import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:intl/intl.dart';
import 'base_text_field.dart';

/// 통화 입력 필드 위젯
/// 원화(KRW)와 달러(USD)를 지원하며 자동 포맷팅을 제공합니다.
class CurrencyInputField extends StatefulWidget {
  final TextEditingController controller;
  final String currency; // 'KRW' or 'USD'
  final String? label;
  final String? hintText;
  final Function(double?)? onChanged;
  final String? Function(String?)? validator;
  final FocusNode? focusNode;
  final TextInputAction? textInputAction;
  final Function()? onEditingComplete;
  final bool enabled;

  const CurrencyInputField({
    super.key,
    required this.controller,
    required this.currency,
    this.label,
    this.hintText,
    this.onChanged,
    this.validator,
    this.focusNode,
    this.textInputAction,
    this.onEditingComplete,
    this.enabled = true,
  });

  @override
  State<CurrencyInputField> createState() => _CurrencyInputFieldState();
}

class _CurrencyInputFieldState extends State<CurrencyInputField> {
  late TextEditingController _formattedController;

  @override
  void initState() {
    super.initState();
    _formattedController = TextEditingController();
    _updateFormattedValue();
    widget.controller.addListener(_onControllerChanged);
  }

  @override
  void dispose() {
    widget.controller.removeListener(_onControllerChanged);
    _formattedController.dispose();
    super.dispose();
  }

  void _onControllerChanged() {
    _updateFormattedValue();
  }

  void _updateFormattedValue() {
    final value = double.tryParse(widget.controller.text.replaceAll(',', ''));
    if (value != null) {
      _formattedController.text = _formatCurrency(value);
    } else {
      _formattedController.text = '';
    }
  }

  String _formatCurrency(double value) {
    if (widget.currency == 'KRW') {
      return NumberFormat.decimalPattern().format(value.toInt());
    } else {
      return NumberFormat('#,##0.00').format(value);
    }
  }

  double? _parseValue(String text) {
    final cleanText = text.replaceAll(',', '').replaceAll('₩', '').replaceAll('\$', '').trim();
    return double.tryParse(cleanText);
  }

  String get _prefixText {
    return widget.currency == 'KRW' ? '₩ ' : '\$ ';
  }

  String get _defaultHintText {
    return widget.currency == 'KRW' ? '금액을 입력하세요' : 'Enter amount';
  }

  @override
  Widget build(BuildContext context) {
    return BaseTextField(
      controller: _formattedController,
      focusNode: widget.focusNode,
      label: widget.label,
      hintText: widget.hintText ?? _defaultHintText,
      textInputAction: widget.textInputAction,
      keyboardType: const TextInputType.numberWithOptions(decimal: true),
      inputFormatters: [
        FilteringTextInputFormatter.allow(RegExp(r'[\d,.]')),
      ],
      prefixText: _prefixText,
      onEditingComplete: widget.onEditingComplete,
      enabled: widget.enabled,
      onChanged: (value) {
        final parsedValue = _parseValue(value);
        if (parsedValue != null) {
          widget.controller.text = parsedValue.toString();
          widget.onChanged?.call(parsedValue);
        } else {
          widget.controller.text = '';
          widget.onChanged?.call(null);
        }
        
        // 포맷팅 업데이트
        if (parsedValue != null) {
          final formattedText = _formatCurrency(parsedValue);
          if (formattedText != value) {
            _formattedController.value = TextEditingValue(
              text: formattedText,
              selection: TextSelection.collapsed(offset: formattedText.length),
            );
          }
        }
      },
      validator: widget.validator ?? (value) {
        if (value == null || value.isEmpty) {
          return '금액을 입력해주세요';
        }
        final parsedValue = _parseValue(value);
        if (parsedValue == null || parsedValue <= 0) {
          return '올바른 금액을 입력해주세요';
        }
        return null;
      },
    );
  }
}