Add types for agent and transcription attributes (#733)

+---
+"client-sdk-android": minor
+---
+
+Add types for agent and transcription attributes

@@ -14,6 +14,7 @@ dagger = "2.46"
 groupie = "2.9.0"
 junit-lib = "4.13.2"
 junit-jupiter = "5.5.0"
+klaxon = "5.5"
 kotlinx-serialization = "1.5.0"
 leakcanaryAndroid = "2.8.1"
 lint = "30.0.1"
@@ -48,6 +49,7 @@ dagger-lib = { module = "com.google.dagger:dagger", version.ref = "dagger" }
 dagger-compiler = { module = "com.google.dagger:dagger-compiler", version.ref = "dagger" }
 groupie = { module = "com.github.lisawray.groupie:groupie", version.ref = "groupie" }
 groupie-viewbinding = { module = "com.github.lisawray.groupie:groupie-viewbinding", version.ref = "groupie" }
+klaxon = { module = "com.beust:klaxon", version.ref = "klaxon" }
 noise = { module = "com.github.paramsen:noise", version.ref = "noise" }
 androidx-lifecycle-common-java8 = { module = "androidx.lifecycle:lifecycle-common-java8", version.ref = "androidx-lifecycle" }
 androidx-lifecycle-runtime-ktx = { module = "androidx.lifecycle:lifecycle-runtime-ktx", version.ref = "androidx-lifecycle" }

@@ -148,6 +148,8 @@ dependencies {
     api libs.okhttp.lib
     implementation libs.okhttp.coroutines
     api libs.audioswitch
+    implementation libs.klaxon
+
     implementation libs.androidx.annotation
     implementation libs.androidx.core
     implementation libs.protobuf.javalite

+/*
+ * Copyright 2025 LiveKit, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.livekit.android.room.types
+
+import com.beust.klaxon.Converter
+import com.beust.klaxon.Json
+import com.beust.klaxon.JsonValue
+import com.beust.klaxon.Klaxon
+
+private fun <T> Klaxon.convert(k: kotlin.reflect.KClass<*>, fromJson: (JsonValue) -> T, toJson: (T) -> String, isUnion: Boolean = false) =
+    this.converter(
+        object : Converter {
+            @Suppress("UNCHECKED_CAST")
+            override fun toJson(value: Any) = toJson(value as T)
+            override fun fromJson(jv: JsonValue) = fromJson(jv) as Any
+            override fun canConvert(cls: Class<*>) = cls == k.java || (isUnion && cls.superclass == k.java)
+        },
+    )
+
+private val klaxon = Klaxon()
+    .convert(AgentInput::class, { AgentInput.fromValue(it.string!!) }, { "\"${it.value}\"" })
+    .convert(AgentOutput::class, { AgentOutput.fromValue(it.string!!) }, { "\"${it.value}\"" })
+    .convert(AgentState::class, { AgentState.fromValue(it.string!!) }, { "\"${it.value}\"" })
+
+data class AgentAttributes(
+    @Json(name = "lk.agent.inputs")
+    val lkAgentInputs: List<AgentInput>? = null,
+
+    @Json(name = "lk.agent.outputs")
+    val lkAgentOutputs: List<AgentOutput>? = null,
+
+    @Json(name = "lk.agent.state")
+    val lkAgentState: AgentState? = null,
+
+    @Json(name = "lk.publish_on_behalf")
+    val lkPublishOnBehalf: String? = null,
+) {
+    fun toJson() = klaxon.toJsonString(this)
+
+    companion object {
+        fun fromJson(json: String) = klaxon.parse<AgentAttributes>(json)
+    }
+}
+
+enum class AgentInput(val value: String) {
+    Audio("audio"),
+    Text("text"),
+    Video("video");
+
+    companion object {
+        fun fromValue(value: String): AgentInput = when (value) {
+            "audio" -> Audio
+            "text" -> Text
+            "video" -> Video
+            else -> throw IllegalArgumentException()
+        }
+    }
+}
+
+enum class AgentOutput(val value: String) {
+    Audio("audio"),
+    Transcription("transcription");
+
+    companion object {
+        fun fromValue(value: String): AgentOutput = when (value) {
+            "audio" -> Audio
+            "transcription" -> Transcription
+            else -> throw IllegalArgumentException()
+        }
+    }
+}
+
+enum class AgentState(val value: String) {
+    Idle("idle"),
+    Initializing("initializing"),
+    Listening("listening"),
+    Speaking("speaking"),
+    Thinking("thinking");
+
+    companion object {
+        fun fromValue(value: String): AgentState = when (value) {
+            "idle" -> Idle
+            "initializing" -> Initializing
+            "listening" -> Listening
+            "speaking" -> Speaking
+            "thinking" -> Thinking
+            else -> throw IllegalArgumentException()
+        }
+    }
+}
+
+/**
+ * Schema for transcription-related attributes
+ */
+data class TranscriptionAttributes(
+    /**
+     * The segment id of the transcription
+     */
+    @Json(name = "lk.segment_id")
+    val lkSegmentID: String? = null,
+
+    /**
+     * The associated track id of the transcription
+     */
+    @Json(name = "lk.transcribed_track_id")
+    val lkTranscribedTrackID: String? = null,
+
+    /**
+     * Whether the transcription is final
+     */
+    @Json(name = "lk.transcription_final")
+    val lkTranscriptionFinal: Boolean? = null,
+) {
+    fun toJson() = klaxon.toJsonString(this)
+
+    companion object {
+        fun fromJson(json: String) = klaxon.parse<TranscriptionAttributes>(json)
+    }
+}