@Tags(['snapshot'])
library;

import 'package:doormile_cx/data/dev_doormile_api.dart';
import 'package:doormile_cx/data/doormile_api.dart';
import 'package:doormile_cx/data/location_service.dart';
import 'package:doormile_cx/main.dart';
import 'package:doormile_cx/state/app_state.dart';
import 'package:flutter/material.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';

/// Renders each screen at phone size and writes it to `test/snapshots/`.
///
/// This is a **design** check, not a regression check. A deliberate redesign
/// would fail every one of these, which is worthless as a test signal, so the
/// `snapshot` tag is skipped in a normal run (see `dart_test.yaml`) and the
/// pictures are rendered on demand:
///
///     flutter test test/design_snapshot_test.dart --run-skipped --update-goldens
///
/// It exists because the only honest way to review a visual rebuild is to look
/// at it, and this produces the same pictures on any machine, with the real
/// fonts, without a device attached.
///
/// The real fonts are loaded first — without that, Flutter's test harness draws
/// everything in Ahem's black boxes and the pictures are worthless.
Future<void> _loadFonts() async {
  for (final (family, asset) in const [
    ('Manrope', 'assets/fonts/Manrope-VF.ttf'),
    ('GeistMono', 'assets/fonts/GeistMono-VF.ttf'),
    // The icon font too, or every glyph in the picture is a hollow box.
    ('packages/lucide_icons_flutter/Lucide',
        'packages/lucide_icons_flutter/assets/lucide.ttf'),
  ]) {
    final loader = FontLoader(family)..addFont(rootBundle.load(asset));
    await loader.load();
  }
}

Future<void> _settle(WidgetTester tester, [int ms = 800]) async {
  await tester.pump();
  await tester.pump(Duration(milliseconds: ms));
  await tester.pump(const Duration(milliseconds: 400));
}

Future<void> _shot(WidgetTester tester, String name) async {
  await expectLater(
    find.byType(MaterialApp),
    matchesGoldenFile('snapshots/$name.png'),
  );
}

void main() {
  late DevDoormileApi api;

  setUp(() {
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(
      const MethodChannel('plugins.flutter.io/path_provider'),
      (call) async => '/tmp',
    );
    api = DevDoormileApi();
    DoormileApi.overrideInstance(api);
    LocationService.instance = FixedLocationService();
  });

  tearDown(() => DoormileApi.overrideInstance(null));

  testWidgets('screens', (tester) async {
    await _loadFonts();

    // One phone, portrait: 390x844 at 3x, the frame the design was drawn in.
    tester.view.physicalSize = const Size(1170, 2532);
    tester.view.devicePixelRatio = 3.0;
    addTearDown(tester.view.reset);

    final state = AppState();
    await tester.pumpWidget(DoormileApp(initialState: state));
    await _settle(tester);

    // Image.asset resolves off the frame loop, so in a test it never paints
    // unless it is decoded first — without this the wordmark is a blank gap in
    // every picture of the entrance.
    await tester.runAsync(() async {
      await precacheImage(
        const AssetImage('assets/images/doormile-logo.png'),
        tester.element(find.byType(MaterialApp)),
      );
    });
    await _settle(tester);
    await _shot(tester, '01-sign-in');

    await tester.tap(find.text('Create account'));
    await _settle(tester);
    await _shot(tester, '01b-sign-up');
    await tester.tap(find.byIcon(LucideIcons.arrowLeft).first);
    await _settle(tester);

    await tester.enterText(find.byType(TextField).first, '9876543210');
    await _settle(tester, 200);
    await tester.tap(find.text('Continue'));
    await _settle(tester);
    await _shot(tester, '02-verify');

    final boxes = find.byType(TextField);
    for (var i = 0; i < 4; i++) {
      await tester.enterText(boxes.at(i), '1');
      await tester.pump();
    }
    await _settle(tester);
    await _shot(tester, '03-home');

    await tester.tap(find.text('Orders'));
    await _settle(tester);
    await _shot(tester, '04-orders');

    await tester.tap(find.text('Account'));
    await _settle(tester);
    await _shot(tester, '05-account');

    await tester.tap(find.text('Home'));
    await _settle(tester);
    await tester.tap(find.text('Miler assigned'));
    await _settle(tester);
    await _shot(tester, '06-tracking');
    await tester.tap(find.byIcon(LucideIcons.arrowLeft).first);
    await _settle(tester);

    // Booking: one screen, plus the two escape hatches.
    await tester.tap(find.text('Start booking'));
    await _settle(tester);
    await _shot(tester, '07-send-empty');

    await tester.tap(find.text('Chennai').first);
    await _settle(tester);
    await _shot(tester, '08-send-ready');

    // The window row is below the fold on a phone, and a ListView does not
    // build what it has not reached.
    // The window already carries the first available slot, so scroll to the
    // package row beneath it — a string that is there either way.
    await tester.dragUntilVisible(
      find.text('1 package'),
      find.byType(Scrollable).first,
      const Offset(0, -220),
    );
    await _settle(tester);
    await tester.tap(find.text('Change').last);
    await _settle(tester);
    await _shot(tester, '09-window-sheet');
    await tester.tap(find.textContaining('Use ').first);
    await _settle(tester);

    await tester.tap(find.text('Book pickup'));
    await _settle(tester);
    await _shot(tester, '11-booked');

    // A finished order, for the receipt treatment.
    await tester.tap(find.text('Back to home'));
    await _settle(tester);
    await tester.tap(find.text('Orders'));
    await _settle(tester);
    await tester.tap(find.text('Completed'));
    await _settle(tester);
    await tester.tap(find.text('Salem, Tamil Nadu'));
    await _settle(tester);
    await _shot(tester, '12-receipt');

    await tester.pump(const Duration(seconds: 3));
  });
}