import 'package:flutter_test/flutter_test.dart';
import 'package:shared_preferences/shared_preferences.dart';

import 'package:miler/utils/device.dart';

/// ─────────────────────────────────────────────────────────────────────────
/// THE SIGN-IN MUST NOT DIE ON A FIELD IT DOES NOT SEND
///
/// `ensureDeviceId` threw on every unhappy path, and it is awaited on the line
/// before the PIN check posts — inside the sign-in's outer `try`. So the throw
/// was caught as "Could not reach the server" before a single byte left the
/// phone, and the MPIN screen then reported it as **"Incorrect MPIN"**. For
/// every phone number, on every attempt.
///
/// It threw for a guaranteed reason, not a rare one: it asked for
/// `androidInfo` unconditionally, which raises on iOS.
///
/// There are no platform channels in a widget test, so `device_info_plus`
/// raises `MissingPluginException` here — which makes this file an exact
/// reproduction of the iOS path. Under the old code every test below throws.
/// ─────────────────────────────────────────────────────────────────────────
void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  setUp(() => SharedPreferences.setMockInitialValues({}));

  test('hands back an id even when the platform cannot supply one', () async {
    final prefs = await SharedPreferences.getInstance();

    final id = await DeviceUtils.ensureDeviceId(prefs);

    expect(id, isNotEmpty, reason: 'a sign-in cannot wait for a device id');
    expect(
      id,
      startsWith(DeviceUtils.unknownDeviceId),
      reason: 'a generated id says so, so a log can be read honestly',
    );
  });

  test('the id is stable across calls — that is the whole job', () async {
    final prefs = await SharedPreferences.getInstance();

    final first = await DeviceUtils.ensureDeviceId(prefs);
    final second = await DeviceUtils.ensureDeviceId(prefs);

    expect(second, first);
    expect(prefs.getString('deviceId'), first);
  });

  test('a stored hardware id is never replaced by a generated one', () async {
    SharedPreferences.setMockInitialValues({'deviceId': 'real-hardware-id'});
    final prefs = await SharedPreferences.getInstance();

    expect(await DeviceUtils.ensureDeviceId(prefs), 'real-hardware-id');
  });

  test('two installs do not collide', () async {
    final prefs = await SharedPreferences.getInstance();
    final a = await DeviceUtils.ensureDeviceId(prefs);

    SharedPreferences.setMockInitialValues({});
    final b = await DeviceUtils.ensureDeviceId(
      await SharedPreferences.getInstance(),
    );

    expect(a, isNot(b));
  });

  test('the push token degrades to empty rather than throwing', () async {
    // Same contract, for the same reason: a rider who declined notifications
    // still has a shift to start.
    final prefs = await SharedPreferences.getInstance();
    expect(await DeviceUtils.ensureFcmToken(prefs), '');
  });
}