import React, { useEffect, useMemo, useState } from 'react';
import { api, errorMessage } from '../../services/apiClient.ts';
import type { Kandang, Site } from '../../types/api.ts';
import { Banner } from '../ui/Feedback.tsx';
import FeedInButtonGrid from './FeedInButtonGrid.tsx';

type FeedInButtonPanelProps = {
  variant?: 'default' | 'kiosk';
};

const hasConfiguredUrls = (kandang: Kandang): boolean =>
  (kandang.feed_in_button_urls ?? []).some((entry) => entry.url.trim());

const FeedInButtonPanel: React.FC<FeedInButtonPanelProps> = ({ variant = 'default' }) => {
  const [sites, setSites] = useState<Site[]>([]);
  const [kandangs, setKandangs] = useState<Kandang[]>([]);
  const [selectedSiteId, setSelectedSiteId] = useState<string | null>(null);
  const [selectedKandangId, setSelectedKandangId] = useState<number | 'all'>('all');
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const isKiosk = variant === 'kiosk';

  useEffect(() => {
    let cancelled = false;
    (async () => {
      setLoading(true);
      setError(null);
      try {
        const nextSites = await api.sites.list();
        if (cancelled) return;
        setSites(nextSites);
        setSelectedSiteId((prev) => {
          if (prev && nextSites.some((site) => site.id === prev)) return prev;
          return nextSites[0]?.id ?? null;
        });
      } catch (err) {
        if (!cancelled) setError(errorMessage(err));
      } finally {
        if (!cancelled) setLoading(false);
      }
    })();
    return () => {
      cancelled = true;
    };
  }, []);

  useEffect(() => {
    if (selectedSiteId == null) {
      setKandangs([]);
      return;
    }
    let cancelled = false;
    (async () => {
      setLoading(true);
      setError(null);
      try {
        const nextKandangs = await api.kandangs.list({ site_id: selectedSiteId });
        if (cancelled) return;
        setKandangs(nextKandangs);
        setSelectedKandangId('all');
      } catch (err) {
        if (!cancelled) setError(errorMessage(err));
      } finally {
        if (!cancelled) setLoading(false);
      }
    })();
    return () => {
      cancelled = true;
    };
  }, [selectedSiteId]);

  const filterableKandangs = useMemo(() => kandangs.filter(hasConfiguredUrls), [kandangs]);

  const displayedKandangs = useMemo(() => {
    if (selectedKandangId === 'all') return filterableKandangs;
    return filterableKandangs.filter((kandang) => kandang.id === selectedKandangId);
  }, [filterableKandangs, selectedKandangId]);

  const chipClass = (active: boolean) =>
    `px-4 py-2 rounded-full text-sm font-semibold border transition-colors ${
      active
        ? 'bg-red-600 text-white border-red-600 shadow-sm'
        : 'bg-white text-gray-700 border-gray-300 hover:border-red-300 hover:text-red-600'
    }`;

  return (
    <div className={isKiosk ? 'max-w-5xl mx-auto space-y-6' : 'space-y-6'}>
      {error && <Banner kind="error">{error}</Banner>}

      {(sites.length > 1 || filterableKandangs.length > 0) && (
        <div className="bg-white rounded-xl shadow-sm border border-gray-200 p-4 space-y-4">
          {sites.length > 1 && (
            <div className="flex flex-col sm:flex-row sm:items-center gap-2">
              <label className="text-sm font-medium text-gray-700 shrink-0" htmlFor="feed-in-site">
                Site
              </label>
              <select
                id="feed-in-site"
                value={selectedSiteId ?? ''}
                onChange={(e) => setSelectedSiteId(e.target.value ? e.target.value : null)}
                className="border border-gray-300 rounded-md px-3 py-2 text-sm w-full sm:max-w-xs focus:ring-red-500 focus:border-red-500"
              >
                {sites.map((site) => (
                  <option key={site.id} value={site.id}>
                    {site.site_name}
                  </option>
                ))}
              </select>
            </div>
          )}

          {filterableKandangs.length > 0 && (
            <div>
              <p className="text-sm font-medium text-gray-700 mb-2">Kandang</p>
              <div className="flex flex-wrap gap-2">
                <button
                  type="button"
                  className={chipClass(selectedKandangId === 'all')}
                  onClick={() => setSelectedKandangId('all')}
                >
                  Semua
                </button>
                {filterableKandangs.map((kandang) => (
                  <button
                    key={kandang.id}
                    type="button"
                    className={chipClass(selectedKandangId === kandang.id)}
                    onClick={() => setSelectedKandangId(kandang.id)}
                  >
                    {kandang.kandang_name}
                  </button>
                ))}
              </div>
            </div>
          )}
        </div>
      )}

      {loading ? (
        <div className="text-center text-sm text-gray-500 py-10">Memuat kandang...</div>
      ) : (
        <FeedInButtonGrid kandangs={displayedKandangs} variant={variant} />
      )}
    </div>
  );
};

export default FeedInButtonPanel;