feat(dashpay): QR contact exchange on the add-contact screen

DashWallet.xcodeproj/project.pbxproj

@@ -111,6 +111,7 @@
 		1C2D3E4F5A6B7C8D9E0F1A2B /* TransferAmountHostingController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8C9D0E1F2A3B4C5D6E7F809 /* TransferAmountHostingController.swift */; };
 		1C887F21B0826303D34B8D90 /* ContactsScreen.swift in Sources */ = {isa = PBXBuildFile; fileRef = 764BAE3F8A6B30668FEB1FA6 /* ContactsScreen.swift */; };
 		1CDA90D00719D6249F2761AC /* ContactItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2CE7E8766B8C1601A85AAB4F /* ContactItem.swift */; };
+		9E51F3B86C207A15D2B84E60 /* DashPayUserLink.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4D0A7C21B5E39F04A11C2D57 /* DashPayUserLink.swift */; };
 		1F3FF21B0295D5A326F08B74 /* OrderPreviewFeeRow.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0D1A08496F925D17031493E /* OrderPreviewFeeRow.swift */; };
 		1FAFEA3F516E6CBDD2B49010 /* SwiftDashSDKContactsService.swift in Sources */ = {isa = PBXBuildFile; fileRef = 02357928871603392E797C9A /* SwiftDashSDKContactsService.swift */; };
 		215F9BB0CAADF4D47D95C444 /* DWAvatarUploadClientTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5E2D975669CB53883D56803 /* DWAvatarUploadClientTests.swift */; };
@@ -2544,6 +2545,7 @@
 		2AFF01DA243F4559003718DC /* DWDPRegistrationStatus.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = DWDPRegistrationStatus.m; sourceTree = "<group>"; };
 		2C4FDA5A52AB80D7F349A7AF /* WalletSendService.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = WalletSendService.swift; sourceTree = "<group>"; };
 		2CE7E8766B8C1601A85AAB4F /* ContactItem.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = ContactItem.swift; sourceTree = "<group>"; };
+		4D0A7C21B5E39F04A11C2D57 /* DashPayUserLink.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = DashPayUserLink.swift; sourceTree = "<group>"; };
 		2DCBA057E553F81F54ACE6E1 /* StorageRecordDetailViews.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = StorageRecordDetailViews.swift; sourceTree = "<group>"; };
 		2E7EE6B2E027DC4062E9983E /* ContactProfileSheet.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = ContactProfileSheet.swift; sourceTree = "<group>"; };
 		2F134B2E67D68A97892FD760 /* WalletsScreen.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = WalletsScreen.swift; sourceTree = "<group>"; };
@@ -6697,6 +6699,7 @@
 			isa = PBXGroup;
 			children = (
 				2CE7E8766B8C1601A85AAB4F /* ContactItem.swift */,
+				4D0A7C21B5E39F04A11C2D57 /* DashPayUserLink.swift */,
 				02357928871603392E797C9A /* SwiftDashSDKContactsService.swift */,
 			);
 			path = Contacts;
@@ -11116,6 +11119,7 @@
 				E4165429FE629AE7E9CB7E22 /* DWIdentityRegistrationController.swift in Sources */,
 				A15ED0B9E7AAF29C694E4E16 /* DWIdentityAuthorizer.swift in Sources */,
 				1CDA90D00719D6249F2761AC /* ContactItem.swift in Sources */,
+				9E51F3B86C207A15D2B84E60 /* DashPayUserLink.swift in Sources */,
 				1FAFEA3F516E6CBDD2B49010 /* SwiftDashSDKContactsService.swift in Sources */,
 				1C887F21B0826303D34B8D90 /* ContactsScreen.swift in Sources */,
 				07B6BD15F525AAF000B53162 /* AddContactScreen.swift in Sources */,

DashWallet/Sources/Infrastructure/SwiftDashSDK/Contacts/DashPayUserLink.swift

@@ -0,0 +1,68 @@
+//
+//  DashPayUserLink.swift
+//  DashWallet
+//
+//  QR/link payload identifying a DashPay user: the Platform identity
+//  id (base58) plus the preferred DPNS username, encoded as
+//
+//      dashpay://user?id=<base58-identity-id>&username=<label>
+//
+//  Rendered as "my QR code" on the add-contact screen and parsed back
+//  when another user scans it. Parsing is pure and offline; it proves
+//  nothing — the username claim must be verified against Platform
+//  (DPNS lookup, identity id match) before it is shown as that user.
+//
+
+import Foundation
+import SwiftDashSDK
+
+struct DashPayUserLink: Equatable {
+    /// 32-byte Platform identity id.
+    let identityId: Data
+    /// Preferred DPNS label, stored without the ".dash" suffix.
+    let username: String
+
+    var identityIdBase58: String { identityId.toBase58String() }
+
+    /// Canonical URI form — the QR payload.
+    var uriString: String {
+        var components = URLComponents()
+        components.scheme = "dashpay"
+        components.host = "user"
+        components.queryItems = [
+            URLQueryItem(name: "id", value: identityIdBase58),
+            URLQueryItem(name: "username", value: username),
+        ]
+        return components.string ?? "dashpay://user"
+    }
+
+    /// Parse a scanned string. Accepts only the canonical
+    /// `dashpay://user` shape carrying a valid 32-byte base58 `id` and
+    /// a non-empty `username` (a trailing ".dash" is tolerated and
+    /// stripped). Anything else — payment URIs, invitation links, bare
+    /// usernames — returns nil.
+    static func parse(_ string: String) -> DashPayUserLink? {
+        let trimmed = string.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard let components = URLComponents(string: trimmed),
+              components.scheme?.lowercased() == "dashpay",
+              components.host?.lowercased() == "user"
+        else { return nil }
+
+        var identityId: Data?
+        var username: String?
+        for item in components.queryItems ?? [] {
+            switch item.name.lowercased() {
+            case "id": identityId = item.value.flatMap { Data.identifier(fromBase58: $0) }
+            case "username": username = item.value
+            default: break
+            }
+        }
+
+        guard let identityId, identityId.count == 32 else { return nil }
+        let label = (username ?? "")
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+            .withoutDashSuffix
+        guard !label.isEmpty else { return nil }
+        return DashPayUserLink(identityId: identityId, username: label)
+    }
+}

DashWallet/Sources/UI/DashPay/Contacts/SwiftUI/AddContactScreen.swift

@@ -11,6 +11,11 @@
 //  subtitle, elevated rounded white search field, white card result
 //  rows on the gray background.
 //
+//  QR entry points ("My QR" / "Scan QR" buttons under the search
+//  field): scan another user's `dashpay://user` code — verified
+//  against Platform before the send-confirmation sheet opens — and
+//  show your own (`MyDashPayUserQRSheet`).
+//
 
 import SwiftDashSDK
 import SwiftUI
@@ -46,6 +51,11 @@ struct AddContactScreen: View {
     /// Username of the recipient of a just-sent request — drives the
     /// centered success card (nil = hidden).
     @State private var sentToUsername: String?
+    @State private var showScanner = false
+    @State private var showMyQR = false
+    /// A scanned user QR is being verified against Platform (DPNS
+    /// lookup + identity id match) — drives the blocking spinner.
+    @State private var isVerifyingScan = false
 
     @ObservedObject private var service = SwiftDashSDKContactsService.shared
 
@@ -61,6 +71,9 @@ struct AddContactScreen: View {
                         height: 52)
                         .padding(.horizontal, 24)
                         .padding(.top, 22)
+                    qrButtonsRow
+                        .padding(.horizontal, 24)
+                        .padding(.top, 12)
                     resultsList
                 }
             }
@@ -71,6 +84,18 @@ struct AddContactScreen: View {
                         .foregroundColor(.dash.blue)
                 }
             }
+            .fullScreenCover(isPresented: $showScanner) {
+                GenericQRScannerView(
+                    onQRCodeScanned: { handleScannedCode($0) },
+                    onCancel: { showScanner = false })
+            }
+            .sheet(isPresented: $showMyQR) {
+                if let link = myUserLink {
+                    MyDashPayUserQRSheet(
+                        link: link,
+                        displayName: DWCurrentUserIdentityInfo.shared.displayName)
+                }
+            }
             .onChange(of: query) { _, _ in
                 scheduleSearch()
             }
@@ -98,7 +123,19 @@ struct AddContactScreen: View {
                     onAccept: { accept(target) })
             }
             .overlay {
-                if let username = sentToUsername {
+                if isVerifyingScan {
+                    VStack(spacing: 12) {
+                        SwiftUI.ProgressView()
+                        Text(NSLocalizedString("Verifying user…", comment: "DashPay Contacts: spinner after scanning a user QR code"))
+                            .font(.system(size: 14, weight: .medium))
+                            .foregroundColor(.dash.secondaryText)
+                    }
+                    .padding(24)
+                    .background(
+                        RoundedRectangle(cornerRadius: 16, style: .continuous)
+                            .fill(Color.dash.secondaryBackground)
+                            .shadow(color: Color.dash.shadow, radius: 24, x: 0, y: 8))
+                } else if let username = sentToUsername {
                     VStack(spacing: 12) {
                         Image(systemName: "checkmark.circle.fill")
                             .font(.system(size: 44))
@@ -122,6 +159,44 @@ struct AddContactScreen: View {
         }
     }
 
+    /// "My QR" + "Scan QR" side by side under the search field. "My
+    /// QR" needs an identity with a DPNS name (the QR encodes both),
+    /// so before that "Scan QR" spans the full width alone.
+    private var qrButtonsRow: some View {
+        HStack(spacing: 10) {
+            if myUserLink != nil {
+                qrActionButton(
+                    NSLocalizedString("My QR", comment: "DashPay Contacts: shows the user's own contact QR code"),
+                    systemImage: "qrcode") {
+                    showMyQR = true
+                }
+            }
+            qrActionButton(
+                NSLocalizedString("Scan QR", comment: ""),
+                systemImage: "qrcode.viewfinder") {
+                showScanner = true
+            }
+        }
+    }
+
+    private func qrActionButton(_ title: String, systemImage: String, action: @escaping () -> Void) -> some View {
+        Button(action: action) {
+            HStack(spacing: 6) {
+                Image(systemName: systemImage)
+                    .font(.system(size: 17, weight: .medium))
+                Text(title)
+                    .font(.system(size: 15, weight: .semibold))
+            }
+            .foregroundColor(.dash.blue)
+            .frame(maxWidth: .infinity)
+            .frame(height: 46)
+            .background(
+                RoundedRectangle(cornerRadius: 10, style: .continuous)
+                    .fill(Color.dash.blue.opacity(0.1)))
+        }
+        .buttonStyle(.plain)
+    }
+
     /// Android search screen header: icon, headline, subtitle.
     private var header: some View {
         VStack(spacing: 6) {
@@ -281,6 +356,54 @@ struct AddContactScreen: View {
         }
     }
 
+    // MARK: My QR / scanning
+
+    /// The current user's scannable identity payload — nil until the
+    /// identity is registered AND owns a DPNS name (the QR encodes
+    /// both, so there is nothing honest to show before that).
+    private var myUserLink: DashPayUserLink? {
+        guard let identityId = DWCurrentUserIdentityInfo.shared.identityId,
+              let username = DWCurrentUserIdentityInfo.shared.username
+        else { return nil }
+        return DashPayUserLink(identityId: identityId, username: username.withoutDashSuffix)
+    }
+
+    /// Scanned QR → parse → verify against Platform → the same
+    /// send-confirmation sheet a search result tap opens. Verification
+    /// is an exact-username DPNS search whose result must carry the
+    /// scanned identity id — the sheet then renders a Platform-backed
+    /// `DpnsSearchResult`, never the QR's own unproven claim.
+    private func handleScannedCode(_ value: String) {
+        showScanner = false
+        guard let link = DashPayUserLink.parse(value) else {
+            errorMessage = NSLocalizedString("This isn't a DashPay user QR code.", comment: "DashPay Contacts: scanned QR is a payment/invitation/foreign code")
+            return
+        }
+        // Mirror the scanned name into the search field so the results
+        // list behind the confirmation sheet shows the same user.
+        query = link.username
+        isVerifyingScan = true
+        Task {
+            defer { isVerifyingScan = false }
+            do {
+                let matches = try await service.searchUsernames(prefix: link.username)
+                guard let match = matches.first(where: {
+                    $0.identityId == link.identityId
+                        && $0.fullName.withoutDashSuffix.lowercased() == link.username.lowercased()
+                }) else {
+                    errorMessage = String(
+                        format: NSLocalizedString("%@ couldn't be verified on the Dash network. The QR code may be outdated.", comment: "DashPay Contacts: scanned username doesn't resolve to the scanned identity"),
+                        link.username)
+                    return
+                }
+                checkEligibilityIfNeeded(match)
+                previewTarget = match
+            } catch {
+                errorMessage = error.localizedDescription
+            }
+        }
+    }
+
     // MARK: Search
 
     private var trimmedQuery: String {
@@ -526,3 +649,76 @@ struct AddContactPreviewSheet: View {
         .frame(height: 48)
     }
 }
+
+// MARK: - MyDashPayUserQRSheet
+
+/// "My QR" — the counterpart of the scan button: renders the current
+/// user's `DashPayUserLink` (identity id + preferred username) as a
+/// Dash-branded QR code (`QRCodeGenerator.dashStyledImage`) another
+/// Dash Wallet can scan to open the send-request confirmation for
+/// this user.
+struct MyDashPayUserQRSheet: View {
+    let link: DashPayUserLink
+    let displayName: String?
+
+    @Environment(\.dismiss) private var dismiss
+    @State private var qrImage: UIImage?
+
+    var body: some View {
+        NavigationStack {
+            ZStack {
+                Color.dash.primaryBackground.ignoresSafeArea()
+                VStack(spacing: 6) {
+                    Text(displayName ?? link.username)
+                        .font(.system(size: 22, weight: .bold))
+                        .foregroundColor(.dash.primaryText)
+                        .padding(.top, 20)
+                    if displayName != nil {
+                        Text(link.username)
+                            .font(.system(size: 14))
+                            .foregroundColor(.dash.secondaryText)
+                    }
+                    Group {
+                        if let qrImage {
+                            Image(uiImage: qrImage)
+                                .resizable()
+                                .scaledToFit()
+                        } else {
+                            SwiftUI.ProgressView()
+                        }
+                    }
+                    .frame(width: 240, height: 240)
+                    .padding(20)
+                    // The branded QR draws Dash-blue modules on a
+                    // transparent background — keep the card white in
+                    // dark mode so camera scanners keep their contrast.
+                    .background(
+                        RoundedRectangle(cornerRadius: 20, style: .continuous)
+                            .fill(Color.white)
+                            .shadow(color: Color.dash.shadow, radius: 16, x: 0, y: 4))
+                    .padding(.top, 14)
+                    Text(NSLocalizedString("Let another Dash Wallet user scan this code to add you as a contact.", comment: "DashPay Contacts: caption under the user's own QR code"))
+                        .font(.system(size: 14))
+                        .foregroundColor(.dash.tertiaryText)
+                        .multilineTextAlignment(.center)
+                        .fixedSize(horizontal: false, vertical: true)
+                        .padding(.horizontal, 32)
+                        .padding(.top, 14)
+                    Spacer()
+                }
+            }
+            .toolbar {
+                ToolbarItem(placement: .topBarTrailing) {
+                    Button(NSLocalizedString("Close", comment: "")) { dismiss() }
+                        .foregroundColor(.dash.blue)
+                }
+            }
+        }
+        .presentationDetents([.medium, .large])
+        .onAppear {
+            if qrImage == nil {
+                qrImage = QRCodeGenerator.dashStyledImage(for: link.uriString, size: 240)
+            }
+        }
+    }
+}