import { useState, useRef, useEffect } from 'react';
import { useParams, useNavigate } from 'react-router-dom';
import Layout from '../components/layout/Layout';
import { useAuth } from '../contexts/AuthContext';
import { mockPrivateMessages } from '../mocks/messages';
import { mockUsers } from '../mocks/users';
import { Send, Video, Upload, X, Check, Link as LinkIcon } from 'lucide-react';

const MatchChatPage = () => {
  const { matchId } = useParams();
  const { user } = useAuth();
  const navigate = useNavigate();
  const [messages, setMessages] = useState(mockPrivateMessages);
  const [newMessage, setNewMessage] = useState('');
  const [selectedFile, setSelectedFile] = useState(null);
  const [isTransferring, setIsTransferring] = useState(false);
  const [transferProgress, setTransferProgress] = useState(0);
  const [webrtcStatus, setWebrtcStatus] = useState('disconnected'); // disconnected, connecting, connected, failed
  const [showLinkInput, setShowLinkInput] = useState(false);
  const [videoLink, setVideoLink] = useState('');
  const messagesEndRef = useRef(null);
  const fileInputRef = useRef(null);

  // Partner user (mockup)
  const partner = mockUsers[1]; // sarah_swing

  const scrollToBottom = () => {
    messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
  };

  useEffect(() => {
    scrollToBottom();
  }, [messages]);

  const handleSendMessage = (e) => {
    e.preventDefault();
    if (!newMessage.trim()) return;

    const message = {
      id: messages.length + 1,
      room_id: 10,
      user_id: user.id,
      username: user.username,
      content: newMessage,
      type: 'text',
      created_at: new Date().toISOString(),
    };

    setMessages([...messages, message]);
    setNewMessage('');
  };

  const handleFileSelect = (e) => {
    const file = e.target.files[0];
    if (file && file.type.startsWith('video/')) {
      setSelectedFile(file);
    } else {
      alert('Proszę wybrać plik wideo');
    }
  };

  const simulateWebRTCConnection = () => {
    setWebrtcStatus('connecting');
    setTimeout(() => {
      setWebrtcStatus('connected');
    }, 1500);
  };

  const handleStartTransfer = () => {
    if (!selectedFile) return;

    // Simulate WebRTC connection
    simulateWebRTCConnection();

    setTimeout(() => {
      setIsTransferring(true);
      setTransferProgress(0);

      // Simulate transfer progress
      const interval = setInterval(() => {
        setTransferProgress((prev) => {
          if (prev >= 100) {
            clearInterval(interval);
            setIsTransferring(false);
            setSelectedFile(null);
            setWebrtcStatus('disconnected');

            // Add message about completed transfer
            const message = {
              id: messages.length + 1,
              room_id: 10,
              user_id: user.id,
              username: user.username,
              content: `📹 Video sent: ${selectedFile.name} (${(selectedFile.size / 1024 / 1024).toFixed(2)} MB)`,
              type: 'video',
              created_at: new Date().toISOString(),
            };
            setMessages((prev) => [...prev, message]);

            return 0;
          }
          return prev + 5;
        });
      }, 200);
    }, 2000);
  };

  const handleCancelTransfer = () => {
    setIsTransferring(false);
    setTransferProgress(0);
    setSelectedFile(null);
    setWebrtcStatus('disconnected');
  };

  const handleSendLink = (e) => {
    e.preventDefault();
    if (!videoLink.trim()) return;

    const message = {
      id: messages.length + 1,
      room_id: 10,
      user_id: user.id,
      username: user.username,
      content: `🔗 Video link: ${videoLink}`,
      type: 'link',
      created_at: new Date().toISOString(),
    };

    setMessages([...messages, message]);
    setVideoLink('');
    setShowLinkInput(false);
  };

  const handleEndMatch = () => {
    navigate(`/matches/${matchId}/rate`);
  };

  const getWebRTCStatusColor = () => {
    switch (webrtcStatus) {
      case 'connected':
        return 'text-green-600';
      case 'connecting':
        return 'text-yellow-600';
      case 'failed':
        return 'text-red-600';
      default:
        return 'text-gray-400';
    }
  };

  const getWebRTCStatusText = () => {
    switch (webrtcStatus) {
      case 'connected':
        return 'Connected (P2P)';
      case 'connecting':
        return 'Connecting...';
      case 'failed':
        return 'Connection failed';
      default:
        return 'Disconnected';
    }
  };

  return (
    <Layout>
      <div className="max-w-4xl mx-auto">
        <div className="bg-white rounded-lg shadow-md overflow-hidden">
          {/* Header with Partner Info */}
          <div className="bg-primary-600 text-white p-4">
            <div className="flex items-center justify-between">
              <div className="flex items-center space-x-4">
                <img
                  src={partner.avatar}
                  alt={partner.username}
                  className="w-12 h-12 rounded-full border-2 border-white"
                />
                <div>
                  <h2 className="text-xl font-bold">{partner.username}</h2>
                  <p className="text-sm text-primary-100">⭐ {partner.rating} • {partner.matches_count} collaborations</p>
                </div>
              </div>
              <button
                onClick={handleEndMatch}
                className="px-4 py-2 bg-white text-primary-600 rounded-md hover:bg-primary-50 transition-colors"
              >
                End & rate
              </button>
            </div>
          </div>

          {/* WebRTC Status Bar */}
          <div className="bg-gray-50 border-b px-4 py-2 flex items-center justify-between">
            <div className="flex items-center space-x-2">
              <div className={`w-2 h-2 rounded-full ${webrtcStatus === 'connected' ? 'bg-green-500' : 'bg-gray-300'}`} />
              <span className={`text-sm font-medium ${getWebRTCStatusColor()}`}>
                {getWebRTCStatusText()}
              </span>
            </div>
            <span className="text-xs text-gray-500">
              {webrtcStatus === 'connected' ? '🔒 E2E Encrypted (DTLS/SRTP)' : 'WebRTC ready to connect'}
            </span>
          </div>

          <div className="flex flex-col h-[calc(100vh-320px)]">
            {/* Messages */}
            <div className="flex-1 overflow-y-auto p-4 space-y-4">
              {messages.map((message) => {
                const isOwnMessage = message.user_id === user.id;
                return (
                  <div
                    key={message.id}
                    className={`flex ${isOwnMessage ? 'justify-end' : 'justify-start'}`}
                  >
                    <div className={`flex items-start space-x-2 max-w-md ${isOwnMessage ? 'flex-row-reverse space-x-reverse' : ''}`}>
                      <img
                        src={isOwnMessage ? user.avatar : partner.avatar}
                        alt={message.username}
                        className="w-8 h-8 rounded-full"
                      />
                      <div>
                        <div className="flex items-baseline space-x-2 mb-1">
                          <span className="text-sm font-medium text-gray-900">
                            {message.username}
                          </span>
                          <span className="text-xs text-gray-500">
                            {new Date(message.created_at).toLocaleTimeString('en-US', { hour: '2-digit', minute: '2-digit' })}
                          </span>
                        </div>
                        <div
                          className={`rounded-lg px-4 py-2 ${
                            isOwnMessage
                              ? 'bg-primary-600 text-white'
                              : 'bg-gray-100 text-gray-900'
                          }`}
                        >
                          {message.content}
                        </div>
                      </div>
                    </div>
                  </div>
                );
              })}
              <div ref={messagesEndRef} />
            </div>

            {/* Video Transfer Section */}
            {(selectedFile || isTransferring) && (
              <div className="border-t bg-blue-50 p-4">
                <div className="bg-white rounded-lg p-4 shadow-sm">
                  <div className="flex items-center justify-between mb-3">
                    <div className="flex items-center space-x-3">
                      <Video className="w-6 h-6 text-primary-600" />
                      <div>
                        <p className="font-medium text-gray-900">{selectedFile?.name}</p>
                        <p className="text-sm text-gray-500">
                          {selectedFile && `${(selectedFile.size / 1024 / 1024).toFixed(2)} MB`}
                        </p>
                      </div>
                    </div>
                    {!isTransferring && (
                      <button
                        onClick={() => setSelectedFile(null)}
                        className="text-gray-400 hover:text-gray-600"
                      >
                        <X className="w-5 h-5" />
                      </button>
                    )}
                  </div>

                  {isTransferring ? (
                    <>
                      <div className="mb-2">
                        <div className="flex justify-between text-sm text-gray-600 mb-1">
                          <span>Transferring via WebRTC...</span>
                          <span>{transferProgress}%</span>
                        </div>
                        <div className="w-full bg-gray-200 rounded-full h-2">
                          <div
                            className="bg-primary-600 h-2 rounded-full transition-all duration-200"
                            style={{ width: `${transferProgress}%` }}
                          />
                        </div>
                      </div>
                      <button
                        onClick={handleCancelTransfer}
                        className="w-full px-4 py-2 bg-red-600 text-white rounded-md hover:bg-red-700 transition-colors"
                      >
                        Cancel
                      </button>
                    </>
                  ) : (
                    <button
                      onClick={handleStartTransfer}
                      className="w-full px-4 py-2 bg-primary-600 text-white rounded-md hover:bg-primary-700 transition-colors flex items-center justify-center space-x-2"
                    >
                      <Upload className="w-4 h-4" />
                      <span>Send video (P2P)</span>
                    </button>
                  )}
                </div>
              </div>
            )}

            {/* Link Input Section */}
            {showLinkInput && (
              <div className="border-t bg-yellow-50 p-4">
                <div className="bg-white rounded-lg p-4 shadow-sm">
                  <form onSubmit={handleSendLink} className="space-y-3">
                    <div>
                      <label className="block text-sm font-medium text-gray-700 mb-2">
                        Video link (Google Drive, Dropbox, etc.)
                      </label>
                      <input
                        type="url"
                        value={videoLink}
                        onChange={(e) => setVideoLink(e.target.value)}
                        placeholder="https://drive.google.com/..."
                        className="w-full px-3 py-2 border border-gray-300 rounded-md focus:ring-primary-500 focus:border-primary-500"
                        required
                      />
                    </div>
                    <div className="flex space-x-2">
                      <button
                        type="submit"
                        className="flex-1 px-4 py-2 bg-primary-600 text-white rounded-md hover:bg-primary-700 transition-colors"
                      >
                        Send link
                      </button>
                      <button
                        type="button"
                        onClick={() => {
                          setShowLinkInput(false);
                          setVideoLink('');
                        }}
                        className="px-4 py-2 bg-gray-200 text-gray-700 rounded-md hover:bg-gray-300 transition-colors"
                      >
                        Cancel
                      </button>
                    </div>
                  </form>
                </div>
              </div>
            )}

            {/* Message Input & Actions */}
            <div className="border-t p-4 bg-gray-50">
              <div className="flex space-x-2 mb-3">
                <input
                  type="file"
                  ref={fileInputRef}
                  onChange={handleFileSelect}
                  accept="video/*"
                  className="hidden"
                />
                <button
                  onClick={() => fileInputRef.current?.click()}
                  disabled={isTransferring || selectedFile}
                  className="flex-1 px-4 py-2 bg-primary-600 text-white rounded-md hover:bg-primary-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center space-x-2"
                >
                  <Video className="w-4 h-4" />
                  <span>Send video (WebRTC)</span>
                </button>
                <button
                  onClick={() => setShowLinkInput(!showLinkInput)}
                  disabled={isTransferring}
                  className="px-4 py-2 bg-gray-600 text-white rounded-md hover:bg-gray-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed flex items-center space-x-2"
                >
                  <LinkIcon className="w-4 h-4" />
                  <span>Link</span>
                </button>
              </div>

              <form onSubmit={handleSendMessage} className="flex space-x-2">
                <input
                  type="text"
                  value={newMessage}
                  onChange={(e) => setNewMessage(e.target.value)}
                  placeholder="Write a message..."
                  className="flex-1 px-4 py-2 border border-gray-300 rounded-lg focus:ring-primary-500 focus:border-primary-500"
                />
                <button
                  type="submit"
                  className="px-4 py-2 bg-primary-600 text-white rounded-lg hover:bg-primary-700 transition-colors"
                >
                  <Send className="w-5 h-5" />
                </button>
              </form>
            </div>
          </div>
        </div>

        {/* Info Box */}
        <div className="mt-4 p-4 bg-blue-50 border border-blue-200 rounded-lg">
          <p className="text-sm text-blue-800">
            <strong>🚀 WebRTC P2P Functionality Mockup:</strong> In the full version, videos will be transferred directly
            between users via RTCDataChannel, with chunking and progress monitoring.
            The server is only used for SDP/ICE exchange (signaling).
          </p>
        </div>
      </div>
    </Layout>
  );
};

export default MatchChatPage;