feat: mention user on username tap

Signed-off-by: Infi <infi@infi.sh>

app/src/main/java/chat/revolt/api/internals/MessageProcessor.kt

@@ -0,0 +1,22 @@
+package chat.revolt.api.internals
+
+import chat.revolt.api.RevoltAPI
+
+object MessageProcessor {
+    private val MentionRegex = Regex("@((?:\\p{L}|[\\d_.-])+)#([0-9]{4})", RegexOption.IGNORE_CASE)
+
+    fun processOutgoing(content: String): String {
+        val mentions = MentionRegex.findAll(content).map { it.value }.toList()
+
+        return mentions.fold(content) { acc, mention ->
+            val (username, discriminator) = MentionRegex.matchEntire(mention)?.destructured
+                ?: return@fold acc
+
+            val user =
+                RevoltAPI.userCache.values.find { it.username == username && it.discriminator == discriminator }
+
+            val userId = user?.id ?: return@fold acc
+            acc.replace(mention, "<@$userId>")
+        }
+    }
+}

app/src/main/java/chat/revolt/components/chat/Message.kt

@@ -64,11 +64,11 @@ import chat.revolt.api.internals.WebCompat
 import chat.revolt.api.internals.solidColor
 import chat.revolt.api.routes.microservices.january.asJanuaryProxyUrl
 import chat.revolt.api.schemas.AutumnResource
-import chat.revolt.api.schemas.Message as MessageSchema
 import chat.revolt.api.schemas.User
 import chat.revolt.components.generic.UserAvatar
 import chat.revolt.components.generic.UserAvatarWidthPlaceholder
 import chat.revolt.internals.markdown.LongClickableSpan
+import chat.revolt.api.schemas.Message as MessageSchema
 
 @Composable
 fun authorColour(message: MessageSchema): Brush {
@@ -163,6 +163,7 @@ fun Message(
     parse: (MessageSchema) -> SpannableStringBuilder = { SpannableStringBuilder(it.content) },
     onMessageContextMenu: () -> Unit = {},
     onAvatarClick: () -> Unit = {},
+    onNameClick: (() -> Unit)? = null,
     canReply: Boolean = false,
     onReply: () -> Unit = {}
 ) {
@@ -252,7 +253,17 @@ fun Message(
                                     brush = authorColour(message)
                                 ),
                                 maxLines = 1,
-                                overflow = TextOverflow.Ellipsis
+                                overflow = TextOverflow.Ellipsis,
+                                modifier = Modifier.then(
+                                    if (onNameClick != null)
+                                        Modifier.combinedClickable(
+                                            onClick = onNameClick,
+                                            onLongClick = {
+                                                onMessageContextMenu()
+                                            }
+                                        )
+                                    else Modifier
+                                )
                             )
 
                             InlineBadges(

app/src/main/java/chat/revolt/screens/chat/views/channel/ChannelScreen.kt

@@ -347,6 +347,11 @@ fun ChannelScreen(
                                     onUserSheetOpenFor(author, channel?.server)
                                 }
                             },
+                            onNameClick = {
+                                val author = message.author?.let { RevoltAPI.userCache[it] }
+                                    ?: return@Message
+                                viewModel.putAtCursorPosition("@${author.username}#${author.discriminator}")
+                            },
                             canReply = true,
                             onReply = {
                                 if (viewModel.pendingReplies.size >= 5) {

app/src/main/java/chat/revolt/screens/chat/views/channel/ChannelScreenViewModel.kt

@@ -14,6 +14,7 @@ import chat.revolt.R
 import chat.revolt.api.RevoltAPI
 import chat.revolt.api.RevoltJson
 import chat.revolt.api.internals.ChannelUtils
+import chat.revolt.api.internals.MessageProcessor
 import chat.revolt.api.internals.PermissionBit
 import chat.revolt.api.internals.Roles
 import chat.revolt.api.internals.SpecialUsers
@@ -211,7 +212,7 @@ class ChannelScreenViewModel : ViewModel() {
 
             sendMessage(
                 activeChannel!!.id!!,
-                pendingMessageContent.trimIndent(),
+                MessageProcessor.processOutgoing(pendingMessageContent.trimIndent()),
                 attachments = if (attachmentIds.isEmpty()) null else attachmentIds,
                 replies = pendingReplies
             )