/**
 * Test-only utilities for seeding the feature flag override cache.
 *
 * Replaces the removed `_setOverridesForTesting` export from
 * `assistant-feature-flags.ts`. Lives here (not in the source module)
 * because production modules should not expose test backdoors.
 *
 * No source-module imports
 * ------------------------
 * This file has ZERO runtime imports from `src/`. It accesses the feature flag
 * cache's state via the shared `globalThis.vellumAssistant.featureFlagCache`
 * slot that `src/config/feature-flag-cache.ts` also reads/writes, typed by the
 * shared ambient `VellumFeatureFlagCache` (declared in
 * `src/vellum-assistant-namespace.d.ts`). That ambient type is pure
 * compile-time information — referencing it adds nothing to this file's runtime
 * import graph — so keeping the helper off the production import graph (what
 * protects the test preload from a broken `node_modules` symlink, DB ghost #3)
 * still holds.
 */

function flagSlot(): VellumFeatureFlagCache {
  const ns = (globalThis.vellumAssistant ??= {});
  return (ns.featureFlagCache ??= { overrides: null, fromGateway: false });
}

/**
 * Synchronously seed the feature flag override cache for the current test.
 *
 * Sets the cache to a clone of `overrides` and marks it as
 * gateway-populated, so subsequent `initFeatureFlagOverrides()` calls are
 * no-ops (preventing the production retry loop from running during tests).
 *
 * Tests that want the gateway IPC retry path to actually run should not
 * call this — they should leave the cache empty or call
 * `clearFeatureFlagOverridesCache()` from `assistant-feature-flags.ts`.
 */
export function setOverridesForTesting(
  overrides: Record<string, boolean | string>,
): void {
  const s = flagSlot();
  s.overrides = { ...overrides };
  s.fromGateway = true;
}