@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 [
    ('PlusJakartaSans', 'assets/fonts/PlusJakartaSans-Variable.ttf'),
    ('Switzer', 'assets/fonts/Switzer-Variable.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();
  }
}

/// Runs the clock forward until a screen has stopped moving.
///
/// Four pumps, not two. An entrance animation is started by a zero-delay
/// `Future.delayed` inside `flutter_animate`, and under the test binding's fake
/// clock that timer only fires on the pump *after* the widget was built — so
/// the controller begins life part-way through the first elapse and a two-pump
/// settle photographs the screen mid-fade. Everything here is under a second,
/// so the extra frames cost nothing and the pictures are of settled screens.
Future<void> _settle(WidgetTester tester, [int ms = 800]) async {
  await tester.pump();
  await tester.pump(Duration(milliseconds: ms));
  for (var i = 0; i < 4; i++) {
    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));

    // Image.asset resolves off the frame loop, so in a test it never paints
    // unless it is decoded first — without this the mark and the wordmark are
    // blank gaps in every picture of the entrance.
    await tester.runAsync(() async {
      for (final asset in const [
        'assets/images/doormile-icon.png',
        'assets/images/doormile-logo.png',
      ]) {
        await precacheImage(
          AssetImage(asset),
          tester.element(find.byType(MaterialApp)),
        );
      }
    });

    // Both beats, with raw pumps: `_settle` always runs four extra 400ms
    // frames at the end, which is 2.5s — past the moment the splash hands
    // over, so it would photograph the login screen instead of either one.
    // The clock does not start until the engine says it has rasterized a
    // frame and the composition has parsed, which under the test binding is
    // about 1.2s. Both shots are taken relative to that, not to pumpWidget.
    await tester.pump();
    await tester.pump(const Duration(milliseconds: 2000));
    await _shot(tester, '00-splash-animation');

    // Past the handover, plus a frame for the switch to settle.
    await tester.pump(const Duration(milliseconds: 1200));
    await tester.pump(const Duration(milliseconds: 400));
    await _shot(tester, '00b-splash-mark');

    // The splash holds for its own minimum — and the waits in front of it — before handing over.
    await _settle(tester, 4400);
    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');

    await tester.enterText(find.byType(TextField).first, '1111');
    await _settle(tester);
    await _shot(tester, '03-home');

    // The pickup address is a live value in the header, so the search that
    // changes it is reachable from Home rather than only from the booking.
    await tester.tap(find.text('38 Mettupalayam Road'));
    await _settle(tester);
    await _shot(tester, '03b-pickup-search');
    await tester.tapAt(const Offset(200, 40)); // through the scrim
    await _settle(tester);

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

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

    await tester.tap(find.bySemanticsLabel('Home'));
    await _settle(tester);
    // The live card, by its reference. Home's quick-dispatch chips are
    // named after cities too, so a bare 'Chennai' finder now hits a
    // shortcut that starts a new booking instead.
    await tester.tap(find.text('DM-482913'));
    await _settle(tester);
    await _shot(tester, '06-tracking');

    // `ensureVisible`, not `dragUntilVisible`.
    //
    // `IndexedStack` keeps all three tab roots alive under the pushed route,
    // so a positional `Scrollable` finder picks Home's list — which the
    // tracking screen is covering. `ensureVisible` finds the target's own
    // scrollable ancestor and needs no finder at all.
    await tester.ensureVisible(find.text('Cancel this pickup'));
    await tester.pump();
    await tester.tap(find.text('Cancel this pickup'));
    await _settle(tester);
    await _shot(tester, '06b-cancel-sheet');
    await tester.tapAt(const Offset(200, 40));
    await _settle(tester);

    await tester.tap(find.byIcon(LucideIcons.arrowLeft).first);
    await _settle(tester);

    // Booking: state, district, window, then one screen.
    await tester.tap(find.text('BOOK NOW'));
    await _settle(tester);
    await _shot(tester, '07-destination-states');

    await tester.tap(find.text('Tamil Nadu'));
    await _settle(tester);
    await _shot(tester, '07b-destination-districts');

    // The live card, by its reference. Home's quick-dispatch chips are
    // named after cities too, so a bare 'Chennai' finder now hits a
    // shortcut that starts a new booking instead.
    await tester.tap(find.text('DM-482913'));
    await _settle(tester);
    // The dev backend allows several destinations, so the row ticked rather
    // than closing the sheet — the choice is confirmed.
    await tester.tap(find.textContaining('Send to ').first);
    await _settle(tester);
    // The window sheet follows the destination on its own: the customer
    // chooses their slot, it is never chosen for them.
    await _shot(tester, '09-window-sheet');
    await tester.tap(find.textContaining('Use ').first);
    await _settle(tester);
    await _shot(tester, '08-send');

    // The map editor behind the FROM row: the one screen in the flow whose
    // subject is a picture.
    await tester.tap(find.text('ORIGIN'));
    await _settle(tester);
    await _shot(tester, '10-pickup-map');
    await tester.tap(find.byIcon(LucideIcons.arrowLeft).first);
    await _settle(tester);

    await tester.tap(find.text('Confirm Booking'));
    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.bySemanticsLabel('Orders'));
    await _settle(tester);
    await tester.tap(find.textContaining('Past'));
    await _settle(tester);
    await _shot(tester, '04b-orders-completed');
    await tester.tap(find.text('Salem'));
    await _settle(tester);
    await _shot(tester, '12-receipt');

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