import React, { useState, useMemo, useEffect } from 'react';
import { 
  Search, 
  Download, 
  Settings, 
  ShieldAlert, 
  Hash, 
  Globe, 
  Filter,
  Trash2,
  ChevronLeft,
  ChevronRight,
  Info,
  Smartphone
} from 'lucide-react';

const App = () => {
  const [countryCode, setCountryCode] = useState('1');
  const [startNumber, setStartNumber] = useState('5550100');
  const [count, setCount] = useState(100);
  const [numbers, setNumbers] = useState([]);
  const [isGenerating, setIsGenerating] = useState(false);
  const [searchTerm, setSearchTerm] = useState('');
  const [currentPage, setCurrentPage] = useState(1);
  const [showDisclaimer, setShowDisclaimer] = useState(true);
  const itemsPerPage = 10;

  // Mock Carrier/Metadata Logic
  const generateMetadata = (num) => {
    const carriers = ['Mobile One', 'Global Connect', 'TeleNet', 'Horizon Wireless'];
    return {
      carrier: carriers[Math.floor(Math.random() * carriers.length)],
      type: Math.random() > 0.3 ? 'Mobile' : 'Landline',
      valid: true
    };
  };

  const handleGenerate = () => {
    setIsGenerating(true);
    setTimeout(() => {
      const newBatch = [];
      const base = parseInt(startNumber);
      
      for (let i = 0; i < Math.min(count, 1000); i++) {
        const fullNum = `+${countryCode}${base + i}`;
        newBatch.push({
          id: i,
          raw: base + i,
          formatted: fullNum,
          ...generateMetadata(fullNum)
        });
      }
      setNumbers(newBatch);
      setIsGenerating(false);
      setCurrentPage(1);
    }, 800);
  };

  const filteredNumbers = useMemo(() => {
    return numbers.filter(n => 
      n.formatted.includes(searchTerm) || n.carrier.toLowerCase().includes(searchTerm.toLowerCase())
    );
  }, [numbers, searchTerm]);

  const paginatedNumbers = useMemo(() => {
    const start = (currentPage - 1) * itemsPerPage;
    return filteredNumbers.slice(start, start + itemsPerPage);
  }, [filteredNumbers, currentPage]);

  const exportCSV = () => {
    const headers = "ID,Full Number,Type,Carrier\n";
    const rows = numbers.map(n => `${n.id},${n.formatted},${n.type},${n.carrier}`).join("\n");
    const blob = new Blob([headers + rows], { type: 'text/csv' });
    const url = window.URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.setAttribute('hidden', '');
    a.setAttribute('href', url);
    a.setAttribute('download', 'phone_export.csv');
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
  };

  if (showDisclaimer) {
    return (
      <div className="min-h-screen bg-slate-900 flex items-center justify-center p-4">
        <div className="bg-white rounded-2xl p-8 max-w-md w-full shadow-2xl">
          <div className="flex items-center justify-center w-16 h-16 bg-blue-100 rounded-full mb-6 mx-auto">
            <ShieldAlert className="text-blue-600 w-8 h-8" />
          </div>
          <h2 className="text-2xl font-bold text-center mb-4 text-slate-800">Ethical Use Policy</h2>
          <p className="text-slate-600 mb-6 text-center leading-relaxed">
            This tool is designed for **research, testing, and educational purposes only**. 
            Generating numbers does not imply ownership or access to real user data. 
            Automated calling or SMS via this tool is strictly prohibited.
          </p>
          <button 
            onClick={() => setShowDisclaimer(false)}
            className="w-full bg-blue-600 hover:bg-blue-700 text-white font-semibold py-3 rounded-xl transition-all shadow-lg active:scale-95"
          >
            I Accept & Continue
          </button>
        </div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-slate-50 flex flex-col font-sans">
      {/* Header */}
      <header className="bg-white border-b sticky top-0 z-10 px-6 py-4 flex flex-wrap items-center justify-between gap-4">
        <div className="flex items-center gap-2">
          <div className="bg-blue-600 p-2 rounded-lg">
            <Smartphone className="text-white w-6 h-6" />
          </div>
          <h1 className="text-xl font-bold text-slate-800">TeleScope <span className="text-blue-600">Pro</span></h1>
        </div>
        
        <div className="flex items-center gap-3">
          <div className="relative">
            <Search className="absolute left-3 top-1/2 -translate-y-1/2 text-slate-400 w-4 h-4" />
            <input 
              type="text" 
              placeholder="Search results..."
              className="pl-10 pr-4 py-2 bg-slate-100 rounded-full text-sm border-none focus:ring-2 focus:ring-blue-500 w-48 md:w-64"
              value={searchTerm}
              onChange={(e) => setSearchTerm(e.target.value)}
            />
          </div>
          <button 
            onClick={exportCSV}
            disabled={numbers.length === 0}
            className="p-2 hover:bg-slate-100 rounded-full transition-colors disabled:opacity-30"
          >
            <Download className="w-5 h-5 text-slate-600" />
          </button>
        </div>
      </header>

      <main className="flex-1 p-4 md:p-8 max-w-6xl mx-auto w-full">
        {/* Controls Grid */}
        <div className="grid md:grid-cols-4 gap-4 mb-8">
          <div className="bg-white p-4 rounded-xl shadow-sm border border-slate-200">
            <label className="block text-xs font-semibold text-slate-500 uppercase mb-2 flex items-center gap-1">
              <Globe className="w-3 h-3" /> Country Code
            </label>
            <input 
              type="text" 
              value={countryCode}
              onChange={(e) => setCountryCode(e.target.value.replace(/\D/g, ''))}
              className="w-full text-lg font-medium outline-none"
              placeholder="1"
            />
          </div>
          <div className="bg-white p-4 rounded-xl shadow-sm border border-slate-200 col-span-2">
            <label className="block text-xs font-semibold text-slate-500 uppercase mb-2 flex items-center gap-1">
              <Hash className="w-3 h-3" /> Starting Number
            </label>
            <input 
              type="text" 
              value={startNumber}
              onChange={(e) => setStartNumber(e.target.value.replace(/\D/g, ''))}
              className="w-full text-lg font-medium outline-none"
              placeholder="5550100"
            />
          </div>
          <div className="bg-white p-4 rounded-xl shadow-sm border border-slate-200">
            <label className="block text-xs font-semibold text-slate-500 uppercase mb-2 flex items-center gap-1">
              <Settings className="w-3 h-3" /> Batch Size (Max 1k)
            </label>
            <input 
              type="number" 
              value={count}
              onChange={(e) => setCount(Math.min(1000, e.target.value))}
              className="w-full text-lg font-medium outline-none"
              max="1000"
            />
          </div>
        </div>

        <button 
          onClick={handleGenerate}
          disabled={isGenerating}
          className="w-full mb-8 bg-slate-900 hover:bg-black text-white py-4 rounded-2xl font-bold text-lg shadow-xl transition-all active:scale-[0.98] disabled:bg-slate-400"
        >
          {isGenerating ? 'Generating Numbers...' : 'Generate Exploration Batch'}
        </button>

        {/* Analytics Mini-Dashboard */}
        {numbers.length > 0 && (
          <div className="grid grid-cols-2 md:grid-cols-4 gap-4 mb-8">
            <div className="bg-blue-50 border border-blue-100 p-4 rounded-2xl">
              <p className="text-blue-600 text-xs font-bold uppercase">Total Batch</p>
              <p className="text-2xl font-black text-blue-900">{numbers.length}</p>
            </div>
            <div className="bg-green-50 border border-green-100 p-4 rounded-2xl">
              <p className="text-green-600 text-xs font-bold uppercase">Valid Format</p>
              <p className="text-2xl font-black text-green-900">100%</p>
            </div>
            <div className="bg-purple-50 border border-purple-100 p-4 rounded-2xl">
              <p className="text-purple-600 text-xs font-bold uppercase">Regions</p>
              <p className="text-2xl font-black text-purple-900">1</p>
            </div>
            <div className="bg-amber-50 border border-amber-100 p-4 rounded-2xl">
              <p className="text-amber-600 text-xs font-bold uppercase">Unique Carriers</p>
              <p className="text-2xl font-black text-amber-900">4</p>
            </div>
          </div>
        )}

        {/* Results Table */}
        <div className="bg-white rounded-2xl shadow-sm border border-slate-200 overflow-hidden">
          <div className="overflow-x-auto">
            <table className="w-full text-left border-collapse">
              <thead className="bg-slate-50 border-b border-slate-200">
                <tr>
                  <th className="p-4 text-xs font-bold text-slate-500 uppercase tracking-wider">#</th>
                  <th className="p-4 text-xs font-bold text-slate-500 uppercase tracking-wider">Phone Number</th>
                  <th className="p-4 text-xs font-bold text-slate-500 uppercase tracking-wider">Carrier</th>
                  <th className="p-4 text-xs font-bold text-slate-500 uppercase tracking-wider">Type</th>
                  <th className="p-4 text-xs font-bold text-slate-500 uppercase tracking-wider">Status</th>
                </tr>
              </thead>
              <tbody>
                {paginatedNumbers.map((num, idx) => (
                  <tr key={num.id} className="border-b border-slate-50 hover:bg-slate-50 transition-colors">
                    <td className="p-4 text-sm text-slate-400">{(currentPage - 1) * itemsPerPage + idx + 1}</td>
                    <td className="p-4 font-mono font-semibold text-slate-800">{num.formatted}</td>
                    <td className="p-4 text-sm text-slate-600">{num.carrier}</td>
                    <td className="p-4">
                      <span className="px-2 py-1 bg-slate-100 text-slate-600 text-[10px] font-bold rounded uppercase">
                        {num.type}
                      </span>
                    </td>
                    <td className="p-4">
                      <div className="flex items-center gap-1 text-green-600 font-bold text-xs">
                        <div className="w-2 h-2 bg-green-500 rounded-full animate-pulse" />
                        Active
                      </div>
                    </td>
                  </tr>
                ))}
                {numbers.length === 0 && (
                  <tr>
                    <td colSpan="5" className="p-20 text-center">
                      <div className="flex flex-col items-center opacity-40">
                        <Info className="w-12 h-12 mb-2" />
                        <p className="text-lg font-medium">No numbers generated yet</p>
                        <p className="text-sm">Enter a start number and click generate to begin.</p>
                      </div>
                    </td>
                  </tr>
                )}
              </tbody>
            </table>
          </div>
          
          {/* Pagination */}
          {filteredNumbers.length > itemsPerPage && (
            <div className="p-4 bg-slate-50 border-t flex items-center justify-between">
              <p className="text-sm text-slate-500">
                Showing {((currentPage - 1) * itemsPerPage) + 1} to {Math.min(currentPage * itemsPerPage, filteredNumbers.length)} of {filteredNumbers.length}
              </p>
              <div className="flex gap-2">
                <button 
                  onClick={() => setCurrentPage(p => Math.max(1, p - 1))}
                  className="p-2 bg-white border rounded-lg hover:bg-slate-50 disabled:opacity-50"
                  disabled={currentPage === 1}
                >
                  <ChevronLeft className="w-4 h-4" />
                </button>
                <button 
                  onClick={() => setCurrentPage(p => p + 1)}
                  className="p-2 bg-white border rounded-lg hover:bg-slate-50 disabled:opacity-50"
                  disabled={currentPage * itemsPerPage >= filteredNumbers.length}
                >
                  <ChevronRight className="w-4 h-4" />
                </button>
              </div>
            </div>
          )}
        </div>
      </main>

      <footer className="p-6 text-center text-slate-400 text-xs">
        <p>© 2024 TeleScope Research Lab • For Educational Use Only</p>
      </footer>
    </div>
  );
};

export default App;