Add NotConfiguredException with a better error message than provided by the server. (#7233)

The previous error text "genai config not found" is ambiguous and as a
generic ServerException did not provide documentation for resolutions.

Author: emilypgoogle

firebase-ai/CHANGELOG.md

@@ -1,4 +1,6 @@
 # Unreleased
+* [changed] Added better description for requests which fail due to the Gemini API not being
+  configured.
 * [feature] added support for Imagen Editing, including inpainting, outpainting, control, style 
   transfer, and subject references (#7075)
 

firebase-ai/src/main/kotlin/com/google/firebase/ai/common/APIController.kt

@@ -334,6 +334,9 @@ private suspend fun validateResponse(response: HttpResponse) {
   if (message.contains("The prompt could not be submitted")) {
     throw PromptBlockedException(message)
   }
+  if (message.contains("genai config not found")) {
+    throw APINotConfiguredException()
+  }
   getServiceDisabledErrorDetailsOrNull(error)?.let {
     val errorMessage =
       if (it.metadata?.get("service") == "firebasevertexai.googleapis.com") {

firebase-ai/src/main/kotlin/com/google/firebase/ai/common/Exceptions.kt

@@ -89,6 +89,16 @@ internal constructor(
 internal class UnsupportedUserLocationException(cause: Throwable? = null) :
   FirebaseCommonAIException("User location is not supported for the API use.", cause)
 
+/**
+ * The user's project does not have the Gemini Developer API enabled in the Firebase Console.
+ *
+ * See the Firebase documentation for the
+ * [steps](https://firebase.google.com/docs/ai-logic/faq-and-troubleshooting?api=dev#error-genai-config-not-found)
+ * to enable the Gemini Developer API.
+ */
+internal class APINotConfiguredException(cause: Throwable? = null) :
+  FirebaseCommonAIException("Gemini Developer API not enabled in Firebase console.", cause)
+
 /**
  * Some form of state occurred that shouldn't have.
  *

firebase-ai/src/main/kotlin/com/google/firebase/ai/type/Exceptions.kt

@@ -61,6 +61,8 @@ internal constructor(message: String, cause: Throwable? = null) : RuntimeExcepti
               ContentBlockedException(cause.message ?: "", cause.cause)
             is com.google.firebase.ai.common.QuotaExceededException ->
               QuotaExceededException(cause.message ?: "", cause.cause)
+            is com.google.firebase.ai.common.APINotConfiguredException ->
+              APINotConfiguredException(cause.cause)
             else -> UnknownException(cause.message ?: "", cause)
           }
         is TimeoutCancellationException ->
@@ -149,6 +151,16 @@ internal constructor(message: String, cause: Throwable? = null) :
 public class UnsupportedUserLocationException internal constructor(cause: Throwable? = null) :
   FirebaseAIException("User location is not supported for the API use.", cause)
 
+/**
+ * The user's project does not have the Gemini Developer API enabled in the Firebase Console.
+ *
+ * See the Firebase documentation for the
+ * [steps](https://firebase.google.com/docs/ai-logic/faq-and-troubleshooting?api=dev#error-genai-config-not-found)
+ * to enable the Gemini Developer API.
+ */
+internal class APINotConfiguredException internal constructor(cause: Throwable? = null) :
+  FirebaseAIException("Gemini Developer API not enabled in Firebase console.", cause)
+
 /**
  * Some form of state occurred that shouldn't have.
  *