feat(messenger): share and copy a link to a message

apps/flipcash/core/src/main/kotlin/com/flipcash/app/core/chat/ChatStep.kt

@@ -66,6 +66,20 @@ sealed interface ChatStep : FlowStep, Parcelable {
         Sheet,
         com.getcode.navigation.FullscreenSheet
 
+    /**
+     * Sharing one message into the viewer's other chats — [InviteToGroup]'s sheet with the
+     * message's link as what it hands out. Returns the chat picked first, as that one does.
+     *
+     * @param messageId the message's per-chat sequence, the `{seq}` in its link.
+     */
+    @Parcelize
+    @Serializable
+    data class ShareMessage(val messageId: Long) :
+        ChatStep,
+        NavigationRetVal<GroupInviteResult>,
+        Sheet,
+        com.getcode.navigation.FullscreenSheet
+
     @Parcelize
     @Serializable
     data class Profile(

apps/flipcash/core/src/main/kotlin/com/flipcash/app/core/util/Linkify.kt

@@ -59,4 +59,18 @@ object Linkify {
      */
     fun groupChatInvite(chatId: ChatId): String? =
         chatId.bytes.toList().uuid?.let { "https://app.flipcash.com/chat/$it" }
+
+    /**
+     * A link to one message — `app.flipcash.com/chat/{chatId}/m/{seq}`, where [sequence] is the
+     * message's per-chat id.
+     *
+     * The chat id takes the form the router reads back: a group's dashed UUID, as in
+     * [groupChatInvite], and a DM's base64url, as in [tipChatById]. The id's form is how the router
+     * tells a group link from a DM one, so it has to be written that way rather than as either alone.
+     */
+    fun message(chatId: ChatId, sequence: Long): String {
+        val id = chatId.bytes.toList().uuid?.toString()
+            ?: chatId.bytes.encodeBase64(urlSafe = true)
+        return "https://app.flipcash.com/chat/$id/m/$sequence"
+    }
 }

apps/flipcash/core/src/main/res/values/strings.xml

@@ -1097,6 +1097,7 @@
     <string name="title_messageNotDeleted">Message Not Deleted</string>
     <string name="description_messageNotDeleted">The message couldn\'t be deleted, so it is still visible to everyone.</string>
     <string name="title_clipboardLabelMessage">Message</string>
+    <string name="title_clipboardLabelMessageLink">Message Link</string>
     <string name="title_reactionNotAdded">Couldn\'t add reaction</string>
     <string name="title_reactionLimitReached">This message has the maximum number of reactions</string>
     <string name="title_reactionsCount">%1$d Reactions</string>
@@ -1509,6 +1510,8 @@
     <string name="action_claimUsername">Claim your username</string>
     <string name="placeholder_minimumToChat">Not set</string>
     <string name="title_shareProfileToChats">Share Profile</string>
+    <string name="title_shareMessageToChats">Share Message</string>
+    <string name="action_forwardMessage">Forward</string>
     <!-- Who the share sheet is for: display name, then @handle -->
     <string name="action_showProfileCard">Show Profile Card</string>
     <string name="action_copyLink">Copy Link</string>

apps/flipcash/features/messenger/src/main/kotlin/com/flipcash/app/messenger/ChatFlowScreen.kt

@@ -20,6 +20,7 @@ import com.flipcash.app.core.chat.ChatIdentifier
 import com.flipcash.app.core.chat.ChatParticipant
 import com.flipcash.app.core.chat.ChatSendResult
 import com.flipcash.app.core.chat.ChatStep
+import com.flipcash.app.core.util.Linkify
 import com.flipcash.app.core.chat.ProfileOrigin
 import com.flipcash.app.core.chat.GroupInviteResult
 import com.flipcash.features.messenger.R
@@ -136,6 +137,9 @@ private fun chatEntryProvider(
     annotatedEntry<ChatStep.InviteToGroup> {
         FlowGroupInviteSheet()
     }
+    annotatedEntry<ChatStep.ShareMessage> { step ->
+        FlowShareMessageSheet(step.messageId)
+    }
 
     annotatedEntry<ChatStep.Profile> { step ->
         FlowChatProfileScreen(step.contact, step.origin)
@@ -302,6 +306,45 @@ private fun FlowGroupInviteSheet() {
     )
 }
 
+/**
+ * [ChatStep.ShareMessage]: the invite sheet handing out one message's link. Same send path and
+ * result as [FlowGroupInviteSheet]; the link is the whole subject.
+ */
+@Composable
+private fun FlowShareMessageSheet(messageId: Long) {
+    val viewModel = flowSharedViewModel<ChatViewModel>()
+    val state by viewModel.stateFlow.collectAsStateWithLifecycle()
+    val inviteViewModel = hiltViewModel<GroupInviteViewModel>()
+    val inviteState by inviteViewModel.state.collectAsStateWithLifecycle()
+    val dismissSheet = LocalBottomSheetDismissDispatcher.current
+    val link = remember(state.chatId, messageId) {
+        state.chatId?.let { Linkify.message(it, messageId) }
+    }
+
+    // The chat the message is in stays in the list: sending a link to a message back into its own
+    // chat is how you point at something further up, and the card draws there like anywhere else.
+
+    val keyboard = rememberKeyboardController()
+    val resultBack = resultBackNavigator<GroupInviteResult>(exit = dismissSheet)
+    LaunchedEffect(inviteViewModel) {
+        inviteViewModel.invited.collect { chatId ->
+            keyboard.hideIfVisible { resultBack.returnValue(GroupInviteResult(chatId)) }
+        }
+    }
+
+    GroupInviteSheet(
+        inviteUrl = link,
+        subject = ShareToChatsSubject.Message,
+        state = inviteState,
+        onShare = {},
+        onCopy = { viewModel.dispatchEvent(ChatViewModel.Event.CopyMessageLink(messageId)) },
+        onToggle = inviteViewModel::toggle,
+        onMessageChanged = inviteViewModel::onMessageChanged,
+        onInvite = { link?.let(inviteViewModel::invite) },
+        onDismiss = dismissSheet,
+    )
+}
+
 @Composable
 private fun FlowChatProfileScreen(participant: ChatParticipant, origin: ProfileOrigin) {
     val viewModel = flowSharedViewModel<ChatProfileViewModel>()

apps/flipcash/features/messenger/src/main/kotlin/com/flipcash/app/messenger/internal/ChatViewModel.kt

@@ -1018,6 +1018,13 @@ internal class ChatViewModel @AssistedInject constructor(
         // flow, and the bar's caller has already captured the message to push the route with.
         data object ReportRequested : Event
 
+        /** Puts a link to [messageId] on the clipboard — `Linkify.message`. */
+        data class CopyMessageLink(val messageId: Long) : Event
+
+        // Dismisses the bar, as ReportRequested does: the share sheet is opened by the bar's caller,
+        // which has the navigator and has already captured the message.
+        data object ShareMessageRequested : Event
+
         data object SubmitEdit : Event
         data object CancelEdit : Event
         data object EditingEnded : Event
@@ -2654,6 +2661,16 @@ internal class ChatViewModel @AssistedInject constructor(
             }
             .launchIn(viewModelScope)
 
+        eventFlow.filterIsInstance<Event.CopyMessageLink>()
+            .onEach { event ->
+                val chatId = stateFlow.value.chatId ?: return@onEach
+                clipboardManager.setText(
+                    text = Linkify.message(chatId, event.messageId),
+                    label = resources.getString(R.string.title_clipboardLabelMessageLink),
+                )
+            }
+            .launchIn(viewModelScope)
+
         eventFlow.filterIsInstance<Event.CopyMessage>()
             .onEach { event ->
                 clipboardManager.setText(
@@ -3900,6 +3917,12 @@ internal class ChatViewModel @AssistedInject constructor(
                 Event.ReportRequested -> { state ->
                     state.copy(selection = null, confirmingDelete = false)
                 }
+                is Event.CopyMessageLink -> { state ->
+                    state.copy(selection = null, confirmingDelete = false)
+                }
+                Event.ShareMessageRequested -> { state ->
+                    state.copy(selection = null, confirmingDelete = false)
+                }
                 is Event.EditMessage -> { state ->
                     state.copy(
                         selection = null,

apps/flipcash/features/messenger/src/main/kotlin/com/flipcash/app/messenger/internal/screens/GroupInviteSheet.kt

@@ -115,9 +115,18 @@ internal fun CodeNavigator.openGroupInvite() {
     }
 }
 
+/** Opens the sheet on a message's link; the chat picked first opens once the sends are out. */
+internal fun CodeNavigator.openMessageShare(messageId: Long) {
+    navigateForResult<GroupInviteResult>(ChatStep.ShareMessage(messageId)) { result ->
+        if (result is NavResultOrCanceled.ReturnValue) {
+            navigate(AppRoute.Messaging.Chat(ChatIdentifier.ByChatId(result.value.chatId)))
+        }
+    }
+}
+
 /**
- * What [GroupInviteSheet] hands out: a group's invite link, or a person's profile link. The two
- * differ in their copy, in what the Share tile gives the system share sheet, and in whether the
+ * What [GroupInviteSheet] hands out: a group's invite link, a person's profile link, or a link to
+ * one message. They differ in their copy, in what the Share tile gives the system share sheet, and in whether the
  * group's analytics fire; the rest of the sheet is the same.
  */
 internal sealed interface ShareToChatsSubject {
@@ -136,6 +145,12 @@ internal sealed interface ShareToChatsSubject {
         val displayName: String?,
         val preview: TipCodePreview?,
     ) : ShareToChatsSubject
+
+    /**
+     * A message, handed out as its link. The sheet's URL is the link itself, so nothing else is
+     * carried: the recipient's app draws the message card from it.
+     */
+    data object Message : ShareToChatsSubject
 }
 
 /**
@@ -262,6 +277,7 @@ internal fun GroupInviteSheet(
                                                 username = subject.username,
                                                 preview = subject.preview,
                                             )
+                                            ShareToChatsSubject.Message -> Shareable.MessageLink(inviteUrl)
                                         }
                                     )
                                 }
@@ -273,7 +289,7 @@ internal fun GroupInviteSheet(
                             label = stringResource(
                                 when {
                                     copied -> R.string.action_inviteLinkCopied
-                                    subject is ShareToChatsSubject.User -> R.string.action_copyLink
+                                    subject !is ShareToChatsSubject.Group -> R.string.action_copyLink
                                     else -> R.string.action_copyInviteLink
                                 }
                             ),
@@ -347,7 +363,11 @@ internal fun GroupInviteSheet(
                 }
                 .onSizeChanged { headerHeight = with(density) { it.height.toDp() } },
             title = stringResource(
-                if (subject is ShareToChatsSubject.User) R.string.title_shareProfileToChats else R.string.title_invitePeople
+                when (subject) {
+                    is ShareToChatsSubject.User -> R.string.title_shareProfileToChats
+                    is ShareToChatsSubject.Message -> R.string.title_shareMessageToChats
+                    is ShareToChatsSubject.Group -> R.string.title_invitePeople
+                }
             ),
             titleAlignment = Alignment.CenterHorizontally,
             contentPadding = PaddingValues(HeaderPadding),
@@ -375,7 +395,7 @@ internal fun GroupInviteSheet(
                     hazeState = hazeState,
                     sending = state.sending,
                     sendLabel = stringResource(
-                        if (subject is ShareToChatsSubject.User) R.string.action_send else R.string.action_invite
+                        if (subject is ShareToChatsSubject.Group) R.string.action_invite else R.string.action_send
                     ),
                     onMessageChanged = onMessageChanged,
                     onInvite = onInvite,

apps/flipcash/features/messenger/src/main/kotlin/com/flipcash/app/messenger/internal/screens/components/ChatTopBar.kt

@@ -19,11 +19,13 @@ import androidx.compose.foundation.layout.statusBars
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.outlined.ArrowBack
-import androidx.compose.material.icons.automirrored.outlined.Reply
-import androidx.compose.material.icons.outlined.ContentCopy
-import androidx.compose.material.icons.outlined.Delete
+import androidx.compose.material.icons.automirrored.filled.Reply
+import androidx.compose.material.icons.filled.ContentCopy
+import androidx.compose.material.icons.filled.Delete
 import androidx.compose.material.icons.outlined.Edit
-import androidx.compose.material.icons.outlined.Feedback
+import androidx.compose.material.icons.filled.Feedback
+import com.flipcash.app.messenger.internal.screens.openMessageShare
+import androidx.compose.material.icons.automirrored.filled.Forward
 import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.Icon
@@ -113,6 +115,11 @@ internal fun ChatTopBar(
                     // Resolved here rather than in the bar: reporting is its own top-level
                     // flow now, so it needs the chat's id, and this is the nearest scope holding
                     // both that and the navigator.
+                    onShareMessage = {
+                        keyboard.hideIfVisible {
+                            navigator.openMessageShare(target.selection.messageId)
+                        }
+                    },
                     onReport = {
                         state.chatId?.let { chatId ->
                             navigator.push(
@@ -265,53 +272,52 @@ private fun MessageSelectionBar(
     selection: ChatListItem.ContentBubble,
     keyboard: KeyboardController,
     dispatch: (ChatViewModel.Event) -> Unit,
+    onShareMessage: () -> Unit,
     onReport: () -> Unit,
 ) {
     val capabilities = selection.capabilities
     val body = selection.plainText
 
-    // Order is priority: the first actions keep their icons when the bar runs out of room. Reply
-    // leads because it is the most common action and the only one a cash bubble offers — burying it
-    // is the one choice that would leave that bubble's bar empty. Delete follows: putting the one
-    // action with a confirmation behind a menu makes it a three-tap job. Report goes last: it is
-    // the rarest of the five and the only one that is never about your own message, so it is the
-    // right one to collapse into the overflow on a narrow screen.
+    // Order is priority: the first actions keep their icons when the bar runs out of room, and it
+    // matches iOS's menu: Copy, Reply, Forward, Edit, Delete, Report. Report goes last: it is the
+    // rarest and the only one that is never about your own message, so it is the right one to
+    // collapse into the overflow on a narrow screen. Forward hands out the message's link; the
+    // sheet it opens has the Copy Link tile, so the bar has no copy-link row of its own.
+    // Copy and edit both act on the message's text, so a bubble without any is offered neither.
     val actions = buildList {
+        if (body != null && MessageCapability.Copy in capabilities) {
+            add(
+                MessageAction(
+                    label = stringResource(R.string.action_copy),
+                    icon = Icons.Filled.ContentCopy,
+                    testTag = "action_copy_message",
+                    onClick = { dispatch(ChatViewModel.Event.CopyMessage(body)) },
+                )
+            )
+        }
         if (MessageCapability.Reply in capabilities) {
             add(
                 MessageAction(
                     label = stringResource(R.string.action_reply),
-                    icon = Icons.AutoMirrored.Outlined.Reply,
+                    icon = Icons.AutoMirrored.Filled.Reply,
                     testTag = "action_reply_message",
                     onClick = { dispatch(ChatViewModel.Event.ReplyRequested(selection)) },
                 )
             )
         }
-        if (MessageCapability.Delete in capabilities) {
+        if (MessageCapability.Link in capabilities) {
             add(
                 MessageAction(
-                    label = stringResource(R.string.action_delete),
-                    icon = Icons.Outlined.Delete,
-                    testTag = "action_delete_message",
+                    label = stringResource(R.string.action_forwardMessage),
+                    icon = Icons.AutoMirrored.Filled.Forward,
+                    testTag = "action_share_message",
                     onClick = {
-                        keyboard.hideIfVisible {
-                            dispatch(ChatViewModel.Event.DeleteMessage(selection.messageId))
-                        }
+                        dispatch(ChatViewModel.Event.ShareMessageRequested)
+                        onShareMessage()
                     },
                 )
             )
         }
-        // Copy and edit both act on the message's text, so a bubble without any is offered neither.
-        if (body != null && MessageCapability.Copy in capabilities) {
-            add(
-                MessageAction(
-                    label = stringResource(R.string.action_copy),
-                    icon = Icons.Outlined.ContentCopy,
-                    testTag = "action_copy_message",
-                    onClick = { dispatch(ChatViewModel.Event.CopyMessage(body)) },
-                )
-            )
-        }
         if (body != null && MessageCapability.Edit in capabilities) {
             add(
                 MessageAction(
@@ -324,11 +330,25 @@ private fun MessageSelectionBar(
                 )
             )
         }
+        if (MessageCapability.Delete in capabilities) {
+            add(
+                MessageAction(
+                    label = stringResource(R.string.action_delete),
+                    icon = Icons.Filled.Delete,
+                    testTag = "action_delete_message",
+                    onClick = {
+                        keyboard.hideIfVisible {
+                            dispatch(ChatViewModel.Event.DeleteMessage(selection.messageId))
+                        }
+                    },
+                )
+            )
+        }
         if (MessageCapability.Report in capabilities) {
             add(
                 MessageAction(
                     label = stringResource(R.string.title_report),
-                    icon = Icons.Outlined.Feedback,
+                    icon = Icons.Filled.Feedback,
                     testTag = "action_report_message",
                     // Unlike the others this one leaves the chat, so nothing on the way back
                     // dismisses the bar. Clearing it here means the transcript is at rest behind