import { existsSync } from "node:fs";import { resolve } from "node:path";import type { AppContext } from "../../app-context";import { resolveBinary, runCommandAsync } from "../../core/command";import { SttIntegrationError } from "../../services/stt";import type { SttMode } from "../../services/stt";import { TtsIntegrationError } from "../../services/tts";import type { TtsMode } from "../../services/tts";const AUDIO_DEFAULT_MODE = "strict";const AUDIO_TRANSCODE_TIMEOUT_MS = 60_000; export const parseField = (value: FormDataEntryValue | null): string | undefined => {  if (typeof value !== "string") return undefined;  const trimmed = value.trim();  return trimmed.length > 0 ? trimmed : undefined;}; export const parseMode = (value: FormDataEntryValue | null): SttMode => {  const modeValue = (parseField(value) ?? AUDIO_DEFAULT_MODE).toLowerCase();  if (modeValue === "strict" || modeValue === "best_effort") {    return modeValue;  }  throw new SttIntegrationError(400, "invalid_mode", "mode must be strict or best_effort");}; export const parseJsonMode = (value: unknown): TtsMode => {  if (typeof value !== "string" || value.trim().length === 0) {    return AUDIO_DEFAULT_MODE;  }  const normalized = value.trim().toLowerCase();  if (normalized === "strict" || normalized === "best_effort") {    return normalized;  }  throw new TtsIntegrationError(400, "invalid_mode", "mode must be strict or best_effort");}; export const looksLikeWav = (bytes: Uint8Array): boolean => {  // Verify the RIFF/WAVE header rather than trusting a client-supplied MIME  // type: a client sending arbitrary bytes as audio/wav would otherwise skip  // transcode and feed non-WAV data straight to the STT engine.  if (bytes.length < 12) return false;  const riff = String.fromCharCode(...bytes.slice(0, 4));  const wave = String.fromCharCode(...bytes.slice(8, 12));  return riff === "RIFF" && wave === "WAVE";}; type AudioModelError = new (  status: number,  code: string,  message: string,  details?: Record<string, unknown>,) => Error; const resolveAudioModelPath = (  context: AppContext,  requested: string | undefined,  subdir: "stt" | "tts",  envVariable: string,  IntegrationError: AudioModelError,): { requestedModel: string; modelPath: string } => {  const requestedModel = requested || process.env[envVariable]?.trim();  if (!requestedModel) {    throw new IntegrationError(      400,      "model_missing",      `No ${subdir.toUpperCase()} model provided. Set model field or ${envVariable}.`,    );  }   const modelPath = requestedModel.includes("/")    ? resolve(requestedModel)    : resolve(context.config.models_dir, subdir, requestedModel);   if (!existsSync(modelPath)) {    throw new IntegrationError(      400,      "model_not_found",      `${subdir.toUpperCase()} model path does not exist`,      { requested_model: requestedModel, resolved_model_path: modelPath },    );  }   return { requestedModel, modelPath };}; export const resolveSttModelPath = (  context: AppContext,  modelField: FormDataEntryValue | null,): { requestedModel: string; modelPath: string } =>  resolveAudioModelPath(    context,    parseField(modelField),    "stt",    "LOCAL_STUDIO_STT_MODEL",    SttIntegrationError,  ); export const resolveTtsModelPath = (  context: AppContext,  modelValue: unknown,): { requestedModel: string; modelPath: string } =>  resolveAudioModelPath(    context,    typeof modelValue === "string" ? modelValue.trim() : undefined,    "tts",    "LOCAL_STUDIO_TTS_MODEL",    TtsIntegrationError,  ); export const ensureServiceLease = async (  context: AppContext,  mode: SttMode | TtsMode,  serviceId: "stt" | "tts",): Promise<Record<string, unknown> | null> => {  const holder = await context.processManager.findInferenceProcess(context.config.inference_port);  if (!holder) {    return null;  }   if (mode === "best_effort") {    return null;  }   return {    code: "gpu_lease_conflict",    requested_service: { id: serviceId },    holder_service: { id: "llm" },    actions: ["best_effort"],  };}; export const defaultTranscodeToWav = async (options: {  sourcePath: string;  outputPath: string;}): Promise<string> => {  const ffmpegPath = resolveBinary(process.env["LOCAL_STUDIO_FFMPEG_CLI"] ?? "ffmpeg");  if (!ffmpegPath) {    throw new SttIntegrationError(      503,      "ffmpeg_missing",      "ffmpeg is required for non-WAV uploads. Install ffmpeg or upload WAV input.",    );  }   const result = await runCommandAsync(    ffmpegPath,    ["-y", "-i", options.sourcePath, "-ac", "1", "-ar", "16000", "-f", "wav", options.outputPath],    { timeoutMs: AUDIO_TRANSCODE_TIMEOUT_MS },  );   if (result.timedOut) {    throw new SttIntegrationError(504, "audio_transcode_timeout", "Audio transcode timed out", {      stderr: result.stderr,      stdout: result.stdout,    });  }   if (result.status !== 0) {    throw new SttIntegrationError(      400,      "audio_transcode_failed",      "Failed to transcode audio to WAV",      {        exit_code: result.status,        signal: result.signal,        stderr: result.stderr,        stdout: result.stdout,      },    );  }   return options.outputPath;};