halkyon/packages/halkyon_app/lib/src/testing/fake_speech_input.dart

import 'package:flutter/foundation.dart';
import 'package:halkyon_app/src/speech/speech_input.dart';

/// A [SpeechInput] the test speaks into: [say] hands words on, [finish]
/// ends the listen.
class FakeSpeechInput() implements SpeechInput {
  @override
  bool supported = true;

  /// Whether the device can listen when asked: false as if the microphone
  /// were refused.
  bool listens = true;

  /// The languages asked to listen in, in order.
  final languages = <String?>[];

  ValueChanged<String>? _onWords;
  VoidCallback? _onDone;

  /// Whether a listen is under way.
  bool get listening => _onWords != null;

  /// Hands on [words], as all heard so far.
  void say(String words) => _onWords?.call(words);

  /// Ends the listen, as the recogniser does after a pause.
  void finish() {
    final done = _onDone;
    _onWords = null;
    _onDone = null;
    done?.call();
  }

  @override
  Future<bool> listen({
    required String? language,
    required ValueChanged<String> onWords,
    required VoidCallback onDone,
  }) async {
    languages.add(language);
    if (!listens) {
      return false;
    }
    _onWords = onWords;
    _onDone = onDone;
    return true;
  }

  @override
  Future<void> stop() async => finish();
}