import 'package:flutter/material.dart';

import '../components/user_tile.dart';
import '../constants.dart';
import '../services/auth/auth_service.dart';
import '../services/user_service.dart';
import 'chat_page.dart';

class ConversationsPage extends StatelessWidget {
  ConversationsPage({super.key});

  // auth service
  final AuthService _authService = AuthService();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Conversations'),
        backgroundColor: Colors.transparent,
        foregroundColor: Colors.grey.shade800,
        elevation: 0,
      ),
      body: _buildUserMatchesList(),
    );
  }

  // build the list of matches for the current user
  Widget _buildUserMatchesList() {
    final currentUser = _authService.getCurrentUser();

    if (currentUser == null) {
      return const Center(child: Text('Error: User not logged in'));
    }

    return StreamBuilder<List<Map<String, dynamic>>>(
      stream: UserService.getMatchedUsersStream(currentUser.uid),
      builder: (context, snapshot) {
        // error
        if (snapshot.hasError) {
          return Text('Error: ${snapshot.error.toString()}');
        }

        // loading
        if (snapshot.connectionState == ConnectionState.waiting) {
          return const Center(child: CircularProgressIndicator());
        }

        // return list view
        if (snapshot.hasData) {
          final matchedUsers = snapshot.data!;
          if (matchedUsers.isEmpty) {
            return const Center(child: Text('No matches yet'));
          }
          return ListView(
            children: matchedUsers
                .map<Widget>(
                    (userData) => _buildUserListItem(userData, context))
                .toList(),
          );
        } else {
          return const Center(child: Text('No matches found'));
        }
      },
    );
  }

  // build individual user list item
  Widget _buildUserListItem(
      Map<String, dynamic> userData, BuildContext context) {
    return UserTile(
      text: userData[Constants.dbFieldUsersEmail],
      onTap: () {
        // tapped on a user -> go to chat page
        Navigator.push(
          context,
          MaterialPageRoute(
            builder: (context) => ChatPage(
              receiverEmail: userData[Constants.dbFieldUsersEmail],
              receiverID: userData[Constants.dbFieldUsersID],
            ),
          ),
        );
      },
    );
  }
}