import { useState, useEffect } from 'react';
import { IconTrophy, IconMapPin, IconCloud, IconHash, IconChartBar } from '@tabler/icons-react';

/**
 * Компонент для отображения Top-N статистики
 */
function TopNStats({ data, loading }) {
  const [topCountries, setTopCountries] = useState([]);
  const [topProviders, setTopProviders] = useState([]);
  const [_topCommunities, _setTopCommunities] = useState([]);

  useEffect(() => {
    if (!data || !Array.isArray(data.servers)) return;

    // Подсчет по странам
    const countriesMap = new Map();
    data.servers.forEach(s => {
      const country = s.country || 'Unknown';
      countriesMap.set(country, (countriesMap.get(country) || 0) + 1);
    });
    const topC = Array.from(countriesMap.entries())
      .map(([name, count]) => ({ name, count }))
      .sort((a, b) => b.count - a.count)
      .slice(0, 5);
    setTopCountries(topC);

    // Подсчет по провайдерам
    const providersMap = new Map();
    data.servers.forEach(s => {
      const provider = s.provider || 'Unknown';
      providersMap.set(provider, (providersMap.get(provider) || 0) + 1);
    });
    const topP = Array.from(providersMap.entries())
      .map(([name, count]) => ({ name, count }))
      .sort((a, b) => b.count - a.count)
      .slice(0, 5);
    setTopProviders(topP);

  }, [data]);

  if (loading) {
    return (
      <div className="card">
        <div className="card-body text-center py-4">
          <div className="spinner-border spinner-border-sm me-2" role="status"></div>
          <span className="text-muted">Загрузка статистики...</span>
        </div>
      </div>
    );
  }

  const getFlagEmoji = (countryCode) => {
    if (!countryCode) return '🌐';
    const map = { SWE: 'SE', UK: 'GB', RU: 'RU', US: 'US', DE: 'DE', NL: 'NL', SG: 'SG' };
    const cc = (map[countryCode.toUpperCase()] || countryCode).slice(0, 2);
    if (cc.length !== 2) return '🌐';
    return cc.replace(/./g, (ch) => String.fromCodePoint(127397 + ch.charCodeAt()));
  };

  return (
    <div className="row g-2 g-md-3">
      {/* Top Страны */}
      <div className="col-12 col-md-6">
        <div className="card h-100">
          <div className="card-header">
            <h3 className="card-title">
              <IconMapPin className="me-2" size={20} />
              Top-5 Стран
            </h3>
          </div>
          <div className="card-body">
            {topCountries.length === 0 ? (
              <div className="text-center text-muted">Нет данных</div>
            ) : (
              <div className="list-group list-group-flush">
                {topCountries.map((item, idx) => {
                  const maxCount = topCountries[0]?.count || 1;
                  const percentage = ((item.count / maxCount) * 100).toFixed(0);
                  return (
                    <div key={item.name} className="list-group-item px-0">
                      <div className="d-flex align-items-center justify-content-between mb-1">
                        <div className="d-flex align-items-center">
                          <span className="me-2" style={{ fontSize: idx === 0 ? '1.5rem' : '1.2rem' }}>
                            {idx === 0 ? '🏆' : getFlagEmoji(item.name)}
                          </span>
                          <strong>{item.name}</strong>
                        </div>
                        <span className="badge bg-blue-lt text-blue">{item.count}</span>
                      </div>
                      <div className="progress" style={{ height: 6 }}>
                        <div 
                          className="progress-bar bg-blue" 
                          style={{ width: `${percentage}%` }}
                          role="progressbar"
                          aria-valuenow={percentage}
                          aria-valuemin="0"
                          aria-valuemax="100"
                        ></div>
                      </div>
                    </div>
                  );
                })}
              </div>
            )}
          </div>
        </div>
      </div>

      {/* Top Провайдеры */}
      <div className="col-12 col-md-6">
        <div className="card h-100">
          <div className="card-header">
            <h3 className="card-title">
              <IconCloud className="me-2" size={20} />
              Top-5 Провайдеров
            </h3>
          </div>
          <div className="card-body">
            {topProviders.length === 0 ? (
              <div className="text-center text-muted">Нет данных</div>
            ) : (
              <div className="list-group list-group-flush">
                {topProviders.map((item, idx) => {
                  const maxCount = topProviders[0]?.count || 1;
                  const percentage = ((item.count / maxCount) * 100).toFixed(0);
                  return (
                    <div key={item.name} className="list-group-item px-0">
                      <div className="d-flex align-items-center justify-content-between mb-1">
                        <div className="d-flex align-items-center">
                          <span className="me-2" style={{ fontSize: '1.2rem' }}>
                            {idx === 0 ? '🏆' : '☁️'}
                          </span>
                          <strong className="text-truncate" style={{ maxWidth: 200 }}>{item.name}</strong>
                        </div>
                        <span className="badge bg-green-lt text-green">{item.count}</span>
                      </div>
                      <div className="progress" style={{ height: 6 }}>
                        <div 
                          className="progress-bar bg-green" 
                          style={{ width: `${percentage}%` }}
                          role="progressbar"
                          aria-valuenow={percentage}
                          aria-valuemin="0"
                          aria-valuemax="100"
                        ></div>
                      </div>
                    </div>
                  );
                })}
              </div>
            )}
          </div>
        </div>
      </div>
    </div>
  );
}

export default TopNStats;