import { BarChart3, Trash2, Clock, Users, MessageSquare, Video, Mic, ChevronDown, ChevronUp, Hand, BarChart2, Download } from 'lucide-react';
import { useState } from 'react';
import api from '../services/api';
import { useLanguage } from '../contexts/LanguageContext';
import toast from 'react-hot-toast';

export default function AnalyticsList({ analytics, onRefresh, isOwner = true }) {
  const [loading, setLoading] = useState({});
  const [expanded, setExpanded] = useState({});
  const [exportMenu, setExportMenu] = useState({});
  const { t, language } = useLanguage();

  const formatDate = (dateStr) => {
    if (!dateStr) return '—';
    return new Date(dateStr).toLocaleDateString(language === 'de' ? 'de-DE' : 'en-US', {
      day: '2-digit',
      month: '2-digit',
      year: 'numeric',
      hour: '2-digit',
      minute: '2-digit',
    });
  };

  const formatDurationSec = (sec) => {
    if (!sec || sec <= 0) return '0m';
    const minutes = Math.floor(sec / 60);
    const hours = Math.floor(minutes / 60);
    const mins = minutes % 60;
    const secs = sec % 60;
    if (hours > 0) return `${hours}h ${mins}m`;
    if (minutes > 0) return `${mins}m ${secs}s`;
    return `${secs}s`;
  };

  const handleDelete = async (id) => {
    if (!confirm(t('analytics.deleteConfirm'))) return;
    setLoading(prev => ({ ...prev, [id]: 'deleting' }));
    try {
      await api.delete(`/analytics/${id}`);
      toast.success(t('analytics.deleted'));
      onRefresh?.();
    } catch {
      toast.error(t('analytics.deleteFailed'));
    } finally {
      setLoading(prev => ({ ...prev, [id]: null }));
    }
  };

  const toggleExpand = (id) => {
    setExpanded(prev => ({ ...prev, [id]: !prev[id] }));
  };

  const toggleExportMenu = (id) => {
    setExportMenu(prev => ({ ...prev, [id]: !prev[id] }));
  };

  const handleExport = async (id, format) => {
    setExportMenu(prev => ({ ...prev, [id]: false }));
    setLoading(prev => ({ ...prev, [id]: 'exporting' }));
    try {
      const response = await api.get(`/analytics/${id}/export/${format}`, { responseType: 'blob' });
      const disposition = response.headers['content-disposition'];
      const match = disposition?.match(/filename="?([^"]+)"?/);
      const filename = match?.[1] || `analytics.${format}`;
      const url = window.URL.createObjectURL(response.data);
      const a = document.createElement('a');
      a.href = url;
      a.download = filename;
      document.body.appendChild(a);
      a.click();
      a.remove();
      window.URL.revokeObjectURL(url);
      toast.success(t('analytics.exportSuccess'));
    } catch {
      toast.error(t('analytics.exportFailed'));
    } finally {
      setLoading(prev => ({ ...prev, [id]: null }));
    }
  };

  // Extract user summary from BBB learning analytics callback data
  // Payload: { meeting_id, data: { duration, start, finish, attendees: [{ name, moderator, duration, engagement: { chats, talks, raisehand, emojis, poll_votes, talk_time } }] } }
  const getUserSummary = (data) => {
    const attendees = data?.data?.attendees;
    if (!Array.isArray(attendees)) return [];
    return attendees.map(a => ({
      name: a.name || '—',
      isModerator: !!a.moderator,
      duration: a.duration || 0,
      talkTime: a.engagement?.talk_time || 0,
      chats: a.engagement?.chats || 0,
      talks: a.engagement?.talks || 0,
      raiseHand: a.engagement?.raisehand || 0,
      emojis: a.engagement?.emojis || 0,
      pollVotes: a.engagement?.poll_votes || 0,
    }));
  };

  const getMeetingSummary = (data) => ({
    duration: data?.data?.duration || 0,
    start: data?.data?.start || null,
    finish: data?.data?.finish || null,
    files: data?.data?.files || [],
    polls: data?.data?.polls || [],
  });

  if (!analytics || analytics.length === 0) {
    return (
      <div className="text-center py-12">
        <BarChart3 size={48} className="mx-auto text-th-text-s/40 mb-3" />
        <p className="text-th-text-s text-sm">{t('analytics.noData')}</p>
      </div>
    );
  }

  return (
    <div className="space-y-3">
      {analytics.map(entry => {
        const users = getUserSummary(entry.data);
        const meeting = getMeetingSummary(entry.data);
        const isExpanded = expanded[entry.id];
        const totalParticipants = users.length;
        const totalMessages = users.reduce((sum, u) => sum + u.chats, 0);

        return (
          <div key={entry.id} className="card p-4">
            <div className="flex items-start justify-between gap-4">
              <div className="flex-1 min-w-0">
                <div className="flex items-center gap-2 mb-1">
                  <h4 className="text-sm font-medium text-th-text truncate">
                    {entry.meetingName || entry.meetingId}
                  </h4>
                </div>

                <div className="flex flex-wrap items-center gap-x-4 gap-y-1 text-xs text-th-text-s">
                  <span className="flex items-center gap-1">
                    <Clock size={12} />
                    {meeting.start ? formatDate(meeting.start) : formatDate(entry.createdAt)}
                  </span>
                  <span className="flex items-center gap-1">
                    <BarChart2 size={12} />
                    {formatDurationSec(meeting.duration)}
                  </span>
                  <span className="flex items-center gap-1">
                    <Users size={12} />
                    {totalParticipants} {t('analytics.participants')}
                  </span>
                  <span className="flex items-center gap-1">
                    <MessageSquare size={12} />
                    {totalMessages} {t('analytics.messages')}
                  </span>
                </div>
              </div>

              <div className="flex items-center gap-1 flex-shrink-0">
                <div className="relative">
                  <button
                    onClick={() => toggleExportMenu(entry.id)}
                    disabled={loading[entry.id] === 'exporting'}
                    className="p-2 rounded-lg hover:bg-th-hover text-th-text-s hover:text-th-text transition-colors"
                    title={t('analytics.export')}
                  >
                    <Download size={16} />
                  </button>
                  {exportMenu[entry.id] && (
                    <div className="absolute right-0 top-full mt-1 bg-th-bg border border-th-border rounded-lg shadow-lg z-10 min-w-[120px] py-1">
                      <button
                        onClick={() => handleExport(entry.id, 'csv')}
                        className="w-full text-left px-3 py-1.5 text-sm text-th-text hover:bg-th-hover transition-colors"
                      >
                        CSV
                      </button>
                      <button
                        onClick={() => handleExport(entry.id, 'xlsx')}
                        className="w-full text-left px-3 py-1.5 text-sm text-th-text hover:bg-th-hover transition-colors"
                      >
                        Excel (.xlsx)
                      </button>
                      <button
                        onClick={() => handleExport(entry.id, 'pdf')}
                        className="w-full text-left px-3 py-1.5 text-sm text-th-text hover:bg-th-hover transition-colors"
                      >
                        PDF
                      </button>
                    </div>
                  )}
                </div>
                <button
                  onClick={() => toggleExpand(entry.id)}
                  className="p-2 rounded-lg hover:bg-th-hover text-th-text-s hover:text-th-text transition-colors"
                  title={isExpanded ? t('analytics.collapse') : t('analytics.expand')}
                >
                  {isExpanded ? <ChevronUp size={16} /> : <ChevronDown size={16} />}
                </button>
                {isOwner && (
                <button
                  onClick={() => handleDelete(entry.id)}
                  disabled={loading[entry.id] === 'deleting'}
                  className="p-2 rounded-lg hover:bg-th-hover text-th-text-s hover:text-th-error transition-colors"
                  title={t('common.delete')}
                >
                  <Trash2 size={16} />
                </button>
                )}
              </div>
            </div>

            {isExpanded && users.length > 0 && (
              <div className="mt-4 border-t border-th-border pt-4">
                <div className="overflow-x-auto">
                  <table className="w-full text-sm">
                    <thead>
                      <tr className="text-left text-xs text-th-text-s border-b border-th-border">
                        <th className="pb-2 pr-4 font-medium">{t('analytics.userName')}</th>
                        <th className="pb-2 pr-4 font-medium">{t('analytics.role')}</th>
                        <th className="pb-2 pr-4 font-medium">
                          <span className="flex items-center gap-1"><Clock size={11} />{t('analytics.duration')}</span>
                        </th>
                        <th className="pb-2 pr-4 font-medium">
                          <span className="flex items-center gap-1"><Mic size={11} />{t('analytics.talkTime')}</span>
                        </th>
                        <th className="pb-2 pr-4 font-medium">
                          <span className="flex items-center gap-1"><MessageSquare size={11} />{t('analytics.messages')}</span>
                        </th>
                        <th className="pb-2 pr-4 font-medium">
                          <span className="flex items-center gap-1"><Hand size={11} />{t('analytics.raiseHand')}</span>
                        </th>
                        <th className="pb-2 font-medium">{t('analytics.reactions')}</th>
                      </tr>
                    </thead>
                    <tbody>
                      {users.map((u, i) => (
                        <tr key={i} className="border-b border-th-border/50 last:border-0">
                          <td className="py-2 pr-4 text-th-text font-medium">{u.name}</td>
                          <td className="py-2 pr-4">
                            <span className={`px-2 py-0.5 rounded-full text-[10px] font-medium ${
                              u.isModerator
                                ? 'bg-th-accent/15 text-th-accent'
                                : 'bg-th-bg-s text-th-text-s'
                            }`}>
                              {u.isModerator ? t('analytics.moderator') : t('analytics.viewer')}
                            </span>
                          </td>
                          <td className="py-2 pr-4 text-th-text-s">{formatDurationSec(u.duration)}</td>
                          <td className="py-2 pr-4 text-th-text-s">{formatDurationSec(u.talkTime)}</td>
                          <td className="py-2 pr-4 text-th-text-s">{u.chats}</td>
                          <td className="py-2 pr-4 text-th-text-s">{u.raiseHand}</td>
                          <td className="py-2 text-th-text-s">{u.emojis}</td>
                        </tr>
                      ))}
                    </tbody>
                  </table>
                </div>
              </div>
            )}
          </div>
        );
      })}
    </div>
  );
}
