Fix screenshot prompt carry-over and model routing issues

Author: Android-PowerUser

app/src/main/kotlin/com/google/ai/sample/GenerativeAiViewModelFactory.kt

@@ -35,6 +35,7 @@ enum class ModelOption(
     val additionalDownloadUrls: List<String> = emptyList(),
     val requiresVisionBackend: Boolean = false
 ) {
+    PUTER_GPT_5_4_NANO("GPT-5.4 Nano (Puter)", "openai/gpt-5.4-nano", ApiProvider.PUTER, supportsScreenshot = true),
     PUTER_GLM5("GLM-5V Turbo (Puter)", "openrouter:z-ai/glm-5v-turbo", ApiProvider.PUTER, supportsScreenshot = true),
     MISTRAL_LARGE_3("Mistral Large 3", "mistral-large-latest", ApiProvider.MISTRAL),
     MISTRAL_MEDIUM_3_1("Mistral Medium 3.1", "mistral-medium-latest", ApiProvider.MISTRAL),

app/src/main/kotlin/com/google/ai/sample/MenuScreen.kt

@@ -215,10 +215,14 @@ fun MenuScreen(
                                 }
                                 val normalModels = allModels.filter {
                                     it != ModelOption.MISTRAL_MEDIUM_3_1 &&
+                                        it != ModelOption.PUTER_GPT_5_4_NANO &&
                                         it.apiProvider != ApiProvider.VERCEL &&
                                         !STRIKETHROUGH_MODELS.contains(it)
                                 }
-                                val orderedModels = listOf(ModelOption.MISTRAL_MEDIUM_3_1) +
+                                val orderedModels = listOf(
+                                    ModelOption.PUTER_GPT_5_4_NANO,
+                                    ModelOption.MISTRAL_MEDIUM_3_1
+                                ) +
                                     normalModels +
                                     vercelModels +
                                     STRIKETHROUGH_MODELS
@@ -288,7 +292,7 @@ fun MenuScreen(
                             ModelOption.GPT_OSS_120B -> "This is a pure text model\nCerebras sometimes discontinues free access in the Free Tier, displaying an \"Error 404: gpt-oss-120b does not exist or you do not have access to it\" message, or changes the rate limits."
                             ModelOption.MISTRAL_LARGE_3 -> "Mistral AI rejects requests containing non-black images with a 429 Error: Rate limit exceeded response"
                             ModelOption.GEMINI_3_FLASH -> "Google often rejects requests to this model with a 503 Model is exhausted error"
-                            ModelOption.PUTER_GLM5 -> "This model is expensive and uses up the free quota quickly. Consider GPT 5.4 nano"
+                            ModelOption.PUTER_GLM5 -> "This model is expensive and uses up the free quota quickly. Consider GPT-5.4 Nano."
                             ModelOption.GPT_5_1_CODEX_MAX,
                             ModelOption.GPT_5_1_CODEX_MINI,
                             ModelOption.GPT_5_NANO -> "Vercel requires a credit card"

app/src/main/kotlin/com/google/ai/sample/feature/multimodal/PhotoReasoningViewModel.kt

@@ -1191,7 +1191,8 @@ class PhotoReasoningViewModel(
                     }
 
                 // CerebrasRequest braucht stream-Feld — inline als JSON-String um Datenklasse nicht zu ändern
-                val streamingBody = """{"model":"$modelName","messages":${Json.encodeToString(apiMessages)},"max_completion_tokens":1024,"temperature":0.2,"top_p":1.0,"stream":true}"""
+                val selectedModelName = com.google.ai.sample.GenerativeAiViewModelFactory.getCurrentModel().modelName
+                val streamingBody = """{"model":"$selectedModelName","messages":${Json.encodeToString(apiMessages)},"max_completion_tokens":1024,"temperature":0.2,"top_p":1.0,"stream":true}"""
                 val mediaType = "application/json".toMediaType()
                 val client = OkHttpClient()
 
@@ -1859,7 +1860,7 @@ class PhotoReasoningViewModel(
                 context = context,
                 inputContentJson = inputContentJson,
                 chatHistoryJson = chatHistoryJson,
-                modelName = generativeModel.modelName,
+                modelName = currentModel.modelName,
                 apiKey = apiKey,
                 apiProvider = currentModel.apiProvider,
                 tempFilePaths = tempFilePaths
@@ -2168,30 +2169,10 @@ class PhotoReasoningViewModel(
     private fun createGenericScreenshotPrompt(): String {
         val latestTask = latestUserTaskInput.trim()
         if (latestTask.isNotBlank()) {
+            latestUserTaskInput = ""
             return latestTask
         }
 
-        val lastUserMessage = _chatState.getAllMessages()
-            .asReversed()
-            .firstOrNull { it.participant == PhotoParticipant.USER && it.text.isNotBlank() }
-            ?.text
-            ?.trim()
-
-        if (!lastUserMessage.isNullOrBlank()) {
-            val screenInfoMarker = "\n\nScreen elements:\n"
-            return lastUserMessage.substringBefore(screenInfoMarker).trim()
-        }
-
-        val persistedInput = _userInput.value.trim()
-        if (persistedInput.isNotBlank()) {
-            return persistedInput
-        }
-
-        val lastKnownInput = currentUserInput.trim()
-        if (lastKnownInput.isNotBlank()) {
-            return lastKnownInput
-        }
-
         return ""
     }