/**
 * `useJailDistribution` hook.
 *
 * Fetches per-jail ban counts for the jail distribution chart.
 * Re-fetches automatically when `timeRange` or `origin` changes.
 */

import { useCallback, useEffect, useRef, useState } from "react";
import { fetchBansByJail } from "../api/dashboard";
import { handleFetchError, createStringErrorAdapter } from "../utils/fetchError";
import type { BanOriginFilter, JailBanCount, TimeRange } from "../types/ban";

// ---------------------------------------------------------------------------
// Return type
// ---------------------------------------------------------------------------

/** Return value shape for {@link useJailDistribution}. */
export interface UseJailDistributionResult {
  /** Jails ordered by ban count descending. */
  jails: JailBanCount[];
  /** Total ban count for the selected window. */
  total: number;
  /** True while a fetch is in flight. */
  loading: boolean;
  /** Error message or `null`. */
  error: string | null;
  /** Re-fetch the data immediately. */
  reload: () => void;
}

// ---------------------------------------------------------------------------
// Hook
// ---------------------------------------------------------------------------

/**
 * Fetch and expose per-jail ban counts for the `JailDistributionChart` component.
 *
 * @param timeRange - Time-range preset: `"24h"`, `"7d"`, `"30d"`, or `"365d"`.
 * @param origin    - Origin filter: `"all"`, `"blocklist"`, or `"selfblock"`.
 * @returns Jail list, total count, loading state, and error.
 */
export function useJailDistribution(
  timeRange: TimeRange,
  origin: BanOriginFilter,
): UseJailDistributionResult {
  const [jails, setJails] = useState<JailBanCount[]>([]);
  const [total, setTotal] = useState<number>(0);
  const [loading, setLoading] = useState<boolean>(true);
  const [error, setError] = useState<string | null>(null);

  const abortRef = useRef<AbortController | null>(null);

  const load = useCallback((): void => {
    abortRef.current?.abort();
    const controller = new AbortController();
    abortRef.current = controller;

    setLoading(true);
    setError(null);

    fetchBansByJail(timeRange, origin, "fail2ban", controller.signal)
      .then((data) => {
        if (controller.signal.aborted) return;
        setJails(data.jails);
        setTotal(data.total);
      })
      .catch((err: unknown) => {
        if (controller.signal.aborted) return;
        handleFetchError(err, createStringErrorAdapter(setError), "Failed to fetch jail distribution");
      })
      .finally(() => {
        if (!controller.signal.aborted) {
          setLoading(false);
        }
      });
  }, [timeRange, origin]);

  useEffect(() => {
    load();
    return (): void => {
      abortRef.current?.abort();
    };
  }, [load]);

  return { jails, total, loading, error, reload: load };
}