import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../app/app_router.dart';
import '../app/app_state.dart';
import '../services/api.dart';
import '../services/auth_storage.dart';

/// Screen to invite additional Payfrit users to join a group order
/// Shown after selecting Delivery or Takeaway
class GroupOrderInviteScreen extends StatefulWidget {
  const GroupOrderInviteScreen({super.key});

  @override
  State<GroupOrderInviteScreen> createState() => _GroupOrderInviteScreenState();
}

class _GroupOrderInviteScreenState extends State<GroupOrderInviteScreen> {
  final List<UserSearchResult> _invitedUsers = [];
  final TextEditingController _searchController = TextEditingController();
  bool _isSearching = false;
  int? _currentUserId;

  List<UserSearchResult> _searchResults = [];

  @override
  void initState() {
    super.initState();
    _loadCurrentUserId();
  }

  Future<void> _loadCurrentUserId() async {
    final auth = await AuthStorage.loadAuth();
    if (auth != null && mounted) {
      setState(() {
        _currentUserId = auth.userId;
      });
    }
  }

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

  Future<void> _searchUsers(String query) async {
    if (query.isEmpty) {
      setState(() {
        _searchResults = [];
        _isSearching = false;
      });
      return;
    }

    if (query.length < 3) {
      setState(() {
        _searchResults = [];
        _isSearching = false;
      });
      return;
    }

    setState(() => _isSearching = true);

    try {
      final results = await Api.searchUsers(
        query: query,
        currentUserId: _currentUserId,
      );

      if (mounted && _searchController.text == query) {
        // Filter out already invited users
        final filteredResults = results.where((user) =>
            !_invitedUsers.any((invited) => invited.userId == user.userId)).toList();

        setState(() {
          _searchResults = filteredResults;
          _isSearching = false;
        });
      }
    } catch (e) {
      debugPrint('[GroupOrderInvite] Search error: $e');
      if (mounted) {
        setState(() {
          _searchResults = [];
          _isSearching = false;
        });
      }
    }
  }

  void _inviteUser(UserSearchResult user) {
    if (!_invitedUsers.any((u) => u.userId == user.userId)) {
      setState(() {
        _invitedUsers.add(user);
        _searchResults = [];
        _searchController.clear();
      });

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text('Invitation sent to ${user.name}', style: const TextStyle(color: Colors.black)),
          backgroundColor: const Color(0xFF90EE90),
          behavior: SnackBarBehavior.floating,
          margin: const EdgeInsets.only(bottom: 80, left: 16, right: 16),
        ),
      );
    }
  }

  void _removeInvite(UserSearchResult user) {
    setState(() {
      _invitedUsers.removeWhere((u) => u.userId == user.userId);
    });
  }

  void _continueToRestaurants() {
    // Store invited users in app state
    final appState = context.read<AppState>();
    final invitedUserIds = _invitedUsers.map((u) => u.userId).toList();
    appState.setGroupOrderInvites(invitedUserIds);

    Navigator.of(context).pushReplacementNamed(AppRoutes.restaurantSelect);
  }

  void _skipInvites() {
    Navigator.of(context).pushReplacementNamed(AppRoutes.restaurantSelect);
  }

  @override
  Widget build(BuildContext context) {
    final appState = context.watch<AppState>();
    final orderTypeLabel = appState.isDelivery ? 'Delivery' : 'Takeaway';

    return Scaffold(
      backgroundColor: Colors.black,
      appBar: AppBar(
        backgroundColor: Colors.black,
        foregroundColor: Colors.white,
        title: Text('$orderTypeLabel Order'),
        elevation: 0,
      ),
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              // Header
              const Icon(
                Icons.group_add,
                color: Colors.white54,
                size: 48,
              ),
              const SizedBox(height: 16),
              const Text(
                "Invite others to join",
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 22,
                  fontWeight: FontWeight.bold,
                ),
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: 8),
              Text(
                "Add Payfrit users to share this order.\n${appState.isDelivery ? 'Split the delivery fee between everyone!' : 'Everyone pays for their own items.'}",
                style: const TextStyle(
                  color: Colors.white70,
                  fontSize: 14,
                ),
                textAlign: TextAlign.center,
              ),

              const SizedBox(height: 24),

              // Search field
              TextField(
                controller: _searchController,
                onChanged: _searchUsers,
                style: const TextStyle(color: Colors.white),
                decoration: InputDecoration(
                  hintText: 'Search by phone or email...',
                  hintStyle: const TextStyle(color: Colors.white38),
                  prefixIcon: const Icon(Icons.search, color: Colors.white54),
                  suffixIcon: _isSearching
                      ? const Padding(
                          padding: EdgeInsets.all(12),
                          child: SizedBox(
                            width: 20,
                            height: 20,
                            child: CircularProgressIndicator(
                              strokeWidth: 2,
                              color: Colors.white54,
                            ),
                          ),
                        )
                      : null,
                  filled: true,
                  fillColor: Colors.grey.shade900,
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(12),
                    borderSide: BorderSide.none,
                  ),
                ),
              ),

              // Search results
              if (_searchResults.isNotEmpty) ...[
                const SizedBox(height: 8),
                Container(
                  decoration: BoxDecoration(
                    color: Colors.grey.shade900,
                    borderRadius: BorderRadius.circular(12),
                  ),
                  child: Column(
                    children: _searchResults.map((user) {
                      return ListTile(
                        leading: CircleAvatar(
                          backgroundColor: Colors.blue.withAlpha(50),
                          child: Text(
                            user.name[0].toUpperCase(),
                            style: const TextStyle(color: Colors.blue),
                          ),
                        ),
                        title: Text(
                          user.name,
                          style: const TextStyle(color: Colors.white),
                        ),
                        subtitle: Text(
                          user.phone,
                          style: const TextStyle(color: Colors.white54),
                        ),
                        trailing: IconButton(
                          icon: const Icon(Icons.person_add, color: Colors.blue),
                          onPressed: () => _inviteUser(user),
                        ),
                      );
                    }).toList(),
                  ),
                ),
              ],

              const SizedBox(height: 16),

              // Invited users list
              if (_invitedUsers.isNotEmpty) ...[
                const Text(
                  'Invited:',
                  style: TextStyle(
                    color: Colors.white70,
                    fontSize: 14,
                    fontWeight: FontWeight.w500,
                  ),
                ),
                const SizedBox(height: 8),
                Wrap(
                  spacing: 8,
                  runSpacing: 8,
                  children: _invitedUsers.map((user) {
                    return Chip(
                      avatar: CircleAvatar(
                        backgroundColor: Colors.green.withAlpha(50),
                        child: const Icon(
                          Icons.check,
                          size: 16,
                          color: Colors.green,
                        ),
                      ),
                      label: Text(user.name),
                      deleteIcon: const Icon(Icons.close, size: 18),
                      onDeleted: () => _removeInvite(user),
                      backgroundColor: Colors.grey.shade800,
                      labelStyle: const TextStyle(color: Colors.white),
                    );
                  }).toList(),
                ),
              ],

              const Spacer(),

              // Continue button
              if (_invitedUsers.isNotEmpty)
                FilledButton.icon(
                  onPressed: _continueToRestaurants,
                  icon: const Icon(Icons.group),
                  label: Text('Continue with ${_invitedUsers.length + 1} people'),
                  style: FilledButton.styleFrom(
                    padding: const EdgeInsets.symmetric(vertical: 16),
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                  ),
                )
              else
                FilledButton(
                  onPressed: _continueToRestaurants,
                  style: FilledButton.styleFrom(
                    padding: const EdgeInsets.symmetric(vertical: 16),
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                  ),
                  child: const Text('Continue Alone'),
                ),

              const SizedBox(height: 12),

              // Skip button
              TextButton(
                onPressed: _skipInvites,
                child: const Text(
                  'Skip this step',
                  style: TextStyle(color: Colors.white54),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}