BIDI mini refactoring and new additions (#7267)

The PR does the following:
- Introduce a new MissingPermissionsException which would be thrown
incase the audio permission is not given by the end user.
- Add helper functions to LiveSession to help the developer track if the
audio session is running or not and if the underlying websocket
connection is active or not..

Author: VinayGuthal

firebase-ai/CHANGELOG.md

@@ -1,5 +1,10 @@
 # Unreleased
 
+- [feature] Introduced `MissingPermissionsException`, which is thrown when the necessary permissions
+  have not been granted by the user.
+- [feature] Added helper functions to `LiveSession` to allow developers to track the status of the
+  audio session and the underlying websocket connection.
+
 # 17.2.0
 
 - [feature] Added support for returning thought summaries, which are synthesized versions of a

firebase-ai/api.txt

@@ -879,6 +879,8 @@ package com.google.firebase.ai.type {
 
   @com.google.firebase.ai.type.PublicPreviewAPI public final class LiveSession {
     method public suspend Object? close(kotlin.coroutines.Continuation<? super kotlin.Unit>);
+    method public boolean isAudioConversationActive();
+    method public boolean isClosed();
     method public kotlinx.coroutines.flow.Flow<com.google.firebase.ai.type.LiveServerMessage> receive();
     method public suspend Object? send(com.google.firebase.ai.type.Content content, kotlin.coroutines.Continuation<? super kotlin.Unit>);
     method public suspend Object? send(String text, kotlin.coroutines.Continuation<? super kotlin.Unit>);
@@ -918,6 +920,10 @@ package com.google.firebase.ai.type {
     method public static String? asTextOrNull(com.google.firebase.ai.type.Part);
   }
 
+  public final class PermissionMissingException extends com.google.firebase.ai.type.FirebaseAIException {
+    ctor public PermissionMissingException(String message, Throwable? cause = null);
+  }
+
   public final class PromptBlockedException extends com.google.firebase.ai.type.FirebaseAIException {
     method public com.google.firebase.ai.type.GenerateContentResponse? getResponse();
     property public final com.google.firebase.ai.type.GenerateContentResponse? response;

firebase-ai/gradle.properties

@@ -12,5 +12,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-version=17.2.1
+version=17.3.0
 latestReleasedVersion=17.2.0

firebase-ai/src/main/kotlin/com/google/firebase/ai/LiveGenerativeModel.kt

@@ -55,7 +55,8 @@ internal constructor(
   private val tools: List<Tool>? = null,
   private val systemInstruction: Content? = null,
   private val location: String,
-  private val controller: APIController,
+  private val firebaseApp: FirebaseApp,
+  private val controller: APIController
 ) {
   internal constructor(
     modelName: String,
@@ -78,6 +79,7 @@ internal constructor(
     tools,
     systemInstruction,
     location,
+    firebaseApp,
     APIController(
       apiKey,
       modelName,
@@ -119,7 +121,11 @@ internal constructor(
       val receivedJson = JSON.parseToJsonElement(receivedJsonStr)
 
       return if (receivedJson is JsonObject && "setupComplete" in receivedJson) {
-        LiveSession(session = webSession, blockingDispatcher = blockingDispatcher)
+        LiveSession(
+          session = webSession,
+          blockingDispatcher = blockingDispatcher,
+          firebaseApp = firebaseApp
+        )
       } else {
         webSession.close()
         throw ServiceConnectionHandshakeFailedException("Unable to connect to the server")

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

@@ -231,6 +231,10 @@ public class AudioRecordInitializationFailedException(message: String) :
 public class ServiceConnectionHandshakeFailedException(message: String, cause: Throwable? = null) :
   FirebaseAIException(message, cause)
 
+/** The request is missing a permission that is required to perform the requested operation. */
+public class PermissionMissingException(message: String, cause: Throwable? = null) :
+  FirebaseAIException(message, cause)
+
 /** Catch all case for exceptions not explicitly expected. */
 public class UnknownException internal constructor(message: String, cause: Throwable? = null) :
   FirebaseAIException(message, cause)

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

@@ -17,10 +17,13 @@
 package com.google.firebase.ai.type
 
 import android.Manifest.permission.RECORD_AUDIO
+import android.content.pm.PackageManager
 import android.media.AudioFormat
 import android.media.AudioTrack
 import android.util.Log
 import androidx.annotation.RequiresPermission
+import androidx.core.content.ContextCompat
+import com.google.firebase.FirebaseApp
 import com.google.firebase.ai.common.JSON
 import com.google.firebase.ai.common.util.CancelledCoroutineScope
 import com.google.firebase.ai.common.util.accumulateUntil
@@ -58,7 +61,8 @@ public class LiveSession
 internal constructor(
   private val session: ClientWebSocketSession,
   @Blocking private val blockingDispatcher: CoroutineContext,
-  private var audioHelper: AudioHelper? = null
+  private var audioHelper: AudioHelper? = null,
+  private val firebaseApp: FirebaseApp,
 ) {
   /**
    * Coroutine scope that we batch data on for [startAudioConversation].
@@ -93,6 +97,14 @@ internal constructor(
   public suspend fun startAudioConversation(
     functionCallHandler: ((FunctionCallPart) -> FunctionResponsePart)? = null
   ) {
+
+    val context = firebaseApp.applicationContext
+    if (
+      ContextCompat.checkSelfPermission(context, RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED
+    ) {
+      throw PermissionMissingException("Audio access not provided by the user")
+    }
+
     FirebaseAIException.catchAsync {
       if (scope.isActive) {
         Log.w(
@@ -131,6 +143,12 @@ internal constructor(
     }
   }
 
+  /** Indicates whether the underlying websocket connection is active. */
+  public fun isClosed(): Boolean = !(session.isActive && !session.incoming.tryReceive().isClosed)
+
+  /** Indicates whether an audio conversation is being used for this session object. */
+  public fun isAudioConversationActive(): Boolean = (audioHelper != null)
+
   /**
    * Receives responses from the model for both streaming and standard requests.
    *