import React, { useState, useEffect, useRef } from 'react';
import { 
  MessageSquare, 
  Users, 
  Send, 
  QrCode, 
  CheckCircle2, 
  Play, 
  Terminal, 
  LogOut,
  AlertCircle,
  Unlock,
  ShieldCheck,
  RefreshCw
} from 'lucide-react';

type Status = 'DISCONNECTED' | 'INITIALIZING' | 'QR_CODE' | 'CONNECTED' | 'ERROR';

function App() {
  const [isAuthenticated, setIsAuthenticated] = useState<boolean>(false);
  const [passkey, setPasskey] = useState('');
  const [loginError, setLoginError] = useState('');
  const [isLoggingIn, setIsLoggingIn] = useState(false);
  
  const [status, setStatus] = useState<Status>('DISCONNECTED');
  const [qrCode, setQrCode] = useState('');
  const [logs, setLogs] = useState<string[]>([]);
  const [phone, setPhone] = useState('');
  const [message, setMessage] = useState('');
  const [isSending, setIsSending] = useState(false);
  const [activeTab, setActiveTab] = useState<'direct' | 'group'>('direct');
  const [groups, setGroups] = useState<any[]>([]);
  const [selectedGroup, setSelectedGroup] = useState('');
  const logsEndRef = useRef<HTMLDivElement>(null);

  // Check initial authentication
  useEffect(() => {
    const savedPasskey = localStorage.getItem('passkey');
    if (savedPasskey) {
      checkInitialAuth(savedPasskey);
    }
  }, []);

  const checkInitialAuth = async (key: string) => {
    try {
      const response = await fetch('/api/status', {
        headers: { 'x-passkey': key }
      });
      if (response.ok) {
        setIsAuthenticated(true);
      } else {
        localStorage.removeItem('passkey');
      }
    } catch (e) {
      console.error('Initial auth check failed:', e);
    }
  };

  const handleLogin = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!passkey) return;
    setIsLoggingIn(true);
    setLoginError('');
    try {
      const response = await fetch('/api/login', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ passkey })
      });
      if (response.ok) {
        localStorage.setItem('passkey', passkey);
        setIsAuthenticated(true);
        setLoginError('');
      } else {
        setLoginError('Invalid passkey. Please try again.');
      }
    } catch (err) {
      setLoginError('Could not connect to server.');
    } finally {
      setIsLoggingIn(false);
    }
  };

  const handleLogout = () => {
    localStorage.removeItem('passkey');
    setIsAuthenticated(false);
    setPasskey('');
  };

  useEffect(() => {
    if (!isAuthenticated) return;

    const pollStatus = async () => {
      const savedPasskey = localStorage.getItem('passkey') || '';
      try {
        const response = await fetch('/api/status', {
          headers: { 'x-passkey': savedPasskey }
        });
        if (response.status === 401) {
          handleLogout();
          return;
        }
        if (response.ok) {
          const data = await response.json();
          setStatus(data.status);
          setQrCode(data.qrCode);
          setLogs(data.logs);
          
          if (data.status === 'CONNECTED' && groups.length === 0) {
            fetchGroups();
          }
        }
      } catch (err) {
        console.error('Polling error:', err);
      }
    };

    pollStatus();
    const interval = setInterval(pollStatus, 3000);
    return () => clearInterval(interval);
  }, [isAuthenticated, groups.length]);

  const fetchGroups = async () => {
    const savedPasskey = localStorage.getItem('passkey') || '';
    try {
      const response = await fetch('/api/groups', {
        headers: { 'x-passkey': savedPasskey }
      });
      if (response.ok) {
        const data = await response.json();
        if (data.groups) setGroups(data.groups);
      }
    } catch (err) {
      console.error('Fetch groups error:', err);
    }
  };

  const startService = async () => {
    const savedPasskey = localStorage.getItem('passkey') || '';
    try {
      await fetch('/api/start', { 
        method: 'POST',
        headers: { 'x-passkey': savedPasskey }
      });
    } catch (err) {
      console.error('Start service error:', err);
    }
  };

  const sendMessage = async (e: React.FormEvent) => {
    e.preventDefault();
    setIsSending(true);
    const savedPasskey = localStorage.getItem('passkey') || '';
    const recipient = activeTab === 'direct' ? phone : selectedGroup;
    
    try {
      const response = await fetch('/api/send', {
        method: 'POST',
        headers: { 
          'Content-Type': 'application/json',
          'x-passkey': savedPasskey
        },
        body: JSON.stringify({
          phone: recipient,
          message,
          isGroup: activeTab === 'group'
        })
      });
      if (response.ok) {
        setMessage('');
        alert('Message sent successfully!');
      } else {
        const data = await response.json();
        alert(`Error: ${data.error}`);
      }
    } catch (err) {
      alert(`Network error: ${err}`);
    } finally {
      setIsSending(false);
    }
  };

  useEffect(() => {
    logsEndRef.current?.scrollIntoView({ behavior: 'smooth' });
  }, [logs]);

  if (!isAuthenticated) {
    return (
      <div className="min-h-screen bg-[#0f172a] flex items-center justify-center p-4 font-sans">
        <div className="max-w-md w-full bg-[#1e293b] rounded-3xl shadow-2xl border border-white/5 overflow-hidden">
          <div className="p-8 text-center">
            <div className="w-20 h-20 bg-orange-500/20 rounded-2xl flex items-center justify-center mx-auto mb-6 border border-orange-500/30 shadow-inner">
              <ShieldCheck className="w-10 h-10 text-orange-500" />
            </div>
            <h1 className="text-3xl font-bold text-white mb-2">Restricted Access</h1>
            <p className="text-slate-400 mb-8">Enter your security passkey to manage the WPPConnect server.</p>
            
            <form onSubmit={handleLogin} className="space-y-4">
              <input
                type="password"
                placeholder="Security Passkey..."
                value={passkey}
                onChange={(e) => setPasskey(e.target.value)}
                className="w-full px-6 py-4 bg-slate-900/50 border border-slate-700 rounded-2xl focus:ring-4 focus:ring-orange-500/20 focus:border-orange-500 outline-none transition-all text-center text-xl font-mono tracking-widest text-white placeholder:tracking-normal placeholder:font-sans placeholder:text-slate-500"
                autoFocus
              />
              
              {loginError && (
                <div className="flex items-center justify-center gap-2 text-red-400 text-sm font-medium bg-red-500/10 py-3 rounded-xl border border-red-500/20">
                  <AlertCircle className="w-4 h-4" />
                  {loginError}
                </div>
              )}

              <button
                type="submit"
                disabled={isLoggingIn}
                className="w-full bg-orange-500 hover:bg-orange-600 disabled:bg-orange-500/50 text-white font-bold py-4 rounded-2xl transition-all shadow-lg shadow-orange-500/25 flex items-center justify-center gap-3 active:scale-[0.98]"
              >
                {isLoggingIn ? <RefreshCw className="w-5 h-5 animate-spin" /> : <Unlock className="w-5 h-5" />}
                Unlock Dashboard
              </button>
            </form>
          </div>
          <div className="bg-slate-900/50 py-4 text-center">
            <p className="text-slate-500 text-xs font-semibold tracking-widest uppercase">Hugging Face Space Security</p>
          </div>
        </div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-[#f8f9fa] text-gray-900 font-sans selection:bg-orange-100 selection:text-orange-900">
      <div className="max-w-6xl mx-auto px-4 py-8">
        <header className="flex flex-col md:flex-row md:items-center justify-between gap-4 mb-8 bg-white p-6 rounded-2xl shadow-sm border border-gray-100">
          <div className="flex items-center gap-4">
            <div className="w-12 h-12 bg-gradient-to-br from-orange-500 to-red-500 rounded-xl flex items-center justify-center shadow-lg shadow-orange-200">
              <MessageSquare className="w-6 h-6 text-white" />
            </div>
            <div>
              <h1 className="text-2xl font-bold tracking-tight text-gray-900">WPPConnect Portal</h1>
              <div className="flex items-center gap-2 mt-1">
                <div className={`w-2 h-2 rounded-full ${status === 'CONNECTED' ? 'bg-green-500' : 'bg-red-500'}`} />
                <span className="text-xs font-semibold uppercase tracking-wider text-gray-500">{status}</span>
              </div>
            </div>
          </div>
          
          <div className="flex items-center gap-3">
            <button 
              onClick={startService}
              disabled={status === 'CONNECTED' || status === 'INITIALIZING'}
              className="flex items-center gap-2 px-4 py-2.5 bg-orange-600 hover:bg-orange-700 disabled:bg-gray-200 disabled:text-gray-400 text-white text-sm font-semibold rounded-xl transition-all shadow-md shadow-orange-100"
            >
              <Play className="w-4 h-4" />
              Connect WhatsApp
            </button>
            <button 
              onClick={handleLogout}
              className="p-2.5 text-gray-400 hover:text-red-500 hover:bg-red-50 rounded-xl transition-all"
              title="Logout"
            >
              <LogOut className="w-5 h-5" />
            </button>
          </div>
        </header>

        <div className="grid grid-cols-1 lg:grid-cols-2 gap-8">
          <div className="space-y-6">
            <div className="bg-white rounded-2xl shadow-sm border border-gray-100 p-6">
              <div className="flex gap-1 p-1 bg-gray-50 rounded-xl mb-6">
                <button 
                  onClick={() => setActiveTab('direct')}
                  className={`flex-1 flex items-center justify-center gap-2 py-2 text-sm font-semibold rounded-lg transition-all ${activeTab === 'direct' ? 'bg-white shadow-sm text-orange-600' : 'text-gray-500 hover:text-gray-700'}`}
                >
                  <MessageSquare className="w-4 h-4" /> Direct
                </button>
                <button 
                  onClick={() => setActiveTab('group')}
                  className={`flex-1 flex items-center justify-center gap-2 py-2 text-sm font-semibold rounded-lg transition-all ${activeTab === 'group' ? 'bg-white shadow-sm text-orange-600' : 'text-gray-500 hover:text-gray-700'}`}
                >
                  <Users className="w-4 h-4" /> Groups
                </button>
              </div>

              {status !== 'CONNECTED' ? (
                <div className="flex flex-col items-center justify-center py-12 text-center space-y-4">
                  <div className="w-16 h-16 bg-gray-50 rounded-full flex items-center justify-center text-gray-300">
                    <QrCode className="w-8 h-8" />
                  </div>
                  <div>
                    <h3 className="font-semibold text-gray-900">WhatsApp Offline</h3>
                    <p className="text-sm text-gray-500 max-w-[200px] mx-auto mt-1">Authenticate to enable messaging features.</p>
                  </div>
                </div>
              ) : (
                <form onSubmit={sendMessage} className="space-y-5">
                  {activeTab === 'direct' ? (
                    <div className="space-y-2">
                      <label className="block text-sm font-medium text-gray-700">Recipient Phone</label>
                      <input 
                        type="text" 
                        placeholder="e.g. 5511999999999" 
                        value={phone}
                        onChange={(e) => setPhone(e.target.value)}
                        className="w-full px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-orange-500 focus:border-orange-500 outline-none transition-all"
                      />
                    </div>
                  ) : (
                    <div className="space-y-2">
                      <label className="block text-sm font-medium text-gray-700">Select Group</label>
                      <div className="flex gap-2">
                        <select 
                          value={selectedGroup}
                          onChange={(e) => setSelectedGroup(e.target.value)}
                          className="flex-1 px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-orange-500 focus:border-orange-500 outline-none"
                        >
                          <option value="">-- Choose a group --</option>
                          {groups.map((g) => (
                            <option key={g.id._serialized} value={g.id._serialized}>{g.name || g.id.user}</option>
                          ))}
                        </select>
                        <button 
                          type="button"
                          onClick={fetchGroups}
                          className="p-2 bg-gray-100 hover:bg-gray-200 rounded-lg transition-colors"
                          title="Refresh groups"
                        >
                          <RefreshCw className="w-4 h-4 text-gray-600" />
                        </button>
                      </div>
                    </div>
                  )}

                  <div className="space-y-2">
                    <label className="block text-sm font-medium text-gray-700">Message</label>
                    <textarea 
                      rows={4}
                      placeholder="Type your message here..."
                      value={message}
                      onChange={(e) => setMessage(e.target.value)}
                      className="w-full px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-orange-500 focus:border-orange-500 outline-none resize-none"
                    />
                  </div>

                  <button 
                    type="submit"
                    disabled={isSending || !message || (activeTab === 'direct' ? !phone : !selectedGroup)}
                    className="w-full bg-gray-900 hover:bg-gray-800 disabled:bg-gray-300 text-white font-medium py-3 px-4 rounded-lg transition-colors flex items-center justify-center gap-2"
                  >
                    <Send className="w-5 h-5" />
                    {isSending ? 'Sending...' : 'Send Message'}
                  </button>
                </form>
              )}
            </div>
          </div>

          <div className="space-y-6 flex flex-col">
            <div className="bg-white rounded-xl shadow-sm border border-gray-200 p-6 flex flex-col items-center justify-center min-h-[300px]">
              <h2 className="text-lg font-semibold mb-4 border-b pb-2 w-full text-left text-gray-900">Authentication</h2>
              {status === 'QR_CODE' && qrCode ? (
                <div className="flex flex-col items-center animate-in fade-in zoom-in duration-300">
                  <img src={qrCode} alt="WhatsApp QR Code" className="w-64 h-64 border-4 border-white shadow-sm rounded-lg" />
                  <p className="text-sm text-gray-500 mt-4 text-center">Scan this QR code with WhatsApp.</p>
                </div>
              ) : status === 'CONNECTED' ? (
                <div className="flex flex-col items-center text-green-500">
                  <CheckCircle2 className="w-20 h-20 mb-4" />
                  <p className="font-medium text-gray-700">Authenticated & Ready</p>
                </div>
              ) : (
                <div className="flex flex-col items-center text-gray-400">
                  <QrCode className="w-20 h-20 mb-4 opacity-50" />
                  <p className="text-sm">QR Code will appear here</p>
                </div>
              )}
            </div>

            <div className="bg-white rounded-xl shadow-sm border border-gray-200 flex flex-col flex-1 overflow-hidden">
              <div className="p-4 border-b bg-gray-50 flex items-center gap-2">
                <Terminal className="w-5 h-5 text-gray-500" />
                <h2 className="text-sm font-semibold text-gray-700 text-gray-900">System Logs</h2>
              </div>
              <div className="bg-[#1e1e1e] text-[#d4d4d4] p-4 font-mono text-xs overflow-y-auto h-[300px] flex-1">
                {logs.length === 0 ? (
                  <p className="text-gray-500 italic">Waiting for logs...</p>
                ) : (
                  logs.map((log, i) => (
                    <div key={i} className="mb-1 hover:bg-white/5 px-1 rounded">
                      {log}
                    </div>
                  ))
                )}
                <div ref={logsEndRef} />
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}

export default App;