// lib/screens/search_screen.dart
import 'dart:ui';
import 'package:flutter/material.dart';

// Location packages (add to pubspec.yaml)
// geolocator -> for permission & coordinates
// geocoding  -> for reverse geocoding coordinates to a placemark
import 'package:geolocator/geolocator.dart';
import 'package:geocoding/geocoding.dart';

class SearchScreen extends StatefulWidget {
  const SearchScreen({Key? key}) : super(key: key);

  /// Returns a String to the caller via Navigator.pop(string).
  /// Could be:
  ///  - a city name (e.g. "Bengaluru")
  ///  - 'Current Location' or a resolved locality like "Whitefield, Bengaluru"
  @override
  State<SearchScreen> createState() => _SearchScreenState();
}

class _SearchScreenState extends State<SearchScreen> {
  final TextEditingController _ctrl = TextEditingController();
  final List<String> _popularCities = const [
    'Delhi NCR',
    'Mumbai',
    'Kolkata',
    'Bengaluru',
    'Hyderabad',
    'Chandigarh',
    'Pune',
    'Chennai',
    'Ahmedabad',
    'Jaipur',
  ];

  List<String> _filtered = [];
  bool _loadingLocation = false;

  @override
  void initState() {
    super.initState();
    _filtered = List.from(_popularCities);
  }

  @override
  void dispose() {
    _ctrl.dispose();
    super.dispose();
  }

  void _onQueryChanged(String q) {
    final ql = q.trim().toLowerCase();
    setState(() {
      if (ql.isEmpty) {
        _filtered = List.from(_popularCities);
      } else {
        _filtered = _popularCities.where((c) => c.toLowerCase().contains(ql)).toList();
      }
    });
  }

  void _selectAndClose(String city) {
    Navigator.of(context).pop(city);
  }

  Future<void> _useCurrentLocation() async {
    setState(() => _loadingLocation = true);

    try {
      // Check / request permission
      LocationPermission permission = await Geolocator.checkPermission();
      if (permission == LocationPermission.denied) {
        permission = await Geolocator.requestPermission();
      }

      if (permission == LocationPermission.deniedForever || permission == LocationPermission.denied) {
        // Can't get permission — inform user and return a fallback label
        ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('Location permission denied')));
        Navigator.of(context).pop('Current Location');
        return;
      }

      // Get current position
      final pos = await Geolocator.getCurrentPosition(desiredAccuracy: LocationAccuracy.best);

      // Try reverse geocoding to get a readable place name
      try {
        final placemarks = await placemarkFromCoordinates(pos.latitude, pos.longitude);
        if (placemarks.isNotEmpty) {
          final p = placemarks.first;
          final parts = <String>[];
          if ((p.subLocality ?? '').isNotEmpty) parts.add(p.subLocality!);
          if ((p.locality ?? '').isNotEmpty) parts.add(p.locality!);
          if ((p.subAdministrativeArea ?? '').isNotEmpty) parts.add(p.subAdministrativeArea!);
          if ((p.administrativeArea ?? '').isNotEmpty) parts.add(p.administrativeArea!);
          final label = parts.isNotEmpty ? parts.join(', ') : 'Current Location';
          Navigator.of(context).pop(label);
          return;
        }
      } catch (_) {
        // ignore reverse geocode failures and fallback to coordinates or simple label
      }

      // fallback: return lat,lng string or simple label
      Navigator.of(context).pop('${pos.latitude.toStringAsFixed(5)},${pos.longitude.toStringAsFixed(5)}');
    } catch (e) {
      // If any error, fallback to simple label
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Could not determine location: $e')));
      Navigator.of(context).pop('Current Location');
    } finally {
      if (mounted) setState(() => _loadingLocation = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    // Full-screen transparent Scaffold so the BackdropFilter can blur underlying UI.
    return Scaffold(
      backgroundColor: Colors.transparent,
      body: GestureDetector(
        // Tap outside sheet to dismiss
        onTap: () => Navigator.of(context).pop(),
        behavior: HitTestBehavior.opaque,
        child: Stack(
          children: [
            // BackdropFilter + dim overlay
            BackdropFilter(
              filter: ImageFilter.blur(sigmaX: 8.0, sigmaY: 8.0),
              child: Container(color: Colors.black.withOpacity(0.16)),
            ),

            // Align bottom: the sheet content
            Align(
              alignment: Alignment.bottomCenter,
              child: _SearchBottomSheet(
                controller: _ctrl,
                filteredCities: _filtered,
                onCityTap: (city) => _selectAndClose(city),
                onQueryChanged: _onQueryChanged,
                onUseCurrentLocation: _useCurrentLocation,
                loadingLocation: _loadingLocation,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _SearchBottomSheet extends StatelessWidget {
  final TextEditingController controller;
  final List<String> filteredCities;
  final void Function(String) onCityTap;
  final void Function(String) onQueryChanged;
  final Future<void> Function() onUseCurrentLocation;
  final bool loadingLocation;

  const _SearchBottomSheet({
    Key? key,
    required this.controller,
    required this.filteredCities,
    required this.onCityTap,
    required this.onQueryChanged,
    required this.onUseCurrentLocation,
    required this.loadingLocation,
  }) : super(key: key);

  Widget _cityChip(String name, BuildContext context, void Function() onTap) {
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(12),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
        decoration: BoxDecoration(color: Colors.grey[100], borderRadius: BorderRadius.circular(12)),
        child: Text(name, style: const TextStyle(color: Colors.black87)),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    // The bottom sheet container
    return Padding(
      padding: const EdgeInsets.all(0),
      child: Container(
        // limit height so it looks like a sheet
        constraints: BoxConstraints(maxHeight: MediaQuery.of(context).size.height * 0.78, minHeight: 240),
        decoration: const BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
          boxShadow: [BoxShadow(color: Colors.black26, blurRadius: 12)],
        ),
        child: SafeArea(
          top: false,
          child: SingleChildScrollView(
            padding: const EdgeInsets.fromLTRB(20, 18, 20, 28),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // center drag handle
                Center(
                  child: Container(width: 48, height: 6, decoration: BoxDecoration(color: Colors.grey[300], borderRadius: BorderRadius.circular(6))),
                ),
                const SizedBox(height: 12),

                // Header
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    const Text('Set Your Location', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold)),
                    // Close button (inside sheet)
                    InkWell(
                      onTap: () => Navigator.of(context).pop(),
                      borderRadius: BorderRadius.circular(12),
                      child: Container(width: 40, height: 40, decoration: BoxDecoration(color: Colors.grey[100], borderRadius: BorderRadius.circular(10)), child: const Icon(Icons.close, color: Colors.black54)),
                    ),
                  ],
                ),
                const SizedBox(height: 14),

                // Search field (now functional)
                Container(
                  padding: const EdgeInsets.symmetric(horizontal: 12),
                  decoration: BoxDecoration(color: Colors.grey[100], borderRadius: BorderRadius.circular(12)),
                  child: Row(
                    children: [
                      const Icon(Icons.search, color: Colors.black38),
                      const SizedBox(width: 10),
                      Expanded(
                        child: TextField(
                          controller: controller,
                          decoration: const InputDecoration(hintText: 'Search city, area or locality', border: InputBorder.none),
                          textInputAction: TextInputAction.search,
                          onChanged: onQueryChanged,
                          onSubmitted: (v) {
                            final q = v.trim();
                            if (q.isEmpty) return;
                            // If there's an exact/first match in filteredCities, pick it; otherwise pass the raw query.
                            final match = filteredCities.isNotEmpty ? filteredCities.first : null;
                            Navigator.of(context).pop(match ?? q);
                          },
                        ),
                      ),
                      if (controller.text.isNotEmpty)
                        IconButton(
                          icon: const Icon(Icons.clear),
                          onPressed: () {
                            controller.clear();
                            onQueryChanged('');
                          },
                        ),
                    ],
                  ),
                ),
                const SizedBox(height: 14),

                // Use current location button
                ElevatedButton(
                  onPressed: loadingLocation ? null : () => onUseCurrentLocation(),
                  style: ElevatedButton.styleFrom(
                    padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 12),
                    backgroundColor: const Color(0xFF0B63D6),
                    shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                  ),
                  child: Row(
                    children: [
                      const Icon(Icons.my_location, color: Colors.white),
                      const SizedBox(width: 12),
                      Expanded(child: Text(loadingLocation ? 'Detecting location...' : 'Use Current Location', style: const TextStyle(color: Colors.white))),
                      if (loadingLocation)
                        const SizedBox(width: 18, height: 18, child: CircularProgressIndicator(color: Colors.white, strokeWidth: 2))
                      else
                        const Icon(Icons.chevron_right, color: Colors.white),
                    ],
                  ),
                ),
                const SizedBox(height: 18),

                // Popular cities
                const Text('Popular Cities', style: TextStyle(fontWeight: FontWeight.bold)),
                const SizedBox(height: 12),

                Wrap(
                  spacing: 12,
                  runSpacing: 12,
                  children: [
                    for (final city in filteredCities.take(8)) _cityChip(city, context, () => onCityTap(city)),
                    // if filteredCities is empty show empty state
                    if (filteredCities.isEmpty)
                      Padding(
                        padding: const EdgeInsets.symmetric(vertical: 12),
                        child: Text('No suggestions', style: TextStyle(color: Colors.grey[600])),
                      )
                  ],
                ),

                const SizedBox(height: 8),
              ],
            ),
          ),
        ),
      ),
    );
  }
}