import { useState, useEffect, useRef } from 'react';
import { apiFetch } from '../api/apiClient';
import { API_URL } from '../config/authConstants';

const TERMINAL_STATUSES = ['READY', 'FAILED'];
const POLL_INTERVAL_MS = 3000;
const MAX_POLL_ATTEMPTS = 100;

/**
 * Поллинг статуса транскодинга медиа.
 * @param {number|string} advertisingId — id сущности
 * @param {boolean} enabled — включать поллинг
 * @param {string} [path="ads"] — сегмент пути (например, "ads" или "fullscreen-ads")
 * @returns {string} транскодинг-статус и его производные (PROCESSING/READY/FAILED/TIMEOUT)
 */
export function useTranscodingStatusPolling(advertisingId, enabled, path = "ads") {
  const [status, setStatus] = useState('PROCESSING');
  const attemptsRef = useRef(0);

  useEffect(() => {
    if (!enabled || !advertisingId) return;

    attemptsRef.current = 0;
    let cancelled = false;
    let timeoutId;

    const poll = async () => {
      if (cancelled) return;

      try {
        const res = await apiFetch(`${API_URL}/api/v1/admin/${path}/${advertisingId}/status`);

        if (!res.ok) {
          throw new Error(`Status check failed: ${res.status}`);
        }

        const data = await res.json();
        if (cancelled) return;

        setStatus(data.transcodingStatus);

        attemptsRef.current += 1;
        const isTerminal = TERMINAL_STATUSES.includes(data.transcodingStatus);
        const exceededAttempts = attemptsRef.current >= MAX_POLL_ATTEMPTS;

        if (!isTerminal && !exceededAttempts) {
          timeoutId = setTimeout(poll, POLL_INTERVAL_MS);
        } else if (exceededAttempts && !isTerminal) {
          setStatus('TIMEOUT');
        }
      } catch (err) {
        console.warn('Status poll failed, retrying', err);
        timeoutId = setTimeout(poll, POLL_INTERVAL_MS);
      }
    };

    poll();

    return () => {
      cancelled = true;
      clearTimeout(timeoutId);
    };
  }, [advertisingId, enabled, path]);

  return status;
}