import 'package:flutter/material.dart';
import 'chat.dart'; // Import the new Chat class

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

  @override
  State<ChatScreen> createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen> {
  final Chat _chat = Chat('chat1'); // Create an instance of Chat
  final TextEditingController _controller = TextEditingController();

  void _sendMessage() {
    if (_controller.text.isNotEmpty) {
      setState(() {
        _chat.addUserMessage(_controller.text); // Use the Chat instance to add the message
        _controller.clear();
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final width = MediaQuery.of(context).size.width; 
    final isBigScreen = width > 600; // Define threshold for small screens

    return Scaffold(
      appBar: AppBar(
        title: const Text('Chat'),
      ),
      body: Column(
        children: [
          Expanded(
            child: ListView.builder(
              itemCount: _chat.messages.length,
              itemBuilder: (context, index) {
                final message = _chat.messages[index];
                // Align all messages to left for big screens
                final align = message.sender == 'user' && !isBigScreen ? CrossAxisAlignment.end : CrossAxisAlignment.start;
                return Row(
                  mainAxisAlignment: align == CrossAxisAlignment.end ? MainAxisAlignment.end : MainAxisAlignment.start,
                  children: [
                    Container(
                      padding: const EdgeInsets.all(8.0),
                      margin: const EdgeInsets.symmetric(vertical: 4.0),
                      child: Text(
                        '${message.content}',
                        style: const TextStyle(color: Colors.white),
                      ),
                    ),
                  ],
                );
              },
            ),
          ),
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: Row(
              children: [
                Expanded(
                  child: TextField(
                    controller: _controller,
                    decoration: const InputDecoration(hintText: 'Send a message'),
                    onSubmitted: (_) => _sendMessage(),
                  ),
                ),
                IconButton(
                  icon: const Icon(Icons.send),
                  onPressed: _sendMessage,
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}