frontend v0.4.0

.idea/chatapp.iml

@@ -2,7 +2,10 @@
 <module type="JAVA_MODULE" version="4">
   <component name="NewModuleRootManager" inherit-compiler-output="true">
     <exclude-output />
-    <content url="file://$MODULE_DIR$" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/backend/src" isTestSource="false" />
+      <excludeFolder url="file://$MODULE_DIR$/backend/target" />
+    </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>

.idea/dataSources.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DataSourceManagerImpl" format="xml" multifile-model="true">
+    <data-source source="LOCAL" name="chatapp dev" uuid="81992477-fd6f-427e-a27e-7378c26db6ef">
+      <driver-ref>postgresql</driver-ref>
+      <synchronize>true</synchronize>
+      <jdbc-driver>org.postgresql.Driver</jdbc-driver>
+      <jdbc-url>jdbc:postgresql://100.118.108.58:5432/chatapp_dev</jdbc-url>
+      <jdbc-additional-properties>
+        <property name="com.intellij.clouds.kubernetes.db.host.port" />
+        <property name="com.intellij.clouds.kubernetes.db.enabled" value="false" />
+        <property name="com.intellij.clouds.kubernetes.db.container.port" />
+      </jdbc-additional-properties>
+      <working-dir>$ProjectFileDir$</working-dir>
+    </data-source>
+  </component>
+</project>

.idea/gradle.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
+  <component name="GradleSettings">
+    <option name="linkedExternalProjectsSettings">
+      <GradleProjectSettings>
+        <option name="externalProjectPath" value="$PROJECT_DIR$/android" />
+      </GradleProjectSettings>
+    </option>
+  </component>
+</project>

.idea/misc.xml

@@ -1,4 +1,5 @@
 <project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
   <component name="ProjectRootManager" version="2" project-jdk-name="25" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>

android/.gitignore

@@ -1,7 +1,9 @@
 *.iml
 .gradle
 /local.properties
+/keystore.properties
 /.idea/caches
+/.idea/.cache
 /.idea/libraries
 /.idea/modules.xml
 /.idea/workspace.xml
@@ -13,3 +15,4 @@
 .externalNativeBuild
 .cxx
 local.properties
+release/

android/.idea/deploymentTargetSelector.xml

@@ -4,6 +4,14 @@
     <selectionStates>
       <SelectionState runConfigName="app">
         <option name="selectionMode" value="DROPDOWN" />
+        <DropdownSelection timestamp="2026-04-02T14:33:39.814557661Z">
+          <Target type="DEFAULT_BOOT">
+            <handle>
+              <DeviceId pluginId="PhysicalDevice" identifier="serial=00319362N000094" />
+            </handle>
+          </Target>
+        </DropdownSelection>
+        <DialogSelection />
       </SelectionState>
       <SelectionState runConfigName="MainActivity">
         <option name="selectionMode" value="DROPDOWN" />

android/app/build.gradle.kts

@@ -1,3 +1,5 @@
+import java.util.Properties
+
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.compose)
@@ -8,6 +10,25 @@ android {
     namespace = "dev.zxq5.chatapp.android"
     compileSdk = 35
 
+    val keystorePropertiesFile = rootProject.file("local.properties")
+    val keystoreProperties = Properties()
+    if (keystorePropertiesFile.exists()) {
+        keystoreProperties.load(keystorePropertiesFile.inputStream())
+    }
+
+    signingConfigs {
+        create("release") {
+            storeFile = file("${System.getProperty("user.home")}/keystores/chatapp.jks")
+            storePassword = keystoreProperties["KEYSTORE_PASSWORD"] as String? 
+                ?: System.getenv("KEYSTORE_PASSWORD") 
+                ?: ""
+            keyAlias = "chatapp"
+            keyPassword = keystoreProperties["KEY_PASSWORD"] as String? 
+                ?: System.getenv("KEY_PASSWORD") 
+                ?: ""
+        }
+    }
+
     defaultConfig {
         applicationId = "dev.zxq5.chatapp.android"
         minSdk = 26
@@ -20,19 +41,30 @@ android {
 
     buildTypes {
         release {
-            isMinifyEnabled = false
+            isMinifyEnabled = true        // shrinks code
+            isShrinkResources = true      // removes unused resources
+            signingConfig = signingConfigs.getByName("release")
             proguardFiles(
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
             )
+            buildConfigField("String", "BASE_URL", "\"https://chat.zxq5.dev\"")
+        }
+        debug {
+            isMinifyEnabled = false
+            isDebuggable = true
+            applicationIdSuffix = ".debug"  // lets you install both side by side
+            buildConfigField("String", "BASE_URL", "\"http://zxq5-x1:8000\"")
         }
     }
+
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_11
         targetCompatibility = JavaVersion.VERSION_11
     }
     buildFeatures {
         compose = true
+        buildConfig = true
     }
 }
 
@@ -44,7 +76,6 @@ dependencies {
     implementation(libs.ktor.client.auth)        // Auth plugin
     // Kotlinx Serialization
     implementation(libs.kotlinx.serialization.json)
-
     // Coroutines
     implementation(libs.kotlinx.coroutines.android)
 
@@ -73,4 +104,4 @@ dependencies {
     androidTestImplementation(libs.androidx.compose.ui.test.junit4)
     debugImplementation(libs.androidx.compose.ui.tooling)
     debugImplementation(libs.androidx.compose.ui.test.manifest)
-}
+}

android/app/proguard-rules.pro

@@ -18,4 +18,30 @@
 
 # If you keep the line number information, uncomment this to
 # hide the original source file name.
-#-renamesourcefileattribute SourceFile
+#-renamesourcefileattribute SourceFile
+
+# Ktor
+-keep class io.ktor.** { *; }
+-keep class kotlinx.coroutines.** { *; }
+
+# Kotlinx serialization
+-keepattributes *Annotation*, InnerClasses
+-dontnote kotlinx.serialization.AnnotationsKt
+-keep,includedescriptorclasses class dev.zxq5.chatapp.android.**$$serializer { *; }
+-keepclassmembers class dev.zxq5.chatapp.android.** {
+    *** Companion;
+}
+-keepclasseswithmembers class dev.zxq5.chatapp.android.** {
+    kotlinx.serialization.KSerializer serializer(...);
+}
+
+# Keep model classes (serialization needs these)
+-keep class dev.zxq5.chatapp.android.api.model.** { *; }
+-keep class dev.zxq5.chatapp.android.data.model.** { *; }
+
+# Fix for missing errorprone and javax annotations used by Tink and other libraries
+-dontwarn com.google.errorprone.annotations.**
+-dontwarn javax.annotation.**
+
+# Fix for missing java.lang.management referenced by Ktor (not available on Android)
+-dontwarn java.lang.management.**

android/app/src/main/AndroidManifest.xml

@@ -3,6 +3,10 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC"/>
+
 
     <application
         android:name=".ChatApplication"
@@ -15,6 +19,12 @@
         android:supportsRtl="true"
         android:theme="@style/Theme.Chatapp"
         android:usesCleartextTraffic="true">
+
+        <service
+            android:name=".core.service.MessageStreamService"
+            android:foregroundServiceType="dataSync"
+            android:exported="false"/>
+
         <activity
             android:name=".MainActivity"
             android:exported="true"

android/app/src/main/java/dev/zxq5/chatapp/android/ChatApplication.kt

@@ -1,6 +1,9 @@
 package dev.zxq5.chatapp.android
 
 import android.app.Application
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.os.Build
 import dev.zxq5.chatapp.android.core.data.TokenStore
 import dev.zxq5.chatapp.android.data.repository.AuthRepository
 import dev.zxq5.chatapp.android.data.repository.ChatRepository
@@ -8,6 +11,10 @@ import dev.zxq5.chatapp.android.data.repository.SettingsRepository
 
 class ChatApplication : Application() {
 
+    object AppState {
+        var isInForeground = false
+    }
+
     val tokenStore by lazy { TokenStore(this) }
     val authRepository by lazy { AuthRepository(tokenStore) }
     val chatRepository by lazy { ChatRepository(tokenStore) }
@@ -15,5 +22,30 @@ class ChatApplication : Application() {
 
     override fun onCreate() {
         super.onCreate()
+        createNotificationChannels()
+    }
+
+    private fun createNotificationChannels() {
+        val messageChannel = NotificationChannel(
+            "messages",
+            "Messages",
+            NotificationManager.IMPORTANCE_HIGH
+        ).apply {
+            description = "New message notifications"
+            enableVibration(true)
+        }
+
+        // add this — required for the foreground service persistent notification
+        val serviceChannel = NotificationChannel(
+            "service",
+            "Background connection",
+            NotificationManager.IMPORTANCE_LOW
+        ).apply {
+            description = "Keeps messages running in background"
+        }
+
+        val manager = getSystemService(NotificationManager::class.java)
+        manager.createNotificationChannel(messageChannel)
+        manager.createNotificationChannel(serviceChannel)
     }
 }

android/app/src/main/java/dev/zxq5/chatapp/android/MainActivity.kt

@@ -4,25 +4,42 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.ChatBubbleOutline
+import androidx.compose.material.icons.outlined.PeopleOutline
+import androidx.compose.material.icons.outlined.Settings
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.NavigationBar
+import androidx.compose.material3.NavigationBarItem
+import androidx.compose.material3.NavigationBarItemDefaults
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
 import androidx.lifecycle.viewmodel.compose.viewModel
-import dev.zxq5.chatapp.android.core.data.TokenStore
+import dev.zxq5.chatapp.android.ChatApplication.AppState
-import dev.zxq5.chatapp.android.data.repository.AuthRepository
+import dev.zxq5.chatapp.android.core.service.MessageStreamService
 import dev.zxq5.chatapp.android.data.repository.AuthState
-import dev.zxq5.chatapp.android.data.repository.ChatRepository
+import dev.zxq5.chatapp.android.feature.auth.AuthScreen
-import dev.zxq5.chatapp.android.data.repository.SettingsRepository
 import dev.zxq5.chatapp.android.feature.auth.AuthViewModel
+import dev.zxq5.chatapp.android.feature.chat.ChatScreen
 import dev.zxq5.chatapp.android.feature.chat.ChatViewModel
 import dev.zxq5.chatapp.android.feature.chat.Screen
-import dev.zxq5.chatapp.android.feature.settings.SettingsViewModel
+import dev.zxq5.chatapp.android.feature.contacts.ContactsScreen
-import dev.zxq5.chatapp.android.feature.auth.AuthScreen
-import dev.zxq5.chatapp.android.feature.chat.ChatScreen
 import dev.zxq5.chatapp.android.feature.settings.SettingsScreen
+import dev.zxq5.chatapp.android.feature.settings.SettingsViewModel
 import dev.zxq5.chatapp.android.ui.theme.ChatappTheme
 
 class MainActivity : ComponentActivity() {
@@ -30,7 +47,6 @@ class MainActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
         
         val app = application as ChatApplication
-        val tokenStore = app.tokenStore
         val authRepository = app.authRepository
         val chatRepository = app.chatRepository
         val settingsRepository = app.settingsRepository
@@ -44,37 +60,126 @@ class MainActivity : ComponentActivity() {
                 
                 val authState by authViewModel.authState.collectAsState()
                 val currentScreen by chatViewModel.currentScreen.collectAsState()
+                val selectedChannelId by chatViewModel.channelId.collectAsState()
 
-                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
+                LaunchedEffect(authState) {
-                    androidx.compose.foundation.layout.Box(modifier = Modifier.padding(innerPadding)) {
+                    when (authState) {
-                        when (authState) {
+                        AuthState.Authenticated -> MessageStreamService.start(this@MainActivity)
-                            AuthState.Authenticated -> {
+                        AuthState.Unauthenticated -> MessageStreamService.stop(this@MainActivity)
-                                when (currentScreen) {
+                        AuthState.AwaitingTotp -> {}
-                                    Screen.CHAT -> ChatScreen(
+                    }
-                                        viewModel = chatViewModel,
+                }
-                                        onNavigateToSettings = { chatViewModel.navigateTo(Screen.SETTINGS) },
+
-                                        onLogout = { 
+                LaunchedEffect(Unit) {
-                                            authViewModel.logout()
+                    intent.getIntExtra("channel_id", -1).takeIf { it != -1 }?.let {
-                                            chatViewModel.clearChat()
+                        chatViewModel.switchChannel(it.toLong())
-                                        }
+                    }
-                                    )
+                }
-                                    Screen.SETTINGS -> SettingsScreen(
+
-                                        viewModel = settingsViewModel,
+                if (authState == AuthState.Authenticated) {
-                                        onBack = { chatViewModel.navigateTo(Screen.CHAT) },
+                    Scaffold(
-                                        onLogout = {
+                        modifier = Modifier.fillMaxSize(),
-                                            authViewModel.logout()
+                        bottomBar = {
-                                            chatViewModel.clearChat()
+                            // Only show bottom bar if we are NOT inside a specific chat channel
-                                        }
+                            if (selectedChannelId == null) {
-                                    )
+                                BottomDock(
-                                }
+                                    currentScreen = currentScreen,
+                                    onNavigate = { chatViewModel.navigateTo(it) }
+                                )
                             }
-                            AuthState.AwaitingTotp, AuthState.Unauthenticated -> {
+                        }
-                                AuthScreen(viewModel = authViewModel)
+                    ) { innerPadding ->
+                        Box(modifier = Modifier.padding(innerPadding)) {
+                            when (currentScreen) {
+                                Screen.CHAT -> ChatScreen(
+                                    viewModel = chatViewModel,
+                                    onNavigateToSettings = { chatViewModel.navigateTo(Screen.SETTINGS) },
+                                    onLogout = { 
+                                        authViewModel.logout()
+                                        chatViewModel.clearChat()
+                                    }
+                                )
+                                Screen.CONTACTS -> ContactsScreen()
+                                Screen.SETTINGS -> SettingsScreen(
+                                    viewModel = settingsViewModel,
+                                    onLogout = {
+                                        authViewModel.logout()
+                                        chatViewModel.clearChat()
+                                    }
+                                )
                             }
                         }
                     }
+                } else {
+                    AuthScreen(viewModel = authViewModel)
                 }
             }
         }
     }
+
+    override fun onResume() {
+        super.onResume()
+        AppState.isInForeground = true
+    }
+
+    override fun onPause() {
+        super.onPause()
+        AppState.isInForeground = false
+    }
+
+    override fun onNewIntent(intent: android.content.Intent) {
+        super.onNewIntent(intent)
+        intent.getIntExtra("channel_id", -1).takeIf { it != -1 }?.let { channelId ->
+            MessageStreamService.instance?.activeChannelId = channelId.toLong()
+        }
+    }
+}
+
+@Composable
+fun BottomDock(currentScreen: Screen, onNavigate: (Screen) -> Unit) {
+    NavigationBar(
+        containerColor = MaterialTheme.colorScheme.background,
+        tonalElevation = 0.dp,
+        modifier = Modifier
+            .height(80.dp)
+            .border(
+                0.5.dp, 
+                MaterialTheme.colorScheme.outlineVariant.copy(alpha = 0.2f), 
+                RoundedCornerShape(topStart = 0.dp, topEnd = 0.dp)
+            )
+    ) {
+        NavigationBarItem(
+            selected = currentScreen == Screen.CHAT,
+            onClick = { onNavigate(Screen.CHAT) },
+            icon = { Icon(Icons.Outlined.ChatBubbleOutline, contentDescription = "Chat") },
+            label = { Text("chat", style = MaterialTheme.typography.labelSmall) },
+            colors = NavigationBarItemDefaults.colors(
+                selectedIconColor = MaterialTheme.colorScheme.primary,
+                unselectedIconColor = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
+                indicatorColor = Color.Transparent
+            )
+        )
+        NavigationBarItem(
+            selected = currentScreen == Screen.CONTACTS,
+            onClick = { onNavigate(Screen.CONTACTS) },
+            icon = { Icon(Icons.Outlined.PeopleOutline, contentDescription = "Contacts") },
+            label = { Text("contacts", style = MaterialTheme.typography.labelSmall) },
+            colors = NavigationBarItemDefaults.colors(
+                selectedIconColor = MaterialTheme.colorScheme.primary,
+                unselectedIconColor = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
+                indicatorColor = Color.Transparent
+            )
+        )
+        NavigationBarItem(
+            selected = currentScreen == Screen.SETTINGS,
+            onClick = { onNavigate(Screen.SETTINGS) },
+            icon = { Icon(Icons.Outlined.Settings, contentDescription = "Settings") },
+            label = { Text("settings", style = MaterialTheme.typography.labelSmall) },
+            colors = NavigationBarItemDefaults.colors(
+                selectedIconColor = MaterialTheme.colorScheme.primary,
+                unselectedIconColor = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
+                indicatorColor = Color.Transparent
+            )
+        )
+    }
 }

android/app/src/main/java/dev/zxq5/chatapp/android/api/AuthClient.kt

@@ -1,10 +1,11 @@
 package dev.zxq5.chatapp.android.api
 
 import android.util.Log
+import dev.zxq5.chatapp.android.BuildConfig
+import dev.zxq5.chatapp.android.BuildConfig.BASE_URL
 import dev.zxq5.chatapp.android.api.model.LoginRequest
 import dev.zxq5.chatapp.android.api.model.LoginResponse
 import dev.zxq5.chatapp.android.api.model.TOTPSixDigitCode
-import dev.zxq5.chatapp.android.core.BASE_URL
 import dev.zxq5.chatapp.android.core.error.ApiResult
 import dev.zxq5.chatapp.android.api.model.SignupRequest
 import io.ktor.client.HttpClient

android/app/src/main/java/dev/zxq5/chatapp/android/api/ChatClient.kt

@@ -1,14 +1,17 @@
 package dev.zxq5.chatapp.android.api
 
-import dev.zxq5.chatapp.android.core.BASE_URL
+import dev.zxq5.chatapp.android.BuildConfig.BASE_URL
 import dev.zxq5.chatapp.android.api.model.Message
 import dev.zxq5.chatapp.android.api.model.SendMessage
+import dev.zxq5.chatapp.android.api.model.SpaceDto
 import io.ktor.client.HttpClient
+import io.ktor.client.call.body
 import io.ktor.client.engine.android.Android
 import io.ktor.client.plugins.auth.Auth
 import io.ktor.client.plugins.auth.providers.BearerTokens
 import io.ktor.client.plugins.auth.providers.bearer
 import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
+import io.ktor.client.request.get
 import io.ktor.client.request.post
 import io.ktor.client.request.prepareGet
 import io.ktor.client.request.setBody
@@ -16,12 +19,15 @@ import io.ktor.client.statement.bodyAsChannel
 import io.ktor.http.ContentType
 import io.ktor.http.contentType
 import io.ktor.serialization.kotlinx.json.json
-import io.ktor.utils.io.readUTF8Line
+import io.ktor.utils.io.readLine
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
 import kotlinx.serialization.json.Json
+import kotlin.time.Clock
+import kotlin.time.ExperimentalTime
 
 class ChatClient(private val token: String) {
+
     private val http = HttpClient(Android) {
         install(ContentNegotiation) {
             json(Json { ignoreUnknownKeys = true })
@@ -33,18 +39,21 @@ class ChatClient(private val token: String) {
         }
     }
 
-    suspend fun sendMessage(channelId: Int, userId: Int, text: String) {
+    suspend fun getAccessibleChannels(): List<SpaceDto> = http.get("${BASE_URL}/api/accessible_channels").body()
+
+    @OptIn(ExperimentalTime::class)
+    suspend fun sendMessage(channelId: Long, userId: Int, text: String) {
         http.post("${BASE_URL}/api/chat/$channelId") {
             contentType(ContentType.Application.Json)
-            setBody(SendMessage(user_id = userId, text = text, timestamp = System.currentTimeMillis()))
+            setBody(SendMessage(user_id = userId, text = text, timestamp = Clock.System.now()))
         }
     }
 
-    fun messageStream(channelId: Int): Flow<Message> = flow {
+    fun messageStream(channelId: Long): Flow<Message> = flow {
         http.prepareGet("${BASE_URL}/api/events/$channelId").execute { response ->
             val channel = response.bodyAsChannel()
             while (!channel.isClosedForRead) {
-                val line = channel.readUTF8Line(256) ?: break
+                val line = channel.readLine() ?: break
                 if (line.startsWith("data:")) {
                     val json = line.removePrefix("data:").trim()
                     runCatching { Json.decodeFromString<Message>(json) }
@@ -54,4 +63,3 @@ class ChatClient(private val token: String) {
         }
     }
 }
-

android/app/src/main/java/dev/zxq5/chatapp/android/api/SettingsClient.kt

@@ -1,6 +1,7 @@
 package dev.zxq5.chatapp.android.api
 
 import android.util.Log
+import dev.zxq5.chatapp.android.BuildConfig.BASE_URL
 import dev.zxq5.chatapp.android.api.model.AccountDeleteRequest
 import dev.zxq5.chatapp.android.api.model.DisplayNameRequest
 import dev.zxq5.chatapp.android.api.model.PasswordChangeRequest
@@ -10,7 +11,6 @@ import dev.zxq5.chatapp.android.api.model.TotpStatus
 import dev.zxq5.chatapp.android.api.model.UsernameRequest
 import dev.zxq5.chatapp.android.api.model.TotpDeleteRequest
 import dev.zxq5.chatapp.android.api.model.PasswordRequest
-import dev.zxq5.chatapp.android.core.BASE_URL
 import dev.zxq5.chatapp.android.core.error.ApiResult
 import io.ktor.client.HttpClient
 import io.ktor.client.call.body

android/app/src/main/java/dev/zxq5/chatapp/android/api/model/Channel.kt

@@ -0,0 +1,15 @@
+package dev.zxq5.chatapp.android.api.model
+
+import kotlinx.serialization.Serializable
+import kotlin.time.ExperimentalTime
+import kotlin.time.Instant
+
+@Serializable
+data class Channel @OptIn(ExperimentalTime::class) constructor(
+    val id: Long,
+    val name: String,
+    val description: String? = null,
+    val space_id: Long,
+    val created_at: Instant,
+    val updated_at: Instant
+)

android/app/src/main/java/dev/zxq5/chatapp/android/api/model/Message.kt

@@ -1,11 +1,13 @@
 package dev.zxq5.chatapp.android.api.model
 
 import kotlinx.serialization.Serializable
+import kotlin.time.ExperimentalTime
+import kotlin.time.Instant
 
 @Serializable
-data class Message(
+data class Message @OptIn(ExperimentalTime::class) constructor(
     val user_id: Int,
     val display_name: String,
     val text: String,
-    val timestamp: Long
+    val timestamp: Instant
 )

android/app/src/main/java/dev/zxq5/chatapp/android/api/model/SendMessage.kt

@@ -1,10 +1,12 @@
 package dev.zxq5.chatapp.android.api.model
 
 import kotlinx.serialization.Serializable
+import kotlin.time.ExperimentalTime
+import kotlin.time.Instant
 
 @Serializable
-data class SendMessage(
+data class SendMessage @OptIn(ExperimentalTime::class) constructor(
     val user_id: Int,
     val text: String,
-    val timestamp: Long
+    val timestamp: Instant
 )

android/app/src/main/java/dev/zxq5/chatapp/android/api/model/Space.kt

@@ -0,0 +1,28 @@
+package dev.zxq5.chatapp.android.api.model
+
+import kotlinx.serialization.Serializable
+import kotlin.time.ExperimentalTime
+import kotlin.time.Instant
+
+
+@Serializable
+data class Space @OptIn(ExperimentalTime::class) constructor(
+    val id: Long,
+    val name: String,
+    val description: String? = null,
+    val owner_id: Long,
+    val created_at: Instant,
+    val updated_at: Instant
+)
+
+@Serializable
+data class SpaceDto @OptIn(ExperimentalTime::class) constructor(
+    val channels: List<Channel>,
+
+    val id: Long,
+    val name: String,
+    val description: String? = null,
+    val owner_id: Long,
+    val created_at: Instant,
+    val updated_at: Instant
+)

android/app/src/main/java/dev/zxq5/chatapp/android/core/constants.kt

@@ -1,3 +1,3 @@
 package dev.zxq5.chatapp.android.core
 
-const val BASE_URL = "http://zxq5-x1:8000"
+//const val BASE_URL = "http://zxq5-x1:8000"

android/app/src/main/java/dev/zxq5/chatapp/android/core/service/MessageStreamService.kt

@@ -0,0 +1,104 @@
+package dev.zxq5.chatapp.android.core.service
+
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import android.util.Log
+import dev.zxq5.chatapp.android.ChatApplication
+import dev.zxq5.chatapp.android.data.repository.ChatRepository
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.launch
+
+// core/service/MessageStreamService.kt
+class MessageStreamService : Service() {
+
+    private val serviceScope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+    private lateinit var notificationService: NotificationService
+    private lateinit var chatRepository: ChatRepository
+
+    // which channel the user is currently looking at
+    // set by the ViewModel when the user opens/closes a channel
+    var activeChannelId: Long? = null
+        set(value) {
+            field = value
+            Log.d("Service", "activeChannelId set to $value")
+            if (value != null) {
+                // restart stream with new channel
+                currentStreamJob?.cancel()
+                observeMessages()
+            }
+        }
+
+    private var currentStreamJob: kotlinx.coroutines.Job? = null
+
+    companion object {
+        var instance: MessageStreamService? = null
+
+        fun start(context: Context) {
+            val intent = Intent(context, MessageStreamService::class.java)
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                context.startForegroundService(intent)
+            } else {
+                context.startService(intent)
+            }
+        }
+
+        fun stop(context: Context) {
+            context.stopService(Intent(context, MessageStreamService::class.java))
+        }
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+        instance = this
+        notificationService = NotificationService(this)
+        chatRepository = (application as ChatApplication).chatRepository
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        startForeground(
+            NotificationService.FOREGROUND_NOTIFICATION_ID,
+            notificationService.buildForegroundNotification()
+        )
+        observeMessages()
+        return START_STICKY  // restart if killed
+    }
+
+    private fun observeMessages() {
+        val channelId = activeChannelId ?: chatRepository.getLastActiveChannel()
+        Log.d("Service", "observeMessages called, channelId=$channelId")
+        if (channelId == null) {
+            Log.d("Service", "No channel to observe, waiting for switchChannel")
+            return
+        }
+
+        Log.d("Service", "Starting stream for channel $channelId")
+        currentStreamJob = serviceScope.launch {
+            chatRepository.messageStream(channelId)
+                .catch { e -> Log.e("Service", "Stream error", e) }
+                .collect { message ->
+                    if (!ChatApplication.AppState.isInForeground) {  // no channel focused, always notify
+                        notificationService.showMessageNotification(
+                            conversationId = activeChannelId.toString(),
+                            senderName = message.display_name,
+                            messagePreview = message.text.take(80)
+                        )
+                    }
+                }
+        }
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    override fun onDestroy() {
+        super.onDestroy()
+        instance = null
+        serviceScope.cancel()
+    }
+}

android/app/src/main/java/dev/zxq5/chatapp/android/core/service/NotificationService.kt

@@ -0,0 +1,94 @@
+package dev.zxq5.chatapp.android.core.service
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import androidx.core.app.NotificationCompat
+import dev.zxq5.chatapp.android.MainActivity
+import dev.zxq5.chatapp.android.R
+
+class NotificationService(private val context: Context) {
+
+    companion object {
+        const val CHANNEL_ID = "messages"
+        const val FOREGROUND_NOTIFICATION_ID = 1  // ← this needs to exist
+    }
+
+    private val manager = context.getSystemService(NotificationManager::class.java)
+
+    fun createChannels() {
+        // channel for new message notifications
+        val messageChannel = NotificationChannel(
+            CHANNEL_ID,
+            "Messages",
+            NotificationManager.IMPORTANCE_HIGH
+        ).apply {
+            enableVibration(true)
+        }
+
+        // channel for the persistent foreground service notification
+        // low importance so it doesn't make noise
+        val serviceChannel = NotificationChannel(
+            "service",
+            "Background connection",
+            NotificationManager.IMPORTANCE_LOW
+        )
+
+        val mgr = context.getSystemService(NotificationManager::class.java)
+        mgr.createNotificationChannel(messageChannel)
+        mgr.createNotificationChannel(serviceChannel)
+    }
+
+    fun buildForegroundNotification(): Notification {
+        return NotificationCompat.Builder(context, "service")
+            .setSmallIcon(R.drawable.ic_notification)
+            .setContentTitle("chatapp")
+            .setContentText("Connected")
+            .setOngoing(true)
+            .setSilent(true)
+            .build()
+    }
+
+    fun showMessageNotification(
+        conversationId: String,
+        senderName: String,
+        messagePreview: String,   // for E2E this would be "New message" — no plaintext
+        notificationId: Int = conversationId.hashCode()
+    ) {
+        // intent that opens the app to the right conversation when tapped
+        val intent = Intent(context, MainActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_SINGLE_TOP
+            putExtra("conversation_id", conversationId)
+        }
+
+        val pendingIntent = PendingIntent.getActivity(
+            context,
+            notificationId,
+            intent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+        )
+
+        val notification = NotificationCompat.Builder(context, "messages")
+            .setSmallIcon(R.drawable.ic_notification)
+            .setContentTitle(senderName)
+            .setContentText(messagePreview)
+            .setPriority(NotificationCompat.PRIORITY_HIGH)
+            .setContentIntent(pendingIntent)
+            .setAutoCancel(true)         // dismiss on tap
+            .build()
+
+        manager.notify(notificationId, notification)
+    }
+
+    fun dismissNotification(conversationId: String) {
+        manager.cancel(conversationId.hashCode())
+    }
+
+    fun dismissAll() {
+        manager.cancelAll()
+    }
+}

android/app/src/main/java/dev/zxq5/chatapp/android/data/repository/ChatRepository.kt

@@ -3,6 +3,7 @@ package dev.zxq5.chatapp.android.data.repository
 import dev.zxq5.chatapp.android.api.ChatClient
 import dev.zxq5.chatapp.android.core.data.TokenStore
 import dev.zxq5.chatapp.android.api.model.Message
+import dev.zxq5.chatapp.android.api.model.SpaceDto
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.emptyFlow
 
@@ -11,6 +12,8 @@ class ChatRepository(private val tokenStore: TokenStore) {
     private var _chatClient: ChatClient? = null
     private var _lastToken: String? = null
 
+    private var _lastActiveChannel: Long? = null
+
     private fun getChatClient(): ChatClient? {
         val token = tokenStore.get() ?: return null
         if (_chatClient == null || token != _lastToken) {
@@ -25,14 +28,23 @@ class ChatRepository(private val tokenStore: TokenStore) {
         _lastToken = null
     }
 
+    fun getLastActiveChannel(): Long? {
+        return _lastActiveChannel
+    }
+
     fun getUserId() = tokenStore.getUserId()
 
-    suspend fun sendMessage(channelId: Int, text: String) {
+    suspend fun getAccessibleChannels(): List<SpaceDto> {
+        return getChatClient()?.getAccessibleChannels() ?: emptyList()
+    }
+
+    suspend fun sendMessage(channelId: Long, text: String) {
         val userId = tokenStore.getUserId() ?: return
         getChatClient()?.sendMessage(channelId, userId, text)
     }
 
-    fun messageStream(channelId: Int): Flow<Message> {
+    fun messageStream(channelId: Long): Flow<Message> {
+        _lastActiveChannel = channelId
         return getChatClient()?.messageStream(channelId) ?: emptyFlow()
     }
 }

android/app/src/main/java/dev/zxq5/chatapp/android/feature/auth/AuthViewModel.kt

@@ -2,6 +2,7 @@ package dev.zxq5.chatapp.android.feature.auth
 
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import dev.zxq5.chatapp.android.core.service.MessageStreamService
 import dev.zxq5.chatapp.android.data.repository.AuthRepository
 import dev.zxq5.chatapp.android.data.repository.LoginResult
 import dev.zxq5.chatapp.android.data.repository.SignupResult

android/app/src/main/java/dev/zxq5/chatapp/android/feature/chat/ChatViewModel.kt

@@ -3,8 +3,12 @@ package dev.zxq5.chatapp.android.feature.chat
 import android.util.Log
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import dev.zxq5.chatapp.android.api.model.Channel
 import dev.zxq5.chatapp.android.data.repository.ChatRepository
 import dev.zxq5.chatapp.android.api.model.Message
+import dev.zxq5.chatapp.android.api.model.Space
+import dev.zxq5.chatapp.android.api.model.SpaceDto
+import dev.zxq5.chatapp.android.core.service.MessageStreamService
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -12,15 +16,13 @@ import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 
-
-
 class ChatViewModel(private val chatRepository: ChatRepository) : ViewModel() {
 
     private val _messages = MutableStateFlow<List<Message>>(emptyList())
     val messages: StateFlow<List<Message>> = _messages
 
-    private val _channelId = MutableStateFlow<Int?>(null)
+    private val _channelId = MutableStateFlow<Long?>(null)
-    val channelId: StateFlow<Int?> = _channelId
+    val channelId: StateFlow<Long?> = _channelId
 
     private val _currentScreen = MutableStateFlow(Screen.CHAT)
     val currentScreen: StateFlow<Screen> = _currentScreen
@@ -28,11 +30,35 @@ class ChatViewModel(private val chatRepository: ChatRepository) : ViewModel() {
     private val _currentUserId = MutableStateFlow<Int?>(null)
     val currentUserId: StateFlow<Int?> = _currentUserId
 
+    private val _spaces = MutableStateFlow<List<SpaceDto>>(emptyList())
+    val spaces: StateFlow<List<SpaceDto>> = _spaces
+
+    private val _error = MutableStateFlow<String?>(null)
+    val error: StateFlow<String?> = _error
+
+    private val _channelError = MutableStateFlow<String?>(null)
+    val channelError: StateFlow<String?> = _channelError
+
     private var streamJob: Job? = null
 
     init {
         _currentUserId.value = chatRepository.getUserId()
         observeChannel()
+        loadAccessibleChannels()
+    }
+
+    fun loadAccessibleChannels() {
+        _error.value = null
+        viewModelScope.launch {
+            runCatching {
+                chatRepository.getAccessibleChannels()
+            }.onSuccess { data ->
+                _spaces.value = data
+            }.onFailure { e ->
+                Log.e("Chat", "Failed to load spaces", e)
+                _error.value = "Failed to load channels: ${e.message}"
+            }
+        }
     }
 
     private fun observeChannel() {
@@ -40,11 +66,13 @@ class ChatViewModel(private val chatRepository: ChatRepository) : ViewModel() {
             _channelId.collect { id ->
                 streamJob?.cancel()
                 _messages.value = emptyList()
+                _channelError.value = null
                 if (id != null) {
                     streamJob = launch {
                         chatRepository.messageStream(id)
                             .catch { e -> 
                                 Log.e("Chat", "Stream error", e)
+                                _channelError.value = "Connection lost: ${e.message}"
                             }
                             .collect { message ->
                                 _messages.update { it + message }
@@ -59,12 +87,14 @@ class ChatViewModel(private val chatRepository: ChatRepository) : ViewModel() {
         _currentScreen.value = screen
     }
 
-    fun switchChannel(id: Int?) {
+    fun switchChannel(id: Long?) {
         _channelId.value = id
+
+        MessageStreamService.instance?.activeChannelId = id
+
         if (id != null) {
             // Refresh user ID just in case it wasn't available at init
             _currentUserId.value = chatRepository.getUserId()
-            chatRepository.resetClient() 
         }
     }
 
@@ -78,6 +108,7 @@ class ChatViewModel(private val chatRepository: ChatRepository) : ViewModel() {
                 )
             }.onFailure { e ->
                 Log.e("Chat", "Send message error", e)
+                _channelError.value = "Failed to send message"
             }
         }
     }
@@ -86,8 +117,14 @@ class ChatViewModel(private val chatRepository: ChatRepository) : ViewModel() {
         _messages.value = emptyList()
         _channelId.value = null
         _currentUserId.value = null
+        _error.value = null
+        _channelError.value = null
         streamJob?.cancel()
         chatRepository.resetClient()
+        MessageStreamService.instance?.activeChannelId = null
+    }
+
+    fun clearChannelError() {
+        _channelError.value = null
     }
 }
-

android/app/src/main/java/dev/zxq5/chatapp/android/feature/chat/Screen.kt

@@ -1,5 +1,5 @@
 package dev.zxq5.chatapp.android.feature.chat
 
 enum class Screen {
-    CHAT, SETTINGS
+    CHAT, CONTACTS, SETTINGS
 }

android/app/src/main/java/dev/zxq5/chatapp/android/feature/chat/chat.kt

@@ -28,22 +28,21 @@ import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Refresh
+import androidx.compose.material.icons.filled.Send
+import androidx.compose.material3.Button
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.NavigationBar
-import androidx.compose.material3.NavigationBarItem
-import androidx.compose.material3.NavigationBarItemDefaults
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
-import androidx.compose.material.icons.filled.Send
-import androidx.compose.material.icons.outlined.ChatBubbleOutline
-import androidx.compose.material.icons.outlined.Settings
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
@@ -56,26 +55,29 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
+import dev.zxq5.chatapp.android.api.model.Channel
 import dev.zxq5.chatapp.android.api.model.Message
 import java.text.DateFormat
 import java.util.Date
+import kotlin.time.ExperimentalTime
 
 @Composable
 fun ChatScreen(
     viewModel: ChatViewModel,
     onNavigateToSettings: () -> Unit,
-    onLogout: () -> Unit // Note: logout is now part of SettingsScreen in this UI, but we'll keep the param for now
+    onLogout: () -> Unit
 ) {
     val selectedChannelId by viewModel.channelId.collectAsState()
 
     if (selectedChannelId == null) {
         ChannelListScreen(
             viewModel = viewModel,
-            onChannelSelect = { viewModel.switchChannel(it) },
+            onChannelSelect = { viewModel.switchChannel(it) }
-            onNavigateToSettings = onNavigateToSettings
         )
     } else {
         MessageScreen(
@@ -90,20 +92,15 @@ fun ChatScreen(
 @Composable
 fun ChannelListScreen(
     viewModel: ChatViewModel, 
-    onChannelSelect: (Int) -> Unit,
+    onChannelSelect: (Long) -> Unit
-    onNavigateToSettings: () -> Unit
 ) {
+    val spaces by viewModel.spaces.collectAsState()
+    val error by viewModel.error.collectAsState()
+
     Scaffold(
         containerColor = MaterialTheme.colorScheme.background,
         topBar = {
             Column {
-                Spacer(Modifier.height(8.dp))
-                Text(
-                    "contacts",
-                    style = MaterialTheme.typography.labelSmall,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
-                    modifier = Modifier.padding(horizontal = 20.dp)
-                )
                 TopAppBar(
                     title = { 
                         Text(
@@ -115,103 +112,69 @@ fun ChannelListScreen(
                     colors = TopAppBarDefaults.topAppBarColors(
                         containerColor = Color.Transparent,
                         titleContentColor = MaterialTheme.colorScheme.onSurface
-                    )
+                    ),
+                    windowInsets = androidx.compose.foundation.layout.WindowInsets(0, 0, 0, 0),
+
                 )
                 Text(
-                    "5 channels · end-to-end encrypted",
+                    "Public channels - dms coming soon.",
                     style = MaterialTheme.typography.labelSmall,
                     color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.4f),
                     modifier = Modifier.padding(horizontal = 20.dp, vertical = 2.dp)
                 )
                 Spacer(Modifier.height(12.dp))
-                
+            }
-                Row(
+        }
-                    modifier = Modifier
+    ) { padding ->
-                        .fillMaxWidth()
+        if (error != null) {
-                        .background(MaterialTheme.colorScheme.secondary.copy(alpha = 0.2f))
+            Column(
-                        .padding(horizontal = 20.dp, vertical = 8.dp),
+                modifier = Modifier.fillMaxSize().padding(padding),
-                    verticalAlignment = Alignment.CenterVertically
+                horizontalAlignment = Alignment.CenterHorizontally,
-                ) {
+                verticalArrangement = Arrangement.Center
-                    Box(
+            ) {
-                        modifier = Modifier
+                Text(
-                            .size(6.dp)
+                    text = error!!,
-                            .clip(CircleShape)
+                    color = MaterialTheme.colorScheme.error,
-                            .background(MaterialTheme.colorScheme.primary)
+                    textAlign = TextAlign.Center,
-                    )
+                    modifier = Modifier.padding(16.dp)
-                    Spacer(Modifier.width(10.dp))
+                )
-                    Text(
+                Button(onClick = { viewModel.loadAccessibleChannels() }) {
-                        "global · walkie talkie",
+                    Icon(Icons.Default.Refresh, contentDescription = null)
-                        style = MaterialTheme.typography.labelSmall,
+                    Spacer(Modifier.width(8.dp))
-                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    Text("Retry")
-                        modifier = Modifier.weight(1f)
-                    )
-                    Surface(
-                        color = Color.Transparent,
-                        border = border(0.5.dp, MaterialTheme.colorScheme.outlineVariant),
-                        shape = RoundedCornerShape(4.dp)
-                    ) {
-                        Text(
-                            "hold to talk",
-                            modifier = Modifier.padding(horizontal = 8.dp, vertical = 3.dp),
-                            style = MaterialTheme.typography.labelSmall,
-                            color = MaterialTheme.colorScheme.onSurfaceVariant
-                        )
-                    }
                 }
             }
-        },
+        } else {
-        bottomBar = { BottomDock(viewModel, onNavigateToSettings) }
+            LazyColumn(modifier = Modifier.padding(padding).fillMaxSize()) {
-    ) { padding ->
+                spaces.forEach { spaceDto ->
-        LazyColumn(modifier = Modifier.padding(padding).fillMaxSize()) {
+                    item {
-            items(10) { i ->
+                        Text(
-                val id = i + 1
+                            text = spaceDto.name.lowercase(),
-                ChannelItem(id = id, onClick = { onChannelSelect(id) })
+                            modifier = Modifier.padding(horizontal = 20.dp, vertical = 8.dp),
-                HorizontalDivider(
+                            style = MaterialTheme.typography.labelMedium,
-                    modifier = Modifier.padding(horizontal = 20.dp),
+                            color = MaterialTheme.colorScheme.primary,
-                    thickness = 0.5.dp,
+                            fontWeight = FontWeight.Bold
-                    color = MaterialTheme.colorScheme.outlineVariant.copy(alpha = 0.2f)
+                        )
-                )
+                    }
+                    items(spaceDto.channels) { channel ->
+                        ChannelItem(channel = channel, onClick = { onChannelSelect(channel.id) })
+                        HorizontalDivider(
+                            modifier = Modifier.padding(horizontal = 20.dp),
+                            thickness = 0.5.dp,
+                            color = MaterialTheme.colorScheme.outlineVariant.copy(alpha = 0.2f)
+                        )
+                    }
+                    item {
+                        Spacer(Modifier.height(16.dp))
+                    }
+                }
             }
         }
     }
 }
 
 @Composable
-fun BottomDock(viewModel: ChatViewModel, onNavigateToSettings: () -> Unit) {
+fun ChannelItem(channel: Channel, onClick: () -> Unit) {
-    val currentScreen by viewModel.currentScreen.collectAsState()
-    
-    NavigationBar(
-        containerColor = MaterialTheme.colorScheme.background,
-        tonalElevation = 0.dp,
-        modifier = Modifier.border(0.5.dp, MaterialTheme.colorScheme.outlineVariant.copy(alpha = 0.2f), RoundedCornerShape(topStart = 0.dp, topEnd = 0.dp))
-    ) {
-        NavigationBarItem(
-            selected = currentScreen == Screen.CHAT,
-            onClick = { viewModel.navigateTo(Screen.CHAT) },
-            icon = { Icon(Icons.Outlined.ChatBubbleOutline, contentDescription = "Chat") },
-            label = { Text("chat", style = MaterialTheme.typography.labelSmall) },
-            colors = NavigationBarItemDefaults.colors(
-                selectedIconColor = MaterialTheme.colorScheme.primary,
-                unselectedIconColor = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
-                indicatorColor = Color.Transparent
-            )
-        )
-        NavigationBarItem(
-            selected = currentScreen == Screen.SETTINGS,
-            onClick = onNavigateToSettings,
-            icon = { Icon(Icons.Outlined.Settings, contentDescription = "Settings") },
-            label = { Text("settings", style = MaterialTheme.typography.labelSmall) },
-            colors = NavigationBarItemDefaults.colors(
-                selectedIconColor = MaterialTheme.colorScheme.primary,
-                unselectedIconColor = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
-                indicatorColor = Color.Transparent
-            )
-        )
-    }
-}
-
-@Composable
-fun ChannelItem(id: Int, onClick: () -> Unit) {
     Row(
         modifier = Modifier
             .fillMaxWidth()
@@ -227,7 +190,7 @@ fun ChannelItem(id: Int, onClick: () -> Unit) {
             contentAlignment = Alignment.Center
         ) {
             Text(
-                "C$id", 
+                channel.name.take(1).uppercase(), 
                 style = MaterialTheme.typography.labelSmall,
                 color = MaterialTheme.colorScheme.onSurfaceVariant
             )
@@ -235,31 +198,30 @@ fun ChannelItem(id: Int, onClick: () -> Unit) {
         Spacer(Modifier.width(12.dp))
         Column(modifier = Modifier.weight(1f)) {
             Text(
-                text = "channel $id", 
+                text = channel.name, 
                 style = MaterialTheme.typography.bodyLarge,
                 color = MaterialTheme.colorScheme.onSurface
             )
-            Text(
+            if (channel.description != null) {
-                text = "tap to join",
+                Text(
-                style = MaterialTheme.typography.labelSmall,
+                    text = channel.description,
-                color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f)
+                    style = MaterialTheme.typography.labelSmall,
-            )
+                    color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f)
+                )
+            }
         }
-        Text(
-            "14:22",
-            style = MaterialTheme.typography.labelSmall,
-            color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.3f)
-        )
     }
 }
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
-fun MessageScreen(channelId: Int, viewModel: ChatViewModel, onBack: () -> Unit) {
+fun MessageScreen(channelId: Long, viewModel: ChatViewModel, onBack: () -> Unit) {
     val messages by viewModel.messages.collectAsState()
     val currentUserId by viewModel.currentUserId.collectAsState()
+    val channelError by viewModel.channelError.collectAsState()
     var input by remember { mutableStateOf("") }
     val listState = rememberLazyListState()
+    val snackbarHostState = remember { SnackbarHostState() }
 
     LaunchedEffect(messages.size) {
         if (messages.isNotEmpty()) {
@@ -267,8 +229,16 @@ fun MessageScreen(channelId: Int, viewModel: ChatViewModel, onBack: () -> Unit)
         }
     }
 
+    LaunchedEffect(channelError) {
+        channelError?.let {
+            snackbarHostState.showSnackbar(it)
+            viewModel.clearChannelError()
+        }
+    }
+
     Scaffold(
         containerColor = MaterialTheme.colorScheme.background,
+        snackbarHost = { SnackbarHost(snackbarHostState) },
         topBar = {
             TopAppBar(
                 title = { 
@@ -294,6 +264,7 @@ fun MessageScreen(channelId: Int, viewModel: ChatViewModel, onBack: () -> Unit)
                         )
                     }
                 },
+                windowInsets = androidx.compose.foundation.layout.WindowInsets(0, 0, 0, 0),
                 colors = TopAppBarDefaults.topAppBarColors(
                     containerColor = Color.Transparent
                 )
@@ -391,10 +362,13 @@ fun MessageScreen(channelId: Int, viewModel: ChatViewModel, onBack: () -> Unit)
     }
 }
 
+@OptIn(ExperimentalTime::class)
 @Composable
 fun MessageBubble(message: Message, currentUserId: Int?) {
     val time = remember(message.timestamp) {
-        DateFormat.getTimeInstance(DateFormat.SHORT).format(Date(message.timestamp)).lowercase()
+        DateFormat.getTimeInstance(DateFormat.SHORT)
+            .format(Date(message.timestamp.toEpochMilliseconds()))
+            .lowercase()
     }
     
     val isMe = currentUserId != null && message.user_id == currentUserId

android/app/src/main/java/dev/zxq5/chatapp/android/feature/contacts/ContactsScreen.kt

@@ -0,0 +1,52 @@
+package dev.zxq5.chatapp.android.feature.contacts
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ContactsScreen() {
+    Scaffold(
+        containerColor = MaterialTheme.colorScheme.background,
+        topBar = {
+            TopAppBar(
+                title = { 
+                    Text(
+                        "contacts", 
+                        style = MaterialTheme.typography.titleLarge,
+                        color = MaterialTheme.colorScheme.onSurface
+                    ) 
+                },
+                windowInsets = androidx.compose.foundation.layout.WindowInsets(0, 0, 0, 0),
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = Color.Transparent,
+                    titleContentColor = MaterialTheme.colorScheme.onSurface
+                )
+            )
+        }
+    ) { padding ->
+        Box(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(padding),
+            contentAlignment = Alignment.Center
+        ) {
+            Text(
+                text = "Contacts coming soon",
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+    }
+}

android/app/src/main/java/dev/zxq5/chatapp/android/feature/settings/settings.kt

@@ -63,7 +63,6 @@ import androidx.compose.ui.text.style.TextAlign
 @Composable
 fun SettingsScreen(
     viewModel: SettingsViewModel,
-    onBack: () -> Unit,
     onLogout: () -> Unit
 ) {
     val is2faEnabled by viewModel.is2faEnabled.collectAsState()
@@ -88,15 +87,7 @@ fun SettingsScreen(
                         color = MaterialTheme.colorScheme.onSurface
                     ) 
                 },
-                navigationIcon = {
+                windowInsets = androidx.compose.foundation.layout.WindowInsets(0, 0, 0, 0),
-                    IconButton(onClick = onBack) {
-                        Icon(
-                            Icons.AutoMirrored.Filled.ArrowBack, 
-                            contentDescription = "Back",
-                            tint = MaterialTheme.colorScheme.onSurfaceVariant
-                        )
-                    }
-                },
                 colors = TopAppBarDefaults.topAppBarColors(containerColor = Color.Transparent)
             )
         }

android/app/src/main/res/drawable/ic_notification.xml

@@ -0,0 +1,5 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android" android:autoMirrored="true" android:height="24dp" android:tint="#FFFFFF" android:viewportHeight="24" android:viewportWidth="24" android:width="24dp">
+      
+    <path android:fillColor="@android:color/white" android:pathData="M20,2L4,2c-1.1,0 -1.99,0.9 -1.99,2L2,22l4,-4h14c1.1,0 2,-0.9 2,-2L22,4c0,-1.1 -0.9,-2 -2,-2zM18,14L6,14v-2h12v2zM18,11L6,11L6,9h12v2zM18,8L6,8L6,6h12v2z"/>
+    
+</vector>

backend/.idea/backend.iml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="EMPTY_MODULE" version="4">
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/tests" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

backend/.idea/dataSources.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DataSourceManagerImpl" format="xml" multifile-model="true">
+    <data-source source="LOCAL" name="chatapp_dev@100.118.108.58" uuid="b14acf5d-6750-469b-8aea-59c8343eb11c">
+      <driver-ref>postgresql</driver-ref>
+      <synchronize>true</synchronize>
+      <jdbc-driver>org.postgresql.Driver</jdbc-driver>
+      <jdbc-url>jdbc:postgresql://100.118.108.58:5432/chatapp_dev</jdbc-url>
+      <jdbc-additional-properties>
+        <property name="com.intellij.clouds.kubernetes.db.host.port" />
+        <property name="com.intellij.clouds.kubernetes.db.enabled" value="false" />
+        <property name="com.intellij.clouds.kubernetes.db.container.port" />
+      </jdbc-additional-properties>
+      <working-dir>$ProjectFileDir$</working-dir>
+    </data-source>
+  </component>
+</project>

backend/.idea/data_source_mapping.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DataSourcePerFileMappings">
+    <file url="file://$PROJECT_DIR$/sql/schema.sql" value="b14acf5d-6750-469b-8aea-59c8343eb11c" />
+    <file url="file://$PROJECT_DIR$/src/repo/user_repo.rs" value="b14acf5d-6750-469b-8aea-59c8343eb11c" />
+  </component>
+</project>

backend/.idea/inspectionProfiles/Project_Default.xml

@@ -0,0 +1,6 @@
+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="Eslint" enabled="true" level="WARNING" enabled_by_default="true" />
+  </profile>
+</component>

backend/.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/backend.iml" filepath="$PROJECT_DIR$/.idea/backend.iml" />
+    </modules>
+  </component>
+</project>

backend/.idea/sqldialects.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="SqlDialectMappings">
+    <file url="file://$PROJECT_DIR$/sql/schema.sql" dialect="PostgreSQL" />
+    <file url="PROJECT" dialect="PostgreSQL" />
+  </component>
+</project>

backend/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>