feat(chat): forward a message through the share sheet

Flipcash/Core/Controllers/ConversationController.swift

@@ -1834,7 +1834,7 @@ final class ConversationController {
                 case .delete: "Couldn't Delete Message"
                 // Neither of these mutates the transcript, so neither can raise a mutation alert.
                 // Report files straight from its sheet and reports its own outcome there.
-                case .copy, .reply, .report: "Something Went Wrong"
+                case .copy, .reply, .report, .forward: "Something Went Wrong"
                 }
             }
         }

Flipcash/Core/Screens/Conversation/ChatItem+Conversation.swift

@@ -601,10 +601,11 @@ extension ChatItem {
     /// Menu order is fixed here, not at the call site — a `Set` has no order, and the context menu
     /// must not shuffle its rows between renders of the same message.
     ///
-    /// Report goes last: it is the rarest row and the only one that never appears on your own
-    /// message, so the menu reads "yours ends with delete, theirs ends with report".
+    /// Forward follows Reply, as on Android. Report goes
+    /// last: it is the rarest row and the only one that never appears on your own message, so the
+    /// menu reads "yours ends with delete, theirs ends with report".
     nonisolated private static func orderedActions(_ capabilities: Set<MessageCapability>) -> [MessageCapability] {
-        [.copy, .reply, .edit, .delete, .report].filter(capabilities.contains)
+        [.copy, .reply, .forward, .edit, .delete, .report].filter(capabilities.contains)
     }
 
     /// "Read 3:42 PM" / "Read Yesterday" / "Read Monday" / "Read Tue, Jun 17" once the counterpart's

Flipcash/Core/Screens/Conversation/ChatScreenRepresentable.swift

@@ -313,9 +313,9 @@ struct ChatScreenRepresentable: UIViewControllerRepresentable {
                 screen?.focusComposer()
             case .reply:
                 screen?.focusComposer()
-            // Both raise a sheet over the transcript, so the keyboard goes down first.
-            case .delete, .report: screen?.dismissKeyboard()
-            case .copy:            break
+            // Each raises a sheet over the transcript, so the keyboard goes down first.
+            case .delete, .report, .forward: screen?.dismissKeyboard()
+            case .copy:               break
             }
         }
     }

Flipcash/Core/Screens/Conversation/ConversationScreen.swift

@@ -79,6 +79,7 @@ struct ConversationScreen: View {
     /// Whether the encryption explainer opened from the transcript's marker is showing.
     @State private var isShowingEncryptionInfo = false
     @State private var messageReport: MessageReportRequest?
+    @State private var messageShare: MessageShareRequest?
     /// Whether `Group: Gate Shown` has gone out for this visit. The destination is keyed by
     /// conversation ID, so a new push is a new visit; a return from a pushed screen is not.
     @State private var didReportGate = false
@@ -805,6 +806,20 @@ struct ConversationScreen: View {
         .sheet(isPresented: $isShowingEncryptionInfo) {
             E2eeLearnMoreSheet(kind: .dm, isPresented: $isShowingEncryptionInfo)
         }
+        .fullScreenCover(item: $messageShare) { share in
+            ShareToChatsSheet(
+                subject: .message(share.url),
+                isPresented: Binding(
+                    get: { messageShare != nil },
+                    set: { if !$0 { messageShare = nil } }
+                )
+            ) { chatID in
+                // The chat the message is in stays in the picker, and sending there leaves the
+                // viewer where they already are.
+                guard chatID != conversationID else { return }
+                router.push(.tipConversation(chatID))
+            }
+        }
         .fullScreenCover(item: $messageReport) { report in
             NavigationStack {
                 ReportFlowScreen(
@@ -1032,6 +1047,9 @@ struct ConversationScreen: View {
             // that one.
             guard let conversationID else { return }
             messageReport = MessageReportRequest(id: stableID, chatID: conversationID, messageID: message.id)
+        case .forward:
+            guard let conversationID else { return }
+            messageShare = MessageShareRequest(id: stableID, url: .messageLink(in: conversationID, messageID: message.id))
         }
     }
 
@@ -1129,6 +1147,12 @@ struct ConversationScreen: View {
         let messageID: MessageID
     }
 
+    private struct MessageShareRequest: Identifiable {
+        /// The transcript row's stable id.
+        let id: String
+        let url: URL
+    }
+
     private struct ReactionPickerRequest: Identifiable {
         let id: String
         let messageID: MessageID

Flipcash/Core/Screens/Main/Tips/New Group/ShareToChatsSheet.swift

@@ -23,6 +23,9 @@ enum ShareToChatsSubject {
         preview: TipCodePreview? = nil,
         directChatID: ConversationID?
     )
+    /// A link to one message, `/chat/{chatId}/m/{seq}`. The recipient's app draws the message card
+    /// from it, so the link is all that goes out.
+    case message(URL)
 }
 
 /// "Invite People" (nodes 10330:19387, 10330:19549, 10329:12104): hand out a link by Share or Copy,
@@ -65,6 +68,7 @@ struct ShareToChatsSheet: View {
         let url: URL = switch subject {
         case .group(let id): .groupChatInvite(for: id)
         case .user(let userID, let username, _, _, _): .tipcard(for: userID, username: username)
+        case .message(let url): url
         }
         self._model = State(initialValue: InvitePeopleViewModel(url: url))
     }
@@ -73,7 +77,7 @@ struct ShareToChatsSheet: View {
     private var groupID: ConversationID? {
         switch subject {
         case .group(let id): id
-        case .user: nil
+        case .user, .message: nil
         }
     }
 
@@ -82,14 +86,16 @@ struct ShareToChatsSheet: View {
         switch subject {
         case .group(let id): id
         case .user(_, _, _, _, let directChatID): directChatID
+        // The message's own chat stays: a link sent there points at something further up.
+        case .message: nil
         }
     }
 
     /// The person whose card Show Profile Card draws. Nil for a group, and for a person with no
     /// display name, who has no card.
     private var card: ProfileCardScreen.Card? {
         switch subject {
-        case .group:
+        case .group, .message:
             return nil
         case .user(let userID, let username, let displayName, _, _):
             guard let displayName, !displayName.isEmpty else { return nil }
@@ -101,20 +107,21 @@ struct ShareToChatsSheet: View {
         switch subject {
         case .group: "Invite People"
         case .user: "Share Profile"
+        case .message: "Share Message"
         }
     }
 
     private var copyTitle: String {
         switch subject {
         case .group: "Copy Invite Link"
-        case .user: "Copy Link"
+        case .user, .message: "Copy Link"
         }
     }
 
     private var sendTitle: String {
         switch subject {
         case .group: "Invite"
-        case .user: "Send"
+        case .user, .message: "Send"
         }
     }
 
@@ -149,13 +156,17 @@ struct ShareToChatsSheet: View {
             .flatMap(UIImage.init(data:))
     }
 
-    /// What Share hands the system share sheet: the group's preview card, or the person's.
-    private func shareItem() -> UIActivityItemSource {
+    /// What Share hands the system share sheet: the group's preview card, the person's, or a message's bare link.
+    private func shareItems() -> [Any] {
         switch subject {
         case .group:
-            GroupInviteShareItem(url: model.url, title: title, icon: icon())
+            [GroupInviteShareItem(url: model.url, title: title, icon: icon())]
         case .user(_, _, let displayName, let preview, _):
-            TipCodeShareItem.profile(url: model.url, displayName: displayName, preview: preview)
+            [TipCodeShareItem.profile(url: model.url, displayName: displayName, preview: preview)]
+        case .message:
+            // The URL itself, not an item source: the system builds the preview card from the link
+            // rather than from a group invite's fallback title.
+            [model.url]
         }
     }
 
@@ -267,7 +278,7 @@ struct ShareToChatsSheet: View {
                     .scaledToFit()
             } action: {
                 if groupID != nil { Analytics.groupInviteShared(method: .share) }
-                ShareSheet.present(activityItem: shareItem()) { _ in }
+                ShareSheet.present(activityItems: shareItems()) { _ in }
             }
             .accessibilityIdentifier("group-invite-send")
 

Flipcash/Utilities/URL+Links.swift

@@ -45,6 +45,12 @@ extension URL {
         URL(string: "https://app.flipcash.com/chat/\(conversationID.linkPathComponent)")!
     }
 
+    /// A link to one message — `app.flipcash.com/chat/{chatId}/m/{seq}`, where `seq` is the
+    /// message's per-chat id. `Route` parses it back to ``Route/Path/chatMessage(_:_:)``.
+    nonisolated static func messageLink(in conversationID: ConversationID, messageID: MessageID) -> URL {
+        URL(string: "https://app.flipcash.com/chat/\(conversationID.linkPathComponent)/m/\(messageID.value)")!
+    }
+
     /// The in-app link a chat opens through, for the push tap that has no `target_url` to follow.
     ///
     /// The same id an invite link carries, routed the same way, so a group the user has not joined

FlipcashCore/Sources/FlipcashCore/Models/Conversation/MessageCapability.swift

@@ -15,6 +15,8 @@ public enum MessageCapability: String, Hashable, Sendable, Codable, CaseIterable
     case edit
     case delete
     case report
+    /// Send a link to the message into other chats, or out through the system share sheet.
+    case forward
 }
 
 extension MessageCapability {
@@ -27,14 +29,15 @@ extension MessageCapability {
         case .edit:   "Edit"
         case .delete: "Delete"
         case .report: "Report"
+        case .forward: "Forward"
         }
     }
 
     /// Whether the menu should render this row in its destructive style.
     public var isDestructive: Bool {
         switch self {
         // Report is red to match Report on the profile menus, though nothing is destroyed.
-        case .copy, .reply, .edit: false
+        case .copy, .reply, .edit, .forward: false
         case .delete, .report:     true
         }
     }
@@ -57,6 +60,12 @@ extension MessageCapability {
     /// | Own message, unconfirmed | no |
     /// | A tombstone | no |
     ///
+    /// Forward is granted wherever Android grants `Link`: any
+    /// text, photo or cash message a participant sent and the server confirmed, since only those
+    /// have a sequence to point at. A tombstone, a system notice, a widget, and a message this client
+    /// could not decrypt don't get it. Like Report, it survives `isMember` and `canPost`: a reader
+    /// outside a group can still pass a message along.
+    ///
     /// `conversation` is accepted but unread today: it is the seam a group-chat permissions model
     /// plugs into (an admin deleting another member's message, a read-only channel), and taking it
     /// now means adding that model does not change every call site. It is optional because the
@@ -67,8 +76,8 @@ extension MessageCapability {
     /// the Join panel stands where the composer would, so there is nothing to reply with.
     ///
     /// `canPost` is false when the viewer fails a speaker rule (with membership). Reply goes with the
-    /// composer, since a reply is a post, matching Android. Copy, Report and the sender's own
-    /// Edit/Delete are not posting and stay. Reactions are not decided here.
+    /// composer, since a reply is a post, matching Android. Copy, Report, the link rows and the
+    /// sender's own Edit/Delete are not posting and stay. Reactions are not decided here.
     ///
     /// `now` is a parameter rather than `Date.now` so the result stays a function of its inputs.
     public static func resolve(
@@ -105,7 +114,8 @@ extension MessageCapability {
             // authored it so there is nothing to edit, and delete is deliberately withheld from
             // a payment record. Someone else's payment is still reportable — a payment is a thing
             // a person did to you.
-            return message.isFromSelf(selfUserID) ? [.reply] : [.reply, .report]
+            guard message.isFromSelf(selfUserID) else { return [.reply, .report, .forward] }
+            return message.eventSequence > 0 ? [.reply, .forward] : [.reply]
         case .widget(.unrecognized):
             // Drawn as an unsupported message: nothing this client can act on.
             return []
@@ -121,7 +131,9 @@ extension MessageCapability {
         }
 
         guard message.isFromSelf(selfUserID) else {
-            return hasText ? [.copy, .reply, .report] : [.reply, .report]
+            return hasText
+                ? [.copy, .reply, .report, .forward]
+                : [.reply, .report, .forward]
         }
 
         // An unconfirmed message has no `eventSequence` to send as `expected_event_sequence`, so no
@@ -131,7 +143,7 @@ extension MessageCapability {
             return []
         }
 
-        var capabilities: Set<MessageCapability> = [.reply]
+        var capabilities: Set<MessageCapability> = [.reply, .forward]
         if hasText {
             capabilities.insert(.copy)
             if isWithin(policy.editWindow, of: message, at: now) {

FlipcashCore/Sources/FlipcashCore/Models/Conversation/MessagePolicy.swift

@@ -93,7 +93,7 @@ public struct MessagePolicy: Hashable, Sendable {
         switch capability {
         case .edit:                  editWindow
         case .delete:                deleteWindow
-        case .copy, .reply, .report: nil
+        case .copy, .reply, .report, .forward: nil
         }
     }