import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:qr_flutter/qr_flutter.dart';

import 'package:miler/views/Dashboard/pickups/collect_payment.dart';

/// The payment screen is the only place in the app where money changes hands,
/// and it is read by two people at once — the rider holding the phone and the
/// customer being asked to pay. So the things worth testing are the things
/// either of them would dispute afterwards:
///
///  • the amount comes from the booking and nowhere else;
///  • the page says which consignment is being paid for;
///  • the QR is on the page, carrying that amount, not in a dialog;
///  • a short payment cannot be recorded without a figure and a reason.
void main() {
  Future<void> pump(
    WidgetTester tester,
    Map<String, dynamic> stop, {
    Map<String, dynamic> verification = const {},
    String? initialMethod,
    double textScale = 1.0,
  }) async {
    tester.view.physicalSize = const Size(390 * 3, 844 * 3);
    tester.view.devicePixelRatio = 3.0;
    addTearDown(tester.view.resetPhysicalSize);
    addTearDown(tester.view.resetDevicePixelRatio);

    await tester.pumpWidget(
      ScreenUtilInit(
        designSize: const Size(390, 844),
        builder: (_, _) => MaterialApp(
          builder: (context, child) => MediaQuery(
            data: MediaQuery.of(
              context,
            ).copyWith(textScaler: TextScaler.linear(textScale)),
            child: child!,
          ),
          home: CollectPaymentPage(
            pickup: stop,
            verificationData: verification,
            initialMethod: initialMethod,
          ),
        ),
      ),
    );
    // Not pumpAndSettle: the slide-to-confirm control animates its hint
    // forever, so a settle never comes. Two frames is enough for this page,
    // which has no entrance animation of its own.
    await tester.pump();
    await tester.pump(const Duration(milliseconds: 400));
  }

  Map<String, dynamic> stopOf({double due = 450, double pickupAmt = 0}) =>
      <String, dynamic>{
        'orderid': 'DM-99120',
        'type': 'pickup',
        'pickupqty': '3',
        'Quantity': '3',
        'pickupcustomer': 'Priya Sharma',
        'tenantname': 'Chettinad Textiles',
        'pickupaddress': '12/3B, Second Cross Street, Ram Nagar, Coimbatore',
        'collectionamt': '$due',
        if (pickupAmt > 0) 'pickupamt': '$pickupAmt',
      };

  testWidgets('the amount is the booking\'s, and it names who owes it', (
    tester,
  ) async {
    await pump(tester, stopOf(due: 450));

    expect(find.text('₹450'), findsOneWidget);
    expect(find.text('from Priya Sharma'), findsOneWidget);
  });

  testWidgets('the page says what the money is for', (tester) async {
    await pump(
      tester,
      stopOf(),
      verification: {
        'weight': '4.5',
        'pickup': {'collected': 3},
      },
    );

    // The consignment, the shipper it belongs to, and what was actually taken —
    // this is the half of the screen a customer paying at his own door needs
    // before he will trust the number above it.
    expect(find.text('What this pays for'), findsOneWidget);
    expect(find.text('DM-99120'), findsOneWidget);
    expect(find.text('Chettinad Textiles'), findsOneWidget);
    expect(find.text('3 collected'), findsOneWidget);
    expect(find.text('4.5 kg'), findsOneWidget);
  });

  testWidgets('cash is the default, and it shows no QR', (tester) async {
    await pump(tester, stopOf());

    expect(find.byType(QrImageView), findsNothing);
    expect(find.textContaining('Slide — took ₹450 by Cash'), findsOneWidget);
  });

  testWidgets('choosing UPI puts the QR on the page, not behind a dialog', (
    tester,
  ) async {
    await pump(tester, stopOf(due: 450));

    expect(find.byType(QrImageView), findsNothing);
    await tester.tap(find.text('UPI / QR'));
    await tester.pump(const Duration(milliseconds: 300));

    // On the page, next to the consignment it is settling — no dialog, and
    // nothing hidden behind a further confirm.
    expect(find.byType(QrImageView), findsOneWidget);
    expect(find.text('₹450 to miler@upi'), findsOneWidget);
  });

  group('the UPI intent', () {
    test('carries the amount, the payee and the consignment', () {
      final uri = buildUpiUri(
        payeeVpa: 'shop@okhdfcbank',
        payeeName: 'Chettinad Textiles',
        orderId: 'DM-99120',
        amount: 450,
      );

      // The amount is baked in, so the customer cannot pay the wrong figure by
      // mistyping it; the note makes the payment identifiable in his own
      // statement weeks later.
      expect(uri, contains('pa=shop%40okhdfcbank'));
      expect(uri, contains('am=450.00'));
      expect(uri, contains('cu=INR'));
      expect(uri, contains(Uri.encodeComponent('Miler pickup DM-99120')));
    });

    test('escapes a payee name that would otherwise break the intent', () {
      final uri = buildUpiUri(
        payeeVpa: 'shop@upi',
        payeeName: 'Ram & Co · Traders',
        orderId: '',
        amount: 99.5,
      );

      expect(uri, isNot(contains('&pn=Ram & Co')));
      expect(uri, contains('am=99.50'));
      expect(uri, contains(Uri.encodeComponent('Miler pickup')));
    });
  });

  testWidgets('the caller can open straight onto UPI', (tester) async {
    // The Bookings sheet already asked which method; asking again on arrival
    // would be the extra tap this page exists to remove.
    await pump(tester, stopOf(), initialMethod: 'upi (₹450)');
    expect(find.byType(QrImageView), findsOneWidget);
  });

  testWidgets('a short payment needs a figure and a reason', (tester) async {
    await pump(tester, stopOf(due: 450));

    await tester.ensureVisible(find.text('Paid less'));
    await tester.pump();
    await tester.tap(find.text('Paid less'));
    await tester.pump(const Duration(milliseconds: 300));
    expect(find.text('Enter how much you actually took'), findsOneWidget);

    await tester.enterText(find.byType(TextField).first, '400');
    await tester.pump(const Duration(milliseconds: 300));
    expect(find.text('Say why the customer paid less'), findsOneWidget);

    await tester.enterText(find.byType(TextField).last, 'No change');
    await tester.pump(const Duration(milliseconds: 300));
    expect(find.text('₹50 still owed on this consignment'), findsOneWidget);
  });

  testWidgets('a separate pickup charge is listed, never added up', (
    tester,
  ) async {
    // The office sets what is due. The page explains it; it does not do
    // arithmetic the office has not sanctioned.
    await pump(tester, stopOf(due: 450, pickupAmt: 60));

    expect(find.text('Pickup charge'), findsOneWidget);
    expect(find.text('₹60'), findsOneWidget);
    expect(find.text('Due now'), findsOneWidget);
    expect(find.text('₹510'), findsNothing);
  });

  testWidgets('a prepaid stop is not a payment screen at all', (tester) async {
    await pump(tester, <String, dynamic>{
      'orderid': 'DM-1',
      'pickupcustomer': 'Priya Sharma',
    });

    expect(find.text('Nothing to collect here'), findsOneWidget);
    expect(find.byType(QrImageView), findsNothing);
  });

  for (final scale in const [1.0, 1.5, 2.0]) {
    testWidgets('lays out at ${scale}x text scale', (tester) async {
      await pump(tester, stopOf(due: 1250, pickupAmt: 60), textScale: scale);
      expect(tester.takeException(), isNull);

      await tester.ensureVisible(find.text('UPI / QR'));
      await tester.pump();
      await tester.tap(find.text('UPI / QR'));
      await tester.pump(const Duration(milliseconds: 300));
      expect(tester.takeException(), isNull);
    });
  }
}