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

Future<bool> showCrossPaichanDialog({
  required BuildContext context,
  required String currentPaicha,
  required String newPaicha,
}) async {
  final dialogFocus = FocusNode();
  var selectedIndex = 0; // 0 = "否" (default), 1 = "是"

  final dialogFuture = showDialog<bool>(
    context: context,
    barrierDismissible: false,
    builder: (ctx) => StatefulBuilder(
      builder: (ctx, setDialogState) {
        void dismissAsNo() => Navigator.of(ctx).pop(false);
        void confirmSwitch() => Navigator.of(ctx).pop(true);

        return KeyboardListener(
          focusNode: dialogFocus,
          onKeyEvent: (event) {
            if (event is! KeyDownEvent) return;
            if (event.logicalKey == LogicalKeyboardKey.arrowUp) {
              setDialogState(() => selectedIndex = 0);
            } else if (event.logicalKey == LogicalKeyboardKey.arrowDown) {
              setDialogState(() => selectedIndex = 1);
            } else if (event.logicalKey == LogicalKeyboardKey.enter) {
              selectedIndex == 0 ? dismissAsNo() : confirmSwitch();
            } else if (event.logicalKey == LogicalKeyboardKey.escape) {
              dismissAsNo();
            }
          },
          child: PopScope(
            canPop: false,
            onPopInvokedWithResult: (didPop, _) {
              if (!didPop) dismissAsNo();
            },
            child: AlertDialog(
              backgroundColor: Colors.orange.shade50,
              title: Row(
                children: [
                  Icon(Icons.warning_amber, color: Colors.orange.shade800),
                  const SizedBox(width: 8),
                  Text(
                    '跨排产号扫描',
                    style: TextStyle(color: Colors.orange.shade900),
                  ),
                ],
              ),
              content: Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  Text(
                    '当前排产号：$currentPaicha\n'
                    '新排产号：$newPaicha\n\n'
                    '是否切换到新的排产号？\n\n'
                    '选择「是」将放弃当前已扫描的所有数据。',
                    style: const TextStyle(fontSize: 14),
                  ),
                  const SizedBox(height: 16),
                  _DialogOptionButton(
                    label: '否',
                    selected: selectedIndex == 0,
                    onTap: dismissAsNo,
                  ),
                  const SizedBox(height: 8),
                  _DialogOptionButton(
                    label: '是，切换排产号',
                    selected: selectedIndex == 1,
                    onTap: confirmSwitch,
                  ),
                ],
              ),
            ),
          ),
        );
      },
    ),
  );

  WidgetsBinding.instance.addPostFrameCallback((_) {
    dialogFocus.requestFocus();
  });

  final result = await dialogFuture;
  dialogFocus.dispose();
  return result ?? false;
}

class _DialogOptionButton extends StatelessWidget {
  final String label;
  final bool selected;
  final VoidCallback onTap;

  const _DialogOptionButton({
    required this.label,
    required this.selected,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: double.infinity,
      height: 40,
      child: ElevatedButton(
        onPressed: onTap,
        style: ElevatedButton.styleFrom(
          backgroundColor: selected
              ? Colors.blue.shade700
              : Colors.grey.shade200,
          foregroundColor: selected ? Colors.white : Colors.black87,
          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
        ),
        child: Text(
          label,
          style: TextStyle(
            fontWeight: selected ? FontWeight.w800 : FontWeight.w600,
          ),
        ),
      ),
    );
  }
}