import 'package:gravity_sdk/gravity_sdk.dart';

class SelectedContent {
  const SelectedContent({required this.campaign, required this.content});
  final Campaign campaign;
  final CampaignContent content;
}

SelectedContent? selectRoot(ContentResponse response) {
  for (final campaign in response.data) {
    for (final variation in campaign.payload) {
      for (final content in variation.contents) {
        if (content.step == null) {
          return SelectedContent(campaign: campaign, content: content);
        }
      }
    }
  }
  return null;
}

Future<SelectedContent?> loadSelectedContent({
  required String selector,
  required PageContext pageContext,
}) async {
  final response = await GravitySDK.instance.getContentBySelector(
    selector: selector,
    pageContext: pageContext,
  );
  return selectRoot(response);
}

// Один объект на одно фактическое размещение полученного контента.
// Загрузка не считается показом. Показ фиксируем после появления UI.
class ContentExposure {
  ContentExposure(this.selected);
  final SelectedContent selected;
  bool _shown = false;
  bool _visible = false;

  void onVisibility(double fraction) {
    if (fraction > 0 && !_shown) {
      _shown = true;
      GravitySDK.instance.sendContentEngagement(
        ContentImpressionEngagement(selected.content, selected.campaign),
      );
    }
    if (fraction >= 0.5 && !_visible) {
      _visible = true;
      GravitySDK.instance.sendContentEngagement(
        ContentVisibleImpressionEngagement(selected.content, selected.campaign),
      );
    }
  }

  void click() {
    GravitySDK.instance.sendContentEngagement(
      ContentClickEngagement(selected.content, selected.campaign),
    );
  }
}