Add 'Send private message' action to chat user sheet

app/src/main/java/com/bitchat/android/nostr/GeohashRepository.kt

@@ -43,6 +43,20 @@ class GeohashRepository(
         }?.key
     }
 
+    fun findPubkeyByShortId(shortId: String): String? {
+        // First check cached nicknames (fastest)
+        var found = geoNicknames.keys.firstOrNull { it.startsWith(shortId, ignoreCase = true) }
+        if (found != null) return found
+
+        // If not found in nicknames (e.g. anon user), check all known participants across all geohashes
+        for (participants in geohashParticipants.values) {
+            found = participants.keys.firstOrNull { it.startsWith(shortId, ignoreCase = true) }
+            if (found != null) return found
+        }
+
+        return null
+    }
+
     // peerID alias -> nostr pubkey mapping for geohash DMs and temp aliases
     private val nostrKeyMapping: MutableMap<String, String> = mutableMapOf()
 

app/src/main/java/com/bitchat/android/ui/ChatUserSheet.kt

@@ -40,6 +40,7 @@ fun ChatUserSheet(
     val isDark = colorScheme.background.red + colorScheme.background.green + colorScheme.background.blue < 1.5f
     val standardGreen = if (isDark) Color(0xFF32D74B) else Color(0xFF248A3D) // iOS green
     val standardBlue = Color(0xFF007AFF) // iOS blue
+    val standardPurple = if (isDark) Color(0xFFBF5AF2) else Color(0xFFAF52DE) // iOS purple
     val standardRed = Color(0xFFFF3B30) // iOS red
     val standardGrey = if (isDark) Color(0xFF8E8E93) else Color(0xFF6D6D70) // iOS grey
 
@@ -92,6 +93,33 @@ fun ChatUserSheet(
 
                     // Only show user actions for other users' messages or when no message is selected
                     if (selectedMessage?.sender != viewModel.nickname.value) {
+                        // Send private message action
+                        item {
+                            UserActionRow(
+                                title = stringResource(R.string.action_private_message_title, targetNickname),
+                                subtitle = stringResource(R.string.action_private_message_subtitle),
+                                titleColor = standardPurple,
+                                onClick = {
+                                    val selectedLocationChannel = viewModel.selectedLocationChannel.value
+                                    if (selectedLocationChannel is com.bitchat.android.geohash.ChannelID.Location) {
+                                        if (selectedMessage?.senderPeerID?.startsWith("nostr:") == true) {
+                                            val shortId = selectedMessage.senderPeerID!!.substring(6)
+                                            viewModel.startGeohashDMByShortId(shortId)
+                                        } else {
+                                            viewModel.startGeohashDMByNickname(targetNickname)
+                                        }
+                                    } else {
+                                        // Mesh chat
+                                        val peerID = selectedMessage?.senderPeerID ?: viewModel.getPeerIDForNickname(targetNickname)
+                                        if (peerID != null) {
+                                            viewModel.showPrivateChatSheet(peerID)
+                                        }
+                                    }
+                                    onDismiss()
+                                }
+                            )
+                        }
+
                         // Slap action
                         item {
                             UserActionRow(

app/src/main/java/com/bitchat/android/ui/ChatViewModel.kt

@@ -1065,6 +1065,18 @@ class ChatViewModel(
         }
     }
 
+    fun startGeohashDMByNickname(nickname: String) {
+        geohashViewModel.startGeohashDMByNickname(nickname) { convKey ->
+            showPrivateChatSheet(convKey)
+        }
+    }
+
+    fun startGeohashDMByShortId(shortId: String) {
+        geohashViewModel.startGeohashDMByShortId(shortId) { convKey ->
+            showPrivateChatSheet(convKey)
+        }
+    }
+
     fun selectLocationChannel(channel: com.bitchat.android.geohash.ChannelID) {
         geohashViewModel.selectLocationChannel(channel)
     }

app/src/main/java/com/bitchat/android/ui/GeohashViewModel.kt

@@ -273,6 +273,25 @@ class GeohashViewModel(
         Log.d(TAG, "🗨️ Started geohash DM with ${pubkeyHex} -> ${convKey} (geohash=${gh})")
     }
 
+    fun startGeohashDMByNickname(nickname: String, onStartPrivateChat: (String) -> Unit) {
+        val pubkey = repo.findPubkeyByNickname(nickname)
+        if (pubkey != null) {
+            startGeohashDM(pubkey, onStartPrivateChat)
+        } else {
+            Log.w(TAG, "Cannot start geohash DM: nickname '$nickname' not found in repo")
+            // Optionally notify user
+        }
+    }
+
+    fun startGeohashDMByShortId(shortId: String, onStartPrivateChat: (String) -> Unit) {
+        val pubkey = repo.findPubkeyByShortId(shortId)
+        if (pubkey != null) {
+            startGeohashDM(pubkey, onStartPrivateChat)
+        } else {
+             Log.w(TAG, "Cannot start geohash DM: shortId '$shortId' not found in repo")
+        }
+    }
+
     fun getNostrKeyMapping(): Map<String, String> = repo.getNostrKeyMapping()
 
     fun blockUserInGeohash(targetNickname: String) {

app/src/main/res/values/strings.xml

@@ -201,7 +201,10 @@
   <string name="action_hug_title">hug %1$s</string>
   <string name="action_hug_subtitle">send a friendly hug message</string>
   <string name="action_block_title">block %1$s</string>
-  <string name="action_block_subtitle">block all messages from this user</string>
+    <string name="action_block_subtitle">block all messages from this user</string>
+    <string name="action_private_message_title">message %1$s</string>
+    <string name="action_private_message_subtitle">send a private message</string>
+
 
   <!-- Location channels sheet -->
   <string name="location_channels_title">#location channels</string>