face detection + multi faces check

filtering before crop prompt - do we need to have user crop photos with only one face?

app/build.gradle.kts

@@ -72,4 +72,10 @@ dependencies {
 
     // Coil Images
     implementation(libs.coil.compose)
+
+    // ML Kit
+    implementation(libs.mlkit.face.detection)
+    implementation(libs.kotlinx.coroutines.play.services)
+
+
 }

app/src/main/java/com/placeholder/sherpai2/ui/navigation/AppNavHost.kt

@@ -1,8 +1,10 @@
 package com.placeholder.sherpai2.ui.navigation
 
+import android.net.Uri
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.ViewModel
 import androidx.navigation.NavHostController
 import androidx.navigation.NavType
 import androidx.navigation.compose.NavHost
@@ -16,6 +18,19 @@ import java.net.URLDecoder
 import java.net.URLEncoder
 import com.placeholder.sherpai2.ui.tour.TourViewModel
 import com.placeholder.sherpai2.ui.tour.TourScreen
+import com.placeholder.sherpai2.ui.trainingprep.ImageSelectorScreen
+import com.placeholder.sherpai2.ui.trainingprep.TrainingScreen
+import com.placeholder.sherpai2.ui.navigation.AppRoutes
+import com.placeholder.sherpai2.ui.navigation.AppRoutes.ScanResultsScreen
+import com.placeholder.sherpai2.ui.trainingprep.ScanningState
+import com.placeholder.sherpai2.ui.trainingprep.TrainViewModel
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import com.placeholder.sherpai2.ui.trainingprep.ScanResultsScreen
+
+
+
 @Composable
 fun AppNavHost(
     navController: NavHostController,
@@ -71,13 +86,60 @@ fun AppNavHost(
             )
         }
 
+        /** TRAINING FLOW **/
+        composable(AppRoutes.TRAIN) { entry ->
+            val trainViewModel: TrainViewModel = hiltViewModel()
+            val uiState by trainViewModel.uiState.collectAsState()
+
+            // Observe the result from the ImageSelector
+            val selectedUris = entry.savedStateHandle.get<List<Uri>>("selected_image_uris")
+
+            // If we have new URIs and we are currently Idle, start scanning
+            LaunchedEffect(selectedUris) {
+                if (selectedUris != null && uiState is ScanningState.Idle) {
+                    trainViewModel.scanAndTagFaces(selectedUris)
+                    // Clear the handle so it doesn't re-trigger on configuration change
+                    entry.savedStateHandle.remove<List<Uri>>("selected_image_uris")
+                }
+            }
+
+            if (uiState is ScanningState.Idle) {
+                // Initial state: Show start button or prompt
+                TrainingScreen(
+                    onSelectImages = { navController.navigate(AppRoutes.IMAGE_SELECTOR) }
+                )
+            } else {
+                // Processing or Success state: Show the results screen
+                ScanResultsScreen(
+                    state = uiState,
+                    onFinish = {
+                        navController.navigate(AppRoutes.SEARCH) {
+                            popUpTo(AppRoutes.TRAIN) { inclusive = true }
+                        }
+                    }
+                )
+            }
+        }
+
+        composable(AppRoutes.IMAGE_SELECTOR) {
+            ImageSelectorScreen(
+                onImagesSelected = { uris ->
+                    navController.previousBackStackEntry
+                        ?.savedStateHandle
+                        ?.set("selected_image_uris", uris)
+
+                    navController.popBackStack()
+                }
+            )
+        }
+
         /** DUMMY SCREENS FOR OTHER DRAWER ITEMS **/
         //composable(AppRoutes.TOUR) { DummyScreen("Tour (stub)") }
         composable(AppRoutes.MODELS) { DummyScreen("Models (stub)") }
         composable(AppRoutes.INVENTORY) { DummyScreen("Inventory (stub)") }
-        composable(AppRoutes.TRAIN) { DummyScreen("Train (stub)") }
+        //composable(AppRoutes.TRAIN) { DummyScreen("Train (stub)") }
         composable(AppRoutes.TAGS) { DummyScreen("Tags (stub)") }
         composable(AppRoutes.UPLOAD) { DummyScreen("Upload (stub)") }
-        composable(AppRoutes.SETTINGS) { DummyScreen("Settings (stub)") }
+        composable(AppRoutes.SETTINGS) { DummyScreen("Settings (stub)") }        
     }
 }

app/src/main/java/com/placeholder/sherpai2/ui/navigation/AppRoutes.kt

@@ -20,4 +20,13 @@ object AppRoutes {
     const val UPLOAD = "upload"
     const val SETTINGS = "settings"
     const val IMAGE_DETAIL = "IMAGE_DETAIL"
+
+    const val CROP_SCREEN = "CROP_SCREEN"
+    const val IMAGE_SELECTOR = "Image Selection"
+    const val TRAINING_SCREEN = "TRAINING_SCREEN"
+
+    const val ScanResultsScreen = "First Scan Results"
+
+
+    //const val IMAGE_DETAIL = "IMAGE_DETAIL"
 }

app/src/main/java/com/placeholder/sherpai2/ui/presentation/AppDrawerContent.kt

@@ -7,7 +7,10 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.Label
+import androidx.compose.material.icons.automirrored.filled.List
 import androidx.compose.material.icons.filled.*
+import androidx.compose.material3.HorizontalDivider
 import com.placeholder.sherpai2.ui.navigation.AppRoutes
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -26,16 +29,20 @@ fun AppDrawerContent(
             modifier = Modifier.padding(16.dp)
         )
 
-        Divider(Modifier.fillMaxWidth(), thickness = DividerDefaults.Thickness)
+        HorizontalDivider(
+            Modifier.fillMaxWidth(),
+            thickness = DividerDefaults.Thickness,
+            color = DividerDefaults.color
+        )
 
         // Main drawer items
         val mainItems = listOf(
             Triple(AppRoutes.SEARCH, "Search", Icons.Default.Search),
             Triple(AppRoutes.TOUR, "Tour", Icons.Default.Place),
             Triple(AppRoutes.MODELS, "Models", Icons.Default.ModelTraining),
-            Triple(AppRoutes.INVENTORY, "Inventory", Icons.Default.List),
+            Triple(AppRoutes.INVENTORY, "Inventory", Icons.AutoMirrored.Filled.List),
             Triple(AppRoutes.TRAIN, "Train", Icons.Default.Train),
-            Triple(AppRoutes.TAGS, "Tags", Icons.Default.Label)
+            Triple(AppRoutes.TAGS, "Tags", Icons.AutoMirrored.Filled.Label)
         )
 
         Column(modifier = Modifier.padding(vertical = 8.dp)) {

app/src/main/java/com/placeholder/sherpai2/ui/tour/TourScreen.kt

@@ -15,8 +15,8 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import com.placeholder.sherpai2.data.local.model.ImageWithEverything
 
 @Composable
-fun TourScreen(viewModel: TourViewModel = hiltViewModel()) {
-    val images by viewModel.recentImages.collectAsState()
+fun TourScreen(tourViewModel: TourViewModel = hiltViewModel(), onImageClick: (String) -> Unit) {
+    val images by tourViewModel.recentImages.collectAsState()
 
     Column(modifier = Modifier.fillMaxSize()) {
         // Header with image count
@@ -42,11 +42,11 @@ fun TourScreen(viewModel: TourViewModel = hiltViewModel()) {
 fun ImageCard(image: ImageWithEverything) {
     Card(modifier = Modifier.fillMaxWidth(), elevation = CardDefaults.cardElevation(4.dp)) {
         Column(modifier = Modifier.padding(12.dp)) {
-            Text(text = image.imageUri, style = MaterialTheme.typography.bodyMedium)
+            Text(text = image.tags.toString(), style = MaterialTheme.typography.bodyMedium)
 
             // Tags row with placeholders if fewer than 3
             Row(modifier = Modifier.padding(top = 8.dp)) {
-                val tags = image.tags.map { it.name } // adjust depending on your entity
+                val tags = image.tags.map { it.tagId } // adjust depending on your entity
                 tags.forEach { tag ->
                     TagComposable(tag)
                 }

app/src/main/java/com/placeholder/sherpai2/ui/trainingprep/ImageSelectorScreen.kt

@@ -0,0 +1,130 @@
+package com.placeholder.sherpai2.ui.trainingprep
+
+import android.net.Uri
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.layout.*
+
+import androidx.compose.foundation.lazy.grid.GridCells
+import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.AddPhotoAlternate
+import androidx.compose.material.icons.filled.Close
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.unit.dp
+import androidx.compose.material3.Text
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.platform.LocalContext
+import coil.compose.AsyncImage
+import androidx.compose.foundation.lazy.grid.items
+
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ImageSelectorScreen(
+    onImagesSelected: (List<Uri>) -> Unit
+) {
+    //1. Persist state across configuration changes
+    var selectedUris by rememberSaveable { mutableStateOf<List<Uri>>(emptyList()) }
+    val context = LocalContext.current
+
+    val launcher = rememberLauncherForActivityResult(
+        ActivityResultContracts.OpenMultipleDocuments()
+    ) { uris ->
+        // 2. Take first 10 and try to persist permissions
+        val limitedUris = uris.take(10)
+        selectedUris = limitedUris
+    }
+
+    Scaffold(
+        topBar = { TopAppBar(title = { Text("Select Training Photos") }) }
+    ) { padding ->
+        Column(
+            modifier = Modifier
+                .padding(padding)
+                .padding(16.dp)
+                .fillMaxSize(),
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            OutlinedCard(
+                onClick = { launcher.launch(arrayOf("image/*")) },
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                Column(
+                    modifier = Modifier.padding(24.dp),
+                    horizontalAlignment = Alignment.CenterHorizontally
+                ) {
+                    Icon(Icons.Default.AddPhotoAlternate, contentDescription = null)
+                    Spacer(Modifier.height(8.dp))
+                    Text("Select up to 10 images of the person")
+                    Text(
+                        text = "${selectedUris.size} / 10 selected",
+                        style = MaterialTheme.typography.labelLarge,
+                        color = if (selectedUris.size == 10) MaterialTheme.colorScheme.error
+                        else if (selectedUris.isNotEmpty()) MaterialTheme.colorScheme.primary
+                        else MaterialTheme.colorScheme.outline
+                    )
+                }
+            }
+
+            // 3. Conditional rendering for empty state
+            if (selectedUris.isEmpty()) {
+                Box(Modifier
+                    .weight(1f)
+                    .fillMaxWidth(), contentAlignment = Alignment.Center) {
+                    Text("No images selected", style = MaterialTheme.typography.bodyMedium)
+                }
+            } else {
+                LazyVerticalGrid(
+                    columns = GridCells.Fixed(3),
+                    modifier = Modifier.weight(1f),
+                    contentPadding = PaddingValues(4.dp)
+                ) {
+                    items(selectedUris, key = { it.toString() }) { uri ->
+                        Box(modifier = Modifier.padding(4.dp)) {
+                            AsyncImage(
+                                model = uri,
+                                contentDescription = null,
+                                modifier = Modifier
+                                    .aspectRatio(1f)
+                                    .clip(RoundedCornerShape(8.dp)),
+                                contentScale = ContentScale.Crop
+                            )
+                            // 4. Ability to remove specific images
+                            Surface(
+                                onClick = { selectedUris = selectedUris - uri },
+                                modifier = Modifier
+                                    .align(Alignment.TopEnd)
+                                    .padding(4.dp),
+                                shape = CircleShape,
+                                color = MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.8f)
+                            ) {
+                                Icon(
+                                    Icons.Default.Close,
+                                    contentDescription = "Remove",
+                                    modifier = Modifier.size(16.dp)
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+
+            Button(
+                modifier = Modifier.fillMaxWidth(),
+                enabled = selectedUris.isNotEmpty(),
+                onClick = { onImagesSelected(selectedUris) }
+            ) {
+                Text("Start Face Detection")
+            }
+        }
+    }
+}

app/src/main/java/com/placeholder/sherpai2/ui/trainingprep/ScanResultsScreen.kt

@@ -0,0 +1,74 @@
+package com.placeholder.sherpai2.ui.trainingprep
+
+import android.net.Uri
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.*
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.unit.dp
+import coil.compose.rememberAsyncImagePainter
+
+@Composable
+fun ScanResultsScreen(
+    state: ScanningState,
+    onFinish: () -> Unit
+) {
+    Column(
+        modifier = Modifier.fillMaxSize().padding(16.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.Center
+    ) {
+        when (state) {
+            is ScanningState.Processing -> {
+                CircularProgressIndicator()
+                Spacer(Modifier.height(16.dp))
+                Text("Analyzing faces... ${state.current} / ${state.total}")
+            }
+            is ScanningState.Success -> {
+                Text(
+                    text = "Analysis Complete!",
+                    style = MaterialTheme.typography.headlineMedium
+                )
+
+                LazyColumn(modifier = Modifier.weight(1f).padding(vertical = 16.dp)) {
+                    items(state.results) { result ->
+                        Row(
+                            modifier = Modifier.fillMaxWidth().padding(8.dp),
+                            verticalAlignment = Alignment.CenterVertically
+                        ) {
+                            Image(
+                                painter = rememberAsyncImagePainter(result.uri),
+                                contentDescription = null,
+                                modifier = Modifier.size(60.dp).clip(RoundedCornerShape(8.dp)),
+                                contentScale = ContentScale.Crop
+                            )
+                            Spacer(Modifier.width(16.dp))
+                            Column {
+                                Text(if (result.faceCount > 0) "✅ Face Detected" else "❌ No Face")
+                                if (result.hasMultipleFaces) {
+                                    Text(
+                                        "⚠️ Multiple faces (${result.faceCount})",
+                                        color = MaterialTheme.colorScheme.error,
+                                        style = MaterialTheme.typography.bodySmall
+                                    )
+                                }
+                            }
+                        }
+                    }
+                }
+
+                Button(onClick = onFinish, modifier = Modifier.fillMaxWidth()) {
+                    Text("Done")
+                }
+            }
+            else -> {}
+        }
+    }
+}

app/src/main/java/com/placeholder/sherpai2/ui/trainingprep/TrainViewModel.kt

@@ -0,0 +1,107 @@
+package com.placeholder.sherpai2.ui.trainingprep
+
+import android.content.Context
+import android.net.Uri
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.google.mlkit.vision.common.InputImage
+import com.google.mlkit.vision.face.FaceDetection
+import com.google.mlkit.vision.face.FaceDetectorOptions
+import com.placeholder.sherpai2.domain.repository.ImageRepository
+import com.placeholder.sherpai2.domain.repository.TaggingRepository
+import dagger.hilt.android.lifecycle.HiltViewModel
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
+import kotlinx.coroutines.awaitAll
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Semaphore
+import kotlinx.coroutines.sync.withPermit
+import kotlinx.coroutines.tasks.await
+import kotlinx.coroutines.withContext
+import javax.inject.Inject
+
+sealed class ScanningState {
+    object Idle : ScanningState()
+    data class Processing(val current: Int, val total: Int) : ScanningState()
+    data class Success(val results: List<ScanResult>) : ScanningState()
+}
+
+data class ScanResult(
+    val uri: Uri,
+    val faceCount: Int,
+    val hasMultipleFaces: Boolean = faceCount > 1
+)
+
+@HiltViewModel
+class TrainViewModel @Inject constructor(
+    @ApplicationContext private val context: Context,
+    private val imageRepository: ImageRepository,
+    private val taggingRepository: TaggingRepository
+) : ViewModel() {
+
+    private val _uiState = MutableStateFlow<ScanningState>(ScanningState.Idle)
+    val uiState: StateFlow<ScanningState> = _uiState.asStateFlow()
+
+    private val semaphore = Semaphore(2)
+
+    fun scanAndTagFaces(uris: List<Uri>) = viewModelScope.launch {
+        val total = uris.size
+        _uiState.value = ScanningState.Processing(0, total)
+
+        val detector = FaceDetection.getClient(faceOptions())
+        val allImages = imageRepository.getAllImages().first()
+        val uriToIdMap = allImages.associate { it.image.imageUri to it.image.imageId }
+
+        var completedCount = 0
+
+        val scanResults = withContext(Dispatchers.Default) {
+            uris.map { uri ->
+                async {
+                    semaphore.withPermit {
+                        val faceCount = detectFaceCount(detector, uri)
+
+                        // Tagging logic
+                        if (faceCount > 0) {
+                            uriToIdMap[uri.toString()]?.let { id ->
+                                taggingRepository.addTagToImage(id, "face", "ML_KIT", 1.0f)
+                                if (faceCount > 1) {
+                                    taggingRepository.addTagToImage(id, "multiple_faces", "ML_KIT", 1.0f)
+                                }
+                            }
+                        }
+
+                        completedCount++
+                        _uiState.value = ScanningState.Processing(completedCount, total)
+
+                        ScanResult(uri, faceCount)
+                    }
+                }
+            }.awaitAll()
+        }
+
+        detector.close()
+        _uiState.value = ScanningState.Success(scanResults)
+    }
+
+    private suspend fun detectFaceCount(
+        detector: com.google.mlkit.vision.face.FaceDetector,
+        uri: Uri
+    ): Int = withContext(Dispatchers.IO) {
+        return@withContext try {
+            val image = InputImage.fromFilePath(context, uri)
+            val faces = detector.process(image).await()
+            faces.size // Returns actual count
+        } catch (e: Exception) {
+            0
+        }
+    }
+
+    private fun faceOptions() = FaceDetectorOptions.Builder()
+        .setPerformanceMode(FaceDetectorOptions.PERFORMANCE_MODE_FAST)
+        .build()
+}

app/src/main/java/com/placeholder/sherpai2/ui/trainingprep/TrainingScreen.kt

@@ -0,0 +1,31 @@
+package com.placeholder.sherpai2.ui.trainingprep
+
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.Button
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.hilt.lifecycle.viewmodel.compose.hiltViewModel
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun TrainingScreen(
+    onSelectImages: () -> Unit
+) {
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Training") }
+            )
+        }
+    ) { padding ->
+        Button(
+            modifier = Modifier.padding(padding),
+            onClick = onSelectImages
+        ) {
+            Text("Select Images")
+        }
+    }
+}