import 'package:flutter/material.dart';

import '../infrastructure/controller.dart';
import '../infrastructure/loadable_state.dart';
import '../infrastructure/state_extensions.dart';
import 'components/background_loading_indicator.dart';
import 'components/error_bar.dart';
import 'components/primary_loading_indicator.dart';

class LoadableControllerConsumer<TController extends Controller<TState>, TState extends LoadableState> extends StatelessWidget {
  final Widget child;
  const LoadableControllerConsumer({required this.child, super.key});

  final Duration animationDuration = const Duration(milliseconds: 200);

  @override
  Widget build(BuildContext context) {
    var state = context.readController<TController>().state;
    return Column(
      children: [
        ErrorBar(visible: state.errorBarVisible()),
        Expanded(
          child: Stack(
            children: [
              PrimaryLoadingIndicator(visible: !state.hasStateData()),
              BackgroundLoadingIndicator(visible: state.isBackgroundLoading() && !state.errorBarVisible()),

              AnimatedOpacity(
                  opacity: state.hasStateData() ? 1.0 : 0.0,
                  duration: animationDuration,
                  curve: Curves.easeInOut,
                  child: state.hasStateData() ? child : const SizedBox.shrink()
              ),
            ],
          ),
        )
      ],
    );
  }
}