lib/screens/data_shield_screen.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:intl/intl.dart';
import '../services/vector_service.dart';
import '../services/storage_service.dart';
import '../services/telemetry_service.dart';
import 'app_lock_screen.dart';
import 'vpn_shield_screen.dart';

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

  @override
  State<DataShieldScreen> createState() => _DataShieldScreenState();
}

class _DataShieldScreenState extends State<DataShieldScreen> {
  int _embeddingCount = 0;
  
  List<PrivacyStory> stories = [];
  List<AppDataUsage> dataUsage = [];
  List<SensorAccess> activeSensors = [];
  bool isLoading = true;
  bool hasPermission = false;
  String selectedLanguage = 'english'; // english or hindi
  DateTime lastScan = DateTime.now();

  Timer? _sensorTimer;

  @override
  void initState() {
    super.initState();
    _loadEmbeddingCount();
    _fetchTelemetry();
    _sensorTimer = Timer.periodic(const Duration(seconds: 60), (_) {
      _fetchActiveSensors();
    });
  }

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

  Future<void> _loadEmbeddingCount() async {
    if (!VectorService.isReady) return;
    final db = await StorageService().database;
    final count = await VectorService().embeddingCount(db);
    if (mounted) setState(() => _embeddingCount = count);
  }

  Future<void> _fetchTelemetry() async {
    if (!mounted) return;
    setState(() => isLoading = true);
    
    final perm = await TelemetryService.hasUsagePermission();
    final st = await TelemetryService.getPrivacyStories();
    final dUsage = await TelemetryService.getDataUsage();
    final sensors = await TelemetryService.getActiveSensors();

    if (mounted) {
      setState(() {
        hasPermission = perm;
        stories = st;
        dataUsage = dUsage;
        activeSensors = sensors;
        lastScan = DateTime.now();
        isLoading = false;
      });
    }
  }

  Future<void> _fetchActiveSensors() async {
    final sensors = await TelemetryService.getActiveSensors();
    if (mounted) {
      setState(() {
        activeSensors = sensors;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF0F1117),
      appBar: AppBar(
        title: const Text(
          'Data Shield',
          style: TextStyle(fontWeight: FontWeight.bold, color: Colors.white),
        ),
        backgroundColor: const Color(0xFF1A1D27),
        foregroundColor: Colors.white,
        elevation: 0,
        actions: [
          // Language Toggle
          Padding(
            padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 8),
            child: Container(
              decoration: BoxDecoration(
                color: const Color(0xFF2D3145),
                borderRadius: BorderRadius.circular(20),
              ),
              child: Row(
                children: [
                  _langButton('EN', 'english'),
                  _langButton('हिं', 'hindi'),
                ],
              ),
            ),
          ),
          IconButton(
            icon: const Icon(Icons.refresh, color: Colors.white70),
            tooltip: 'Refresh',
            onPressed: () {
              _fetchTelemetry();
            },
          ),
          IconButton(
            icon: const Icon(Icons.shield, color: Colors.white70),
            tooltip: 'DNS Shield',
            onPressed: () => Navigator.push(
              context,
              MaterialPageRoute(builder: (_) => const VpnShieldScreen()),
            ),
          ),
          IconButton(
            icon: const Icon(Icons.lock_outline, color: Colors.white70),
            tooltip: 'App Lock',
            onPressed: () => Navigator.push(
              context,
              MaterialPageRoute(builder: (_) => const AppLockScreen()),
            ),
          ),
        ],
      ),
      floatingActionButton: FloatingActionButton.extended(
        onPressed: isLoading ? null : _fetchTelemetry,
        backgroundColor: Colors.blueAccent,
        icon: isLoading 
            ? const SizedBox(width: 20, height: 20, child: CircularProgressIndicator(color: Colors.white, strokeWidth: 2))
            : const Icon(Icons.search, color: Colors.white),
        label: const Text('Scan Now', style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold)),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            if (!hasPermission && !isLoading) _buildPermissionBanner(),
            const SizedBox(height: 16),
            _buildLiveSensorStatus(),
            const SizedBox(height: 24),
            _sectionHeader('📊 Privacy Stories'),
            const SizedBox(height: 8),
            if (isLoading && stories.isEmpty) 
               const Center(child: Padding(padding: EdgeInsets.all(20), child: CircularProgressIndicator()))
            else
               ...stories.map(_buildStoryCard).toList(),
            const SizedBox(height: 24),
            if (dataUsage.isNotEmpty) ...[
              _sectionHeader('📤 Data Sent (last 24h)'),
              const SizedBox(height: 8),
              _buildDataUsageSection(),
              const SizedBox(height: 24),
            ],
            _sectionHeader('🛡️ System Status'),
            const SizedBox(height: 8),
            _buildSystemStatusCard(),
            const SizedBox(height: 80), // Fab spacing
          ],
        ),
      ),
    );
  }

  Widget _langButton(String label, String langVal) {
    final active = selectedLanguage == langVal;
    return GestureDetector(
      onTap: () => setState(() => selectedLanguage = langVal),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
        decoration: BoxDecoration(
          color: active ? Colors.blueAccent : Colors.transparent,
          borderRadius: BorderRadius.circular(20),
        ),
        child: Text(
          label,
          style: TextStyle(
            color: active ? Colors.white : Colors.white54,
            fontWeight: active ? FontWeight.bold : FontWeight.normal,
            fontSize: 13,
          ),
        ),
      ),
    );
  }

  Widget _buildPermissionBanner() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Colors.amber.shade900.withValues(alpha: 0.2),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: Colors.amber.shade700),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Icon(Icons.warning_amber_rounded, color: Colors.amber.shade300),
              const SizedBox(width: 8),
              const Expanded(
                child: Text(
                  'Grant Usage Access for full insights',
                  style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 16),
                ),
              ),
            ],
          ),
          const SizedBox(height: 8),
          const Text(
            'Premithius reads app usage locally. Nothing leaves your device.',
            style: TextStyle(color: Colors.white70, fontSize: 13),
          ),
          const SizedBox(height: 12),
          ElevatedButton(
            onPressed: () async {
              const platform = MethodChannel('flutter/platform_channel');
              try {
                await platform.invokeMethod('openSettingsIntent', 'android.settings.USAGE_ACCESS_SETTINGS');
              } catch (_) {}
            },
            style: ElevatedButton.styleFrom(
              backgroundColor: Colors.amber.shade700,
              foregroundColor: Colors.white,
            ),
            child: const Text('Open Settings'),
          ),
        ],
      ),
    );
  }

  Widget _buildLiveSensorStatus() {
    final activeMic = activeSensors.where((s) => s.sensor == 'microphone').toList();
    final activeCam = activeSensors.where((s) => s.sensor == 'camera').toList();

    return Row(
      children: [
        Expanded(child: _buildSensorCard('Microphone', Icons.mic, activeMic)),
        const SizedBox(width: 12),
        Expanded(child: _buildSensorCard('Camera', Icons.videocam, activeCam)),
      ],
    );
  }

  Widget _buildSensorCard(String title, IconData icon, List<SensorAccess> activeList) {
    final bool isActive = activeList.isNotEmpty;
    final Color bgColor = isActive ? Colors.red.shade900 : Colors.green.shade900.withValues(alpha: 0.5);
    final Color borderColor = isActive ? Colors.red.shade400 : Colors.green.shade700;
    
    return Container(
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: bgColor,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: borderColor, width: 2),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Icon(icon, color: Colors.white, size: 20),
              const SizedBox(width: 8),
              Text(title, style: const TextStyle(color: Colors.white, fontWeight: FontWeight.bold)),
              if (isActive) ...[
                const Spacer(),
                Container(
                  width: 8, height: 8,
                  decoration: const BoxDecoration(
                    color: Colors.white,
                    shape: BoxShape.circle,
                  ),
                ),
              ]
            ],
          ),
          const SizedBox(height: 8),
          Text(
            isActive ? "LIVE — ${activeList.first.appName}" : "No apps listening",
            style: const TextStyle(color: Colors.white70, fontSize: 13),
            maxLines: 1, overflow: TextOverflow.ellipsis,
          )
        ],
      ),
    );
  }

  Widget _buildStoryCard(PrivacyStory story) {
    Color badgeColor;
    switch(story.severity) {
      case 'CRITICAL': badgeColor = Colors.red; break;
      case 'HIGH': badgeColor = Colors.orange; break;
      case 'MEDIUM': badgeColor = Colors.amber; break;
      case 'SAFE': badgeColor = Colors.green; break;
      default: badgeColor = Colors.grey;
    }

    final text = selectedLanguage == 'hindi' ? story.hindi : story.english;

    return Container(
      margin: const EdgeInsets.only(bottom: 12),
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFF1A1D27),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: const Color(0xFF2D3145)),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withValues(alpha: 0.2),
            blurRadius: 8,
            offset: const Offset(0, 4),
          ),
        ],
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(story.emoji, style: const TextStyle(fontSize: 32)),
          const SizedBox(width: 16),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Container(
                  padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                  decoration: BoxDecoration(
                    color: badgeColor.withValues(alpha: 0.2),
                    borderRadius: BorderRadius.circular(4),
                    border: Border.all(color: badgeColor),
                  ),
                  child: Text(story.severity, style: TextStyle(color: badgeColor, fontSize: 10, fontWeight: FontWeight.bold)),
                ),
                const SizedBox(height: 8),
                Text(
                  text,
                  style: const TextStyle(
                    color: Colors.white,
                    height: 1.4,
                    fontSize: 14,
                  ),
                ),
                if (story.packageName.isNotEmpty && story.severity != 'SAFE') ...[
                  const SizedBox(height: 12),
                  SizedBox(
                    height: 32,
                    child: OutlinedButton(
                      style: OutlinedButton.styleFrom(
                        foregroundColor: Colors.white70,
                        side: const BorderSide(color: Colors.white24),
                        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
                      ),
                      onPressed: () async {
                        const channel = MethodChannel('in.inmodel.premithius/accessibility');
                        try {
                          await channel.invokeMethod('launchApp', {'packageName': story.packageName});
                        } catch (_) {}
                      },
                      child: const Text('Open App', style: TextStyle(fontSize: 12)),
                    ),
                  )
                ]
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildDataUsageSection() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFF1A1D27),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: const Color(0xFF2D3145)),
      ),
      child: Column(
        children: dataUsage.take(5).map((usage) {
          final maxMb = dataUsage.first.mbSent;
          final pct = maxMb > 0 ? (usage.mbSent / maxMb) : 0.0;
          return Padding(
            padding: const EdgeInsets.only(bottom: 12.0),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Text(usage.appName, style: const TextStyle(color: Colors.white, fontSize: 13, fontWeight: FontWeight.bold)),
                    Text("${usage.mbSent.toStringAsFixed(1)} MB", style: const TextStyle(color: Colors.white70, fontSize: 12)),
                  ],
                ),
                const SizedBox(height: 6),
                LinearProgressIndicator(
                  value: pct,
                  backgroundColor: const Color(0xFF2D3145),
                  color: usage.mbSent > 100 ? Colors.redAccent : Colors.blueAccent,
                  minHeight: 6,
                  borderRadius: BorderRadius.circular(4),
                ),
              ],
            ),
          );
        }).toList(),
      ),
    );
  }

  Widget _sectionHeader(String title) {
    return Text(
      title,
      style: const TextStyle(
        color: Colors.white,
        fontSize: 18,
        fontWeight: FontWeight.bold,
        letterSpacing: 0.3,
      ),
    );
  }

  Widget _buildSystemStatusCard() {
    final bool vecReady = VectorService.isReady;
    final String vecVersion = VectorService.vecVersion;

    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFF1A1D27),
        borderRadius: BorderRadius.circular(16),
        border: Border.all(
          color: const Color(0xFF2D3145),
          width: 1,
        ),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withValues(alpha: 0.3),
            blurRadius: 12,
            offset: const Offset(0, 4),
          ),
        ],
      ),
      child: Column(
        children: [
          _statusRow(
            'Layer 1 — India Threat Pack',
            true,
            'ACTIVE',
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _statusRow(
            'Layer 2 — Vector Search',
            vecReady,
            vecReady ? 'ACTIVE' : 'DISABLED',
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _statusRow(
            'Layer 3 — Random Forest',
            true,
            'ACTIVE',
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _statusRow(
            'Layer 4 — MobileBERT',
            true,
            'ACTIVE',
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _infoRow(
            Icons.extension,
            'sqlite-vec version',
            vecReady ? vecVersion : 'not loaded',
            vecReady ? Colors.blueAccent : Colors.grey,
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _infoRow(
            Icons.storage,
            'Embeddings in store',
            vecReady ? '$_embeddingCount' : '—',
            vecReady ? Colors.blueAccent : Colors.grey,
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _infoRow(
            Icons.bar_chart,
            'Usage Stats Permission',
            hasPermission ? 'GRANTED' : 'NEEDED',
            hasPermission ? Colors.green : Colors.amber,
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _infoRow(
            Icons.article,
            'Privacy Stories',
            '${stories.length} generated',
            Colors.blueAccent,
          ),
          const Divider(color: Color(0xFF2D3145), height: 16),
          _infoRow(
            Icons.schedule,
            'Last scan',
            DateFormat('HH:mm:ss').format(lastScan),
            Colors.white70,
          ),
        ],
      ),
    );
  }

  Widget _statusRow(String label, bool isActive, String statusText) {
    final Color statusColor =
        isActive ? const Color(0xFF00E676) : Colors.grey;
    final Color pillBg =
        isActive ? const Color(0xFF00E676).withValues(alpha: 0.15) : Colors.grey.withValues(alpha: 0.15);

    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Expanded(
          child: Text(
            label,
            style: const TextStyle(
              color: Colors.white70,
              fontSize: 14,
            ),
          ),
        ),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
          decoration: BoxDecoration(
            color: pillBg,
            borderRadius: BorderRadius.circular(20),
            border: Border.all(color: statusColor.withValues(alpha: 0.5)),
          ),
          child: Text(
            statusText,
            style: TextStyle(
              color: statusColor,
              fontSize: 12,
              fontWeight: FontWeight.bold,
              letterSpacing: 0.5,
            ),
          ),
        ),
      ],
    );
  }

  Widget _infoRow(IconData icon, String label, String value, Color valueColor) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Row(
          children: [
            Icon(icon, color: Colors.white54, size: 16),
            const SizedBox(width: 8),
            Text(
              label,
              style: const TextStyle(color: Colors.white70, fontSize: 14),
            ),
          ],
        ),
        Text(
          value,
          style: TextStyle(
            color: valueColor,
            fontSize: 14,
            fontWeight: FontWeight.w600,
            fontFamily: 'monospace',
          ),
        ),
      ],
    );
  }
}