import React, { useState, useEffect } from 'react';
import { useAuth } from '../context/AuthContext';
import api from '../api/axios';

function History() {
  const { isAuthenticated } = useAuth();
  const [sessions, setSessions] = useState([]);
  const [selectedSession, setSelectedSession] = useState(null);
  const [sessionGames, setSessionGames] = useState([]);
  const [loading, setLoading] = useState(true);
  const [showChatImport, setShowChatImport] = useState(false);
  const [closingSession, setClosingSession] = useState(null);

  useEffect(() => {
    loadSessions();
  }, []);

  const loadSessions = async () => {
    try {
      const response = await api.get('/sessions');
      setSessions(response.data);
    } catch (err) {
      console.error('Failed to load sessions', err);
    } finally {
      setLoading(false);
    }
  };

  const loadSessionGames = async (sessionId) => {
    try {
      const response = await api.get(`/sessions/${sessionId}/games`);
      setSessionGames(response.data);
      setSelectedSession(sessionId);
    } catch (err) {
      console.error('Failed to load session games', err);
    }
  };

  const handleCloseSession = async (sessionId, notes) => {
    try {
      await api.post(`/sessions/${sessionId}/close`, { notes });
      await loadSessions();
      setClosingSession(null);
      if (selectedSession === sessionId) {
        setSelectedSession(null);
        setSessionGames([]);
      }
    } catch (err) {
      alert('Failed to close session');
    }
  };

  if (loading) {
    return (
      <div className="flex justify-center items-center h-64">
        <div className="text-xl text-gray-600">Loading...</div>
      </div>
    );
  }

  return (
    <div className="max-w-7xl mx-auto">
      <h1 className="text-4xl font-bold mb-8 text-gray-800">Session History</h1>

      <div className="grid md:grid-cols-3 gap-6">
        {/* Sessions List */}
        <div className="md:col-span-1">
          <div className="bg-white rounded-lg shadow-lg p-6">
            <h2 className="text-2xl font-semibold mb-4 text-gray-800">Sessions</h2>
            
            {sessions.length === 0 ? (
              <p className="text-gray-500">No sessions found</p>
            ) : (
              <div className="space-y-2 max-h-[600px] overflow-y-auto">
                {sessions.map(session => (
                  <div
                    key={session.id}
                    onClick={() => loadSessionGames(session.id)}
                    className={`p-4 border rounded-lg cursor-pointer transition ${
                      selectedSession === session.id
                        ? 'border-indigo-500 bg-indigo-50'
                        : 'border-gray-300 hover:border-indigo-300'
                    }`}
                  >
                    <div className="flex justify-between items-start mb-2">
                      <div className="font-semibold text-gray-800">
                        Session #{session.id}
                      </div>
                      {session.is_active === 1 && (
                        <span className="bg-green-100 text-green-800 text-xs px-2 py-1 rounded">
                          Active
                        </span>
                      )}
                    </div>
                    <div className="text-sm text-gray-600">
                      {new Date(session.created_at).toLocaleDateString()}
                    </div>
                    <div className="text-sm text-gray-500">
                      {session.games_played} game{session.games_played !== 1 ? 's' : ''} played
                    </div>
                    
                    {isAuthenticated && session.is_active === 1 && (
                      <button
                        onClick={(e) => {
                          e.stopPropagation();
                          setClosingSession(session.id);
                        }}
                        className="mt-2 w-full bg-yellow-600 text-white px-3 py-1 rounded text-sm hover:bg-yellow-700 transition"
                      >
                        Close Session
                      </button>
                    )}
                  </div>
                ))}
              </div>
            )}
          </div>
        </div>

        {/* Session Details */}
        <div className="md:col-span-2">
          {selectedSession ? (
            <div className="bg-white rounded-lg shadow-lg p-6">
              <div className="flex justify-between items-start mb-6">
                <div>
                  <h2 className="text-2xl font-semibold text-gray-800">
                    Session #{selectedSession}
                  </h2>
                  <p className="text-gray-600">
                    {sessions.find(s => s.id === selectedSession)?.created_at && 
                      new Date(sessions.find(s => s.id === selectedSession).created_at).toLocaleString()}
                  </p>
                </div>
                
                {isAuthenticated && sessions.find(s => s.id === selectedSession)?.is_active === 1 && (
                  <button
                    onClick={() => setShowChatImport(true)}
                    className="bg-indigo-600 text-white px-4 py-2 rounded-lg hover:bg-indigo-700 transition"
                  >
                    Import Chat Log
                  </button>
                )}
              </div>

              {showChatImport && (
                <ChatImportPanel
                  sessionId={selectedSession}
                  onClose={() => setShowChatImport(false)}
                  onImportComplete={() => {
                    loadSessionGames(selectedSession);
                    setShowChatImport(false);
                  }}
                />
              )}

              {sessionGames.length === 0 ? (
                <p className="text-gray-500">No games played in this session</p>
              ) : (
                <div>
                  <h3 className="text-xl font-semibold mb-4 text-gray-700">
                    Games Played ({sessionGames.length})
                  </h3>
                  <div className="space-y-3">
                    {sessionGames.map((game, index) => (
                      <div key={game.id} className="border border-gray-200 rounded-lg p-4">
                        <div className="flex justify-between items-start mb-2">
                          <div>
                            <div className="font-semibold text-lg text-gray-800">
                              {index + 1}. {game.title}
                            </div>
                            <div className="text-gray-600">{game.pack_name}</div>
                          </div>
                          <div className="text-right">
                            <div className="text-sm text-gray-500">
                              {new Date(game.played_at).toLocaleTimeString()}
                            </div>
                            {game.manually_added === 1 && (
                              <span className="inline-block mt-1 text-xs bg-yellow-100 text-yellow-800 px-2 py-1 rounded">
                                Manual
                              </span>
                            )}
                          </div>
                        </div>
                        
                        <div className="grid grid-cols-2 md:grid-cols-4 gap-2 text-sm text-gray-600">
                          <div>
                            <span className="font-semibold">Players:</span> {game.min_players}-{game.max_players}
                          </div>
                          <div>
                            <span className="font-semibold">Type:</span> {game.game_type || 'N/A'}
                          </div>
                          <div>
                            <span className="font-semibold">Popularity:</span>{' '}
                            <span className={game.popularity_score >= 0 ? 'text-green-600' : 'text-red-600'}>
                              {game.popularity_score > 0 ? '+' : ''}{game.popularity_score}
                            </span>
                          </div>
                        </div>
                      </div>
                    ))}
                  </div>
                </div>
              )}
            </div>
          ) : (
            <div className="bg-white rounded-lg shadow-lg p-6 flex items-center justify-center h-64">
              <p className="text-gray-500 text-lg">Select a session to view details</p>
            </div>
          )}
        </div>
      </div>

      {/* Close Session Modal */}
      {closingSession && (
        <CloseSessionModal
          sessionId={closingSession}
          onClose={() => setClosingSession(null)}
          onConfirm={handleCloseSession}
        />
      )}
    </div>
  );
}

function CloseSessionModal({ sessionId, onClose, onConfirm }) {
  const [notes, setNotes] = useState('');

  return (
    <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
      <div className="bg-white rounded-lg p-8 max-w-md w-full">
        <h2 className="text-2xl font-bold mb-4">Close Session #{sessionId}</h2>
        
        <div className="mb-4">
          <label className="block text-gray-700 font-semibold mb-2">
            Session Notes (optional)
          </label>
          <textarea
            value={notes}
            onChange={(e) => setNotes(e.target.value)}
            className="w-full px-4 py-2 border border-gray-300 rounded-lg h-32"
            placeholder="Add any notes about this session..."
          />
        </div>
        
        <div className="flex gap-4">
          <button
            onClick={() => onConfirm(sessionId, notes)}
            className="flex-1 bg-indigo-600 text-white py-3 rounded-lg hover:bg-indigo-700 transition"
          >
            Close Session
          </button>
          <button
            onClick={onClose}
            className="flex-1 bg-gray-600 text-white py-3 rounded-lg hover:bg-gray-700 transition"
          >
            Cancel
          </button>
        </div>
      </div>
    </div>
  );
}

function ChatImportPanel({ sessionId, onClose, onImportComplete }) {
  const [chatData, setChatData] = useState('');
  const [importing, setImporting] = useState(false);
  const [result, setResult] = useState(null);

  const handleImport = async () => {
    if (!chatData.trim()) {
      alert('Please enter chat data');
      return;
    }

    setImporting(true);
    setResult(null);

    try {
      const parsedData = JSON.parse(chatData);
      const response = await api.post(`/sessions/${sessionId}/chat-import`, {
        chatData: parsedData
      });
      setResult(response.data);
      setTimeout(() => {
        onImportComplete();
      }, 2000);
    } catch (err) {
      alert('Import failed: ' + (err.response?.data?.error || err.message));
    } finally {
      setImporting(false);
    }
  };

  return (
    <div className="bg-gray-50 border border-gray-300 rounded-lg p-6 mb-6">
      <h3 className="text-xl font-semibold mb-4">Import Chat Log</h3>
      
      <p className="text-sm text-gray-600 mb-4">
        Paste JSON array with format: [{"{"}"username": "...", "message": "...", "timestamp": "..."{"}"}]
        <br />
        The system will detect "thisgame++" and "thisgame--" patterns and update game popularity.
      </p>
      
      <div className="mb-4">
        <label className="block text-gray-700 font-semibold mb-2">Chat JSON Data</label>
        <textarea
          value={chatData}
          onChange={(e) => setChatData(e.target.value)}
          className="w-full px-4 py-2 border border-gray-300 rounded-lg h-48 font-mono text-sm"
          placeholder='[{"username":"Alice","message":"thisgame++","timestamp":"2024-01-01T12:00:00Z"}]'
          disabled={importing}
        />
      </div>
      
      {result && (
        <div className="mb-4 p-4 bg-green-50 border border-green-300 rounded-lg">
          <p className="font-semibold text-green-800">Import Successful!</p>
          <p className="text-sm text-green-700">
            Imported {result.messagesImported} messages, processed {result.votesProcessed} votes
          </p>
          {result.votesByGame && Object.keys(result.votesByGame).length > 0 && (
            <div className="mt-2 text-sm">
              <p className="font-semibold">Votes by game:</p>
              <ul className="list-disc list-inside">
                {Object.values(result.votesByGame).map((vote, i) => (
                  <li key={i}>
                    {vote.title}: +{vote.upvotes} / -{vote.downvotes}
                  </li>
                ))}
              </ul>
            </div>
          )}
        </div>
      )}
      
      <div className="flex gap-4">
        <button
          onClick={handleImport}
          disabled={importing}
          className="bg-indigo-600 text-white px-6 py-2 rounded-lg hover:bg-indigo-700 transition disabled:bg-gray-400"
        >
          {importing ? 'Importing...' : 'Import'}
        </button>
        <button
          onClick={onClose}
          className="bg-gray-600 text-white px-6 py-2 rounded-lg hover:bg-gray-700 transition"
        >
          Close
        </button>
      </div>
    </div>
  );
}

export default History;