refactor(ai-logic): use nano banana GA models

firebase-ai/README.md

@@ -30,13 +30,13 @@ You can find the implementation for each feature by clicking on the links below:
 ### Gemini 3
 - [Translate text](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/TranslationViewModel.kt): Use Gemini 3.1 Flash-Lite to translate text
 - [SVG Generator](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/SvgViewModel.kt): Use Gemini 3.5 Flash to create SVG illustrations
-- [Gemini 3.1 Flash Image (Nano Banana 2)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBanana2ViewModel.kt): Generate and/or edit images using Nano Banana 2 preview
-- [Gemini 3 Pro Image (Nano Banana Pro)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaProViewModel.kt): Generate and/or edit images using Nano Banana Pro preview
+- [Gemini 3.1 Flash Image (Nano Banana 2)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBanana2ViewModel.kt): Generate and/or edit images using Nano Banana 2
+- [Gemini 3 Pro Image (Nano Banana Pro)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaProViewModel.kt): Generate and/or edit images using Nano Banana Pro
 
 ### Nano Banana
-- [Gemini 3.1 Flash Image (Nano Banana 2)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBanana2ViewModel.kt): Generate and/or edit images using Nano Banana 2 preview
-- [Gemini 3 Pro Image (Nano Banana Pro)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaProViewModel.kt): Generate and/or edit images using Nano Banana Pro preview
-- [Gemini 2.5 Flash Image (Nano Banana)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaViewModel.kt): Generate and/or edit images using Nano Banana (GA)
+- [Gemini 3.1 Flash Image (Nano Banana 2)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBanana2ViewModel.kt): Generate and/or edit images using Nano Banana 2
+- [Gemini 3 Pro Image (Nano Banana Pro)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaProViewModel.kt): Generate and/or edit images using Nano Banana Pro
+- [Gemini 2.5 Flash Image (Nano Banana)](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaViewModel.kt): Generate and/or edit images using Nano Banana
 
 ### Multimodal understanding
 - [Audio Summarization](app/src/main/java/com/google/firebase/quickstart/ai/feature/text/AudioSummarizationViewModel.kt): Use Gemini 3.1 Flash Lite to summarize an audio file

firebase-ai/app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBanana2ViewModel.kt

@@ -5,37 +5,48 @@ import kotlinx.serialization.Serializable
 import com.google.firebase.Firebase
 import com.google.firebase.ai.Chat
 import com.google.firebase.ai.ai
+import com.google.firebase.ai.type.AspectRatio
 import com.google.firebase.ai.type.Content
 import com.google.firebase.ai.type.GenerativeBackend
 import com.google.firebase.ai.type.ResponseModality
 import com.google.firebase.ai.type.generationConfig
+import com.google.firebase.ai.type.imageConfig
 import com.google.firebase.quickstart.ai.ui.UiChatMessage
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
 
 @Serializable
 object NanoBanana2Route
 
 class NanoBanana2ViewModel : ChatViewModel() {
-
-    override val initialPrompt: String = """
+    override val initialPrompt: String by lazy {
+        val currentMonthAndYear = SimpleDateFormat("MMM yyyy", Locale.US).format(Date())
+        """
         A photo of a glossy magazine cover, the minimal blue cover
         has the large bold words Nano Banana. The text is in a serif
         font and fills the view. No other text. In front of the text
         there is a portrait of a person in a sleek and minimal dress.
         She is playfully holding the number 2, which is the focal point.
-        Put the issue number and "Feb 2026" date in the corner along with
+        Put the issue number and "$currentMonthAndYear" date in the corner along with
         a barcode. The magazine is on a shelf against an orange plastered
         wall, within a designer store.
         """.trimIndent()
+    }
 
     private val chat: Chat
 
     init {
         val generativeModel = Firebase.ai(
             backend = GenerativeBackend.googleAI()
         ).generativeModel(
-            modelName = "gemini-3.1-flash-image-preview",
+            modelName = "gemini-3.1-flash-image",
             generationConfig = generationConfig {
                 responseModalities = listOf(ResponseModality.TEXT, ResponseModality.IMAGE)
+                // Optionally specify additional configuration
+                imageConfig = imageConfig {
+                    aspectRatio = AspectRatio.PORTRAIT_3x4
+                }
             }
         )
         chat = generativeModel.startChat()

firebase-ai/app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaProViewModel.kt

@@ -5,10 +5,12 @@ import kotlinx.serialization.Serializable
 import com.google.firebase.Firebase
 import com.google.firebase.ai.Chat
 import com.google.firebase.ai.ai
+import com.google.firebase.ai.type.AspectRatio
 import com.google.firebase.ai.type.Content
 import com.google.firebase.ai.type.GenerativeBackend
 import com.google.firebase.ai.type.ResponseModality
 import com.google.firebase.ai.type.generationConfig
+import com.google.firebase.ai.type.imageConfig
 import com.google.firebase.quickstart.ai.ui.UiChatMessage
 
 @Serializable
@@ -36,9 +38,13 @@ class NanoBananaProViewModel : ChatViewModel() {
         val generativeModel = Firebase.ai(
             backend = GenerativeBackend.googleAI()
         ).generativeModel(
-            modelName = "gemini-3-pro-image-preview",
+            modelName = "gemini-3-pro-image",
             generationConfig = generationConfig {
                 responseModalities = listOf(ResponseModality.TEXT, ResponseModality.IMAGE)
+                // Optionally specify additional configuration
+                imageConfig = imageConfig {
+                    aspectRatio = AspectRatio.SQUARE_1x1
+                }
             }
         )
         chat = generativeModel.startChat()

firebase-ai/app/src/main/java/com/google/firebase/quickstart/ai/ui/navigation/FirebaseAISamples.kt

@@ -88,23 +88,23 @@ val FIREBASE_AI_SAMPLES = listOf(
     ),
     Sample(
         title = "Gemini 3.1 Flash Image (Nano Banana 2)",
-        description = "Generate and/or edit images using Nano Banana 2 preview",
+        description = "Generate and/or edit images using Nano Banana 2",
         route = NanoBanana2Route,
         screenType = ScreenType.CHAT,
         viewModelClass = NanoBanana2ViewModel::class,
         categories = listOf(Category.NANO_BANANA, Category.GEMINI3)
     ),
     Sample(
         title = "Gemini 3 Pro Image (Nano Banana Pro)",
-        description = "Generate and/or edit images using Nano Banana Pro preview",
+        description = "Generate and/or edit images using Nano Banana Pro",
         route = NanoBananaProRoute,
         screenType = ScreenType.CHAT,
         viewModelClass = NanoBananaProViewModel::class,
         categories = listOf(Category.NANO_BANANA, Category.GEMINI3)
     ),
     Sample(
         title = "Gemini 2.5 Flash Image (Nano Banana)",
-        description = "Generate and/or edit images using Nano Banana (GA)",
+        description = "Generate and/or edit images using Nano Banana",
         route = NanoBananaRoute,
         screenType = ScreenType.CHAT,
         viewModelClass = NanoBananaViewModel::class,
@@ -187,6 +187,5 @@ val FIREBASE_AI_SAMPLES = listOf(
         screenType = ScreenType.HYBRID,
         viewModelClass = HybridInferenceViewModel::class,
         categories = listOf(Category.HYBRID)
-
     )
 )