import 'package:flutter/material.dart';

import '../infrastructure/controller.dart';
import '../infrastructure/loadable_state.dart';
import '../infrastructure/state_extensions.dart';

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

  @override
  Widget build(BuildContext context) {
    var state = context.readController<TController>().state;
    return Stack(
      children: [
        if(!state.hasStateData()) const Center(child: CircularProgressIndicator()),

        AnimatedSwitcher(
          duration: const Duration(milliseconds: 100),
          transitionBuilder: (Widget child, Animation<double> animation) => SlideTransition(
              position: Tween<Offset>(
                begin: const Offset(0.0, -1.0),
                end: Offset.zero,
              ).animate(animation),
              child: child,
            ),
          child: state.isBackgroundLoading() ? const LinearProgressIndicator() : const SizedBox.shrink(),
        ),

        AnimatedOpacity(
          opacity: state.hasStateData() ? 1.0 : 0.0,
          duration: const Duration(milliseconds: 100),
          curve: Curves.easeInOut,
          child: state.hasStateData() ? child(context, state) : const SizedBox.shrink()
        ),
      ],
    );
  }
}