feat: Add simple scan feature

app/src/main/AndroidManifest.xml

@@ -305,6 +305,11 @@
             android:name=".features.scan.ContinuousScanActivity"
             android:screenOrientation="portrait"
             android:theme="@style/OFFTheme.NoActionBar" />
+        <activity
+            android:name=".features.simplescan.SimpleScanActivity"
+            android:screenOrientation="portrait"
+            android:theme="@style/OFFTheme.NoActionBar"
+            tools:ignore="LockedOrientationActivity" />
         <activity
             android:name=".features.product.edit.ProductEditActivity"
             android:screenOrientation="portrait"

app/src/main/java/openfoodfacts/github/scrachx/openfood/features/compare/ProductCompareActivity.kt

@@ -6,25 +6,27 @@ import android.content.Intent
 import android.content.SharedPreferences
 import android.content.pm.PackageManager.PERMISSION_GRANTED
 import android.os.Bundle
-import android.widget.Toast
 import androidx.activity.result.launch
 import androidx.activity.viewModels
 import androidx.core.app.ActivityCompat.shouldShowRequestPermissionRationale
 import androidx.core.content.ContextCompat.checkSelfPermission
-import androidx.lifecycle.Lifecycle
+import androidx.core.view.isVisible
+import androidx.lifecycle.flowWithLifecycle
 import androidx.lifecycle.lifecycleScope
-import androidx.lifecycle.repeatOnLifecycle
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.LinearLayoutManager.HORIZONTAL
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import com.squareup.picasso.Picasso
 import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.rx2.await
 import openfoodfacts.github.scrachx.openfood.R
 import openfoodfacts.github.scrachx.openfood.databinding.ActivityProductComparisonBinding
+import openfoodfacts.github.scrachx.openfood.features.compare.ProductCompareViewModel.SideEffect
 import openfoodfacts.github.scrachx.openfood.features.shared.BaseActivity
+import openfoodfacts.github.scrachx.openfood.features.simplescan.SimpleScanActivityContract
 import openfoodfacts.github.scrachx.openfood.images.ProductImage
 import openfoodfacts.github.scrachx.openfood.listeners.CommonBottomListenerInstaller.installBottomNavigation
 import openfoodfacts.github.scrachx.openfood.listeners.CommonBottomListenerInstaller.selectNavigationItem
@@ -48,8 +50,8 @@ class ProductCompareActivity : BaseActivity() {
 
     private val viewModel: ProductCompareViewModel by viewModels()
 
-    private val scanProductContract = registerForActivityResult(ScanProductActivityContract()) { product ->
-        product?.let { viewModel.addProductToCompare(it) }
+    private val scanProductContract = registerForActivityResult(SimpleScanActivityContract()) { barcode ->
+        barcode?.let { viewModel.barcodeDetected(it) }
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -67,18 +69,31 @@ class ProductCompareActivity : BaseActivity() {
         }
 
         lifecycleScope.launch {
-            repeatOnLifecycle(Lifecycle.State.STARTED) {
-                viewModel.alreadyExistFlow.collect {
-                    Toast.makeText(this@ProductCompareActivity, getString(R.string.product_already_exists_in_comparison), Toast.LENGTH_SHORT).show()
+            viewModel.sideEffectFlow
+                .flowWithLifecycle(lifecycle)
+                .collect {
+                    when (it) {
+                        is SideEffect.ProductAlreadyAdded -> showProductAlreadyAddedDialog()
+                        is SideEffect.ProductNotFound -> showProductNotFoundDialog()
+                        is SideEffect.ConnectionError -> showConnectionErrorDialog()
+                    }
                 }
-            }
         }
         lifecycleScope.launch {
-            repeatOnLifecycle(Lifecycle.State.STARTED) {
-                viewModel.productsFlow.collect { products ->
+            viewModel.productsFlow
+                .flowWithLifecycle(lifecycle)
+                .distinctUntilChanged()
+                .collect { products ->
                     createAdapter(products)
                 }
-            }
+        }
+        lifecycleScope.launch {
+            viewModel.loadingVisibleFlow
+                .flowWithLifecycle(lifecycle)
+                .distinctUntilChanged()
+                .collect {
+                    binding.comparisonProgressView.isVisible = it
+                }
         }
 
         binding.productComparisonButton.setOnClickListener {
@@ -161,9 +176,36 @@ class ProductCompareActivity : BaseActivity() {
         }
     }
 
+    private fun showProductAlreadyAddedDialog() {
+        MaterialAlertDialogBuilder(this)
+            .setMessage(R.string.product_already_exists_in_comparison)
+            .setPositiveButton(R.string.ok_button) { dialog, _ ->
+                dialog.dismiss()
+            }
+            .show()
+    }
+
+    private fun showProductNotFoundDialog() {
+        MaterialAlertDialogBuilder(this)
+            .setMessage(R.string.txtDialogsContentPowerMode)
+            .setPositiveButton(R.string.ok_button) { dialog, _ ->
+                dialog.dismiss()
+            }
+            .show()
+    }
+
+    private fun showConnectionErrorDialog() {
+        MaterialAlertDialogBuilder(this)
+            .setTitle(R.string.alert_dialog_warning_title)
+            .setMessage(R.string.txtConnectionError)
+            .setPositiveButton(R.string.ok_button) { dialog, _ ->
+                dialog.dismiss()
+            }
+            .show()
+    }
+
     companion object {
         const val KEY_PRODUCTS_TO_COMPARE = "products_to_compare"
-        const val KEY_COMPARE_PRODUCT = "compare_product"
 
         @JvmStatic
         fun start(context: Context, product: Product) {

app/src/main/java/openfoodfacts/github/scrachx/openfood/features/compare/ProductCompareViewModel.kt

@@ -1,5 +1,6 @@
 package openfoodfacts.github.scrachx.openfood.features.compare
 
+import android.util.Log
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
@@ -14,37 +15,55 @@ import openfoodfacts.github.scrachx.openfood.analytics.AnalyticsEvent
 import openfoodfacts.github.scrachx.openfood.analytics.MatomoAnalytics
 import openfoodfacts.github.scrachx.openfood.models.Product
 import openfoodfacts.github.scrachx.openfood.models.entities.additive.AdditiveName
+import openfoodfacts.github.scrachx.openfood.network.OpenFoodAPIClient
 import openfoodfacts.github.scrachx.openfood.repositories.ProductRepository
 import openfoodfacts.github.scrachx.openfood.utils.CoroutineDispatchers
 import openfoodfacts.github.scrachx.openfood.utils.LocaleManager
+import openfoodfacts.github.scrachx.openfood.utils.Utils
 import javax.inject.Inject
 
 @HiltViewModel
 class ProductCompareViewModel @Inject constructor(
     private val productRepository: ProductRepository,
     private val localeManager: LocaleManager,
     private val matomoAnalytics: MatomoAnalytics,
-    private val coroutineDispatchers: CoroutineDispatchers
+    private val coroutineDispatchers: CoroutineDispatchers,
+    private val openFoodAPIClient: OpenFoodAPIClient,
 ) : ViewModel() {
 
-    private val _alreadyExistFlow = MutableSharedFlow<Unit>()
-    val alreadyExistFlow = _alreadyExistFlow.asSharedFlow()
+    private val _sideEffectFlow = MutableSharedFlow<SideEffect>()
+    val sideEffectFlow = _sideEffectFlow.asSharedFlow()
 
-    private val _productsFlow = MutableStateFlow<List<CompareProduct>>(emptyList())
+    private val _productsFlow = MutableStateFlow(listOf<CompareProduct>())
     val productsFlow = _productsFlow.asStateFlow()
 
+    private val _loadingVisibleFlow = MutableStateFlow(false)
+    val loadingVisibleFlow = _loadingVisibleFlow.asStateFlow()
+
+    fun barcodeDetected(barcode: String) {
+        viewModelScope.launch {
+            if (isProductAlreadyAdded(barcode)) {
+                emitSideEffect(SideEffect.ProductAlreadyAdded)
+            } else {
+                fetchProduct(barcode)
+            }
+        }
+    }
+
     fun addProductToCompare(product: Product) {
         viewModelScope.launch {
-            if (_productsFlow.value.any { it.product.code == product.code }) {
-                _alreadyExistFlow.emit(Unit)
+            if (isProductAlreadyAdded(product.code)) {
+                emitSideEffect(SideEffect.ProductAlreadyAdded)
             } else {
+                _loadingVisibleFlow.emit(true)
                 matomoAnalytics.trackEvent(AnalyticsEvent.AddProductToComparison(product.code))
                 val result = withContext(coroutineDispatchers.io()) {
                     CompareProduct(product, fetchAdditives(product))
                 }
                 withContext(coroutineDispatchers.main()) {
                     updateProductList(result)
                 }
+                _loadingVisibleFlow.emit(false)
             }
         }
     }
@@ -53,6 +72,10 @@ class ProductCompareViewModel @Inject constructor(
         return localeManager.getLanguage()
     }
 
+    private fun isProductAlreadyAdded(barcode: String): Boolean {
+        return _productsFlow.value.any { it.product.code == barcode }
+    }
+
     private fun updateProductList(item: CompareProduct) {
         val newList = _productsFlow.value + item
         _productsFlow.value = newList
@@ -71,8 +94,38 @@ class ProductCompareViewModel @Inject constructor(
             .filter { it.isNotNull }
     }
 
+    private suspend fun fetchProduct(barcode: String) {
+        _loadingVisibleFlow.emit(true)
+        withContext(coroutineDispatchers.io()) {
+            try {
+                val product = openFoodAPIClient.getProductStateFull(barcode, userAgent = Utils.HEADER_USER_AGENT_SCAN).product
+                if (product == null) {
+                    emitSideEffect(SideEffect.ProductNotFound)
+                } else {
+                    addProductToCompare(product)
+                }
+            } catch (t: Throwable) {
+                Log.w("ProductCompareViewModel", t.message, t)
+                emitSideEffect(SideEffect.ConnectionError)
+            }
+        }
+    }
+
+    private suspend fun emitSideEffect(effect: SideEffect) {
+        withContext(coroutineDispatchers.main()) {
+            _sideEffectFlow.emit(effect)
+            _loadingVisibleFlow.emit(false)
+        }
+    }
+
     data class CompareProduct(
         val product: Product,
         val additiveNames: List<AdditiveName>
     )
+
+    sealed class SideEffect {
+        object ProductAlreadyAdded : SideEffect()
+        object ProductNotFound : SideEffect()
+        object ConnectionError : SideEffect()
+    }
 }