import { useState, useEffect } from 'react';
import { useNavigate, Link } from 'react-router-dom';
import Layout from '../components/layout/Layout';
import { useAuth } from '../contexts/AuthContext';
import { matchesAPI } from '../services/api';
import { MessageCircle, Check, X, Loader2, Users, Calendar, MapPin } from 'lucide-react';
import { connectSocket, disconnectSocket, getSocket } from '../services/socket';

const MatchesPage = () => {
  const { user } = useAuth();
  const navigate = useNavigate();
  const [matches, setMatches] = useState([]);
  const [loading, setLoading] = useState(true);
  const [filter, setFilter] = useState('all'); // 'all', 'pending', 'accepted'
  const [processingMatchId, setProcessingMatchId] = useState(null);

  useEffect(() => {
    loadMatches();

    // Connect to socket for real-time updates
    const token = localStorage.getItem('token');
    if (token && user) {
      connectSocket(token, user.id);

      const socket = getSocket();
      if (socket) {
        // Listen for match notifications
        socket.on('match_request_received', handleMatchRequestReceived);
        socket.on('match_accepted', handleMatchAccepted);
        socket.on('match_cancelled', handleMatchCancelled);
      }
    }

    return () => {
      const socket = getSocket();
      if (socket) {
        socket.off('match_request_received', handleMatchRequestReceived);
        socket.off('match_accepted', handleMatchAccepted);
        socket.off('match_cancelled', handleMatchCancelled);
      }
      disconnectSocket();
    };
  }, [user]);

  const loadMatches = async () => {
    try {
      setLoading(true);
      const result = await matchesAPI.getMatches();
      setMatches(result.data || []);
    } catch (error) {
      console.error('Failed to load matches:', error);
    } finally {
      setLoading(false);
    }
  };

  const handleMatchRequestReceived = (data) => {
    // Reload matches to show new request
    loadMatches();
  };

  const handleMatchAccepted = (data) => {
    // Reload matches to update status
    loadMatches();
  };

  const handleMatchCancelled = (data) => {
    // Remove cancelled match from list
    setMatches(prev => prev.filter(m => m.slug !== data.matchSlug));
  };

  const handleAccept = async (matchSlug) => {
    try {
      setProcessingMatchId(matchSlug);
      await matchesAPI.acceptMatch(matchSlug);

      // Reload matches
      await loadMatches();

      // Show success message
      alert('Match accepted! You can now chat with your partner.');
    } catch (error) {
      console.error('Failed to accept match:', error);
      alert('Failed to accept match. Please try again.');
    } finally {
      setProcessingMatchId(null);
    }
  };

  const handleReject = async (matchSlug) => {
    if (!confirm('Are you sure you want to reject this match request?')) {
      return;
    }

    try {
      setProcessingMatchId(matchSlug);
      await matchesAPI.deleteMatch(matchSlug);

      // Remove from list
      setMatches(prev => prev.filter(m => m.slug !== matchSlug));
    } catch (error) {
      console.error('Failed to reject match:', error);
      alert('Failed to reject match. Please try again.');
    } finally {
      setProcessingMatchId(null);
    }
  };

  const handleOpenChat = (match) => {
    if (match.status === 'accepted' && match.roomId) {
      navigate(`/matches/${match.slug}/chat`);
    }
  };

  // Filter matches based on selected filter
  const filteredMatches = matches.filter(match => {
    if (filter === 'all') return true;
    return match.status === filter;
  });

  // Separate pending incoming matches (where user is recipient)
  const pendingIncoming = filteredMatches.filter(m => m.status === 'pending' && !m.isInitiator);
  const otherMatches = filteredMatches.filter(m => !(m.status === 'pending' && !m.isInitiator));

  return (
    <Layout>
      <div className="max-w-4xl mx-auto">
        <div className="mb-6">
          <h1 className="text-3xl font-bold text-gray-900">Match Requests</h1>
          <p className="text-gray-600 mt-2">
            Manage your dance partner connections
          </p>
        </div>

        {/* Filter Tabs */}
        <div className="bg-white rounded-lg shadow-sm p-1 mb-6 flex gap-1">
          <button
            onClick={() => setFilter('all')}
            className={`flex-1 px-4 py-2 rounded-md text-sm font-medium transition-colors ${
              filter === 'all'
                ? 'bg-primary-600 text-white'
                : 'text-gray-600 hover:bg-gray-100'
            }`}
          >
            All ({matches.length})
          </button>
          <button
            onClick={() => setFilter('pending')}
            className={`flex-1 px-4 py-2 rounded-md text-sm font-medium transition-colors ${
              filter === 'pending'
                ? 'bg-primary-600 text-white'
                : 'text-gray-600 hover:bg-gray-100'
            }`}
          >
            Pending ({matches.filter(m => m.status === 'pending').length})
          </button>
          <button
            onClick={() => setFilter('accepted')}
            className={`flex-1 px-4 py-2 rounded-md text-sm font-medium transition-colors ${
              filter === 'accepted'
                ? 'bg-primary-600 text-white'
                : 'text-gray-600 hover:bg-gray-100'
            }`}
          >
            Active ({matches.filter(m => m.status === 'accepted').length})
          </button>
        </div>

        {loading ? (
          <div className="flex justify-center items-center py-12">
            <Loader2 className="w-8 h-8 animate-spin text-primary-600" />
          </div>
        ) : (
          <>
            {/* Pending Incoming Requests Section */}
            {pendingIncoming.length > 0 && (
              <div className="mb-6">
                <h2 className="text-lg font-semibold text-gray-900 mb-3 flex items-center gap-2">
                  <Users className="w-5 h-5 text-amber-600" />
                  Incoming Requests
                </h2>
                <div className="space-y-3">
                  {pendingIncoming.map(match => (
                    <MatchCard
                      key={match.id}
                      match={match}
                      onAccept={handleAccept}
                      onReject={handleReject}
                      onOpenChat={handleOpenChat}
                      processing={processingMatchId === match.slug}
                    />
                  ))}
                </div>
              </div>
            )}

            {/* Other Matches */}
            {otherMatches.length > 0 && (
              <div>
                <h2 className="text-lg font-semibold text-gray-900 mb-3">
                  {pendingIncoming.length > 0 ? 'Other Matches' : 'Your Matches'}
                </h2>
                <div className="space-y-3">
                  {otherMatches.map(match => (
                    <MatchCard
                      key={match.id}
                      match={match}
                      onAccept={handleAccept}
                      onReject={handleReject}
                      onOpenChat={handleOpenChat}
                      processing={processingMatchId === match.slug}
                    />
                  ))}
                </div>
              </div>
            )}

            {/* Empty State */}
            {filteredMatches.length === 0 && (
              <div className="text-center py-12">
                <Users className="w-16 h-16 text-gray-300 mx-auto mb-4" />
                <h3 className="text-lg font-medium text-gray-900 mb-2">
                  No matches found
                </h3>
                <p className="text-gray-600">
                  {filter === 'all'
                    ? 'You have no match requests yet. Connect with other dancers at events!'
                    : `You have no ${filter} matches.`}
                </p>
              </div>
            )}
          </>
        )}
      </div>
    </Layout>
  );
};

const MatchCard = ({ match, onAccept, onReject, onOpenChat, processing }) => {
  const isIncoming = !match.isInitiator && match.status === 'pending';
  const isOutgoing = match.isInitiator && match.status === 'pending';
  const isAccepted = match.status === 'accepted';

  return (
    <div className="bg-white rounded-lg shadow-sm border border-gray-200 p-4 hover:shadow-md transition-shadow">
      <div className="flex items-start justify-between">
        <div className="flex-1">
          <div className="flex items-center gap-3 mb-2">
            <Link to={`/${match.partner.username}`} className="flex-shrink-0">
              <img
                src={match.partner.avatar || `https://api.dicebear.com/7.x/avataaars/svg?seed=${match.partner.username}`}
                alt={match.partner.username}
                className="w-12 h-12 rounded-full hover:ring-2 hover:ring-primary-500 transition-all"
              />
            </Link>
            <div>
              <Link to={`/${match.partner.username}`}>
                <h3 className="font-semibold text-gray-900 hover:text-primary-600 transition-colors">
                  {match.partner.firstName && match.partner.lastName
                    ? `${match.partner.firstName} ${match.partner.lastName}`
                    : match.partner.username}
                </h3>
              </Link>
              <p className="text-sm text-gray-600">@{match.partner.username}</p>
            </div>
          </div>

          <div className="flex items-center gap-4 text-sm text-gray-600 mb-2">
            <div className="flex items-center gap-1">
              <Calendar className="w-4 h-4" />
              <span>{match.event.name}</span>
            </div>
            <div className="flex items-center gap-1">
              <MapPin className="w-4 h-4" />
              <span>{match.event.location}</span>
            </div>
          </div>

          <div className="flex items-center gap-2">
            {isIncoming && (
              <span className="text-xs px-2 py-1 bg-amber-100 text-amber-700 rounded-full font-medium">
                Incoming Request
              </span>
            )}
            {isOutgoing && (
              <span className="text-xs px-2 py-1 bg-blue-100 text-blue-700 rounded-full font-medium">
                Sent Request
              </span>
            )}
            {isAccepted && (
              <span className="text-xs px-2 py-1 bg-green-100 text-green-700 rounded-full font-medium">
                Active Match
              </span>
            )}
          </div>
        </div>

        <div className="flex items-center gap-2 ml-4">
          {isIncoming && (
            <>
              <button
                onClick={() => onAccept(match.slug)}
                disabled={processing}
                className="p-2 bg-green-600 text-white rounded-full hover:bg-green-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
                title="Accept"
              >
                {processing ? (
                  <Loader2 className="w-5 h-5 animate-spin" />
                ) : (
                  <Check className="w-5 h-5" />
                )}
              </button>
              <button
                onClick={() => onReject(match.slug)}
                disabled={processing}
                className="p-2 bg-red-600 text-white rounded-full hover:bg-red-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
                title="Reject"
              >
                <X className="w-5 h-5" />
              </button>
            </>
          )}

          {isOutgoing && (
            <button
              onClick={() => onReject(match.slug)}
              disabled={processing}
              className="px-3 py-1.5 text-sm border border-gray-300 text-gray-700 rounded-md hover:bg-gray-50 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
            >
              Cancel Request
            </button>
          )}

          {isAccepted && (
            <button
              onClick={() => onOpenChat(match)}
              className="flex items-center gap-2 px-4 py-2 bg-primary-600 text-white rounded-md hover:bg-primary-700 transition-colors"
            >
              <MessageCircle className="w-4 h-4" />
              Open Chat
            </button>
          )}
        </div>
      </div>
    </div>
  );
};

export default MatchesPage;