Merge pull request #2176 from vitorpamplona/claude/ai-post-writing-help-CDPPw

Add AI writing assistance with ML Kit integration

amethyst/build.gradle

@@ -338,6 +338,11 @@ dependencies {
     // Google services model the translate text
     playImplementation libs.google.mlkit.translate
 
+    // On-device AI writing assistance (Gemini Nano via AICore)
+    playImplementation libs.google.mlkit.genai.proofreading
+    playImplementation libs.google.mlkit.genai.prompt
+    playImplementation libs.google.mlkit.genai.rewriting
+
     // PushNotifications
     playImplementation platform(libs.firebase.bom)
     playImplementation libs.firebase.messaging

amethyst/src/fdroid/java/com/vitorpamplona/amethyst/service/ai/NoOpWritingAssistant.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.ai
+
+class NoOpWritingAssistant : WritingAssistant {
+    override suspend fun checkAvailability(): WritingAssistantStatus = WritingAssistantStatus.Unavailable
+
+    override suspend fun transform(
+        text: String,
+        tone: WritingTone,
+    ): WritingResult = WritingResult(text, text, tone)
+
+    override fun close() {}
+}

amethyst/src/fdroid/java/com/vitorpamplona/amethyst/service/ai/WritingAssistantFactory.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.ai
+
+import android.content.Context
+
+object WritingAssistantFactory {
+    @Suppress("UNUSED_PARAMETER")
+    fun create(context: Context): WritingAssistant = NoOpWritingAssistant()
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/model/UiSettings.kt

@@ -38,6 +38,7 @@ data class UiSettings(
     val dontAskForNotificationPermissions: Boolean = false,
     val featureSet: FeatureSetType = FeatureSetType.SIMPLIFIED,
     val gallerySet: ProfileGalleryType = ProfileGalleryType.CLASSIC,
+    val automaticallyProposeAiImprovements: BooleanType = BooleanType.ALWAYS,
 )
 
 enum class ThemeType(

amethyst/src/main/java/com/vitorpamplona/amethyst/model/UiSettingsFlow.kt

@@ -38,6 +38,7 @@ class UiSettingsFlow(
     val dontAskForNotificationPermissions: MutableStateFlow<Boolean> = MutableStateFlow(false),
     val featureSet: MutableStateFlow<FeatureSetType> = MutableStateFlow(FeatureSetType.SIMPLIFIED),
     val gallerySet: MutableStateFlow<ProfileGalleryType> = MutableStateFlow(ProfileGalleryType.CLASSIC),
+    val automaticallyProposeAiImprovements: MutableStateFlow<BooleanType> = MutableStateFlow(BooleanType.ALWAYS),
 ) {
     val listOfFlows: List<Flow<Any?>> =
         listOf<Flow<Any?>>(
@@ -52,6 +53,7 @@ class UiSettingsFlow(
             dontAskForNotificationPermissions,
             featureSet,
             gallerySet,
+            automaticallyProposeAiImprovements,
         )
 
     // emits at every change in any of the propertyes.
@@ -69,6 +71,7 @@ class UiSettingsFlow(
                 flows[8] as Boolean,
                 flows[9] as FeatureSetType,
                 flows[10] as ProfileGalleryType,
+                flows[11] as BooleanType,
             )
         }
 
@@ -85,6 +88,7 @@ class UiSettingsFlow(
             dontAskForNotificationPermissions.value,
             featureSet.value,
             gallerySet.value,
+            automaticallyProposeAiImprovements.value,
         )
 
     fun update(torSettings: UiSettings): Boolean {
@@ -134,6 +138,10 @@ class UiSettingsFlow(
             gallerySet.tryEmit(torSettings.gallerySet)
             any = true
         }
+        if (automaticallyProposeAiImprovements.value != torSettings.automaticallyProposeAiImprovements) {
+            automaticallyProposeAiImprovements.tryEmit(torSettings.automaticallyProposeAiImprovements)
+            any = true
+        }
 
         return any
     }
@@ -164,6 +172,7 @@ class UiSettingsFlow(
                 MutableStateFlow(uiSettings.dontAskForNotificationPermissions),
                 MutableStateFlow(uiSettings.featureSet),
                 MutableStateFlow(uiSettings.gallerySet),
+                MutableStateFlow(uiSettings.automaticallyProposeAiImprovements),
             )
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/model/preferences/UISharedPreferences.kt

@@ -102,6 +102,7 @@ class UiSharedPreferences(
         val UI_DONT_ASK_FOR_NOTIFICATION_PERMISSIONS = booleanPreferencesKey("ui.dont_ask_for_notification_permissions")
         val UI_FEATURE_SET = stringPreferencesKey("ui.feature_set")
         val UI_GALLERY_SET = stringPreferencesKey("ui.gallery_set")
+        val UI_PROPOSE_AI_IMPROVEMENTS = stringPreferencesKey("ui.propose_ai_improvements")
 
         suspend fun uiPreferences(context: Context): UiSettings? =
             try {
@@ -120,6 +121,7 @@ class UiSharedPreferences(
                     dontAskForNotificationPermissions = preferences[UI_DONT_ASK_FOR_NOTIFICATION_PERMISSIONS] ?: false,
                     featureSet = preferences[UI_FEATURE_SET]?.let { FeatureSetType.valueOf(it) } ?: FeatureSetType.SIMPLIFIED,
                     gallerySet = preferences[UI_GALLERY_SET]?.let { ProfileGalleryType.valueOf(it) } ?: ProfileGalleryType.CLASSIC,
+                    automaticallyProposeAiImprovements = preferences[UI_PROPOSE_AI_IMPROVEMENTS]?.let { BooleanType.valueOf(it) } ?: BooleanType.ALWAYS,
                 )
             } catch (e: Exception) {
                 if (e is CancellationException) throw e
@@ -155,6 +157,7 @@ class UiSharedPreferences(
                     preferences[UI_DONT_ASK_FOR_NOTIFICATION_PERMISSIONS] = sharedSettings.dontAskForNotificationPermissions
                     preferences[UI_FEATURE_SET] = sharedSettings.featureSet.name
                     preferences[UI_GALLERY_SET] = sharedSettings.gallerySet.name
+                    preferences[UI_PROPOSE_AI_IMPROVEMENTS] = sharedSettings.automaticallyProposeAiImprovements.name
                 }
             } catch (e: Exception) {
                 if (e is CancellationException) throw e

amethyst/src/main/java/com/vitorpamplona/amethyst/service/ai/MockWritingAssistant.kt

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.ai
+
+import kotlinx.coroutines.delay
+
+/**
+ * TODO: Remove before shipping. Debug-only mock for testing the AI writing help UI
+ * on devices without Gemini Nano / AICore support.
+ */
+class MockWritingAssistant : WritingAssistant {
+    override suspend fun checkAvailability(): WritingAssistantStatus = WritingAssistantStatus.Available
+
+    override suspend fun transform(
+        text: String,
+        tone: WritingTone,
+    ): WritingResult {
+        delay(800)
+
+        val transformed =
+            when (tone) {
+                WritingTone.CORRECT -> {
+                    correctMock(text)
+                }
+
+                WritingTone.REPHRASE -> {
+                    "Here's another way to put it: $text"
+                }
+
+                WritingTone.SHORTER -> {
+                    text
+                        .split(".")
+                        .firstOrNull()
+                        ?.trim()
+                        ?.plus(".") ?: text
+                }
+
+                WritingTone.ELABORATE -> {
+                    "$text Furthermore, this point deserves deeper consideration and nuance."
+                }
+
+                WritingTone.FRIENDLY -> {
+                    "Hey! $text Hope that makes sense! :)"
+                }
+
+                WritingTone.PROFESSIONAL -> {
+                    "I would like to bring to your attention the following: $text"
+                }
+
+                WritingTone.MORE_DIRECT -> {
+                    text.replace("I think ", "").replace("maybe ", "").replace("perhaps ", "")
+                }
+
+                WritingTone.PUNCHY -> {
+                    text.uppercase().replace(".", "!")
+                }
+
+                WritingTone.EMOJIFY -> {
+                    "$text \uD83D\uDE80\uD83D\uDD25\u2728"
+                }
+            }
+
+        return WritingResult(
+            originalText = text,
+            transformedText = transformed,
+            tone = tone,
+        )
+    }
+
+    private fun correctMock(text: String): String =
+        text
+            .replace("teh ", "the ")
+            .replace("dont ", "don't ")
+            .replace("cant ", "can't ")
+            .replace("wont ", "won't ")
+            .replace("i ", "I ")
+
+    override fun close() {}
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/service/ai/WritingAssistant.kt

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.ai
+
+import androidx.compose.runtime.Immutable
+
+interface WritingAssistant {
+    suspend fun checkAvailability(): WritingAssistantStatus
+
+    suspend fun transform(
+        text: String,
+        tone: WritingTone,
+    ): WritingResult
+
+    fun close()
+}
+
+enum class WritingTone {
+    CORRECT,
+    REPHRASE,
+    SHORTER,
+    ELABORATE,
+    FRIENDLY,
+    PROFESSIONAL,
+    MORE_DIRECT,
+    PUNCHY,
+    EMOJIFY,
+}
+
+sealed class WritingAssistantStatus {
+    data object Available : WritingAssistantStatus()
+
+    data object Unavailable : WritingAssistantStatus()
+
+    data object Downloading : WritingAssistantStatus()
+}
+
+@Immutable
+data class WritingResult(
+    val originalText: String,
+    val transformedText: String,
+    val tone: WritingTone,
+)

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/creators/aihelp/AiWritingHelpButton.kt

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.note.creators.aihelp
+
+import androidx.compose.foundation.layout.height
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.AutoAwesome
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.ui.stringRes
+
+@Composable
+fun AiWritingHelpButton(
+    isActive: Boolean,
+    onClick: () -> Unit,
+) {
+    IconButton(
+        onClick = { onClick() },
+    ) {
+        Icon(
+            imageVector = Icons.Outlined.AutoAwesome,
+            contentDescription = stringRes(R.string.ai_writing_help),
+            modifier = Modifier.height(22.dp),
+            tint =
+                if (isActive) {
+                    MaterialTheme.colorScheme.primary
+                } else {
+                    MaterialTheme.colorScheme.onBackground
+                },
+        )
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/creators/aihelp/AiWritingHelpPanel.kt

@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.note.creators.aihelp
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.expandVertically
+import androidx.compose.animation.shrinkVertically
+import androidx.compose.foundation.background
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.service.ai.WritingResult
+import com.vitorpamplona.amethyst.service.ai.WritingTone
+import com.vitorpamplona.amethyst.ui.stringRes
+
+@Composable
+fun AiWritingHelpPanel(
+    isVisible: Boolean,
+    readyResults: Map<WritingTone, WritingResult>,
+    selectedResult: WritingResult?,
+    onToneSelected: (WritingTone) -> Unit,
+    onApply: () -> Unit,
+    onDismiss: () -> Unit,
+) {
+    AnimatedVisibility(
+        visible = isVisible,
+        enter = expandVertically(),
+        exit = shrinkVertically(),
+    ) {
+        Column(
+            modifier =
+                Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 8.dp),
+        ) {
+            selectedResult?.let {
+                AiResultCard(
+                    result = it,
+                    onApply = onApply,
+                    onDismiss = onDismiss,
+                )
+            }
+
+            ToneChipRow(
+                readyTones = readyResults.keys,
+                selectedTone = selectedResult?.tone,
+                onToneSelected = onToneSelected,
+            )
+        }
+    }
+}
+
+@Composable
+private fun AiResultCard(
+    result: WritingResult,
+    onApply: () -> Unit,
+    onDismiss: () -> Unit,
+) {
+    Column(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(vertical = 4.dp)
+                .clip(RoundedCornerShape(12.dp))
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+                .padding(12.dp),
+    ) {
+        Text(
+            text = result.transformedText,
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier =
+                Modifier
+                    .fillMaxWidth()
+                    .heightIn(max = 150.dp)
+                    .verticalScroll(rememberScrollState()),
+        )
+
+        Row(
+            modifier =
+                Modifier
+                    .fillMaxWidth()
+                    .padding(top = 8.dp),
+            horizontalArrangement = Arrangement.End,
+        ) {
+            TextButton(onClick = onDismiss) {
+                Text(stringRes(R.string.ai_writing_dismiss))
+            }
+            OutlinedButton(onClick = onApply) {
+                Text(stringRes(R.string.ai_writing_use_this))
+            }
+        }
+    }
+}
+
+@Composable
+private fun ToneChipRow(
+    readyTones: Set<WritingTone>,
+    selectedTone: WritingTone?,
+    onToneSelected: (WritingTone) -> Unit,
+) {
+    val scrollState = rememberScrollState()
+    Row(
+        modifier =
+            Modifier
+                .horizontalScroll(scrollState)
+                .fillMaxWidth(),
+        horizontalArrangement = Arrangement.spacedBy(6.dp),
+    ) {
+        WritingTone.entries.forEach { tone ->
+            if (tone in readyTones) {
+                FilterChip(
+                    selected = tone == selectedTone,
+                    onClick = { onToneSelected(tone) },
+                    label = { Text(toneDisplayName(tone)) },
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun toneDisplayName(tone: WritingTone): String =
+    when (tone) {
+        WritingTone.CORRECT -> stringRes(R.string.ai_tone_correct)
+        WritingTone.REPHRASE -> stringRes(R.string.ai_tone_rephrase)
+        WritingTone.SHORTER -> stringRes(R.string.ai_tone_shorter)
+        WritingTone.ELABORATE -> stringRes(R.string.ai_tone_elaborate)
+        WritingTone.FRIENDLY -> stringRes(R.string.ai_tone_friendly)
+        WritingTone.PROFESSIONAL -> stringRes(R.string.ai_tone_professional)
+        WritingTone.MORE_DIRECT -> stringRes(R.string.ai_tone_more_direct)
+        WritingTone.PUNCHY -> stringRes(R.string.ai_tone_punchy)
+        WritingTone.EMOJIFY -> stringRes(R.string.ai_tone_emojify)
+    }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/ShortNotePostScreen.kt

@@ -82,6 +82,7 @@ import com.vitorpamplona.amethyst.ui.navigation.navs.Nav
 import com.vitorpamplona.amethyst.ui.navigation.topbars.PostingTopBar
 import com.vitorpamplona.amethyst.ui.note.BaseUserPicture
 import com.vitorpamplona.amethyst.ui.note.NoteCompose
+import com.vitorpamplona.amethyst.ui.note.creators.aihelp.AiWritingHelpPanel
 import com.vitorpamplona.amethyst.ui.note.creators.contentWarning.ContentSensitivityExplainer
 import com.vitorpamplona.amethyst.ui.note.creators.contentWarning.MarkAsSensitiveButton
 import com.vitorpamplona.amethyst.ui.note.creators.emojiSuggestions.ShowEmojiSuggestionList
@@ -144,6 +145,10 @@ fun ShortNotePostScreen(
     val context = LocalContext.current
     val activity = context.getActivity()
 
+    LaunchedEffect(Unit) {
+        postViewModel.initWritingAssistant(context)
+    }
+
     LaunchedEffect(postViewModel, accountViewModel) {
         val baseReplyTo = baseReplyToId?.let { accountViewModel.getNoteIfExists(it) }
         val quote = quoteId?.let { accountViewModel.getNoteIfExists(it) }
@@ -556,6 +561,15 @@ private fun NewPostScreenBody(
             )
         }
 
+        AiWritingHelpPanel(
+            isVisible = postViewModel.showAiPanel,
+            readyResults = postViewModel.aiResults,
+            selectedResult = postViewModel.aiSelectedResult,
+            onToneSelected = postViewModel::selectAiResult,
+            onApply = postViewModel::applyAiResult,
+            onDismiss = postViewModel::dismissAiResult,
+        )
+
         BottomRowActions(postViewModel)
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/ShortNotePostViewModel.kt

@@ -41,9 +41,16 @@ import com.vitorpamplona.amethyst.commons.compose.replaceCurrentWord
 import com.vitorpamplona.amethyst.commons.compose.setTextAndPlaceCursorAtBeginning
 import com.vitorpamplona.amethyst.commons.model.nip30CustomEmojis.EmojiPackState.EmojiMedia
 import com.vitorpamplona.amethyst.model.Account
+import com.vitorpamplona.amethyst.model.BooleanType
 import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.User
+import com.vitorpamplona.amethyst.service.ai.MockWritingAssistant
+import com.vitorpamplona.amethyst.service.ai.WritingAssistant
+import com.vitorpamplona.amethyst.service.ai.WritingAssistantFactory
+import com.vitorpamplona.amethyst.service.ai.WritingAssistantStatus
+import com.vitorpamplona.amethyst.service.ai.WritingResult
+import com.vitorpamplona.amethyst.service.ai.WritingTone
 import com.vitorpamplona.amethyst.service.location.LocationState
 import com.vitorpamplona.amethyst.service.uploads.CompressorQuality
 import com.vitorpamplona.amethyst.service.uploads.MediaCompressor
@@ -140,7 +147,13 @@ import com.vitorpamplona.quartz.utils.Log
 import com.vitorpamplona.quartz.utils.RandomInstance
 import com.vitorpamplona.quartz.utils.TimeUtils
 import kotlinx.collections.immutable.ImmutableList
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.async
+import kotlinx.coroutines.awaitAll
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.launch
@@ -291,6 +304,96 @@ open class ShortNotePostViewModel :
     // Anonymous Reply
     var wantsAnonymousPost by mutableStateOf(false)
 
+    // AI Writing Help for testing
+    private val useMockAi = false
+
+    var aiResults by mutableStateOf<Map<WritingTone, WritingResult>>(emptyMap())
+    var aiSelectedResult by mutableStateOf<WritingResult?>(null)
+    var aiStatus by mutableStateOf<WritingAssistantStatus>(WritingAssistantStatus.Unavailable)
+    private var writingAssistant: WritingAssistant? = null
+    private var aiComputeJob: Job? = null
+    private var lastComputedText: String = ""
+
+    val showAiPanel: Boolean
+        get() {
+            val prefEnabled =
+                accountViewModel.settings.uiSettingsFlow.automaticallyProposeAiImprovements.value ==
+                    BooleanType.ALWAYS
+            return prefEnabled && aiStatus is WritingAssistantStatus.Available && aiResults.isNotEmpty()
+        }
+
+    fun initWritingAssistant(context: android.content.Context) {
+        if (writingAssistant == null) {
+            writingAssistant =
+                if (useMockAi) {
+                    MockWritingAssistant()
+                } else {
+                    WritingAssistantFactory.create(context)
+                }
+            viewModelScope.launch(Dispatchers.IO) {
+                aiStatus = writingAssistant?.checkAvailability() ?: WritingAssistantStatus.Unavailable
+            }
+        }
+    }
+
+    fun precomputeAiResults() {
+        val assistant = writingAssistant ?: return
+        if (aiStatus !is WritingAssistantStatus.Available) return
+        val prefEnabled =
+            accountViewModel.settings.uiSettingsFlow.automaticallyProposeAiImprovements.value ==
+                BooleanType.ALWAYS
+        if (!prefEnabled) return
+
+        val text = message.text.toString().trim()
+        if (text.isBlank() || text == lastComputedText) return
+
+        aiComputeJob?.cancel()
+        aiResults = emptyMap()
+        aiSelectedResult = null
+
+        aiComputeJob =
+            viewModelScope.launch(Dispatchers.IO) {
+                delay(1000)
+                lastComputedText = text
+
+                val results =
+                    coroutineScope {
+                        WritingTone.entries
+                            .map { tone ->
+                                async {
+                                    try {
+                                        assistant.transform(text, tone)
+                                    } catch (e: Exception) {
+                                        if (e is CancellationException) throw e
+                                        null
+                                    }
+                                }
+                            }.awaitAll()
+                            .filterNotNull()
+                            .associateBy { it.tone }
+                    }
+                aiResults = results
+            }
+    }
+
+    fun selectAiResult(tone: WritingTone) {
+        aiSelectedResult = aiResults[tone]
+    }
+
+    fun applyAiResult() {
+        aiSelectedResult?.let {
+            message.setTextAndPlaceCursorAtEnd(it.transformedText)
+            aiSelectedResult = null
+            aiResults = emptyMap()
+            lastComputedText = ""
+            draftTag.newVersion()
+        }
+    }
+
+    fun dismissAiResult() {
+        aiSelectedResult = null
+    }
+
     fun lnAddress(): String? = account.userProfile().lnAddress()
 
     fun hasLnAddress(): Boolean = account.userProfile().lnAddress() != null
@@ -1131,6 +1234,7 @@ open class ShortNotePostViewModel :
             emojiSuggestions?.processCurrentWord(lastWord)
         }
 
+        precomputeAiResults()
         draftTag.newVersion()
     }
 
@@ -1372,6 +1476,8 @@ open class ShortNotePostViewModel :
 
     override fun onCleared() {
         super.onCleared()
+        writingAssistant?.close()
+        writingAssistant = null
         Log.d("Init") { "OnCleared: ${this.javaClass.simpleName}" }
     }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/settings/AppSettingsScreen.kt

@@ -121,6 +121,7 @@ fun SettingsScreen(sharedPrefs: UiSettingsFlow) {
         ImmersiveScrollingChoice(sharedPrefs)
         FeatureSetChoice(sharedPrefs)
         GalleryChoice(sharedPrefs)
+        AiWritingHelpChoice(sharedPrefs)
         PushNotificationSettingsRow(sharedPrefs)
     }
 }
@@ -366,6 +367,26 @@ fun GalleryChoice(sharedPrefs: UiSettingsFlow) {
     }
 }
 
+@Composable
+fun AiWritingHelpChoice(sharedPrefs: UiSettingsFlow) {
+    val aiIndex by sharedPrefs.automaticallyProposeAiImprovements.collectAsState()
+
+    val booleanItems =
+        persistentListOf(
+            TitleExplainer(stringRes(ConnectivityType.ALWAYS.resourceId)),
+            TitleExplainer(stringRes(ConnectivityType.NEVER.resourceId)),
+        )
+
+    SettingsRow(
+        R.string.ai_writing_setting_title,
+        R.string.ai_writing_setting_description,
+        booleanItems,
+        aiIndex.screenCode,
+    ) {
+        sharedPrefs.automaticallyProposeAiImprovements.tryEmit(parseBooleanType(it))
+    }
+}
+
 @Composable
 fun SettingsRow(
     name: Int,

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

@@ -2199,4 +2199,19 @@
     <string name="relay_members_removed">%1$d members removed from relay</string>
     <string name="relay_join_request">Relay join request</string>
     <string name="relay_leave_request">Relay leave request</string>
+
+    <string name="ai_writing_help">AI Writing Help</string>
+    <string name="ai_writing_setting_title">Propose text improvements</string>
+    <string name="ai_writing_setting_description">Uses an on-device AI model to propose text corrections and tone changes.</string>
+    <string name="ai_writing_use_this">Use This</string>
+    <string name="ai_writing_dismiss">Dismiss</string>
+    <string name="ai_tone_correct">Correct</string>
+    <string name="ai_tone_rephrase">Rephrase</string>
+    <string name="ai_tone_shorter">Shorter</string>
+    <string name="ai_tone_elaborate">Elaborate</string>
+    <string name="ai_tone_friendly">Friendly</string>
+    <string name="ai_tone_professional">Professional</string>
+    <string name="ai_tone_more_direct">More Direct</string>
+    <string name="ai_tone_punchy">Punchy</string>
+    <string name="ai_tone_emojify">+ Emoji</string>
 </resources>

amethyst/src/play/java/com/vitorpamplona/amethyst/service/ai/MLKitWritingAssistant.kt

@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.ai
+
+import android.content.Context
+import com.google.android.gms.tasks.Tasks
+import com.google.mlkit.genai.common.FeatureStatus
+import com.google.mlkit.genai.proofreading.Proofreader
+import com.google.mlkit.genai.proofreading.ProofreaderOptions
+import com.google.mlkit.genai.proofreading.Proofreading
+import com.google.mlkit.genai.proofreading.ProofreadingRequest
+import com.google.mlkit.genai.rewriting.Rewriter
+import com.google.mlkit.genai.rewriting.RewriterOptions
+import com.google.mlkit.genai.rewriting.Rewriting
+import com.google.mlkit.genai.rewriting.RewritingRequest
+import com.vitorpamplona.amethyst.service.lang.LanguageTranslatorService
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+class MLKitWritingAssistant(
+    private val context: Context,
+) : WritingAssistant {
+    private var rewriters = mutableMapOf<Long, Rewriter>()
+    private var proofreaders = mutableMapOf<Int, Proofreader>()
+
+    private fun rewriterCacheKey(
+        @RewriterOptions.OutputType outputType: Int,
+        @RewriterOptions.Language language: Int,
+    ): Long = (outputType.toLong() shl 32) or language.toLong()
+
+    private fun getRewriter(
+        @RewriterOptions.OutputType outputType: Int,
+        @RewriterOptions.Language language: Int,
+    ): Rewriter =
+        rewriters.getOrPut(rewriterCacheKey(outputType, language)) {
+            Rewriting.getClient(
+                RewriterOptions
+                    .builder(context)
+                    .setOutputType(outputType)
+                    .setLanguage(language)
+                    .build(),
+            )
+        }
+
+    private fun getProofreader(
+        @ProofreaderOptions.Language language: Int,
+    ): Proofreader =
+        proofreaders.getOrPut(language) {
+            Proofreading.getClient(
+                ProofreaderOptions
+                    .builder(context)
+                    .setInputType(ProofreaderOptions.InputType.KEYBOARD)
+                    .setLanguage(language)
+                    .build(),
+            )
+        }
+
+    override suspend fun checkAvailability(): WritingAssistantStatus =
+        withContext(Dispatchers.IO) {
+            try {
+                val rewriter = getRewriter(RewriterOptions.OutputType.REPHRASE, RewriterOptions.Language.ENGLISH)
+                val status = rewriter.checkFeatureStatus().get()
+                when (status) {
+                    FeatureStatus.AVAILABLE -> WritingAssistantStatus.Available
+                    FeatureStatus.DOWNLOADING -> WritingAssistantStatus.Downloading
+                    else -> WritingAssistantStatus.Unavailable
+                }
+            } catch (e: Exception) {
+                WritingAssistantStatus.Unavailable
+            }
+        }
+
+    override suspend fun transform(
+        text: String,
+        tone: WritingTone,
+    ): WritingResult {
+        val language = detectLanguage(text)
+        val transformedText =
+            when (tone) {
+                WritingTone.CORRECT -> proofread(text, language)
+                WritingTone.REPHRASE -> rewrite(text, RewriterOptions.OutputType.REPHRASE, language)
+                WritingTone.SHORTER -> rewrite(text, RewriterOptions.OutputType.SHORTEN, language)
+                WritingTone.ELABORATE -> rewrite(text, RewriterOptions.OutputType.ELABORATE, language)
+                WritingTone.FRIENDLY -> rewrite(text, RewriterOptions.OutputType.FRIENDLY, language)
+                WritingTone.PROFESSIONAL -> rewrite(text, RewriterOptions.OutputType.PROFESSIONAL, language)
+                WritingTone.EMOJIFY -> rewrite(text, RewriterOptions.OutputType.EMOJIFY, language)
+                WritingTone.MORE_DIRECT -> rewrite(text, RewriterOptions.OutputType.PROFESSIONAL, language)
+                WritingTone.PUNCHY -> rewrite(text, RewriterOptions.OutputType.SHORTEN, language)
+            }
+
+        return WritingResult(
+            originalText = text,
+            transformedText = transformedText,
+            tone = tone,
+        )
+    }
+
+    private suspend fun detectLanguage(text: String): Int =
+        withContext(Dispatchers.IO) {
+            try {
+                val langTag = Tasks.await(LanguageTranslatorService.identifyLanguage(text))
+                mapLanguageTag(langTag)
+            } catch (e: Exception) {
+                RewriterOptions.Language.ENGLISH
+            }
+        }
+
+    private suspend fun rewrite(
+        text: String,
+        @RewriterOptions.OutputType outputType: Int,
+        @RewriterOptions.Language language: Int,
+    ): String =
+        withContext(Dispatchers.IO) {
+            val rewriter = getRewriter(outputType, language)
+            val request = RewritingRequest.builder(text).build()
+            val result = rewriter.runInference(request).get()
+            result.results.firstOrNull()?.text ?: text
+        }
+
+    private suspend fun proofread(
+        text: String,
+        @ProofreaderOptions.Language language: Int,
+    ): String =
+        withContext(Dispatchers.IO) {
+            val proofreader = getProofreader(language)
+            val request = ProofreadingRequest.builder(text).build()
+            val result = proofreader.runInference(request).get()
+            result.results.firstOrNull()?.text ?: text
+        }
+
+    override fun close() {
+        rewriters.values.forEach { it.close() }
+        rewriters.clear()
+        proofreaders.values.forEach { it.close() }
+        proofreaders.clear()
+    }
+
+    companion object {
+        fun mapLanguageTag(tag: String?): Int =
+            when (tag?.lowercase()?.take(2)) {
+                "en" -> RewriterOptions.Language.ENGLISH
+                "ja" -> RewriterOptions.Language.JAPANESE
+                "ko" -> RewriterOptions.Language.KOREAN
+                "de" -> RewriterOptions.Language.GERMAN
+                "fr" -> RewriterOptions.Language.FRENCH
+                "it" -> RewriterOptions.Language.ITALIAN
+                "es" -> RewriterOptions.Language.SPANISH
+                else -> RewriterOptions.Language.ENGLISH
+            }
+    }
+}

amethyst/src/play/java/com/vitorpamplona/amethyst/service/ai/WritingAssistantFactory.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.ai
+
+import android.content.Context
+
+object WritingAssistantFactory {
+    fun create(context: Context): WritingAssistant = MLKitWritingAssistant(context)
+}

gradle/libs.versions.toml

@@ -30,6 +30,9 @@ kotlin = "2.3.20"
 kotlinxCollectionsImmutable = "0.4.0"
 kotlinxCoroutinesCore = "1.10.2"
 kotlinxSerialization = "1.10.0"
+genaiProofreading = "1.0.0-beta1"
+genaiPrompt = "1.0.0-beta2"
+genaiRewriting = "1.0.0-beta1"
 languageId = "17.0.6"
 lifecycleRuntimeKtx = "2.10.0"
 lightcompressor-enhanced = "1.8.1"
@@ -134,6 +137,9 @@ jetbrains-compose-runtime = { module = "org.jetbrains.compose.runtime:runtime",
 jetbrains-compose-ui = { module = "org.jetbrains.compose.ui:ui", version.ref = "jetbrainsCompose" }
 jetbrains-compose-ui-tooling = { module = "org.jetbrains.compose.ui:ui-tooling", version.ref = "jetbrainsCompose" }
 jetbrains-compose-ui-tooling-preview = { module = "org.jetbrains.compose.ui:ui-tooling-preview", version.ref = "jetbrainsCompose" }
+google-mlkit-genai-proofreading = { group = "com.google.mlkit", name = "genai-proofreading", version.ref = "genaiProofreading" }
+google-mlkit-genai-prompt = { group = "com.google.mlkit", name = "genai-prompt", version.ref = "genaiPrompt" }
+google-mlkit-genai-rewriting = { group = "com.google.mlkit", name = "genai-rewriting", version.ref = "genaiRewriting" }
 google-mlkit-language-id = { group = "com.google.mlkit", name = "language-id", version.ref = "languageId" }
 google-mlkit-translate = { group = "com.google.mlkit", name = "translate", version.ref = "translate" }
 jackson-module-kotlin = { group = "com.fasterxml.jackson.module", name = "jackson-module-kotlin", version.ref = "jacksonModuleKotlin" }