/**
 * Global header search — fans out to three independent sources in parallel.
 *
 * Each source is its own `useQuery`, so the fastest one (cases, plain SQL)
 * shows up immediately while the slower vector searches stream in. A failure
 * in one source does not block the others — the result panel renders per-
 * source skeletons and per-source error states.
 *
 * Sources:
 *   - cases     → GET /api/search/cases (SQL ILIKE on case_number/address/parties)
 *   - precedent → GET /api/precedent-library/search (semantic, halachot+chunks)
 *   - documents → GET /api/search (semantic, all case docs + past decisions)
 */

import { useQuery } from "@tanstack/react-query";
import { apiRequest } from "./client";
import type { SearchHit as PrecedentHit } from "./precedent-library";

export type CaseHit = {
  case_number: string;
  title: string;
  property_address: string | null;
  status: string | null;
  practice_area: string | null;
  appeal_subtype: string | null;
};

export type DocumentHit = {
  score: number;
  case_number: string;
  document: string;
  section: string;
  page: number | null;
  content: string;
};

const MIN_QUERY_LEN = 2;
const STALE_MS = 10_000;
const PER_SOURCE_LIMIT = 5;

const enabled = (q: string) => q.trim().length >= MIN_QUERY_LEN;

export function useCasesSearch(query: string) {
  return useQuery({
    queryKey: ["global-search", "cases", query],
    queryFn: ({ signal }) =>
      apiRequest<{ items: CaseHit[]; count: number }>(
        `/api/search/cases?q=${encodeURIComponent(query)}&limit=${PER_SOURCE_LIMIT}`,
        { signal },
      ),
    enabled: enabled(query),
    staleTime: STALE_MS,
    placeholderData: (prev) => prev,
  });
}

export function usePrecedentSearch(query: string) {
  return useQuery({
    queryKey: ["global-search", "precedent", query],
    queryFn: ({ signal }) => {
      const p = new URLSearchParams({
        q: query,
        limit: String(PER_SOURCE_LIMIT),
        include_halachot: "true",
      });
      return apiRequest<{ items: PrecedentHit[]; count: number }>(
        `/api/precedent-library/search?${p.toString()}`,
        { signal },
      );
    },
    enabled: enabled(query),
    staleTime: STALE_MS,
    placeholderData: (prev) => prev,
  });
}

/**
 * The /api/search endpoint returns either an array of DocumentHit, or
 * `{message: "לא נמצאו תוצאות."}` when empty. Normalize to a plain array.
 */
export function useDocumentsSearch(query: string) {
  return useQuery({
    queryKey: ["global-search", "documents", query],
    queryFn: async ({ signal }) => {
      const raw = await apiRequest<DocumentHit[] | { message: string }>(
        `/api/search?query=${encodeURIComponent(query)}&limit=${PER_SOURCE_LIMIT}`,
        { signal },
      );
      return Array.isArray(raw) ? raw : [];
    },
    enabled: enabled(query),
    staleTime: STALE_MS,
    placeholderData: (prev) => prev,
  });
}

export function useGlobalSearch(query: string) {
  const cases = useCasesSearch(query);
  const precedent = usePrecedentSearch(query);
  const documents = useDocumentsSearch(query);

  const isQueryReady = enabled(query);
  const anyLoading =
    isQueryReady && (cases.isLoading || precedent.isLoading || documents.isLoading);

  return {
    cases,
    precedent,
    documents,
    isQueryReady,
    anyLoading,
  };
}