modifier(SwipeToDismissModifier(minDistance: nil, onDismiss: {
             presentationMode.wrappedValue.dismiss()
-        }))
+        } label: {
+            navImage(systemImage: "chevron.left")
+        }
+    }
+    
+    var customNavbar: some View {
+        HStack {
+            navBackButton
+            Spacer()
+        }
+        .padding(.top, 5)
+        .padding(.horizontal)
+        .accentColor(DamusColors.white)
+    }
+    
+    var body: some View {
+        NavigationView {
+            ZStack(alignment: .center) {
+                ZStack(alignment: .topLeading) {
+                    DamusGradient()
+                }
+                TabView(selection: $selectedTab) {
+                    QRView
+                        .tag(0)
+                    if pubkey == damus_state.pubkey {
+                        QRCameraView()
+                            .tag(1)
+                    }
+                }
+                .tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
+                .onAppear {
+                    UIScrollView.appearance().isScrollEnabled = false
+                }
+                .gesture(
+                    DragGesture()
+                        .onChanged { _ in }
+                )
+            }
+        }
+        .navigationTitle("")
+        .navigationBarHidden(true)
+        .overlay(customNavbar, alignment: .top)
+    }
+    
+    var QRView: some View {
+        VStack(alignment: .center) {
+            let profile = damus_state.profiles.lookup(id: pubkey)
+            
+            if (damus_state.profiles.lookup(id: damus_state.pubkey)?.picture) != nil {
+                ProfilePicView(pubkey: pubkey, size: 90.0, highlight: .custom(DamusColors.white, 3.0), profiles: damus_state.profiles, disable_animation: damus_state.settings.disable_animation)
+                    .padding(.top, 50)
+            } else {
+                Image(systemName: "person.fill")
+                    .font(.system(size: 60))
+                    .padding(.top, 50)
+            }
+            
+            if let display_name = profile?.display_name {
+                Text(display_name)
+                    .font(.system(size: 24, weight: .heavy))
+            }
+            if let name = profile?.name {
+                Text("@" + name)
+                    .font(.body)
+            }
+            
+            Spacer()
+            
+            if let key = maybe_key {
+                Image(uiImage: generateQRCode(pubkey: "nostr:" + key))
+                    .interpolation(.none)
+                    .resizable()
+                    .scaledToFit()
+                    .frame(width: 300, height: 300)
+                    .cornerRadius(10)
+                    .overlay(RoundedRectangle(cornerRadius: 10)
+                        .stroke(DamusColors.white, lineWidth: 5.0))
+                    .shadow(radius: 10)
+            }
+            
+            Spacer()
+            
+            Text("Follow me on nostr", comment: "Text on QR code view to prompt viewer looking at screen to follow the user.")
+                .font(.system(size: 24, weight: .heavy))
+                .padding(.top)
+            
+            Text("Scan the code", comment: "Text on QR code view to prompt viewer to scan the QR code on screen with their device camera.")
+                .font(.system(size: 18, weight: .ultraLight))
+            
+            Spacer()
+            
+            Button(action: {
+                selectedTab = 1
+            }) {
+                HStack {
+                    Text("Scan Code", comment: "Button to switch to scan QR Code page.")
+                        .fontWeight(.semibold)
+                }
+                .frame(minWidth: 300, maxWidth: .infinity, maxHeight: 12, alignment: .center)
+            }
+            .buttonStyle(GradientButtonStyle())
+            .padding(50)
+        }
+    }
+    
+    func search_changed(_ new: String) {
+        var str = new
+        guard str.count != 0 else {
+            return
+        }
+        
+        if str.hasPrefix("nostr:") {
+            str.removeFirst("nostr:".count)
+        }
+        
+        if let _ = hex_decode(str), str.count == 64 {
+            self.scanResult = .hex(str)
+            return
+        }
+        
+        if str.starts(with: "npub") {
+            if let _ = try? bech32_decode(str) {
+                self.scanResult = .profile(str)
+                return
+            }
+        }
+    }
+    
+    func QRCameraView() -> some View {
+        return VStack(alignment: .center) {
+            Text("Scan a user's pubkey")
+                .padding(.top, 50)
+                .font(.system(size: 24, weight: .heavy))
+            
+            Spacer()
+
+            CodeScannerView(codeTypes: [.qr], scanMode: .continuous, simulatedData: "npub1k92qsr95jcumkpu6dffurkvwwycwa2euvx4fthv78ru7gqqz0nrs2ngfwd", shouldVibrateOnSuccess: false) { result in
+                switch result {
+                case .success(let result):
+                    search_changed(result.string)
+                    switch scanResult {
+                    case .profile(let prof):
+                        handleProfileScan(prof)
+                    default:
+                        print("Not a profile")
+                    }
+                case .failure(let error):
+                    print(error.localizedDescription)
+                }
+            }
+            .scaledToFit()
+            .frame(width: 300, height: 300)
+            .cornerRadius(10)
+            .overlay(RoundedRectangle(cornerRadius: 10).stroke(DamusColors.white, lineWidth: 5.0))
+            .overlay(RoundedRectangle(cornerRadius: 10).trim(from: 0.0, to: outerTrimEnd).stroke(DamusColors.black, lineWidth: 5.5)
+            .rotationEffect(.degrees(-90)))
+            .shadow(radius: 10)
+            
+            Spacer()
+            
+            if showProfileView {
+                let decoded = try? bech32_decode(scannedCode)
+                let hex = hex_encode(decoded!.data)
+                
+                NavigationLink(
+                    destination: ProfileView(damus_state: damus_state, pubkey: hex),
+                    isActive: $showProfileView,
+                    label: {
+                        EmptyView()
+                    }
+                )
+            }
+            
+            Spacer()
+            
+            Button(action: {
+                selectedTab = 0
+            }) {
+                HStack {
+                    Text("View QR Code", comment: "Button to switch to view users QR Code")
+                        .fontWeight(.semibold)
+                }
+                .frame( maxWidth: .infinity, maxHeight: 12, alignment: .center)
+            }
+            .buttonStyle(GradientButtonStyle())
+            .padding(50)
+        }
+    }
+
+    func profile(for code: String) -> Profile? {
+        let decoded = try? bech32_decode(code)
+        let hex = hex_encode(decoded!.data)
+        return damus_state.profiles.lookup(id: hex)
+    }
+    
+    func handleProfileScan(_ prof: String) {
+        if scannedCode != prof {
+            generator.impactOccurred()
+            cameraAnimate {
+                scannedCode = prof
+                
+                if profile(for: scannedCode) != nil {
+                    DispatchQueue.main.asyncAfter(deadline: .now() + animationDuration) {
+                        showProfileView = true
+                    }
+                } else {
+                    print("Profile not found")
+                }
+            }
+        }
+    }
+
+    func cameraAnimate(completion: @escaping () -> Void) {
+        outerTrimEnd = 0.0
+        withAnimation(.easeInOut(duration: animationDuration)) {
+            outerTrimEnd = 1.05 // Set to 1.05 instead of 1.0 since sometimes `completion()` runs before the value reaches 1.0. This ensures the animation is done.
+        }
+        completion()
     }
     
     func generateQRCode(pubkey: String) -> UIImage {