lib/screens/vpn_shield_screen.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:sqflite/sqflite.dart';
import '../services/vpn_service.dart';
import '../services/storage_service.dart';

class VpnShieldScreen extends StatefulWidget {
  const VpnShieldScreen({super.key});

  @override
  State<VpnShieldScreen> createState() => _VpnShieldScreenState();
}

class _VpnShieldScreenState extends State<VpnShieldScreen> {
  bool _isActive = false;
  VpnStats? _stats;
  int _totalDomains = 0;
  final TextEditingController _domainController = TextEditingController();
  Timer? _pollingTimer;

  @override
  void initState() {
    super.initState();
    _checkStatus();
    _pollingTimer = Timer.periodic(const Duration(seconds: 2), (_) => _checkStatus());
  }

  @override
  void dispose() {
    _pollingTimer?.cancel();
    _domainController.dispose();
    super.dispose();
  }

  Future<void> _checkStatus() async {
    final active = KavachaVpn.isRunning;
    final stats = await KavachaVpn.getStats();
    
    final db = await StorageService().database;
    final totalResult = await db.rawQuery('SELECT COUNT(*) as c FROM scam_domains');
    final total = totalResult.isNotEmpty ? totalResult.first['c'] as int : 0;

    if (mounted) {
      setState(() {
        _isActive = active;
        _stats = stats;
        _totalDomains = total;
      });
    }
  }

  Future<void> _toggleVpn(bool value) async {
    if (value) {
      await KavachaVpn.start();
    } else {
      await KavachaVpn.stop();
    }
    _checkStatus();
  }

  Future<void> _addDomainManually() async {
    final domain = _domainController.text.trim().toLowerCase();
    if (domain.isEmpty) return;
    
    try {
      final db = await StorageService().database;
      await db.insert('scam_domains', {
        'domain': domain,
        'category': 'User Added',
        'source': 'user',
        'hit_count': 0,
        'created_at': DateTime.now().millisecondsSinceEpoch,
      }, conflictAlgorithm: ConflictAlgorithm.ignore);
      
      _domainController.clear();
      await KavachaVpn.reloadBlocklist();
      _checkStatus();
      
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Domain $domain added to blocklist')),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Failed to add domain: $e')),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.black,
      appBar: AppBar(
        title: Text('DNS Shield', style: GoogleFonts.outfit(fontWeight: FontWeight.bold, color: Colors.white)),
        backgroundColor: Colors.transparent,
        iconTheme: const IconThemeData(color: Colors.white),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(24),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            _buildHeader(),
            const SizedBox(height: 32),
            _buildStatsGrid(),
            const SizedBox(height: 32),
            _buildTopBlocked(),
            const SizedBox(height: 32),
            _buildManagement(),
            const SizedBox(height: 48),
            _buildPrivacyNote(),
          ],
        ),
      ),
    );
  }

  Widget _buildHeader() {
    return Container(
      padding: const EdgeInsets.all(24),
      decoration: BoxDecoration(
        color: const Color(0xFF1E1E2C),
        borderRadius: BorderRadius.circular(20),
        border: Border.all(color: _isActive ? Colors.green.withOpacity(0.3) : Colors.white10),
      ),
      child: Column(
        children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Text(
                'VPN Shield',
                style: GoogleFonts.outfit(fontSize: 24, fontWeight: FontWeight.bold, color: Colors.white),
              ),
              Switch(
                value: _isActive,
                onChanged: _toggleVpn,
                activeColor: Colors.greenAccent,
                inactiveThumbColor: Colors.grey,
                inactiveTrackColor: Colors.white24,
              ),
            ],
          ),
          const SizedBox(height: 16),
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            decoration: BoxDecoration(
              color: _isActive ? Colors.green.withOpacity(0.2) : Colors.grey.withOpacity(0.2),
              borderRadius: BorderRadius.circular(20),
            ),
            child: Text(
              _isActive ? 'Active — all DNS protected' : 'Disabled',
              style: GoogleFonts.outfit(
                color: _isActive ? Colors.greenAccent : Colors.grey,
                fontWeight: FontWeight.bold,
              ),
            ),
          ),
          const SizedBox(height: 16),
          Text(
            'Local only — no data sent to any server',
            style: GoogleFonts.outfit(color: Colors.white54, fontSize: 14),
          ),
        ],
      ),
    );
  }

  Widget _buildStatsGrid() {
    return GridView.count(
      crossAxisCount: 2,
      shrinkWrap: true,
      physics: const NeverScrollableScrollPhysics(),
      crossAxisSpacing: 16,
      mainAxisSpacing: 16,
      childAspectRatio: 1.5,
      children: [
        _buildStatCard('Blocked today', '\${_stats?.blockedToday ?? 0}', Colors.orangeAccent),
        _buildStatCard('Total domains', '$_totalDomains', Colors.blueAccent),
        _buildStatCard('Last blocked', _stats?.lastBlockedDomain ?? 'none', Colors.redAccent, isDomain: true),
        _buildStatCard('Status', _isActive ? 'Local TUN' : 'Off', _isActive ? Colors.greenAccent : Colors.grey),
      ],
    );
  }

  Widget _buildStatCard(String title, String value, Color color, {bool isDomain = false}) {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFF1E1E2C),
        borderRadius: BorderRadius.circular(16),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Text(title, style: GoogleFonts.outfit(color: Colors.white54, fontSize: 13)),
          const SizedBox(height: 8),
          Text(
            value,
            style: GoogleFonts.outfit(
              color: color,
              fontSize: isDomain ? 14 : 24,
              fontWeight: FontWeight.bold,
            ),
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
          ),
        ],
      ),
    );
  }

  Widget _buildTopBlocked() {
    final domains = _stats?.topBlockedDomains ?? [];
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Top Blocked Domains', style: GoogleFonts.outfit(fontSize: 18, fontWeight: FontWeight.bold, color: Colors.white)),
        const SizedBox(height: 16),
        if (domains.isEmpty)
          Text('No domains blocked yet.', style: GoogleFonts.outfit(color: Colors.white54)),
        for (var domain in domains)
          Container(
            margin: const EdgeInsets.only(bottom: 12),
            padding: const EdgeInsets.all(16),
            decoration: BoxDecoration(
              color: const Color(0xFF1E1E2C),
              borderRadius: BorderRadius.circular(12),
            ),
            child: Row(
              children: [
                const Icon(Icons.block, color: Colors.redAccent, size: 20),
                const SizedBox(width: 12),
                Expanded(
                  child: Text(domain.domain, style: GoogleFonts.outfit(color: Colors.white, fontSize: 16)),
                ),
                Container(
                  padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
                  decoration: BoxDecoration(
                    color: Colors.red.withOpacity(0.2),
                    borderRadius: BorderRadius.circular(12),
                  ),
                  child: Text('\${domain.hitCount}', style: GoogleFonts.outfit(color: Colors.redAccent, fontWeight: FontWeight.bold)),
                ),
              ],
            ),
          ),
      ],
    );
  }

  Widget _buildManagement() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Blocklist Management', style: GoogleFonts.outfit(fontSize: 18, fontWeight: FontWeight.bold, color: Colors.white)),
        const SizedBox(height: 16),
        Row(
          children: [
            Expanded(
              child: TextField(
                controller: _domainController,
                style: const TextStyle(color: Colors.white),
                decoration: InputDecoration(
                  hintText: 'Add domain manually',
                  hintStyle: const TextStyle(color: Colors.white38),
                  filled: true,
                  fillColor: const Color(0xFF1E1E2C),
                  border: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: BorderSide.none),
                  contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
                ),
              ),
            ),
            const SizedBox(width: 12),
            ElevatedButton(
              onPressed: _addDomainManually,
              style: ElevatedButton.styleFrom(
                backgroundColor: const Color(0xFF6C63FF),
                padding: const EdgeInsets.all(14),
                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
              ),
              child: const Icon(Icons.add, color: Colors.white),
            )
          ],
        ),
      ],
    );
  }

  Widget _buildPrivacyNote() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Colors.blue.withOpacity(0.1),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: Colors.blue.withOpacity(0.3)),
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          const Icon(Icons.privacy_tip, color: Colors.blueAccent),
          const SizedBox(width: 16),
          Expanded(
            child: Text(
              'Premithius VPN runs entirely on your device. DNS queries are checked locally and forwarded to Cloudflare 1.1.1.1 for safe domains only. Blocked domains return NXDOMAIN — no data reaches the scam site.',
              style: GoogleFonts.outfit(color: Colors.white70, fontSize: 13, height: 1.5),
            ),
          ),
        ],
      ),
    );
  }
}