/**
 * Which Exa `/search` params are unusable per `category`.
 *
 * MEASURED against the live API on 2026-08-12, because the published docs are
 * wrong in both directions and the two categories do NOT share a list:
 *
 * | param              | category: "people"        | category: "company"   |
 * |--------------------|---------------------------|-----------------------|
 * | includeDomains     | 200, then SILENTLY IGNORED| 200, genuinely applied|
 * | excludeDomains     | HTTP 400                  | 200, genuinely applied|
 * | startPublishedDate | HTTP 400                  | HTTP 400              |
 * | endPublishedDate   | HTTP 400                  | HTTP 400              |
 *
 * The docs claim all four 400 for people (wrong: `includeDomains` does not)
 * and that `excludeDomains` 400s for company (wrong: it works). Verified by
 * observation, not by reading: `includeDomains: ["github.com"]` on a people
 * search returned five linkedin.com profiles, while the same filter on a
 * company search returned zero results, and `excludeDomains: ["stripe.com"]`
 * removed Stripe from a company search that otherwise ranked it first.
 *
 * The silently-ignored case is the dangerous one — a caller gets plausible
 * results and no signal their filter did nothing — so it is listed here
 * alongside the hard failures even though it does not error. Domain filters
 * are deliberately NOT listed for company, because there they work.
 */
export const EXA_UNSUPPORTED_PARAMS_BY_CATEGORY: Record<
  string,
  readonly string[]
> = {
  people: [
    "includeDomains",
    "excludeDomains",
    "startPublishedDate",
    "endPublishedDate",
  ],
  company: ["startPublishedDate", "endPublishedDate"],
};

/** Params unusable for `category`; empty for categories with no restrictions. */
export function unsupportedParamsForCategory(
  category: string | undefined,
): readonly string[] {
  if (!category) return [];
  return EXA_UNSUPPORTED_PARAMS_BY_CATEGORY[category] ?? [];
}

/**
 * Delete the params that do not work for this category, returning what was
 * removed so the caller can report it. Mutates `body`; a no-op for
 * unrestricted categories.
 *
 * Callers deliberately differ in how they use the return value: the agent
 * workflow step strips silently and reports `droppedParams` (a model cannot
 * foresee a provider incompatibility, and a hard 400 costs it a whole turn),
 * while `dench search` refuses outright (a human who typed the flag meant it,
 * and neither erroring nor silently ignoring it is an acceptable answer).
 */
export function stripUnsupportedParamsForCategory(
  body: Record<string, unknown>,
  category: string | undefined,
): string[] {
  const dropped: string[] = [];
  for (const key of unsupportedParamsForCategory(category)) {
    if (body[key] !== undefined) {
      delete body[key];
      dropped.push(key);
    }
  }
  return dropped;
}