Basic settings

app/build.gradle.kts

@@ -5,6 +5,7 @@ plugins {
     alias(libs.plugins.hilt.android)
     alias(libs.plugins.ksp)
     alias(libs.plugins.secrets)
+    alias(libs.plugins.parcelize)
 }
 
 android {
@@ -66,6 +67,7 @@ dependencies {
     implementation(libs.retrofit.converter.gson)
     implementation(libs.androidx.material3.window.size.class1)
     implementation(libs.okhttp.sse)
+    implementation(libs.androidx.navigation.compose)
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)

app/src/main/AndroidManifest.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools" >
+    xmlns:tools="http://schemas.android.com/tools">
 
     <uses-permission android:name="android.permission.INTERNET" />
 
@@ -8,18 +8,18 @@
         android:name=".ChatApplication"
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
+        android:enableOnBackInvokedCallback="true"
         android:fullBackupContent="@xml/backup_rules"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/Theme.ChatApp"
-        android:enableOnBackInvokedCallback="true">
+        android:theme="@style/Theme.ChatApp">
         <activity
-            android:name=".activity.chat.ChatActivity"
+            android:name=".activity.main.MainActivity"
             android:exported="true"
-            android:theme="@style/Theme.ChatApp"
-            android:windowSoftInputMode="adjustNothing">
+            android:label="@string/title_activity_main"
+            android:theme="@style/Theme.ChatApp">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
@@ -27,9 +27,11 @@
             </intent-filter>
         </activity>
         <activity
-            android:name=".activity.select.SelectModelActivity"
-            android:exported="true"
-            android:theme="@style/Theme.ChatApp" />
+            android:name=".activity.chat.ChatActivity"
+            android:exported="false"
+            android:theme="@style/Theme.ChatApp"
+            android:windowSoftInputMode="adjustNothing">
+        </activity>
     </application>
 
 </manifest>

app/src/main/java/eu/m724/chatapp/activity/chat/ChatActivity.kt

@@ -47,6 +47,7 @@ import androidx.compose.ui.platform.LocalSoftwareKeyboardController
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.navigation.compose.rememberNavController
 import dagger.hilt.android.AndroidEntryPoint
 import eu.m724.chatapp.R
 import eu.m724.chatapp.activity.chat.composable.ChatToolBar
@@ -54,12 +55,15 @@ import eu.m724.chatapp.activity.ui.composable.AnimatedChangingText
 import eu.m724.chatapp.activity.chat.composable.LanguageModelMistakeWarning
 import eu.m724.chatapp.activity.chat.composable.thread.ChatMessageComposer
 import eu.m724.chatapp.activity.chat.composable.thread.ChatResponseErrorNotice
+import eu.m724.chatapp.activity.chat.quick_settings.ChatQuickSettingsEvent
 import eu.m724.chatapp.activity.chat.state.ChatComposerState
 import eu.m724.chatapp.activity.chat.state.rememberChatComposerState
 import eu.m724.chatapp.activity.ui.composable.disableBringIntoViewOnFocus
 import eu.m724.chatapp.activity.ui.composable.hideKeyboardOnScrollUp
 import eu.m724.chatapp.activity.ui.theme.ChatAppTheme
 import eu.m724.chatapp.api.data.response.completion.ChatMessage
+import eu.m724.chatapp.api.data.response.models.LanguageModel
+import eu.m724.chatapp.chat.Chat
 import kotlinx.coroutines.launch
 
 @AndroidEntryPoint
@@ -93,6 +97,8 @@ class ChatActivity : ComponentActivity() {
                 }
             }
 
+            var savedFocus by remember { mutableStateOf(false) }
+
             ChatScreen(
                 windowSizeClass = windowSizeClass,
                 uiState = uiState,
@@ -105,8 +111,8 @@ class ChatActivity : ComponentActivity() {
 
                     coroutineScope.launch {
                         if (threadViewLazyListState.layoutInfo.visibleItemsInfo.find { it.key == "composer" } == null) {
-                            if (uiState.messages.isNotEmpty()) {
-                                threadViewLazyListState.animateScrollToItem(uiState.messages.size)
+                            if (uiState.chat.messages.isNotEmpty()) {
+                                threadViewLazyListState.animateScrollToItem(uiState.chat.messages.size)
                                 // TODO this makes the composer full screen but if the condition above is false it doesn't, that may be kind of unintuitive
                             }
                         }
@@ -114,6 +120,16 @@ class ChatActivity : ComponentActivity() {
                         chatState.requestFocus()
                         softwareKeyboardController?.show()
                     }
+                },
+                onSettingsEvent = { event ->
+                    when (event) {
+                        is ChatQuickSettingsEvent.Visibility -> {
+                            // TODO focus / unfocus
+                        }
+                        is ChatQuickSettingsEvent.ModelSelected -> {
+                            viewModel.selectModel(event.model)
+                        }
+                    }
                 }
             )
 
@@ -122,11 +138,11 @@ class ChatActivity : ComponentActivity() {
                     chatState.composerValue = ""
 
                     // scroll to the last user message
-                    threadViewLazyListState.animateScrollToItem(uiState.messages.size - 2)
+                    threadViewLazyListState.animateScrollToItem(uiState.chat.messages.size - 2)
                 } else {
-                    if (uiState.messages.size > 1) {
+                    if (uiState.chat.messages.size > 1) {
                         // scroll to the last user message too
-                        threadViewLazyListState.animateScrollToItem(uiState.messages.size - 2)
+                        threadViewLazyListState.animateScrollToItem(uiState.chat.messages.size - 2)
                     }
 
                     if (uiState.lastResponseError == null) {
@@ -170,7 +186,8 @@ fun ChatScreen(
     threadViewLazyListState: LazyListState,
     snackbarHostState: SnackbarHostState,
     onSend: () -> Unit,
-    onRequestFocus: () -> Unit
+    onRequestFocus: () -> Unit,
+    onSettingsEvent: (ChatQuickSettingsEvent) -> Unit
 ) {
     val isTablet = windowSizeClass.widthSizeClass > WindowWidthSizeClass.Compact
 
@@ -179,7 +196,7 @@ fun ChatScreen(
             modifier = Modifier.fillMaxSize(),
             topBar = {
                 ChatTopAppBar(
-                    title = uiState.chatTitle ?: stringResource(R.string.title_new_conversation)
+                    title = uiState.chat.title ?: stringResource(R.string.title_new_conversation)
                 )
             },
             snackbarHost = {
@@ -200,7 +217,8 @@ fun ChatScreen(
                 chatComposerState = chatComposerState,
                 threadViewLazyListState = threadViewLazyListState,
                 onSend = onSend,
-                onRequestFocus = onRequestFocus
+                onRequestFocus = onRequestFocus,
+                onSettingsEvent = onSettingsEvent
             )
         }
     }
@@ -214,7 +232,8 @@ fun ChatScreenContent(
     chatComposerState: ChatComposerState,
     threadViewLazyListState: LazyListState,
     onSend: () -> Unit,
-    onRequestFocus: () -> Unit
+    onRequestFocus: () -> Unit,
+    onSettingsEvent: (ChatQuickSettingsEvent) -> Unit
 ) {
     val layout: @Composable (@Composable () -> Unit, @Composable () -> Unit) -> Unit =
         if (isTablet) {
@@ -246,7 +265,7 @@ fun ChatScreenContent(
                     .fillMaxSize()
                     .padding(horizontal = 24.dp),
                 lazyListState = threadViewLazyListState,
-                messages = uiState.messages,
+                messages = uiState.chat.messages,
                 uiState = uiState,
                 chatComposerState = chatComposerState
             )
@@ -263,7 +282,8 @@ fun ChatScreenContent(
                     canSend = (chatComposerState.composerValue.isNotBlank() || uiState.lastResponseError != null) && !uiState.requestInProgress,
                     willRestart = chatComposerState.composerValue.isBlank() && uiState.lastResponseError != null,
                     onSend = onSend,
-                    onEmptySpaceClick = onRequestFocus
+                    onEmptySpaceClick = onRequestFocus,
+                    onSettingsEvent = onSettingsEvent,
                 )
 
                 LanguageModelMistakeWarning(

app/src/main/java/eu/m724/chatapp/activity/chat/ChatActivityUiState.kt

@@ -1,23 +1,15 @@
 package eu.m724.chatapp.activity.chat
 
-import eu.m724.chatapp.activity.chat.state.ChatResponseError
-import eu.m724.chatapp.api.data.response.completion.ChatMessage
+import eu.m724.chatapp.chat.Chat
+import eu.m724.chatapp.chat.ChatResponseError
 
 data class ChatActivityUiState(
-    /**
-     * The title of the current chat
-     */
-    val chatTitle: String? = null,
+    val chat: Chat,
 
     /**
      * Whether a request is in progress (a response is streaming)
      */
     val requestInProgress: Boolean = false,
 
-    val lastResponseError: ChatResponseError? = null,
-
-    /**
-     * All messages in the chat
-     */
-    val messages: List<ChatMessage> = emptyList()
+    val lastResponseError: ChatResponseError? = null
 )

app/src/main/java/eu/m724/chatapp/activity/chat/ChatActivityViewModel.kt

@@ -1,15 +1,18 @@
 package eu.m724.chatapp.activity.chat
 
+import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
-import eu.m724.chatapp.activity.chat.state.ChatResponseError
 import eu.m724.chatapp.api.AiApiService
 import eu.m724.chatapp.api.data.request.completion.ChatCompletionRequest
 import eu.m724.chatapp.api.data.response.completion.ChatCompletionResponseEvent
 import eu.m724.chatapp.api.data.response.completion.ChatMessage
 import eu.m724.chatapp.api.data.response.completion.CompletionFinishReason
+import eu.m724.chatapp.api.data.response.models.LanguageModel
 import eu.m724.chatapp.api.retrofit.sse.SseEvent
+import eu.m724.chatapp.chat.Chat
+import eu.m724.chatapp.chat.ChatResponseError
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -24,9 +27,13 @@ import javax.inject.Inject
 
 @HiltViewModel
 class ChatActivityViewModel @Inject constructor(
-    private val aiApiService: AiApiService
+    private val aiApiService: AiApiService,
+    savedStateHandle: SavedStateHandle
 ) : ViewModel() {
-    private val _uiState = MutableStateFlow(ChatActivityUiState())
+    private val _uiState = MutableStateFlow(ChatActivityUiState(
+        chat = savedStateHandle.get<Chat>("chat") ?: throw IllegalStateException("Chat not provided")
+    ))
+
     val uiState: StateFlow<ChatActivityUiState> = _uiState.asStateFlow()
 
     private val _uiEvents = Channel<ChatActivityUiEvent>()
@@ -42,7 +49,7 @@ class ChatActivityViewModel @Inject constructor(
 
         if (lastUserMessage.role == ChatMessage.Role.Assistant) {
             // If we just removed an Assistant message, we must also remove the respective User message
-            lastUserMessage = messages.removeLast()
+            messages.removeLast()
         }
 
         sendMessage(lastUserMessage.content)
@@ -69,21 +76,23 @@ class ChatActivityViewModel @Inject constructor(
         _uiState.update {
             it.copy(
                 requestInProgress = true,
-                messages = messages + ChatMessage(
-                    role = ChatMessage.Role.Assistant,
-                    content = responseContent
-                ),
-                chatTitle = it.chatTitle ?: promptContent,
-                lastResponseError = null
+                lastResponseError = null,
+                chat = it.chat.copy(
+                    title = it.chat.title ?: promptContent,
+                    messages = messages + ChatMessage(
+                        role = ChatMessage.Role.Assistant,
+                        content = responseContent
+                    )
+                )
             )
         }
 
         aiApiService.getChatCompletion(
             ChatCompletionRequest(
-                model = "free-model",
+                model = _uiState.value.chat.model.id,
                 messages = messages,
                 temperature = 1.0f,
-                maxTokens = 4,
+                maxTokens = 128,
                 frequencyPenalty = 0.0f,
                 presencePenalty = 0.0f
             )
@@ -99,9 +108,11 @@ class ChatActivityViewModel @Inject constructor(
 
                             _uiState.update {
                                 it.copy(
-                                    messages = messages + ChatMessage(
-                                        role = ChatMessage.Role.Assistant,
-                                        content = responseContent
+                                    chat = it.chat.copy(
+                                        messages = messages + ChatMessage(
+                                            role = ChatMessage.Role.Assistant,
+                                            content = responseContent
+                                        )
                                     )
                                 )
                             }
@@ -137,9 +148,21 @@ class ChatActivityViewModel @Inject constructor(
                 it.copy(
                     requestInProgress = false,
                     lastResponseError = error,
-                    messages = messages.toList()
+                    chat = it.chat.copy(
+                        messages = messages.toList()
+                    )
                 )
             }
         }.launchIn(viewModelScope)
     }
+
+    fun selectModel(model: LanguageModel) {
+        _uiState.update {
+            it.copy(
+                chat = it.chat.copy(
+                    model = model
+                )
+            )
+        }
+    }
 }

app/src/main/java/eu/m724/chatapp/activity/chat/composable/ChatToolBar.kt

@@ -1,26 +1,38 @@
 package eu.m724.chatapp.activity.chat.composable
 
+import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.animateColorAsState
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 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.automirrored.filled.Send
+import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material3.ElevatedCard
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.IconButtonDefaults
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalSoftwareKeyboardController
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import eu.m724.chatapp.R
+import eu.m724.chatapp.activity.chat.quick_settings.ChatQuickSettings
+import eu.m724.chatapp.activity.chat.quick_settings.ChatQuickSettingsEvent
+import eu.m724.chatapp.activity.chat.quick_settings.ChatQuickSettingsVisibility
 
 @Composable
 fun ChatToolBar(
@@ -28,31 +40,89 @@ fun ChatToolBar(
     canSend: Boolean,
     willRestart: Boolean,
     onSend: () -> Unit,
-    onEmptySpaceClick: () -> Unit
+    onEmptySpaceClick: () -> Unit,
+    onSettingsEvent: (ChatQuickSettingsEvent) -> Unit
 ) {
+    var settingsOpened by remember { mutableStateOf(false) }
+    val localSoftwareKeyboardController = LocalSoftwareKeyboardController.current
+
+    LaunchedEffect(settingsOpened) {
+        onSettingsEvent(ChatQuickSettingsEvent.Visibility(
+            if (settingsOpened) {
+                ChatQuickSettingsVisibility.OPEN
+            } else {
+                ChatQuickSettingsVisibility.CLOSED
+            }
+        ))
+    }
 
     ElevatedCard(
         modifier = modifier,
         shape = RoundedCornerShape(24.dp)
     ) {
-        Row(
-            modifier = Modifier
-                .fillMaxWidth()
-                .clickable(onClick = onEmptySpaceClick),
-            horizontalArrangement = Arrangement.End
-        ) {
-            SendMessageButton(
+        Column {
+            AnimatedVisibility(settingsOpened) {
+                ChatQuickSettings(
+                    modifier = Modifier.padding(16.dp), // To match the rounded corners
+                    onModelSelected = {
+                        settingsOpened = false
+                        onSettingsEvent(ChatQuickSettingsEvent.ModelSelected(it))
+                    },
+                    onDismiss = {
+                        settingsOpened = false
+                    }
+                )
+            }
+
+            Row(
                 modifier = Modifier
-                    .height(48.dp)
-                    .padding(horizontal = 8.dp),
-                onClick = onSend,
-                enabled = canSend,
-                willRestart = willRestart
-            )
+                    .fillMaxWidth()
+                    .clickable(onClick = onEmptySpaceClick),
+                horizontalArrangement = Arrangement.End
+            ) {
+                SettingsButton(
+                    onClick = {
+                        settingsOpened = !settingsOpened
+                        localSoftwareKeyboardController?.hide() // TODO re show when done
+                    },
+                    modifier = Modifier
+                        .height(48.dp)
+                        .padding(horizontal = 8.dp),
+                )
+
+                Spacer(
+                    modifier = Modifier.weight(1f)
+                )
+
+                SendMessageButton(
+                    modifier = Modifier
+                        .height(48.dp)
+                        .padding(horizontal = 8.dp),
+                    onClick = onSend,
+                    enabled = canSend,
+                    willRestart = willRestart
+                )
+            }
         }
     }
 }
 
+@Composable
+fun SettingsButton(
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    IconButton(
+        onClick = onClick,
+        modifier = modifier
+    ) {
+        Icon(
+            imageVector = Icons.Default.Menu,
+            contentDescription = stringResource(R.string.button_settings_icon_description)
+        )
+    }
+}
+
 @Composable
 fun SendMessageButton(
     onClick: () -> Unit,

app/src/main/java/eu/m724/chatapp/activity/chat/composable/thread/ChatResponseErrorNotice.kt

@@ -14,7 +14,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import eu.m724.chatapp.R
-import eu.m724.chatapp.activity.chat.state.ChatResponseError
+import eu.m724.chatapp.chat.ChatResponseError
 
 @Composable
 fun ChatResponseErrorNotice(

app/src/main/java/eu/m724/chatapp/activity/chat/quick_settings/ChatQuickSettings.kt

@@ -0,0 +1,153 @@
+package eu.m724.chatapp.activity.chat.quick_settings
+
+import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
+import androidx.compose.ui.input.nestedscroll.NestedScrollSource
+import androidx.compose.ui.input.nestedscroll.nestedScroll
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.min
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
+import eu.m724.chatapp.R
+import eu.m724.chatapp.activity.chat.quick_settings.composable.ModelCard
+import eu.m724.chatapp.api.data.response.models.LanguageModel
+
+@Composable
+fun ChatQuickSettings(
+    modifier: Modifier = Modifier,
+    onModelSelected: (LanguageModel) -> Unit,
+    onDismiss: () -> Unit,
+    viewModel: ChatQuickSettingsViewModel = viewModel(),
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+
+    Column(
+        modifier = modifier,
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        if (uiState.modelsLoaded) {
+            ModelList(
+                models = uiState.models,
+                onModelSelected = onModelSelected,
+                onDismiss = onDismiss
+            )
+        } else {
+            CircularProgressIndicator()
+        }
+    }
+}
+
+@Composable
+fun ModelList(
+    models: List<LanguageModel>,
+    onModelSelected: (LanguageModel) -> Unit,
+    onDismiss: () -> Unit
+) {
+    val minHeight = 250.dp
+    val maxHeight = 600.dp // TODO
+
+    var targetHeight by remember { mutableStateOf(minHeight) }
+    val height by animateDpAsState(targetHeight)
+
+    var listState = rememberLazyListState()
+
+    val isScrolledToTop by remember {
+        derivedStateOf {
+            listState.firstVisibleItemIndex == 0 && listState.firstVisibleItemScrollOffset == 0
+        }
+    }
+
+    LaunchedEffect(listState.isScrollInProgress) {
+        if (!listState.isScrollInProgress) {
+            if (targetHeight < 50.dp) {
+                onDismiss()
+            } else if (targetHeight < minHeight + 10.dp) {
+                targetHeight = minHeight
+            } else {
+                targetHeight = maxHeight
+            }
+        }
+    }
+
+    // This is the connection that will intercept scroll events.
+    val nestedScrollConnection = remember {
+        object : NestedScrollConnection {
+            // onPreScroll is called before the child (LazyColumn) gets to scroll.
+            override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
+                if (available.y < 0) { // scroll down (content down, finger up)
+                    if (targetHeight < maxHeight) {
+                        targetHeight = min(targetHeight - available.y.dp / 2, maxHeight)
+                        return available
+                    }
+                }
+
+                // scroll up (content up, finger down)
+                if (available.y > 0 && isScrolledToTop) {
+                    targetHeight = targetHeight - available.y.dp / 2
+                    return available
+                }
+
+                return Offset.Zero
+            }
+
+            override fun onPostScroll(
+                consumed: Offset,
+                available: Offset,
+                source: NestedScrollSource
+            ): Offset {
+                return super.onPostScroll(consumed, available, source)
+            }
+        }
+    }
+
+    LazyColumn(
+        modifier = Modifier
+            .fillMaxWidth()
+            .height(height)
+            .nestedScroll(nestedScrollConnection),
+        state = listState
+    ) { // TODO make this rounded
+        item {
+            Text(
+                text = stringResource(R.string.quick_settings_select_model),
+                style = MaterialTheme.typography.titleLarge
+            ) // TODO center this maybe? but this looks cool too
+        }
+
+        items(
+            items = models,
+            key = { it.id }
+        ) { model ->
+            ModelCard(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 16.dp, vertical = 8.dp),
+                model = model,
+                onSelected = {
+                    onModelSelected(model)
+                }
+            )
+        }
+    }
+}

app/src/main/java/eu/m724/chatapp/activity/chat/quick_settings/ChatQuickSettingsEvent.kt

@@ -0,0 +1,9 @@
+package eu.m724.chatapp.activity.chat.quick_settings
+
+import eu.m724.chatapp.api.data.response.models.LanguageModel
+
+sealed interface ChatQuickSettingsEvent {
+    data class Visibility(val visibility: ChatQuickSettingsVisibility): ChatQuickSettingsEvent
+    data class ModelSelected(val model: LanguageModel): ChatQuickSettingsEvent
+}
+

app/src/main/java/eu/m724/chatapp/activity/chat/quick_settings/ChatQuickSettingsUiState.kt

@@ -0,0 +1,12 @@
+package eu.m724.chatapp.activity.chat.quick_settings
+
+import eu.m724.chatapp.api.data.response.models.LanguageModel
+
+data class ChatQuickSettingsUiState(
+    val modelsLoaded: Boolean = false,
+
+    /**
+     * A list of all available language models.
+     */
+    val models: List<LanguageModel> = listOf()
+)

app/src/main/java/eu/m724/chatapp/activity/chat/quick_settings/ChatQuickSettingsViewModel.kt

@@ -0,0 +1,44 @@
+package eu.m724.chatapp.activity.chat.quick_settings
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import eu.m724.chatapp.api.AiApiService
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+@HiltViewModel
+class ChatQuickSettingsViewModel @Inject constructor(
+    val aiApiService: AiApiService
+) : ViewModel() {
+    private val _uiState = MutableStateFlow(ChatQuickSettingsUiState())
+    val uiState: StateFlow<ChatQuickSettingsUiState> = _uiState.asStateFlow()
+
+    init {
+        loadModels()
+    }
+
+    private fun loadModels() {
+        viewModelScope.launch {
+            val modelsResponse = try {
+                aiApiService.getModels()
+            } catch (e: Exception) {
+                // TODO
+                return@launch
+            }
+
+            val models = modelsResponse.body()!!.data
+
+            _uiState.update {
+                it.copy(
+                    modelsLoaded = true,
+                    models = models
+                )
+            }
+        }
+    }
+}

app/src/main/java/eu/m724/chatapp/activity/chat/quick_settings/ChatQuickSettingsVisibility.kt

@@ -0,0 +1,5 @@
+package eu.m724.chatapp.activity.chat.quick_settings
+
+enum class ChatQuickSettingsVisibility {
+    CLOSED, OPEN, EXPANDED
+}

app/src/main/java/eu/m724/chatapp/activity/chat/quick_settings/composable/ModelCard.kt

@@ -0,0 +1,228 @@
+package eu.m724.chatapp.activity.chat.quick_settings.composable
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.animateContentSize
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.defaultMinSize
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.AccountCircle
+import androidx.compose.material.icons.filled.KeyboardArrowDown
+import androidx.compose.material.icons.filled.KeyboardArrowUp
+import androidx.compose.material3.Card
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import eu.m724.chatapp.R
+import eu.m724.chatapp.api.data.response.models.LanguageModel
+import java.math.RoundingMode
+import java.text.DecimalFormat
+
+@Composable
+fun ModelCard(
+    model: LanguageModel,
+    modifier: Modifier = Modifier,
+    onSelected: () -> Unit = {},
+) {
+    var expanded by remember { mutableStateOf(false) }
+
+    Card(
+        modifier = modifier,
+        onClick = {
+            expanded = !expanded
+        }
+    ) {
+        Column(
+            modifier = Modifier.padding(start = 16.dp, end = 16.dp, top = 16.dp, bottom = 12.dp)
+        ) {
+            Row(
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                Column {
+                    Icon(
+                        imageVector = Icons.Default.AccountCircle,
+                        contentDescription = stringResource(
+                            R.string.model_card_icon_description,
+                            model.name
+                        ),
+                        modifier = Modifier
+                            .size(48.dp)
+                            .fillMaxHeight(),
+                        tint = MaterialTheme.colorScheme.primary
+                    )
+
+                    // TODO this button is awkward
+                    AnimatedVisibility(expanded) {
+                        TextButton(
+                            onClick = onSelected,
+                            contentPadding = PaddingValues(horizontal = 0.dp),
+                            modifier = Modifier
+                                .defaultMinSize(minWidth = 1.dp, minHeight = 1.dp)
+                                .width(48.dp)
+                        ) {
+                            Text(
+                                text = stringResource(R.string.model_card_select)
+                            )
+                        }
+                    }
+                }
+
+                Spacer(modifier = Modifier.width(16.dp))
+
+                Column(
+                    modifier = Modifier.weight(1f)
+                ) {
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.SpaceBetween
+                    ) {
+                        Text(
+                            text = model.name,
+                            style = MaterialTheme.typography.titleLarge,
+                        )
+
+                        ExpandArrowIcon(
+                            expanded = expanded
+                        )
+                    }
+
+                    if (model.description != null) {
+                        Spacer(modifier = Modifier.height(4.dp))
+                        Text(
+                            text = model.description,
+                            modifier = Modifier.animateContentSize(),
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            overflow = TextOverflow.Ellipsis,
+                            maxLines = if (expanded) Int.MAX_VALUE else 1
+                        )
+                    }
+                }
+            }
+
+            Spacer(modifier = Modifier.height(12.dp))
+
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                PriceItem(
+                    icon = Icons.Default.KeyboardArrowUp,
+                    label = stringResource(R.string.model_card_price_input),
+                    price = model.pricing.pricePerMillionInputTokens,
+                    contentDescription = stringResource(R.string.model_card_price_million_input_icon_description)
+                )
+
+                Spacer(modifier = Modifier.width(12.dp))
+
+                PriceItem(
+                    icon = Icons.Default.KeyboardArrowDown,
+                    label = stringResource(R.string.model_card_price_output),
+                    price = model.pricing.pricePerMillionOutputTokens,
+                    contentDescription = stringResource(R.string.model_card_price_million_output_icon_description)
+                )
+
+                Spacer(modifier = Modifier.weight(1f))
+
+                Text(
+                    text = stringResource(R.string.model_card_price_million_tokens),
+                    style = MaterialTheme.typography.labelMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+            }
+        }
+    }
+}
+
+/**
+ * A small, horizontal composable for displaying a single price point.
+ */
+@Composable
+private fun PriceItem(
+    icon: ImageVector,
+    label: String,
+    price: Double,
+    contentDescription: String,
+    modifier: Modifier = Modifier
+) {
+    Row(
+        modifier = modifier,
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Icon(
+            imageVector = icon,
+            contentDescription = contentDescription,
+            // Smaller icon for a more compact look
+            modifier = Modifier.size(16.dp),
+            tint = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        Spacer(modifier = Modifier.width(4.dp))
+        Text(
+            text = label,
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        Spacer(modifier = Modifier.width(4.dp))
+        Text(
+            text = "$${roundToAtMost(price, 3)}",
+            style = MaterialTheme.typography.bodyMedium,
+            fontWeight = FontWeight.SemiBold
+        )
+    }
+}
+
+@Composable
+private fun ExpandArrowIcon(
+    expanded: Boolean
+) {
+    val rotation by animateFloatAsState(
+        targetValue = if (expanded) -180f else 0f,
+        animationSpec = tween(),
+        label = "Arrow rotation animation"
+    )
+
+    Icon(
+        imageVector = Icons.Default.KeyboardArrowDown,
+        contentDescription = stringResource(R.string.model_card_toggle_icon_description),
+        modifier = Modifier
+            .size(16.dp)
+            .rotate(rotation),
+        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+    )
+}
+
+fun roundToAtMost(number: Double, n: Int): String { // TODO localize
+    // Create a pattern with 'n' optional decimal places
+    // For n=3, pattern is "#.###"
+    // For n=0, pattern is "#"
+    val pattern = if (n > 0) "#." + "#".repeat(n) else "#"
+
+    val df = DecimalFormat(pattern)
+    df.roundingMode = RoundingMode.HALF_UP // Or choose another rounding mode
+    return df.format(number)
+}

app/src/main/java/eu/m724/chatapp/activity/main/MainActivity.kt

@@ -0,0 +1,99 @@
+package eu.m724.chatapp.activity.main
+
+import android.content.Intent
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
+import androidx.compose.animation.animateContentSize
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.Button
+import androidx.compose.material3.LinearProgressIndicator
+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.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.lifecycle.viewmodel.compose.viewModel
+import dagger.hilt.android.AndroidEntryPoint
+import eu.m724.chatapp.R
+import eu.m724.chatapp.activity.chat.ChatActivity
+import eu.m724.chatapp.activity.ui.theme.ChatAppTheme
+
+@AndroidEntryPoint
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
+        setContent {
+            ChatAppTheme {
+                Scaffold(
+                    modifier = Modifier.fillMaxSize()
+                ) { innerPadding ->
+                    Content(
+                        modifier = Modifier
+                            .fillMaxSize()
+                            .padding(innerPadding)
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun Content(
+    modifier: Modifier = Modifier,
+    viewModel: MainActivityViewModel = viewModel()
+) {
+    val uiState by viewModel.uiState.collectAsState()
+    val context = LocalContext.current
+
+    LaunchedEffect(Unit) {
+        viewModel.uiEvents.collect { event ->
+            when (event) {
+                is MainActivityUiEvent.StartChat -> {
+                    val intent = Intent(context, ChatActivity::class.java).apply {
+                        putExtra("chat", event.chat)
+                    }
+
+                    context.startActivity(intent)
+                }
+            }
+        }
+    }
+
+    Column(
+        modifier = modifier,
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.SpaceEvenly
+    ) {
+        Text(
+            text = stringResource(R.string.welcome)
+        )
+
+        Button(
+            modifier = Modifier.animateContentSize(),
+            onClick = {
+                viewModel.startConversation()
+            },
+            enabled = !uiState.loading
+        ) {
+            if (uiState.loading) {
+                LinearProgressIndicator()
+            } else {
+                Text(
+                    text = stringResource(R.string.start_new_conversation)
+                )
+            }
+        }
+    }
+}

app/src/main/java/eu/m724/chatapp/activity/main/MainActivityUiEvent.kt

@@ -0,0 +1,9 @@
+package eu.m724.chatapp.activity.main
+
+import eu.m724.chatapp.chat.Chat
+
+sealed interface MainActivityUiEvent {
+    data class StartChat(
+        val chat: Chat,
+    ): MainActivityUiEvent
+}

app/src/main/java/eu/m724/chatapp/activity/main/MainActivityUiState.kt

@@ -0,0 +1,5 @@
+package eu.m724.chatapp.activity.main
+
+data class MainActivityUiState(
+    val loading: Boolean = false
+)

app/src/main/java/eu/m724/chatapp/activity/main/MainActivityViewModel.kt

@@ -0,0 +1,49 @@
+package eu.m724.chatapp.activity.main
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import eu.m724.chatapp.api.AiApiService
+import eu.m724.chatapp.chat.Chat
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+@HiltViewModel
+class MainActivityViewModel @Inject constructor(
+    val aiApiService: AiApiService
+) : ViewModel() {
+    private val _uiState = MutableStateFlow(MainActivityUiState())
+    val uiState: StateFlow<MainActivityUiState> = _uiState.asStateFlow()
+
+    private val _uiEvents = Channel<MainActivityUiEvent>()
+    val uiEvents = _uiEvents.receiveAsFlow()
+
+    fun startConversation() {
+        _uiState.update {
+            it.copy(
+                loading = true
+            )
+        }
+
+        viewModelScope.launch {
+            val modelsResponse = aiApiService.getModels()
+            val models = modelsResponse.body()!!.data
+            val model = models.find { it.id == "meta-llama/llama-3.2-3b-instruct" }
+            println(models)
+
+            val chat = Chat(
+                title = null,
+                model = model!!,
+                messages = emptyList()
+            )
+
+            _uiEvents.send(MainActivityUiEvent.StartChat(chat))
+        }
+    }
+}

app/src/main/java/eu/m724/chatapp/activity/select/SelectModelActivity.kt

@@ -1,352 +0,0 @@
-package eu.m724.chatapp.activity.select
-
-import android.os.Bundle
-import androidx.activity.ComponentActivity
-import androidx.activity.compose.setContent
-import androidx.activity.enableEdgeToEdge
-import androidx.activity.viewModels
-import androidx.compose.animation.AnimatedVisibility
-import androidx.compose.animation.animateContentSize
-import androidx.compose.animation.core.animateFloatAsState
-import androidx.compose.animation.core.tween
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.PaddingValues
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.defaultMinSize
-import androidx.compose.foundation.layout.fillMaxHeight
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.lazy.LazyColumn
-import androidx.compose.material3.Scaffold
-import androidx.compose.material3.Text
-import androidx.compose.runtime.getValue
-import androidx.compose.ui.Modifier
-import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import dagger.hilt.android.AndroidEntryPoint
-import eu.m724.chatapp.activity.ui.theme.ChatAppTheme
-import androidx.compose.foundation.lazy.items
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.AccountCircle
-import androidx.compose.material.icons.filled.ArrowBack
-import androidx.compose.material.icons.filled.Close
-import androidx.compose.material.icons.filled.KeyboardArrowDown
-import androidx.compose.material.icons.filled.KeyboardArrowUp
-import androidx.compose.material.icons.filled.Search
-import androidx.compose.material3.Card
-import androidx.compose.material3.ExperimentalMaterial3Api
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.TextButton
-import androidx.compose.material3.TextField
-import androidx.compose.material3.TextFieldDefaults
-import androidx.compose.material3.TopAppBar
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.draw.rotate
-import androidx.compose.ui.focus.FocusRequester
-import androidx.compose.ui.focus.focusRequester
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.text.style.TextOverflow
-import androidx.compose.ui.unit.dp
-import eu.m724.chatapp.api.data.response.models.LanguageModel
-import java.math.RoundingMode
-import java.text.DecimalFormat
-
-@AndroidEntryPoint
-class SelectModelActivity : ComponentActivity() {
-    private val viewModel: SelectModelViewModel by viewModels()
-
-    @OptIn(ExperimentalMaterial3Api::class)
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-
-        viewModel.getModels()
-
-        enableEdgeToEdge()
-        setContent {
-            ChatAppTheme {
-                Scaffold(
-                    modifier = Modifier.fillMaxSize(),
-                    topBar = {
-                        var searching by remember { mutableStateOf(false) }
-                        var searchQuery by remember { mutableStateOf("") }
-
-                        TopAppBar(
-                            title = {
-                                Text(
-                                    text = "Model picker",
-                                    maxLines = 1
-                                )
-                            },
-                            navigationIcon = {
-                                // TODO animate this
-                                if (!searching) {
-                                    IconButton(
-                                        onClick = {
-                                            // TODO call callback here or whatever
-                                        }
-                                    ) {
-                                        Icon(
-                                            imageVector = Icons.Default.ArrowBack,
-                                            contentDescription = "Exit model picker"
-                                        )
-                                    }
-                                } else {
-                                    IconButton(
-                                        onClick = {
-                                            searching = false
-                                        }
-                                    ) {
-                                        Icon(
-                                            imageVector = Icons.Default.Close,
-                                            contentDescription = "Exit search"
-                                        )
-                                    }
-                                }
-                            },
-                            actions = {
-                                Row(
-                                    modifier = Modifier.animateContentSize(),
-                                    verticalAlignment = Alignment.CenterVertically
-                                ) {
-                                    val focusRequester = remember { FocusRequester() }
-
-                                    TextField(
-                                        value = searchQuery,
-                                        onValueChange = {
-                                            searchQuery = it
-                                        }, // TODO cal here too search or something
-                                        modifier = Modifier.fillMaxWidth(
-                                            if (searching) 1f else 0f
-                                        ).padding(start = 64.dp, end = 64.dp).focusRequester(focusRequester),
-                                        singleLine = true,
-                                        placeholder = {
-                                            Text("Search for a model...")
-                                        },
-                                        colors = TextFieldDefaults.colors(
-                                            unfocusedContainerColor = Color.Transparent,
-                                            focusedContainerColor = Color.Transparent,
-                                            focusedIndicatorColor = Color.Transparent
-                                        )
-                                    )
-
-                                    IconButton(
-                                        onClick = {
-                                            searching = !searching
-                                            if (searching) {
-                                                focusRequester.requestFocus()
-                                            }
-                                        }
-                                    ) {
-                                        Icon(
-                                            imageVector = Icons.Default.Search,
-                                            contentDescription = "Search"
-                                        )
-                                    }
-                                }
-                            }
-                        )
-                    }
-                ) { innerPadding ->
-                    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
-
-                    LazyColumn(
-                        modifier = Modifier.padding(innerPadding)
-                    ) {
-                        items(uiState.models) { model ->
-                            ModelCard(model)
-                        }
-                    }
-                }
-            }
-        }
-    }
-}
-
-@Composable
-fun ModelCard(
-    model: LanguageModel,
-    modifier: Modifier = Modifier,
-    onSelected: () -> Unit = {},
-) {
-    var expanded by remember { mutableStateOf(false) }
-
-    Card(
-        modifier = modifier
-            .fillMaxWidth()
-            .padding(horizontal = 16.dp, vertical = 8.dp),
-        onClick = {
-            expanded = !expanded
-        }
-    ) {
-        Column(
-            modifier = Modifier.padding(start = 16.dp, end = 16.dp, top = 16.dp, bottom = 12.dp)
-        ) {
-            Row(
-                modifier = Modifier.fillMaxWidth()
-            ) {
-                Column {
-                    Icon(
-                        imageVector = Icons.Default.AccountCircle,
-                        contentDescription = "Icon for ${model.name}",
-                        modifier = Modifier.size(48.dp).fillMaxHeight(),
-                        tint = MaterialTheme.colorScheme.primary
-                    )
-
-                    // TODO this button is awkward
-                    AnimatedVisibility(expanded) {
-                        TextButton(
-                            onClick = onSelected,
-                            contentPadding = PaddingValues(horizontal = 0.dp),
-                            modifier = Modifier.defaultMinSize(minWidth = 1.dp, minHeight = 1.dp).width(48.dp)
-                        ) {
-                            Text(
-                                text = "Select"
-                            )
-                        }
-                    }
-                }
-
-                Spacer(modifier = Modifier.width(16.dp))
-
-                Column(
-                    modifier = Modifier.weight(1f)
-                ) {
-                    Row(
-                        modifier = Modifier.fillMaxWidth(),
-                        horizontalArrangement = Arrangement.SpaceBetween
-                    ) {
-                        Text(
-                            text = model.name,
-                            style = MaterialTheme.typography.titleLarge,
-                        )
-
-                        ExpandArrowIcon(
-                            expanded = expanded
-                        )
-                    }
-
-                    if (model.description != null) {
-                        Spacer(modifier = Modifier.height(4.dp))
-                        Text(
-                            text = model.description,
-                            modifier = Modifier.animateContentSize(),
-                            style = MaterialTheme.typography.bodyMedium,
-                            color = MaterialTheme.colorScheme.onSurfaceVariant,
-                            overflow = TextOverflow.Ellipsis,
-                            maxLines = if (expanded) Int.MAX_VALUE else 1
-                        )
-                    }
-                }
-            }
-
-            Spacer(modifier = Modifier.height(12.dp))
-
-            Row(
-                modifier = Modifier.fillMaxWidth(),
-                verticalAlignment = Alignment.CenterVertically
-            ) {
-                PriceItem(
-                    icon = Icons.Default.KeyboardArrowUp,
-                    label = "Input:",
-                    price = model.pricing.pricePerMillionInputTokens,
-                    contentDescription = "Price per million input tokens"
-                )
-
-                Spacer(modifier = Modifier.width(12.dp))
-
-                PriceItem(
-                    icon = Icons.Default.KeyboardArrowDown,
-                    label = "Output:",
-                    price = model.pricing.pricePerMillionOutputTokens,
-                    contentDescription = "Price per million output tokens"
-                )
-
-                Spacer(modifier = Modifier.weight(1f))
-
-                Text(
-                    text = "/ 1M tokens",
-                    style = MaterialTheme.typography.labelMedium,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant
-                )
-            }
-        }
-    }
-}
-
-/**
- * A small, horizontal composable for displaying a single price point.
- */
-@Composable
-private fun PriceItem(
-    icon: androidx.compose.ui.graphics.vector.ImageVector,
-    label: String,
-    price: Double,
-    contentDescription: String,
-    modifier: Modifier = Modifier
-) {
-    Row(
-        modifier = modifier,
-        verticalAlignment = Alignment.CenterVertically
-    ) {
-        Icon(
-            imageVector = icon,
-            contentDescription = contentDescription,
-            // Smaller icon for a more compact look
-            modifier = Modifier.size(16.dp),
-            tint = MaterialTheme.colorScheme.onSurfaceVariant
-        )
-        Spacer(modifier = Modifier.width(4.dp))
-        Text(
-            text = label,
-            style = MaterialTheme.typography.bodySmall,
-            color = MaterialTheme.colorScheme.onSurfaceVariant
-        )
-        Spacer(modifier = Modifier.width(4.dp))
-        Text(
-            text = "$${roundToAtMost(price, 3)}",
-            style = MaterialTheme.typography.bodyMedium,
-            fontWeight = FontWeight.SemiBold
-        )
-    }
-}
-
-@Composable
-private fun ExpandArrowIcon(
-    expanded: Boolean
-) {
-    val rotation by animateFloatAsState(
-        targetValue = if (expanded) -180f else 0f,
-        animationSpec = tween(),
-        label = "Arrow rotation animation"
-    )
-
-    Icon(
-        imageVector = Icons.Default.KeyboardArrowDown,
-        contentDescription = "Toggle details",
-        modifier = Modifier.size(16.dp).rotate(rotation),
-        tint = MaterialTheme.colorScheme.onSurfaceVariant,
-    )
-}
-
-fun roundToAtMost(number: Double, n: Int): String {
-    // Create a pattern with 'n' optional decimal places
-    // For n=3, pattern is "#.###"
-    // For n=0, pattern is "#"
-    val pattern = if (n > 0) "#." + "#".repeat(n) else "#"
-
-    val df = DecimalFormat(pattern)
-    df.roundingMode = RoundingMode.HALF_UP // Or choose another rounding mode
-    return df.format(number)
-}

app/src/main/java/eu/m724/chatapp/activity/select/SelectModelUiState.kt

@@ -1,7 +0,0 @@
-package eu.m724.chatapp.activity.select
-
-import eu.m724.chatapp.api.data.response.models.LanguageModel
-
-data class SelectModelUiState(
-    val models: List<LanguageModel> = listOf()
-)

app/src/main/java/eu/m724/chatapp/activity/select/SelectModelViewModel.kt

@@ -1,42 +0,0 @@
-package eu.m724.chatapp.activity.select
-
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.viewModelScope
-import dagger.hilt.android.lifecycle.HiltViewModel
-import eu.m724.chatapp.api.AiApiService
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.asStateFlow
-import kotlinx.coroutines.flow.update
-import kotlinx.coroutines.launch
-import javax.inject.Inject
-
-@HiltViewModel
-class SelectModelViewModel @Inject constructor(
-    private val aiApiService: AiApiService
-) : ViewModel() {
-    private val _uiState = MutableStateFlow(SelectModelUiState())
-    val uiState: StateFlow<SelectModelUiState> = _uiState.asStateFlow()
-
-    fun getModels() {
-        viewModelScope.launch {
-            val models = aiApiService.getModels()
-
-            if (!models.isSuccessful) {
-                // TODO fail
-                return@launch
-            }
-
-            val languageModels = models.body()?.data
-
-            if (languageModels == null) {
-                // TODO fail too
-                return@launch
-            }
-
-            _uiState.update {
-                it.copy(models = languageModels)
-            }
-        }
-    }
-}

app/src/main/java/eu/m724/chatapp/api/data/response/completion/ChatMessage.kt

@@ -1,11 +1,14 @@
 package eu.m724.chatapp.api.data.response.completion
 
+import android.os.Parcelable
 import com.google.gson.annotations.SerializedName
+import kotlinx.parcelize.Parcelize
 
+@Parcelize
 data class ChatMessage(
     val role: Role,
     val content: String
-) {
+) : Parcelable {
     enum class Role {
         @SerializedName("system")
         System,

app/src/main/java/eu/m724/chatapp/api/data/response/models/LanguageModel.kt

@@ -0,0 +1,60 @@
+package eu.m724.chatapp.api.data.response.models
+
+import android.os.Parcelable
+import com.google.gson.annotations.SerializedName
+import kotlinx.parcelize.Parcelize
+
+/**
+ * Represents a language model.
+ */
+@Parcelize
+data class LanguageModel(
+    /**
+     * The ID of this model.
+     */
+    val id: String,
+
+    /**
+     * The readable name of this model.
+     */
+    val name: String,
+
+    /**
+     * The description of this model. TODO make it null if it equals model name
+     */
+    val description: String?,
+
+    /**
+     * The maximum amount of tokens this model can handle in one sitting.
+     */
+    @SerializedName("context_length")
+    val contextLength: Int,
+
+    /**
+     * The pricing of this model
+     */
+    val pricing: LanguageModelPricing
+) : Parcelable
+
+/**
+ * Represents the pricing of a language model.
+ */
+@Parcelize
+data class LanguageModelPricing(
+    /**
+     * The price per million input tokens
+     */
+    @SerializedName("prompt")
+    val pricePerMillionInputTokens: Double,
+
+    /**
+     * The price per million output tokens
+     */
+    @SerializedName("completion")
+    val pricePerMillionOutputTokens: Double,
+
+    /**
+     * Currency, as a code, like USD
+     */
+    val currency: String
+) : Parcelable

app/src/main/java/eu/m724/chatapp/api/data/response/models/LanguageModelsResponse.kt

@@ -1,54 +1,5 @@
 package eu.m724.chatapp.api.data.response.models
 
-import com.google.gson.annotations.SerializedName
-
 data class LanguageModelsResponse(
     val data: List<LanguageModel>
-)
-
-data class LanguageModel(
-    /**
-     * The ID of this model.
-     */
-    val id: String,
-
-    /**
-     * The readable name of this model.
-     */
-    val name: String,
-
-    /**
-     * The description of this model. TODO make it null if it equals model name
-     */
-    val description: String?,
-
-    /**
-     * The maximum amount of tokens this model can handle in one sitting.
-     */
-    @SerializedName("context_length")
-    val contextLength: Int,
-
-    /**
-     * The pricing of this model
-     */
-    val pricing: LanguageModelPricing
-)
-
-data class LanguageModelPricing(
-    /**
-     * The price per million input tokens
-     */
-    @SerializedName("prompt")
-    val pricePerMillionInputTokens: Double,
-
-    /**
-     * The price per million output tokens
-     */
-    @SerializedName("completion")
-    val pricePerMillionOutputTokens: Double,
-
-    /**
-     * Currency, as a code, like USD
-     */
-    val currency: String
 )

app/src/main/java/eu/m724/chatapp/chat/Chat.kt

@@ -0,0 +1,24 @@
+package eu.m724.chatapp.chat
+
+import android.os.Parcelable
+import eu.m724.chatapp.api.data.response.completion.ChatMessage
+import eu.m724.chatapp.api.data.response.models.LanguageModel
+import kotlinx.parcelize.Parcelize
+
+@Parcelize
+data class Chat(
+    /**
+     * The title of this chat.
+     */
+    val title: String?,
+
+    /**
+     * The model used in this chat.
+     */
+    val model: LanguageModel,
+
+    /**
+     * The messages in this chat.
+     */
+    val messages: List<ChatMessage>
+) : Parcelable

app/src/main/java/eu/m724/chatapp/chat/ChatResponseError.kt

@@ -1,4 +1,4 @@
-package eu.m724.chatapp.activity.chat.state
+package eu.m724.chatapp.chat
 
 sealed interface ChatResponseError { // TODO does this belong here?
     data object LengthLimit: ChatResponseError

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

@@ -8,4 +8,17 @@
     <string name="response_error_length_limit">Too long</string>
     <string name="response_error_generic">Fatal error</string>
     <string name="ai_mistake_warning">AI can make mistakes, double-check.</string>
+    <string name="button_settings_icon_description">Settings</string>
+    <string name="title_activity_main">MainActivity</string>
+    <string name="quick_settings_select_model">Select model</string>
+    <string name="model_card_select">Select</string>
+    <string name="model_card_icon_description">Icon for %1$s</string>
+    <string name="model_card_price_million_input_icon_description">Price per million input tokens</string>
+    <string name="model_card_price_million_output_icon_description">Price per million output tokens</string>
+    <string name="model_card_price_input">Input:</string>
+    <string name="model_card_price_output">Output:</string>
+    <string name="model_card_price_million_tokens">/ 1M tokens</string>
+    <string name="model_card_toggle_icon_description">Toggle details</string>
+    <string name="welcome">Welcome to ChatApp!</string>
+    <string name="start_new_conversation">Start a new conversation</string>
 </resources>

build.gradle.kts

@@ -6,4 +6,5 @@ plugins {
     alias(libs.plugins.hilt.android) apply false
     alias(libs.plugins.ksp) apply false
     alias(libs.plugins.secrets) apply false
+    alias(libs.plugins.parcelize) apply false
 }

gradle/libs.versions.toml

@@ -17,6 +17,8 @@ secrets = "2.0.1"
 loggingInterceptor = "4.12.0"
 material3WindowSizeClass = "1.3.2"
 okhttpSse = "4.12.0"
+navigationCompose = "2.9.0"
+parcelize = "2.1.21"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -42,6 +44,7 @@ retrofit-converter-gson = { group = "com.squareup.retrofit2", name = "converter-
 logging-interceptor = { group = "com.squareup.okhttp3", name = "logging-interceptor", version.ref = "loggingInterceptor" }
 androidx-material3-window-size-class1 = { group = "androidx.compose.material3", name = "material3-window-size-class", version.ref = "material3WindowSizeClass" }
 okhttp-sse = { group = "com.squareup.okhttp3", name = "okhttp-sse", version.ref = "okhttpSse" }
+androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
@@ -49,4 +52,5 @@ kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
 kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
 hilt-android = { id = "com.google.dagger.hilt.android", version.ref = "hilt" }
 ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }
-secrets = { id = "com.google.android.libraries.mapsplatform.secrets-gradle-plugin", version.ref = "secrets" }
+secrets = { id = "com.google.android.libraries.mapsplatform.secrets-gradle-plugin", version.ref = "secrets" }
+parcelize = { id = "org.jetbrains.kotlin.plugin.parcelize", version.ref = "parcelize" }