import 'dart:async';
import 'package:flutter/material.dart';
import 'package:my_app/appeditor/custom/AppEditorWidgetContext.dart';

Widget buildCustomWidget(BuildContext context, AppEditorWidgetContext app) {
  return CounterWidget(app: app);
}

class CounterWidget extends StatefulWidget {
  const CounterWidget({super.key, required this.app});
  final AppEditorWidgetContext app;
  @override
  State<CounterWidget> createState() => _CounterWidgetState();
}

class _CounterWidgetState extends State<CounterWidget> {
  late String _variable;
  late Stream<dynamic> _values;
  bool _busy = false;

  double _number(dynamic value, double fallback) {
    final result = value is num ? value.toDouble() : double.tryParse('$value');
    return result != null && result.isFinite ? result : fallback;
  }

  void _bind() {
    _variable = widget.app.params['variable'] as String? ?? 'custom_counter';
    _values = widget.app.watchVar(_variable);
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) unawaited(_prepare());
    });
  }

  Future<void> _prepare() async {
    try {
      await widget.app.addVar(
        name: _variable,
        value: _number(widget.app.params['initial'], 0),
        storeOnDevice: widget.app.params['storeOnDevice'] == true,
      );
    } catch (error) {
      widget.app.showMessage('ایجاد شمارنده ممکن نشد: $error');
    }
  }

  @override
  void initState() {
    super.initState();
    _bind();
  }

  @override
  void didUpdateWidget(covariant CounterWidget oldWidget) {
    super.didUpdateWidget(oldWidget);
    final name = widget.app.params['variable'] as String? ?? 'custom_counter';
    if (name != _variable || !identical(widget.app, oldWidget.app)) _bind();
  }

  Future<void> _change(double direction) async {
    setState(() => _busy = true);
    final app = widget.app;
    final variable = _variable;
    try {
      await app.addVar(
        name: variable,
        value: _number(app.params['initial'], 0),
        storeOnDevice: app.params['storeOnDevice'] == true,
      );
      if (!mounted) return;
      final current = _number(app.getVar(variable), 0);
      final step = _number(app.params['step'], 1);
      await app.setVar(variable, current + step * direction);
      if (mounted && app.hasAction('onChanged'))
        await app.runAction('onChanged');
    } catch (error) {
      app.showMessage('تغییر شمارنده ممکن نشد: $error');
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<dynamic>(
      stream: _values,
      builder: (context, snapshot) {
        final value = _number(
          snapshot.data,
          _number(widget.app.params['initial'], 0),
        );
        final text = value == value.truncateToDouble()
            ? value.toStringAsFixed(0)
            : '$value';
        return Card(
          child: Padding(
            padding: const EdgeInsets.all(16),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(
                  widget.app.params['title'] as String? ?? 'شمارنده',
                  style: Theme.of(context).textTheme.titleLarge,
                ),
                const SizedBox(height: 12),
                Text(text, style: Theme.of(context).textTheme.headlineLarge),
                const SizedBox(height: 12),
                Wrap(
                  spacing: 16,
                  children: [
                    OutlinedButton(
                      onPressed: _busy ? null : () => _change(-1),
                      child: const Text('−'),
                    ),
                    FilledButton(
                      onPressed: _busy ? null : () => _change(1),
                      child: const Text('+'),
                    ),
                  ],
                ),
              ],
            ),
          ),
        );
      },
    );
  }
}