import { useQuery } from "@tanstack/react-query";
import { api, ApiError } from "@/lib/api";
import type { ClaimDetail } from "@/types";

/**
 * Per-claim detail drawer query (SP4).
 *
 * Returns `{ data, isLoading, isError, error, refetch }`:
 *  - `id === null` (drawer closed): the query is disabled and the hook
 *    short-circuits to the empty drawer state `{ data: null, isLoading:
 *    false, isError: false, error: null }`. `refetch` is a no-op since no
 *    fetch is in flight.
 *  - `id` is set: fetches `GET /api/claims/{id}` via `api.getClaimDetail`.
 *    The response is cached for 30 s so j/k navigation across claims
 *    reuses prior fetches within the drawer session (spec §3.4).
 *  - On 404: `error` is the `ApiError(status=404)` thrown by the client.
 *    We disable retries on 404 so the drawer can render the not-found
 *    state immediately rather than masking it with three back-to-back
 *    retries.
 */
export function useClaimDetail(id: string | null): {
  data: ClaimDetail | null;
  isLoading: boolean;
  isError: boolean;
  error: Error | null;
  refetch: () => void;
} {
  const q = useQuery<ClaimDetail>({
    queryKey: ["claim-detail", id],
    queryFn: () => api.getClaimDetail(id as string),
    enabled: id !== null,
    staleTime: 30 * 1000,
    retry: (failureCount, error) => {
      if (error instanceof ApiError && error.status === 404) return false;
      return failureCount < 3;
    },
  });

  if (id === null) {
    return {
      data: null,
      isLoading: false,
      isError: false,
      error: null,
      refetch: () => {},
    };
  }

  return {
    data: q.data ?? null,
    isLoading: q.isLoading,
    isError: q.isError,
    // `q.error` is typed as `Error | null` (TanStack Query v5's default
    // TError is `Error`); at runtime the api layer throws `ApiError`,
    // which is a subclass of `Error`, so the cast is safe.
    error: q.error,
    // TanStack's refetch returns a Promise; the plan's signature wants
    // a plain `() => void` so consumers can fire-and-forget.
    refetch: () => {
      void q.refetch();
    },
  };
}