Function resolveConfig

packages/engine/src/config.ts:321–464

(overrides?: Partial<EngineConfig>)

 * takes precedence over everything.
 */
export function resolveConfig(overrides?: Partial<EngineConfig>): EngineConfig {
  const env = (key: string): string | undefined => process.env[key];
  const envNum = (key: string, fallback: number): number => {
    const raw = env(key);
    if (raw === undefined || raw === "") return fallback;
    const n = Number(raw);
    return Number.isFinite(n) ? n : fallback;
  };
  const envBool = (key: string, fallback: boolean): boolean => {
    const raw = env(key);
    if (raw === undefined) return fallback;
    return raw === "true";
  };
  const envVp9CpuUsed = (): number => {
    const raw = env("PRODUCER_VP9_CPU_USED");
    if (raw === undefined || raw === "") return DEFAULT_CONFIG.vp9CpuUsed;
    return normalizeVp9CpuUsed(Number(raw));
  };
  const envBrowserGpuMode = (): EngineConfig["browserGpuMode"] => {
    const raw = env("PRODUCER_BROWSER_GPU_MODE");
    if (raw === "hardware" || raw === "software" || raw === "auto") return raw;
    return DEFAULT_CONFIG.browserGpuMode;
  };
  // Tri-state: explicit on/off via env, otherwise auto-detect from total RAM.
  const resolveLowMemoryMode = (): boolean => {
    const raw = env("PRODUCER_LOW_MEMORY_MODE")?.toLowerCase();
    if (raw === "true" || raw === "on" || raw === "1") return true;
    if (raw === "false" || raw === "off" || raw === "0") return false;
    return isLowMemorySystem();
  };
  // Opt-OUT: default ON, disabled only by an explicit falsey value.
  const resolveStaticFrameDedup = (): boolean => {
    const raw = env("HF_STATIC_DEDUP")?.trim().toLowerCase();
    return !(raw === "false" || raw === "off" || raw === "0");
  };

  // Env-var layer (backward compat)
  const fromEnv: Partial<EngineConfig> = {
    concurrency: env("PRODUCER_MAX_WORKERS") ? Number(env("PRODUCER_MAX_WORKERS")) : undefined,
    coresPerWorker: envNum("PRODUCER_CORES_PER_WORKER", DEFAULT_CONFIG.coresPerWorker),
    minParallelFrames: envNum("PRODUCER_MIN_PARALLEL_FRAMES", DEFAULT_CONFIG.minParallelFrames),
    largeRenderThreshold: envNum(
      "PRODUCER_LARGE_RENDER_THRESHOLD",
      DEFAULT_CONFIG.largeRenderThreshold,
    ),

    chromePath: env("PRODUCER_HEADLESS_SHELL_PATH"),
    disableGpu: envBool("PRODUCER_DISABLE_GPU", DEFAULT_CONFIG.disableGpu),
    browserGpuMode: envBrowserGpuMode(),
    enableBrowserPool: envBool("PRODUCER_ENABLE_BROWSER_POOL", DEFAULT_CONFIG.enableBrowserPool),
    browserTimeout: envNum("PRODUCER_PUPPETEER_LAUNCH_TIMEOUT_MS", DEFAULT_CONFIG.browserTimeout),
    protocolTimeout: envNum(
      "PRODUCER_PUPPETEER_PROTOCOL_TIMEOUT_MS",
      DEFAULT_CONFIG.protocolTimeout,
    ),
    expectedChromiumMajor: env("PRODUCER_EXPECTED_CHROMIUM_MAJOR")
      ? Number(env("PRODUCER_EXPECTED_CHROMIUM_MAJOR"))
      : undefined,