// Guards for ChainProgressBar — the rules from shared/PROGRESS.md that
// are easy to break by accident when someone "simplifies" the widget.

import 'package:chain_studio/widgets/chain_progress_bar.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

Widget _host(Widget child, {bool disableAnimations = false}) => MaterialApp(
      home: Scaffold(
        body: MediaQuery(
          data: MediaQueryData(disableAnimations: disableAnimations),
          child: Padding(padding: const EdgeInsets.all(20), child: child),
        ),
      ),
    );

LinearProgressIndicator _indicator(WidgetTester tester) =>
    tester.widget<LinearProgressIndicator>(
      find.byType(LinearProgressIndicator),
    );

void main() {
  testWidgets('no value renders indeterminate, never an empty bar',
      (tester) async {
    await tester.pumpWidget(_host(const ChainProgressBar(stage: 'Verbinden')));
    await tester.pump(const Duration(milliseconds: 100));
    expect(_indicator(tester).value, isNull,
        reason: 'a null value must stay indeterminate, not render as 0');
    expect(find.text('Verbinden'), findsOneWidget);
  });

  testWidgets('a value glides in and is shown as a rounded percentage',
      (tester) async {
    await tester.pumpWidget(
      _host(const ChainProgressBar(value: 0.42, stage: 'Herunterladen')),
    );
    await tester.pump();
    await tester.pump(const Duration(milliseconds: 700));
    expect(_indicator(tester).value, closeTo(0.42, 0.001));
    expect(find.text('42 %'), findsOneWidget);
  });

  testWidgets('the value never walks backwards', (tester) async {
    await tester.pumpWidget(_host(const ChainProgressBar(value: 0.6)));
    await tester.pump(const Duration(milliseconds: 700));
    expect(_indicator(tester).value, closeTo(0.6, 0.001));

    // A recomputation that comes out lower must be ignored: a bar that
    // jumps back destroys trust for the rest of the session.
    await tester.pumpWidget(_host(const ChainProgressBar(value: 0.2)));
    await tester.pump(const Duration(milliseconds: 700));
    expect(_indicator(tester).value, closeTo(0.6, 0.001));
  });

  testWidgets('a standing value still animates while busy', (tester) async {
    await tester.pumpWidget(
      _host(const ChainProgressBar(value: 0.42, busy: true)),
    );
    await tester.pump(const Duration(milliseconds: 700));
    // The highlight is a repeating animation; pumpAndSettle would time
    // out precisely because something is still moving. That is the
    // property under test: the value stands, the bar does not.
    expect(tester.hasRunningAnimations, isTrue);
  });

  testWidgets('nothing animates once the work is done', (tester) async {
    await tester.pumpWidget(
      _host(const ChainProgressBar(value: 1.0, busy: false)),
    );
    await tester.pumpAndSettle();
    expect(tester.hasRunningAnimations, isFalse,
        reason: 'an idle surface must be still');
  });

  testWidgets('reduce-motion drops the highlight but keeps the value',
      (tester) async {
    await tester.pumpWidget(
      _host(
        const ChainProgressBar(value: 0.5, busy: true),
        disableAnimations: true,
      ),
    );
    await tester.pump(const Duration(milliseconds: 700));
    expect(_indicator(tester).value, closeTo(0.5, 0.001));
  });

  testWidgets('detail text replaces the percentage when given',
      (tester) async {
    await tester.pumpWidget(
      _host(const ChainProgressBar(
        value: 0.3,
        stage: 'Herunterladen',
        detail: '3,4 von 12,0 MB',
      )),
    );
    await tester.pump(const Duration(milliseconds: 700));
    expect(find.text('3,4 von 12,0 MB'), findsOneWidget);
    expect(find.text('30 %'), findsNothing);
  });

  testWidgets('screen readers get stage and percentage', (tester) async {
    final handle = tester.ensureSemantics();
    await tester.pumpWidget(
      _host(const ChainProgressBar(value: 0.25, stage: 'Wird entpackt')),
    );
    await tester.pump(const Duration(milliseconds: 700));
    expect(
      tester.getSemantics(find.byType(ChainProgressBar)),
      matchesSemantics(label: 'Wird entpackt', value: '25 %'),
    );
    handle.dispose();
  });
}