feat(asr): propagate participant language per session

cai

2026-08-22 fe5c23af3c46d6a6168d9b77bd703065aa65cbc5

 src/asr_realtime.rs

@@ -34,9 +34,55 @@
pub(crate) struct AudioIngressMetadata {
    pub(crate) input_source_category: String,
    pub(crate) client_fixture_sequence: String,
    pub(crate) language: Option<String>,
}

impl AudioIngressMetadata {
    pub(crate) const ORIGIN_STATUSES: [&'static str; 8] = [
        "controlled_fixture_bound",
        "ordinary_mic_absent",
        "participant_attributes_absent",
        "participant_attributes_invalid",
        "sequence_absent",
        "sequence_replayed_or_regressed",
        "wrong_participant_or_track",
        "origin_unprovable",
    ];

    pub(crate) fn origin_status(attributes: &HashMap<String, String>) -> &'static str {
        let source = attributes.get("inputSourceCategory").map(String::as_str);
        let sequence = attributes.get("clientFixtureSequence").map(String::as_str);
        match (source, sequence) {
            (None, None) => "ordinary_mic_absent",
            (Some("controlled_fixture"), Some(sequence)) if valid_sequence(sequence) => {
                "controlled_fixture_bound"
            }
            (Some("controlled_fixture"), None) => "sequence_absent",
            (Some("controlled_fixture"), Some(_)) => "participant_attributes_invalid",
            (Some(_), _) | (None, Some(_)) => "participant_attributes_invalid",
        }
    }

    pub(crate) fn rejection_status(reason: &str) -> &'static str {
        match reason {
            "incomplete_metadata" => "participant_attributes_absent",
            "invalid_source_or_sequence" => "participant_attributes_invalid",
            _ => "origin_unprovable",
        }
    }

    pub(crate) fn rejected_origin_status(
        reason: &str,
        attributes: &HashMap<String, String>,
    ) -> &'static str {
        let status = Self::origin_status(attributes);
        if status == "sequence_absent" {
            status
        } else {
            Self::rejection_status(reason)
        }
    }

    pub(crate) fn from_participant(
        attributes: &HashMap<String, String>,
    ) -> Result<Option<Self>, &'static str> {
@@ -45,9 +91,16 @@
        match (source, sequence) {
            (None, None) => Ok(None),
            (Some("controlled_fixture"), Some(sequence)) if valid_sequence(sequence) => {
                let language = attributes.get("language").map(String::as_str);
                if let Some(language) = language {
                    if !valid_language(language) {
                        return Err("invalid_language");
                    }
                }
                Ok(Some(Self {
                    input_source_category: "controlled_fixture".to_string(),
                    client_fixture_sequence: sequence.to_string(),
                    language: language.map(str::to_string),
                }))
            }
            (Some(_), _) => Err("invalid_source_or_sequence"),
@@ -62,6 +115,10 @@
        && value
            .chars()
            .all(|ch| ch.is_ascii_alphanumeric() || matches!(ch, '-' | '_' | '.'))
}

fn valid_language(value: &str) -> bool {
    matches!(value, "ja-JP" | "zh-CN")
}

impl RealtimeAsrConfig {
@@ -93,6 +150,31 @@
}

impl RealtimeAsrUpload {
    pub(crate) fn start_with_participant_attributes<F>(
        http: Client,
        config: RealtimeAsrConfig,
        call_id: &str,
        trace_id: &str,
        turn_id: &str,
        initial_samples_48k: &[i16],
        read_attributes: F,
    ) -> Result<Self>
    where
        F: FnOnce() -> HashMap<String, String>,
    {
        let metadata = AudioIngressMetadata::from_participant(&read_attributes())
            .map_err(|reason| anyhow!(reason))?;
        Self::start(
            http,
            config,
            call_id,
            trace_id,
            turn_id,
            initial_samples_48k,
            metadata.as_ref(),
        )
    }

    pub(crate) fn start(
        http: Client,
        config: RealtimeAsrConfig,
@@ -325,7 +407,7 @@
    samples: Vec<i16>,
}

fn session_start_line(
pub(crate) fn session_start_line(
    call_id: &str,
    trace_id: &str,
    turn_id: &str,
@@ -347,7 +429,14 @@
    if let Some(metadata) = ingress_metadata {
        line["inputSourceCategory"] = json!(metadata.input_source_category);
        line["clientFixtureSequence"] = json!(metadata.client_fixture_sequence);
        if let Some(language) = metadata.language.as_deref() {
            line["language"] = json!(language);
        }
    }
    line["audioIngressOriginStatus"] = json!(match ingress_metadata {
        Some(_) => "controlled_fixture_bound",
        None => "ordinary_mic_absent",
    });
    encode_line(line)
}

@@ -458,6 +547,7 @@
        assert_eq!("pcm_s16le", value["audio"]["format"]);
        assert_eq!(16000, value["audio"]["sampleRate"]);
        assert_eq!(1, value["audio"]["channels"]);
        assert_eq!("ordinary_mic_absent", value["audioIngressOriginStatus"]);
    }

    #[test]
@@ -471,14 +561,20 @@
            "clientFixtureSequence".to_string(),
            "fixture-01".to_string(),
        );
        attributes.insert("language".to_string(), "ja-JP".to_string());
        let metadata =
            AudioIngressMetadata::from_participant(&attributes).expect("valid attributes");
        assert_eq!(
            Some(AudioIngressMetadata {
                input_source_category: "controlled_fixture".to_string(),
                client_fixture_sequence: "fixture-01".to_string(),
                language: Some("ja-JP".to_string()),
            }),
            metadata
        );
        assert_eq!(
            "controlled_fixture_bound",
            AudioIngressMetadata::origin_status(&attributes)
        );

        attributes.insert(
@@ -493,6 +589,62 @@
            Ok(None),
            AudioIngressMetadata::from_participant(&HashMap::new())
        );
        attributes.remove("clientFixtureSequence");
        assert_eq!(
            "sequence_absent",
            AudioIngressMetadata::origin_status(&attributes)
        );
        attributes.insert(
            "clientFixtureSequence".to_string(),
            "bad sequence".to_string(),
        );
        assert_eq!(
            "participant_attributes_invalid",
            AudioIngressMetadata::origin_status(&attributes)
        );
        assert_eq!(
            "ordinary_mic_absent",
            AudioIngressMetadata::origin_status(&HashMap::new())
        );
        attributes.insert(
            "clientFixtureSequence".to_string(),
            "fixture-01".to_string(),
        );
        attributes.insert("language".to_string(), "ja-jp".to_string());
        assert_eq!(
            Err("invalid_language"),
            AudioIngressMetadata::from_participant(&attributes)
        );
        attributes.insert("language".to_string(), "ja-JP".to_string());
        assert_eq!(
            "participant_attributes_absent",
            AudioIngressMetadata::rejection_status("incomplete_metadata")
        );
        assert_eq!(
            "participant_attributes_invalid",
            AudioIngressMetadata::rejection_status("invalid_source_or_sequence")
        );
        assert_eq!(
            "origin_unprovable",
            AudioIngressMetadata::rejection_status("sequence_replayed")
        );
        assert_eq!(
            "origin_unprovable",
            AudioIngressMetadata::rejection_status("wrong_participant")
        );
        assert_eq!(
            "origin_unprovable",
            AudioIngressMetadata::rejection_status("unknown")
        );
        let missing_sequence = HashMap::from([(
            "inputSourceCategory".to_string(),
            "controlled_fixture".to_string(),
        )]);
        assert_eq!(
            "sequence_absent",
            AudioIngressMetadata::rejected_origin_status("incomplete_metadata", &missing_sequence)
        );
        assert_eq!(8, AudioIngressMetadata::ORIGIN_STATUSES.len());
    }

    #[test]
@@ -500,6 +652,7 @@
        let bound = AudioIngressMetadata {
            input_source_category: "controlled_fixture".to_string(),
            client_fixture_sequence: "fixture-01".to_string(),
            language: Some("ja-JP".to_string()),
        };
        let absent = serde_json::from_slice::<serde_json::Value>(
            &session_start_line("call-001", "trace-001", "turn-0001", "nonce-001", None)
@@ -507,6 +660,7 @@
        )
        .expect("absent json");
        assert!(absent.get("inputSourceCategory").is_none());
        assert_eq!("ordinary_mic_absent", absent["audioIngressOriginStatus"]);
        let with_metadata = serde_json::from_slice::<serde_json::Value>(
            &session_start_line(
                "call-001",
@@ -520,9 +674,15 @@
        .expect("bound json");
        assert_eq!("controlled_fixture", with_metadata["inputSourceCategory"]);
        assert_eq!("fixture-01", with_metadata["clientFixtureSequence"]);
        assert_eq!("ja-JP", with_metadata["language"]);
        assert_eq!(
            "controlled_fixture_bound",
            with_metadata["audioIngressOriginStatus"]
        );
        let next = AudioIngressMetadata {
            input_source_category: "controlled_fixture".to_string(),
            client_fixture_sequence: "fixture-02".to_string(),
            language: Some("zh-CN".to_string()),
        };
        let next_line = session_start_line(
            "call-001",
@@ -534,12 +694,73 @@
        .expect("next bound session line");
        let next_value: serde_json::Value = serde_json::from_slice(&next_line).expect("next json");
        assert_eq!("fixture-02", next_value["clientFixtureSequence"]);
        assert_eq!("zh-CN", next_value["language"]);
        assert_ne!(
            with_metadata["clientFixtureSequence"],
            next_value["clientFixtureSequence"]
        );
    }

    #[tokio::test]
    async fn production_session_boundary_reads_updated_attributes_per_session() {
        let mut attributes = HashMap::new();
        attributes.insert(
            "inputSourceCategory".to_string(),
            "controlled_fixture".to_string(),
        );
        attributes.insert(
            "clientFixtureSequence".to_string(),
            "fixture-01".to_string(),
        );
        let (url1, captured1, server1) =
            spawn_http_fixture(json!({"code": 0, "data": {"status": "cancelled"}}).to_string());
        let upload1 = RealtimeAsrUpload::start_with_participant_attributes(
            Client::new(),
            fixture_config(url1),
            "call-001",
            "trace-001",
            "turn-0001",
            &vec![1; 9_600],
            || attributes.clone(),
        )
        .expect("session one");
        upload1.cancel("test").await;
        let request1 = captured1.recv().expect("session one request");
        server1.join().expect("session one server");
        assert!(
            request1
                .body
                .contains("\"clientFixtureSequence\":\"fixture-01\"")
        );
        assert!(!request1.body.contains("fixture-02"));

        attributes.insert(
            "clientFixtureSequence".to_string(),
            "fixture-02".to_string(),
        );
        let (url2, captured2, server2) =
            spawn_http_fixture(json!({"code": 0, "data": {"status": "cancelled"}}).to_string());
        let upload2 = RealtimeAsrUpload::start_with_participant_attributes(
            Client::new(),
            fixture_config(url2),
            "call-001",
            "trace-001",
            "turn-0002",
            &vec![1; 9_600],
            || attributes.clone(),
        )
        .expect("session two");
        upload2.cancel("test").await;
        let request2 = captured2.recv().expect("session two request");
        server2.join().expect("session two server");
        assert!(
            request2
                .body
                .contains("\"clientFixtureSequence\":\"fixture-02\"")
        );
        assert!(!request2.body.contains("fixture-01"));
    }

    #[test]
    fn maximum_audio_chunk_stays_within_java_line_limit() {
        let line = audio_chunk_line(1, &vec![0; 8_000]).expect("maximum chunk line");