Feature: support user mentions (#10)

* Support displaying user mentions in posts and push notifications.

* Use simple ext plugin instead.

* Support user autocomplete on smartphones.

* Automatic popup position and height restriction. Ondismiss request.

* Only show non-empty user autocompletion popups.

* Fix merge problems.

core/common/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/core/common/markdown/ArtemisMarkdownTransformer.kt

@@ -1,14 +1,34 @@
 package de.tum.informatics.www1.artemis.native_app.core.common.markdown
 
-object ArtemisMarkdownTransformer {
+abstract class ArtemisMarkdownTransformer {
 
-    private val customMarkdownPattern = "\\[(text|quiz|lecture|modeling|file-upload|programing)](.*)\\(((?:/|\\w|\\d)+)\\)\\[/\\1]".toRegex()
+    private val exerciseMarkdownPattern =
+        "\\[(text|quiz|lecture|modeling|file-upload|programing)](.*)\\(((?:/|\\w|\\d)+)\\)\\[/\\1]".toRegex()
+    private val userMarkdownPattern = "\\[user](.*?)\\((.*?)\\)\\[/user]".toRegex()
 
-    fun transformMarkdown(markdown: String, serverUrl: String): String {
-        return customMarkdownPattern.replace(markdown) { matchResult ->
+    fun transformMarkdown(markdown: String): String {
+        return exerciseMarkdownPattern.replace(markdown) { matchResult ->
             val title = matchResult.groups[2]?.value.orEmpty()
             val url = matchResult.groups[3]?.value.orEmpty()
-            "[$title]($serverUrl$url)"
+            transformExerciseMarkdown(title, url)
+        }.let {
+            userMarkdownPattern.replace(it) { matchResult ->
+                val fullName = matchResult.groups[1]?.value.orEmpty()
+                val userName = matchResult.groups[2]?.value.orEmpty()
+                transformUserMentionMarkdown(
+                    text = matchResult.groups[0]?.value.orEmpty(),
+                    fullName = fullName,
+                    userName = userName
+                )
+            }
         }
     }
+
+    protected abstract fun transformExerciseMarkdown(title: String, url: String): String
+
+    protected abstract fun transformUserMentionMarkdown(
+        text: String,
+        fullName: String,
+        userName: String
+    ): String
 }

core/common/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/core/common/markdown/PostArtemisMarkdownTransformer.kt

@@ -0,0 +1,9 @@
+package de.tum.informatics.www1.artemis.native_app.core.common.markdown
+
+class PostArtemisMarkdownTransformer(val serverUrl: String) : ArtemisMarkdownTransformer() {
+    override fun transformExerciseMarkdown(title: String, url: String): String {
+        return "[$title]($serverUrl$url)"
+    }
+
+    override fun transformUserMentionMarkdown(text: String, fullName: String, userName: String): String = "|||@$fullName|||"
+}

core/common/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/core/common/markdown/PushNotificationArtemisMarkdownTransformer.kt

@@ -0,0 +1,8 @@
+package de.tum.informatics.www1.artemis.native_app.core.common.markdown
+
+object PushNotificationArtemisMarkdownTransformer : ArtemisMarkdownTransformer() {
+
+    override fun transformExerciseMarkdown(title: String, url: String): String = title
+
+    override fun transformUserMentionMarkdown(text: String, fullName: String, userName: String): String = "@$fullName"
+}

core/ui/build.gradle.kts

@@ -36,6 +36,7 @@ dependencies {
     implementation(libs.noties.markwon.ext.strikethrough)
     implementation(libs.noties.markwon.ext.tables)
     implementation(libs.noties.markwon.html)
+    implementation(libs.noties.markwon.simple.ext)
     implementation(libs.noties.markwon.linkify)
     implementation(libs.noties.markwon.image.coil)
 }

core/ui/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/core/ui/markdown/MarkdownText.kt

@@ -2,6 +2,8 @@ package de.tum.informatics.www1.artemis.native_app.core.ui.markdown
 
 import android.content.Context
 import android.text.method.LinkMovementMethod
+import android.text.style.ForegroundColorSpan
+import android.text.style.StrikethroughSpan
 import android.util.TypedValue
 import android.view.View
 import android.widget.TextView
@@ -31,14 +33,15 @@ import androidx.compose.ui.unit.TextUnit
 import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.content.res.ResourcesCompat
 import coil.ImageLoader
-import de.tum.informatics.www1.artemis.native_app.core.common.markdown.ArtemisMarkdownTransformer
+import de.tum.informatics.www1.artemis.native_app.core.common.markdown.PostArtemisMarkdownTransformer
 import de.tum.informatics.www1.artemis.native_app.core.datastore.ServerConfigurationService
 import io.noties.markwon.Markwon
 import io.noties.markwon.ext.strikethrough.StrikethroughPlugin
 import io.noties.markwon.ext.tables.TablePlugin
 import io.noties.markwon.html.HtmlPlugin
 import io.noties.markwon.image.coil.CoilImagesPlugin
 import io.noties.markwon.linkify.LinkifyPlugin
+import io.noties.markwon.simple.ext.SimpleExtPlugin
 import org.koin.compose.koinInject
 
 // Copy from: https://github.com/jeziellago/compose-markdown
@@ -100,15 +103,19 @@ fun MarkdownText(
         serverConfigurationService.serverUrl.collectAsState(initial = "").value
     }
 
-    val transformedMarkdown by remember(markdown, serverUrl) {
-        derivedStateOf {
-            val strippedServerUrl =
-                if (serverUrl.endsWith("/")) serverUrl.substring(
-                    0,
-                    serverUrl.length - 1
-                ) else serverUrl
+    val markdownTransformer = remember(serverUrl) {
+        val strippedServerUrl =
+            if (serverUrl.endsWith("/")) serverUrl.substring(
+                0,
+                serverUrl.length - 1
+            ) else serverUrl
+
+        PostArtemisMarkdownTransformer(strippedServerUrl)
+    }
 
-            ArtemisMarkdownTransformer.transformMarkdown(markdown, strippedServerUrl)
+    val transformedMarkdown by remember(markdown, markdownTransformer) {
+        derivedStateOf {
+            markdownTransformer.transformMarkdown(markdown)
         }
     }
 
@@ -200,10 +207,16 @@ fun createMarkdownRender(context: Context, imageLoader: ImageLoader?): Markwon {
         .usePlugin(StrikethroughPlugin.create())
         .usePlugin(TablePlugin.create(context))
         .usePlugin(LinkifyPlugin.create())
+        // User mentions are transformed to |||@full name|||
+        .usePlugin(SimpleExtPlugin.create { p ->
+            p.addExtension(3, '|') { _, _ ->
+                arrayOf(ForegroundColorSpan(0xff3e8acc.toInt()))
+            }
+        })
         .apply {
             if (imageLoader != null) {
                 usePlugin(CoilImagesPlugin.create(context, imageLoader))
             }
         }
         .build()
-}
+}

feature/course-view/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/courseview/ui/course_overview/CourseUiScreen.kt

@@ -258,9 +258,7 @@ internal fun CourseUiScreen(
                     }
 
                     TAB_COMMUNICATION -> {
-                        val metisModifier = Modifier
-                            .fillMaxSize()
-                            .padding(horizontal = 8.dp)
+                        val metisModifier = Modifier.fillMaxSize()
 
                         if (course.courseInformationSharingConfiguration.supportsMessaging) {
                             val initialConfiguration = remember(conversationId, postId) {

feature/metis/conversation/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/metis/conversation/ui/ConversationDetailScreen.kt

@@ -15,6 +15,7 @@ import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.derivedStateOf
@@ -31,6 +32,7 @@ import de.tum.informatics.www1.artemis.native_app.core.ui.common.BasicHintTextFi
 import de.tum.informatics.www1.artemis.native_app.feature.metis.shared.content.MetisContext
 import de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.chatlist.MetisChatList
 import de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.chatlist.MetisListViewModel
+import de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.reply.LocalReplyAutoCompleteHintProvider
 import de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.shared.isReplyEnabled
 import de.tum.informatics.www1.artemis.native_app.feature.metis.shared.ui.humanReadableName
 import io.github.fornewid.placeholder.material3.placeholder
@@ -134,15 +136,17 @@ fun ConversationScreen(
         val isReplyEnabled = isReplyEnabled(conversationDataState = conversationDataState)
 
         if (conversationDataState.isSuccess) {
-            MetisChatList(
-                modifier = Modifier
-                    .fillMaxSize()
-                    .padding(padding),
-                viewModel = viewModel,
-                listContentPadding = PaddingValues(),
-                onClickViewPost = onClickViewPost,
-                isReplyEnabled = isReplyEnabled
-            )
+            CompositionLocalProvider(LocalReplyAutoCompleteHintProvider provides viewModel) {
+                MetisChatList(
+                    modifier = Modifier
+                        .fillMaxSize()
+                        .padding(padding),
+                    viewModel = viewModel,
+                    listContentPadding = PaddingValues(),
+                    onClickViewPost = onClickViewPost,
+                    isReplyEnabled = isReplyEnabled
+                )
+            }
         }
     }
 }

feature/metis/conversation/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/metis/conversation/ui/chatlist/MetisListViewModel.kt

@@ -186,7 +186,7 @@ internal class MetisListViewModel(
 
     fun createPost(): Deferred<MetisModificationFailure?> {
         return viewModelScope.async(coroutineContext) {
-            val postText = newMessageText.first()
+            val postText = newMessageText.first().text
 
             val conversation =
                 loadConversation() ?: return@async MetisModificationFailure.CREATE_POST

feature/metis/conversation/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/metis/conversation/ui/reply/AutoCompleteCategory.kt

@@ -0,0 +1,5 @@
+package de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.reply
+
+import androidx.annotation.StringRes
+
+class AutoCompleteCategory(@StringRes val name: Int, val items: List<AutoCompleteHint>)

feature/metis/conversation/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/metis/conversation/ui/reply/AutoCompleteHint.kt

@@ -0,0 +1,3 @@
+package de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.reply
+
+data class AutoCompleteHint(val hint: String, val replacementText: String, val id: String)

feature/metis/conversation/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/metis/conversation/ui/reply/InitialReplyTextProvider.kt

@@ -1,10 +1,11 @@
 package de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.reply
 
+import androidx.compose.ui.text.input.TextFieldValue
 import kotlinx.coroutines.flow.Flow
 
 interface InitialReplyTextProvider {
 
-    val newMessageText: Flow<String>
+    val newMessageText: Flow<TextFieldValue>
 
-    fun updateInitialReplyText(text: String)
+    fun updateInitialReplyText(text: TextFieldValue)
 }

feature/metis/conversation/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/metis/conversation/ui/reply/MarkdownTextField.kt

@@ -8,6 +8,7 @@ import androidx.compose.foundation.layout.RowScope
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material3.InputChip
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Text
@@ -22,6 +23,8 @@ import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.focus.onFocusChanged
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.TextFieldValue
 import androidx.compose.ui.unit.dp
 import de.tum.informatics.www1.artemis.native_app.core.ui.markdown.MarkdownText
 import de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.R
@@ -32,13 +35,16 @@ import de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.R
 @Composable
 internal fun MarkdownTextField(
     modifier: Modifier,
-    text: String,
+    textFieldValue: TextFieldValue,
     focusRequester: FocusRequester = remember { FocusRequester() },
     sendButton: @Composable () -> Unit = {},
     topRightButton: @Composable RowScope.() -> Unit = {},
+    onFocusAcquired: () -> Unit = {},
     onFocusLost: () -> Unit = {},
-    onTextChanged: (String) -> Unit
+    onTextChanged: (TextFieldValue) -> Unit
 ) {
+    val text = textFieldValue.text
+
     var selectedType by remember { mutableStateOf(ViewType.TEXT) }
     var hadFocus by remember { mutableStateOf(false) }
 
@@ -81,15 +87,17 @@ internal fun MarkdownTextField(
                             .onFocusChanged { focusState ->
                                 if (focusState.hasFocus) {
                                     hadFocus = true
+                                    onFocusAcquired()
                                 }
 
                                 if (!focusState.hasFocus && hadFocus) {
                                     onFocusLost()
                                     hadFocus = false
                                 }
                             },
-                        value = text,
-                        onValueChange = onTextChanged
+                        value = textFieldValue,
+                        onValueChange = onTextChanged,
+                        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Text)
                     )
                 }
 

feature/metis/conversation/src/main/kotlin/de/tum/informatics/www1/artemis/native_app/feature/metis/conversation/ui/reply/ReplyAutoCompleteHintProvider.kt

@@ -0,0 +1,28 @@
+package de.tum.informatics.www1.artemis.native_app.feature.metis.conversation.ui.reply
+
+import androidx.compose.runtime.ProvidableCompositionLocal
+import androidx.compose.runtime.compositionLocalOf
+import de.tum.informatics.www1.artemis.native_app.core.data.DataState
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flowOf
+
+internal val LocalReplyAutoCompleteHintProvider: ProvidableCompositionLocal<ReplyAutoCompleteHintProvider> = compositionLocalOf {
+    object : ReplyAutoCompleteHintProvider {
+        override val legalTagChars: List<Char> = emptyList()
+
+        override fun produceAutoCompleteHints(
+            tagChar: Char,
+            query: String
+        ): Flow<DataState<List<AutoCompleteCategory>>> = flowOf(DataState.Success(emptyList()))
+    }
+}
+
+internal interface ReplyAutoCompleteHintProvider {
+
+    val legalTagChars: List<Char>
+
+    fun produceAutoCompleteHints(
+        tagChar: Char,
+        query: String
+    ): Flow<DataState<List<AutoCompleteCategory>>>
+}