import 'dart:async';

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:smooth_app/data_models/preferences/user_preferences.dart';
import 'package:smooth_app/pages/preferences/lazy_counter.dart';

/// Widget displaying a Lazy Counter: cached value, refresh button, and loading.
class LazyCounterWidget extends StatefulWidget {
  const LazyCounterWidget(this.lazyCounter);

  final LazyCounter lazyCounter;

  @override
  State<LazyCounterWidget> createState() => _LazyCounterWidgetState();
}

class _LazyCounterWidgetState extends State<LazyCounterWidget> {
  bool _loading = false;

  @override
  void initState() {
    super.initState();
    final UserPreferences userPreferences = context.read<UserPreferences>();
    final int? count = widget.lazyCounter.getLocalCount(userPreferences);
    if (count == null) {
      unawaited(_asyncLoad());
    }
  }

  @override
  Widget build(BuildContext context) {
    final UserPreferences userPreferences = context.watch<UserPreferences>();
    final int? count = widget.lazyCounter.getLocalCount(userPreferences);
    return Row(
      mainAxisSize: MainAxisSize.min,
      mainAxisAlignment: MainAxisAlignment.end,
      crossAxisAlignment: CrossAxisAlignment.center,
      children: <Widget>[
        if (count != null) Text(count.toString()),
        if (_loading)
          const Padding(
            padding: EdgeInsets.symmetric(horizontal: 12),
            child: SizedBox(
              width: 24,
              height: 24,
              child: CircularProgressIndicator.adaptive(),
            ),
          )
        else
          IconButton(
            onPressed: () => _asyncLoad(),
            icon: const Icon(Icons.refresh),
          ),
      ],
    );
  }

  Future<void> _asyncLoad() async {
    if (_loading) {
      return;
    }
    _loading = true;
    final UserPreferences userPreferences = context.read<UserPreferences>();
    if (mounted) {
      setState(() {});
    }
    try {
      final int? value = await widget.lazyCounter.getServerCount();
      if (value != null) {
        await widget.lazyCounter.setLocalCount(
          value,
          userPreferences,
          notify: false,
        );
      }
    } catch (e) {
      //
    } finally {
      _loading = false;
      if (mounted) {
        setState(() {});
      }
    }
  }
}