/**
 * @module embeddings/deterministicEmbedMode
 * @description Single source of truth for "use deterministic test embeddings".
 *
 * Brainy's embedding model is a real WASM transformer — correct, but slow on CPU
 * (a forward pass per text). For TEST tiers that exercise database *logic* (HNSW
 * build + search, graph traversal, metadata filtering, transactions, storage,
 * VFS, find composition), the embedding's semantic *quality* is irrelevant; only
 * a deterministic, content-derived vector is needed. Switching the embedder to a
 * deterministic stand-in keeps every other code path real while turning a
 * multi-hour suite into a sub-minute, gateable one. Semantic quality and the
 * real embedding pipeline are covered separately by the real-model test tier.
 *
 * This flag is honored ONLY outside production: {@link EmbeddingManager} throws
 * if it is set while `NODE_ENV=production` (mock vectors in prod is a security
 * risk). Enabled by env var or global so test setup files can opt in per tier.
 */

interface DeterministicEmbedGlobals {
  __BRAINY_DETERMINISTIC_EMBED__?: boolean
  /** Legacy alias — the original unit-test-only spelling. */
  __BRAINY_UNIT_TEST__?: boolean
}

/**
 * @description Whether the deterministic test embedder should be used instead of
 * the real WASM model. True when `BRAINY_DETERMINISTIC_EMBEDDINGS=true` or the
 * legacy `BRAINY_UNIT_TEST=true` env var is set, or the matching global is set.
 * @returns `true` to use deterministic embeddings, `false` for the real model.
 */
export function isDeterministicEmbedMode(): boolean {
  const g = globalThis as DeterministicEmbedGlobals
  return (
    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS === 'true' ||
    process.env.BRAINY_UNIT_TEST === 'true' ||
    g.__BRAINY_DETERMINISTIC_EMBED__ === true ||
    g.__BRAINY_UNIT_TEST__ === true
  )
}
