import 'package:flutter/material.dart';

class ClearingDropdownMenu<T> extends StatefulWidget {
  final List<DropdownMenuEntry<T>> entries;
  final T? initialValue;
  final void Function(T? item)? onSelected;
  final String? label;

  const ClearingDropdownMenu({
    super.key,
    required this.entries,
    this.initialValue,
    this.onSelected,
    this.label,
  });

  @override
  State<ClearingDropdownMenu<T>> createState() =>
      _ClearingDropdownMenuState<T>();
}

class _ClearingDropdownMenuState<T> extends State<ClearingDropdownMenu<T>> {
  late final TextEditingController _controller;
  final FocusNode _focusNode = FocusNode();
  T? _selectedValue;

  @override
  void initState() {
    super.initState();
    _selectedValue = widget.initialValue;
    _controller = TextEditingController(
        text: _selectedValue != null
            ? widget.entries
                .firstWhere((entry) => entry.value == _selectedValue)
                .label
            : '');

    _focusNode.addListener(_onFocusChange);
  }

  void _onFocusChange() {
    if (!_focusNode.hasFocus) {
      // Check if the current text matches any entry
      final validEntry = widget.entries.any((entry) =>
          entry.label.toLowerCase() == _controller.text.toLowerCase());

      if (!validEntry) {
        // Clear the text and selection
        _controller.clear();
        setState(() {
          _selectedValue = null;
        });
        widget.onSelected?.call(null);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return DropdownMenu<T>(
      controller: _controller,
      focusNode: _focusNode,
      initialSelection: widget.initialValue,
      onSelected: (T? value) {
        setState(() {
          _selectedValue = value;
        });
        widget.onSelected?.call(value);
      },
      dropdownMenuEntries: widget.entries,
      label: widget.label != null ? Text(widget.label!) : null,
    );
  }

  @override
  void dispose() {
    _controller.dispose();
    _focusNode.dispose();
    super.dispose();
  }
}