Migrate VertexAI serialization to be localized (#6631)

There are some considerations to how this should be finalized. Current
implementation details that I've decided on which we can change:
* Based on the example doc, all classes `Foo` have been renamed
`InternalFoo`
* All internal serialization classes, where relevant, are moved to inner
classes of their API counterparts
* All classes only used as child fields for serialization classes have
been moved to inner classes of those classes
* All `toPublic` and `toInternal` methods on API and serialization
classes have been moved inside of those classes and `conversions.kt` has
been mostly emptied.
* A few serialization classes do not have API equivalents and are left
in a `Types.kt` file

Possible changes:
* Change all `InternalFoo` classes to have the same name, referenced as
`Foo.Internal` rather than `Foo.InternalFoo`. This will probably make
the codebase feel cleaner, but I'll wait for opinions on it
* Move serialization only classes out of the internal serialization
classes, either to inner classes of the API classes or top level classes
themselves.
* For classes that have serializers, rename serializers from
`InternalFooSerializer` to `Serializer` for example
`Foo.InternalFoo.Serializer` or `Foo.Internal.Serializer` instead of
`Foo.InternalFoo.InternalFooSerializer` or
`Foo.Internal.InternalFooSerializer`

Author: emilypgoogle

firebase-vertexai/consumer-rules.pro

@@ -20,4 +20,5 @@
 # hide the original source file name.
 #-renamesourcefileattribute SourceFile
 
+-keep class com.google.firebase.vertexai.type.** { *; }
 -keep class com.google.firebase.vertexai.common.** { *; }

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/GenerativeModel.kt

@@ -24,8 +24,6 @@ import com.google.firebase.vertexai.common.APIController
 import com.google.firebase.vertexai.common.CountTokensRequest
 import com.google.firebase.vertexai.common.GenerateContentRequest
 import com.google.firebase.vertexai.common.HeaderProvider
-import com.google.firebase.vertexai.internal.util.toInternal
-import com.google.firebase.vertexai.internal.util.toPublic
 import com.google.firebase.vertexai.type.Content
 import com.google.firebase.vertexai.type.CountTokensResponse
 import com.google.firebase.vertexai.type.FinishReason

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

@@ -19,12 +19,14 @@ package com.google.firebase.vertexai.common
 import android.util.Log
 import com.google.firebase.Firebase
 import com.google.firebase.options
-import com.google.firebase.vertexai.common.server.FinishReason
-import com.google.firebase.vertexai.common.server.GRpcError
-import com.google.firebase.vertexai.common.server.GRpcErrorDetails
 import com.google.firebase.vertexai.common.util.decodeToFlow
 import com.google.firebase.vertexai.common.util.fullModelName
+import com.google.firebase.vertexai.type.CountTokensResponse
+import com.google.firebase.vertexai.type.FinishReason
+import com.google.firebase.vertexai.type.GRpcErrorResponse
+import com.google.firebase.vertexai.type.GenerateContentResponse
 import com.google.firebase.vertexai.type.RequestOptions
+import com.google.firebase.vertexai.type.Response
 import io.ktor.client.HttpClient
 import io.ktor.client.call.body
 import io.ktor.client.engine.HttpClientEngine
@@ -106,31 +108,33 @@ internal constructor(
       install(ContentNegotiation) { json(JSON) }
     }
 
-  suspend fun generateContent(request: GenerateContentRequest): GenerateContentResponse =
+  suspend fun generateContent(request: GenerateContentRequest): GenerateContentResponse.Internal =
     try {
       client
         .post("${requestOptions.endpoint}/${requestOptions.apiVersion}/$model:generateContent") {
           applyCommonConfiguration(request)
           applyHeaderProvider()
         }
         .also { validateResponse(it) }
-        .body<GenerateContentResponse>()
+        .body<GenerateContentResponse.Internal>()
         .validate()
     } catch (e: Throwable) {
       throw FirebaseCommonAIException.from(e)
     }
 
-  fun generateContentStream(request: GenerateContentRequest): Flow<GenerateContentResponse> =
+  fun generateContentStream(
+    request: GenerateContentRequest
+  ): Flow<GenerateContentResponse.Internal> =
     client
-      .postStream<GenerateContentResponse>(
+      .postStream<GenerateContentResponse.Internal>(
         "${requestOptions.endpoint}/${requestOptions.apiVersion}/$model:streamGenerateContent?alt=sse"
       ) {
         applyCommonConfiguration(request)
       }
       .map { it.validate() }
       .catch { throw FirebaseCommonAIException.from(it) }
 
-  suspend fun countTokens(request: CountTokensRequest): CountTokensResponse =
+  suspend fun countTokens(request: CountTokensRequest): CountTokensResponse.Internal =
     try {
       client
         .post("${requestOptions.endpoint}/${requestOptions.apiVersion}/$model:countTokens") {
@@ -275,19 +279,21 @@ private suspend fun validateResponse(response: HttpResponse) {
   throw ServerException(message)
 }
 
-private fun getServiceDisabledErrorDetailsOrNull(error: GRpcError): GRpcErrorDetails? {
+private fun getServiceDisabledErrorDetailsOrNull(
+  error: GRpcErrorResponse.GRpcError
+): GRpcErrorResponse.GRpcError.GRpcErrorDetails? {
   return error.details?.firstOrNull {
     it.reason == "SERVICE_DISABLED" && it.domain == "googleapis.com"
   }
 }
 
-private fun GenerateContentResponse.validate() = apply {
+private fun GenerateContentResponse.Internal.validate() = apply {
   if ((candidates?.isEmpty() != false) && promptFeedback == null) {
     throw SerializationException("Error deserializing response, found no valid fields")
   }
   promptFeedback?.blockReason?.let { throw PromptBlockedException(this) }
   candidates
     ?.mapNotNull { it.finishReason }
-    ?.firstOrNull { it != FinishReason.STOP }
+    ?.firstOrNull { it != FinishReason.Internal.STOP }
     ?.let { throw ResponseStoppedException(this) }
 }

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

@@ -16,6 +16,7 @@
 
 package com.google.firebase.vertexai.common
 
+import com.google.firebase.vertexai.type.GenerateContentResponse
 import io.ktor.serialization.JsonConvertException
 import kotlinx.coroutines.TimeoutCancellationException
 
@@ -66,7 +67,7 @@ internal class InvalidAPIKeyException(message: String, cause: Throwable? = null)
  * @property response the full server response for the request.
  */
 internal class PromptBlockedException(
-  val response: GenerateContentResponse,
+  val response: GenerateContentResponse.Internal,
   cause: Throwable? = null
 ) :
   FirebaseCommonAIException(
@@ -98,7 +99,7 @@ internal class InvalidStateException(message: String, cause: Throwable? = null)
  * @property response the full server response for the request
  */
 internal class ResponseStoppedException(
-  val response: GenerateContentResponse,
+  val response: GenerateContentResponse.Internal,
   cause: Throwable? = null
 ) :
   FirebaseCommonAIException(
@@ -125,3 +126,18 @@ internal class ServiceDisabledException(message: String, cause: Throwable? = nul
 /** Catch all case for exceptions not explicitly expected. */
 internal class UnknownException(message: String, cause: Throwable? = null) :
   FirebaseCommonAIException(message, cause)
+
+internal fun makeMissingCaseException(
+  source: String,
+  ordinal: Int
+): com.google.firebase.vertexai.type.SerializationException {
+  return com.google.firebase.vertexai.type.SerializationException(
+    """
+    |Missing case for a $source: $ordinal
+    |This error indicates that one of the `toInternal` conversions needs updating.
+    |If you're a developer seeing this exception, please file an issue on our GitHub repo:
+    |https://github.com/firebase/firebase-android-sdk
+  """
+      .trimMargin()
+  )
+}

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/common/Request.kt

@@ -16,12 +16,12 @@
 
 package com.google.firebase.vertexai.common
 
-import com.google.firebase.vertexai.common.client.GenerationConfig
-import com.google.firebase.vertexai.common.client.Tool
-import com.google.firebase.vertexai.common.client.ToolConfig
-import com.google.firebase.vertexai.common.shared.Content
-import com.google.firebase.vertexai.common.shared.SafetySetting
 import com.google.firebase.vertexai.common.util.fullModelName
+import com.google.firebase.vertexai.type.Content
+import com.google.firebase.vertexai.type.GenerationConfig
+import com.google.firebase.vertexai.type.SafetySetting
+import com.google.firebase.vertexai.type.Tool
+import com.google.firebase.vertexai.type.ToolConfig
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
@@ -30,21 +30,21 @@ internal sealed interface Request
 @Serializable
 internal data class GenerateContentRequest(
   val model: String? = null,
-  val contents: List<Content>,
-  @SerialName("safety_settings") val safetySettings: List<SafetySetting>? = null,
-  @SerialName("generation_config") val generationConfig: GenerationConfig? = null,
-  val tools: List<Tool>? = null,
-  @SerialName("tool_config") var toolConfig: ToolConfig? = null,
-  @SerialName("system_instruction") val systemInstruction: Content? = null,
+  val contents: List<Content.Internal>,
+  @SerialName("safety_settings") val safetySettings: List<SafetySetting.Internal>? = null,
+  @SerialName("generation_config") val generationConfig: GenerationConfig.Internal? = null,
+  val tools: List<Tool.Internal>? = null,
+  @SerialName("tool_config") var toolConfig: ToolConfig.Internal? = null,
+  @SerialName("system_instruction") val systemInstruction: Content.Internal? = null,
 ) : Request
 
 @Serializable
 internal data class CountTokensRequest(
   val generateContentRequest: GenerateContentRequest? = null,
   val model: String? = null,
-  val contents: List<Content>? = null,
-  val tools: List<Tool>? = null,
-  @SerialName("system_instruction") val systemInstruction: Content? = null,
+  val contents: List<Content.Internal>? = null,
+  val tools: List<Tool.Internal>? = null,
+  @SerialName("system_instruction") val systemInstruction: Content.Internal? = null,
 ) : Request {
   companion object {
     fun forGenAI(generateContentRequest: GenerateContentRequest) =