import 'package:flutter/foundation.dart';
import 'dart:async';

class Debouncer {
  final int milliseconds;
  VoidCallback action;
  Timer _timer;

  Debouncer({ this.milliseconds });

  run(VoidCallback action) {
    if (_timer != null) {
      _timer.cancel();
    }

    _timer = Timer(Duration(milliseconds: milliseconds), action);
  }
}

final _debouncer = Debouncer(milliseconds: 500);

onTextChange(String text) {
  _debouncer.run(() => print(text));
}

Map<String, dynamic> user = jsonDecode(jsonString);

import 'package:json_annotation/json_annotation.dart';

/// This allows the `User` class to access private members in
/// the generated file. The value for this is *.g.dart, where
/// the star denotes the source file name.
part 'user.g.dart';

/// An annotation for the code generator to know that this class needs the
/// JSON serialization logic to be generated.
@JsonSerializable()

class User {
  User(this.name, this.email);

  String name;
  String email;

  /// A necessary factory constructor for creating a new User instance
  /// from a map. Pass the map to the generated `_$UserFromJson()` constructor.
  /// The constructor is named after the source class, in this case User.
  factory User.fromJson(Map<String, dynamic> json) => _$UserFromJson(json);

  /// `toJson` is the convention for a class to declare support for serialization
  /// to JSON. The implementation simply calls the private, generated
  /// helper method `_$UserToJson`.
  Map<String, dynamic> toJson() => _$UserToJson(this);
}

final String byProperty = resolve(json: json, path: "movie", defaultValue: "error");
expect(byProperty, "isFun");

final int byInt = resolve(json: json, path: "earth", defaultValue: 0);
expect(byInt, 199999);

final String byIndex = resolve(json: json, path: "dc.2.name", defaultValue: "error");
expect(byIndex, "Wonder Woman");

final String byIndexThenProperty = resolve(json: json, path: "marvel.0.appear.1.title", defaultValue: "error");
expect(byIndexThenProperty, "The Dark World");

import 'package:google_sign_in/google_sign_in.dart';

Future<String> getPhotoUrl(GoogleSignInAccount account, String userId) async {
  // final authentication = await account.authentication;
  final url = 'https://people.googleapis.com/v1/people/${userId}?personFields=photos';
  final response = await http.get(
    url,
    headers: await account.authHeaders
  );

  final data = json.decode(response.body);
  return data['photos'].first['url'];
}