/// Unit tests for [PaneRegistry].
///
/// Exercises spawn / list / write / resize / close against the real
/// NativePty (posix_spawn via FFI). Events are captured via
/// [RecordingEventSink].
library;

import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:clide/clide.dart';
import 'package:clide/src/panes/registry.dart';
import 'package:test/test.dart';

import '../helpers/timeouts.dart';

void main() {
  if (!Platform.isLinux && !Platform.isMacOS) return;

  group('PaneRegistry', () {
    late RecordingEventSink sink;
    late PaneRegistry registry;

    setUp(() {
      sink = RecordingEventSink();
      registry = PaneRegistry(events: sink);
    });

    tearDown(() => registry.shutdown());

    test('spawn → emits pane.spawned and lists the pane', () async {
      final pane = await registry.spawn(kind: PaneKind.terminal, argv: const ['/bin/echo', 'hi']);

      expect(pane.id, startsWith('p_'));
      expect(pane.kind, PaneKind.terminal);
      expect(registry.panes, contains(pane));
      expect(sink.ofKind('pane.spawned'), hasLength(1));
      final evt = sink.ofKind('pane.spawned').first;
      expect(evt.data['id'], pane.id);
    });

    test('output events base64-encode the child bytes', tags: ['pty'], () async {
      // Subscribe to the sink stream BEFORE spawn so we don't miss
      // any pane.output events that arrive between spawn and listen.
      final buf = StringBuffer();
      final got = Completer<String>();
      final sub = sink.stream.listen((e) {
        if (e.kind != 'pane.output') return;
        buf.write(utf8.decode(base64Decode(e.data['bytes_b64']! as String)));
        if (buf.toString().contains('hello-panes') && !got.isCompleted) {
          got.complete(buf.toString());
        }
      });
      addTearDown(sub.cancel);

      await registry.spawn(
        kind: PaneKind.terminal,
        // Child writes then lingers so the reader's poll has a wide
        // window to see POLLIN before HUP.
        argv: const ['/bin/sh', '-c', 'printf hello-panes; sleep 0.25'],
      );

      final decoded = await got.future.timeout(ioTimeout, onTimeout: () => fail('pane.output never carried "hello-panes" within ${ioTimeout.inSeconds}s'));
      expect(decoded, contains('hello-panes'));
      expect(sink.ofKind('pane.output'), isNotEmpty);
    });

    test('write + resize emit no spurious events, update state', () async {
      final pane = await registry.spawn(kind: PaneKind.terminal, argv: const ['/bin/cat']);

      final writeCount = registry.write(pane.id, utf8.encode('abc'));
      expect(writeCount, greaterThan(0));

      registry.resize(pane.id, cols: 120, rows: 40);
      final resized = sink.ofKind('pane.resized').toList();
      expect(resized, hasLength(1));
      expect(resized.single.data['cols'], 120);
      expect(resized.single.data['rows'], 40);
    });

    test('close is idempotent + emits pane.closed once', () async {
      final pane = await registry.spawn(kind: PaneKind.terminal, argv: const ['/bin/cat']);

      await registry.close(pane.id);
      await registry.close(pane.id); // second call: no-op

      expect(registry.get(pane.id), isNull);
      expect(sink.ofKind('pane.closed'), hasLength(1));
    });

    test('close on unknown id does nothing', () async {
      await registry.close('p_nonexistent');
      expect(sink.ofKind('pane.closed'), isEmpty);
    });

    test('claude kind round-trips on the wire', () async {
      final pane = await registry.spawn(kind: PaneKind.claude, argv: const ['/bin/sh', '-c', 'exit 0']);
      expect(pane.kind, PaneKind.claude);
      expect(pane.toJson()['kind'], 'claude');
    });
  });

  group('RecordingEventSink filters', () {
    test('ofSubsystem narrows events to a single subsystem', () {
      final s = RecordingEventSink();
      final ts = DateTime.now().toUtc();
      s.emit(IpcEvent(subsystem: 'pane', kind: 'spawned', timestamp: ts, data: const {}));
      s.emit(IpcEvent(subsystem: 'git', kind: 'changed', timestamp: ts, data: const {}));
      s.emit(IpcEvent(subsystem: 'pane', kind: 'closed', timestamp: ts, data: const {}));
      expect(s.ofSubsystem('pane'), hasLength(2));
      expect(s.ofSubsystem('git'), hasLength(1));
      expect(s.ofSubsystem('files'), isEmpty);
    });
  });
}