};

export const GOOGLE_MEET_AGENT_TRANSCRIPT_DEBOUNCE_MS = 900;

export const GOOGLE_MEET_OUTPUT_ECHO_SUPPRESSION_TAIL_MS = 3_000;

export const GOOGLE_MEET_TRANSCRIPT_ECHO_LOOKBACK_MS = 45_000;

export function recordGoogleMeetRealtimeEvent(

events: GoogleMeetRealtimeEventEntry[],

};

}

function normalizeTranscriptForEchoMatch(text: string): string[] {

return text

.toLowerCase()

.replace(/['’]/g, "")

.replace(/[^a-z0-9]+/g, " ")

.trim()

.split(/\s+/)

.filter((token) => token.length > 1);

}

function hasMeaningfulEchoOverlap(userTokens: string[], assistantTokens: string[]): boolean {

if (userTokens.length < 4 || assistantTokens.length < 4) {

return false;

}

const assistantTokenSet = new Set(assistantTokens);

const overlap = userTokens.filter((token) => assistantTokenSet.has(token)).length;

return overlap / userTokens.length >= 0.58;

}

export function isGoogleMeetLikelyAssistantEchoTranscript(params: {

transcript: GoogleMeetRealtimeTranscriptEntry[];

text: string;

nowMs?: number;

}): boolean {

const userTokens = normalizeTranscriptForEchoMatch(params.text);

if (userTokens.length < 4) {

return false;

}

const nowMs = params.nowMs ?? Date.now();

const recentAssistantText = params.transcript

.filter((entry) => {

if (entry.role !== "assistant") {

return false;

}

const at = Date.parse(entry.at);

return Number.isFinite(at) && nowMs - at <= GOOGLE_MEET_TRANSCRIPT_ECHO_LOOKBACK_MS;

})

.slice(-6)

.map((entry) => entry.text)

.join(" ");

if (!recentAssistantText.trim()) {

return false;

}

const userNormalized = userTokens.join(" ");

const assistantTokens = normalizeTranscriptForEchoMatch(recentAssistantText);

const assistantNormalized = assistantTokens.join(" ");

return (

(userNormalized.length >= 18 && assistantNormalized.includes(userNormalized)) ||

(assistantNormalized.length >= 18 && userNormalized.includes(assistantNormalized)) ||

hasMeaningfulEchoOverlap(userTokens, assistantTokens)

);

}

export function extendGoogleMeetOutputEchoSuppression(params: {

audio: Buffer;

audioFormat: GoogleMeetConfig["chrome"]["audioFormat"];

nowMs: number;

lastOutputPlayableUntilMs: number;

suppressInputUntilMs: number;

}): { lastOutputPlayableUntilMs: number; suppressInputUntilMs: number; durationMs: number } {

const bytesPerMs = params.audioFormat === "g711-ulaw-8khz" ? 8 : 48;

const durationMs = Math.ceil(params.audio.byteLength / bytesPerMs);

const playbackStartMs = Math.max(params.nowMs, params.lastOutputPlayableUntilMs);

const playbackEndMs = playbackStartMs + durationMs;

return {

durationMs,

lastOutputPlayableUntilMs: playbackEndMs,

suppressInputUntilMs: Math.max(

params.suppressInputUntilMs,

playbackEndMs + GOOGLE_MEET_OUTPUT_ECHO_SUPPRESSION_TAIL_MS,

),

};

}

export function resolveGoogleMeetRealtimeAudioFormat(config: GoogleMeetConfig) {

return config.chrome.audioFormat === "g711-ulaw-8khz"

? REALTIME_VOICE_AUDIO_FORMAT_G711_ULAW_8KHZ

let agentConsultDebounceTimer: ReturnType<typeof setTimeout> | undefined;

const suppressInputForOutput = (audio: Buffer) => {

const bytesPerMs = params.config.chrome.audioFormat === "g711-ulaw-8khz" ? 8 : 48;

const durationMs = Math.ceil(audio.byteLength / bytesPerMs);

const until = Date.now() + durationMs + 900;

suppressInputUntil = Math.max(suppressInputUntil, until);

lastOutputPlayableUntilMs = Math.max(lastOutputPlayableUntilMs, until);

const suppression = extendGoogleMeetOutputEchoSuppression({

audio,

audioFormat: params.config.chrome.audioFormat,

nowMs: Date.now(),

lastOutputPlayableUntilMs,

suppressInputUntilMs: suppressInputUntil,

});

suppressInputUntil = suppression.suppressInputUntilMs;

lastOutputPlayableUntilMs = suppression.lastOutputPlayableUntilMs;

};

const terminateProcess = (proc: BridgeProcess, signal: NodeJS.Signals = "SIGTERM") => {

recordGoogleMeetRealtimeTranscript(transcript, role, text);

params.logger.info(`[google-meet] realtime ${role}: ${text}`);

if (role === "user" && strategy === "agent") {

if (isGoogleMeetLikelyAssistantEchoTranscript({ transcript, text })) {

params.logger.info(`[google-meet] realtime ignored assistant echo transcript: ${text}`);

return;

}

enqueueAgentConsultForUserTranscript(text);

}

}