// Widget-level proof of the sample handling contract (persona
// review 2026-08-27 / sealed-areas rework):
//
//   * The host's sample set (the hub's FlowSummary.sample wire
//     flag) is the ONLY source of the "Example" chip — no host
//     info, no chips. The editor's old content-marker scan had
//     silently drifted from the hub's header and is gone.
//   * Sample flows collapse under one "Examples (N)" group so
//     they are never mistaken for the operator's own work; the
//     group expands only on demand (or when nothing else exists).
//   * An empty list offers "Import example flows" iff the host
//     wired the action (sealed areas start empty on purpose).
//
// Hermetic — temp flows dir, never ~/.chain.

import 'dart:io';

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

import 'package:chain_studio_flow_editor/chain_studio_flow_editor.dart';

Future<void> _pumpEditor(
  WidgetTester tester, {
  required String flowsDir,
  Set<String>? sampleFlowNames,
  Future<void> Function()? onImportSamples,
}) async {
  await tester.runAsync(() async {
    await tester.pumpWidget(
      MaterialApp(
        home: FlowEditorPage(
          flowsDir: flowsDir,
          sampleFlowNames: sampleFlowNames,
          onImportSamples: onImportSamples,
        ),
      ),
    );
    await Future<void>.delayed(const Duration(milliseconds: 100));
  });
  await tester.pump();
  await tester.pump();
}

void main() {
  late Directory tmp;

  setUp(() {
    tmp = Directory.systemTemp.createTempSync('chain_editor_samples_test');
    File('${tmp.path}/my-work.yaml').writeAsStringSync(
      'name: my-work\nsteps: []\n',
    );
    File('${tmp.path}/hello.yaml').writeAsStringSync(
      'name: hello\nsteps: []\n',
    );
  });

  tearDown(() {
    tmp.deleteSync(recursive: true);
  });

  testWidgets('host-reported samples collapse under the examples group', (
    tester,
  ) async {
    await _pumpEditor(
      tester,
      flowsDir: tmp.path,
      sampleFlowNames: const {'hello'},
    );
    // Own flow visible, sample hidden behind the collapsed group.
    expect(find.text('my-work'), findsOneWidget);
    expect(find.text('hello'), findsNothing);
    expect(find.text('Examples (1)'), findsOneWidget);

    await tester.tap(find.text('Examples (1)'));
    await tester.pump();
    expect(find.text('hello'), findsOneWidget);
    // The revealed sample row carries the chip.
    expect(find.text('Example'), findsOneWidget);
  });

  testWidgets('no host sample info means no chips and no group', (
    tester,
  ) async {
    await _pumpEditor(tester, flowsDir: tmp.path, sampleFlowNames: null);
    expect(find.text('my-work'), findsOneWidget);
    expect(find.text('hello'), findsOneWidget);
    expect(find.text('Example'), findsNothing);
    expect(find.textContaining('Examples ('), findsNothing);
  });

  testWidgets('a samples-only list starts expanded', (tester) async {
    File('${tmp.path}/my-work.yaml').deleteSync();
    await _pumpEditor(
      tester,
      flowsDir: tmp.path,
      sampleFlowNames: const {'hello'},
    );
    expect(find.text('hello'), findsOneWidget);
    expect(find.text('Examples (1)'), findsOneWidget);
  });

  testWidgets('the empty list offers the import action when wired', (
    tester,
  ) async {
    File('${tmp.path}/my-work.yaml').deleteSync();
    File('${tmp.path}/hello.yaml').deleteSync();
    var imported = 0;
    await _pumpEditor(
      tester,
      flowsDir: tmp.path,
      onImportSamples: () async {
        imported++;
        File('${tmp.path}/hello.yaml').writeAsStringSync(
          'name: hello\nsteps: []\n',
        );
      },
    );
    final button = find.text('Import example flows');
    expect(button, findsOneWidget);
    await tester.runAsync(() async {
      await tester.tap(button);
      // Let the import callback, the directory re-list (real IO)
      // and the FutureBuilder's completion callback all run.
      await Future<void>.delayed(const Duration(milliseconds: 200));
      await tester.pump();
      await Future<void>.delayed(const Duration(milliseconds: 100));
    });
    await tester.pump();
    await tester.pump();
    expect(imported, 1);
    // The imported flow appears without a manual refresh.
    expect(find.text('hello'), findsOneWidget);
  });

  testWidgets('the empty list stays action-free when nothing is wired', (
    tester,
  ) async {
    File('${tmp.path}/my-work.yaml').deleteSync();
    File('${tmp.path}/hello.yaml').deleteSync();
    await _pumpEditor(tester, flowsDir: tmp.path);
    expect(find.text('Import example flows'), findsNothing);
  });
}