import 'package:flutter/widgets.dart';

import 'screenutil_mixin.dart';
import 'screen_util.dart';

typedef RebuildFactor = bool Function(MediaQueryData old, MediaQueryData data);

typedef ScreenUtilInitBuilder = Widget Function(
  BuildContext context,
  Widget? child,
);

abstract class RebuildFactors {
  static bool size(MediaQueryData old, MediaQueryData data) {
    return old.size != data.size;
  }

  static bool orientation(MediaQueryData old, MediaQueryData data) {
    return old.orientation != data.orientation;
  }

  static bool sizeAndViewInsets(MediaQueryData old, MediaQueryData data) {
    return old.viewInsets != data.viewInsets;
  }

  static bool change(MediaQueryData old, MediaQueryData data) {
    return old != data;
  }

  static bool always(MediaQueryData _, MediaQueryData __) {
    return true;
  }

  static bool none(MediaQueryData _, MediaQueryData __) {
    return false;
  }
}

class ScreenUtilInit extends StatefulWidget {
  /// A helper widget that initializes [ScreenUtil]
  const ScreenUtilInit({
    Key? key,
    this.builder,
    this.child,
    this.rebuildFactor = RebuildFactors.size,
    this.designSize = ScreenUtil.defaultSize,
    this.splitScreenMode = false,
    this.minTextAdapt = false,
    this.useInheritedMediaQuery = false,
    this.responsiveWidgets,
  }) : super(key: key);

  final ScreenUtilInitBuilder? builder;
  final Widget? child;
  final bool splitScreenMode;
  final bool minTextAdapt;
  final bool useInheritedMediaQuery;
  final RebuildFactor rebuildFactor;

  /// The [Size] of the device in the design draft, in dp
  final Size designSize;
  final Iterable<String>? responsiveWidgets;

  @override
  State<ScreenUtilInit> createState() => _ScreenUtilInitState();
}

class _ScreenUtilInitState extends State<ScreenUtilInit>
    with WidgetsBindingObserver {
  late final Iterable<String>? _canMarkedToBuild;
  MediaQueryData? _mediaQueryData;
  final WidgetsBinding _binding = WidgetsBinding.instance;

  @override
  void initState() {
    _canMarkedToBuild = widget.responsiveWidgets;
    super.initState();
    _binding.addObserver(this);
  }

  @override
  void didChangeMetrics() {
    super.didChangeMetrics();
    _revalidate();
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _revalidate();
  }

  MediaQueryData? _newData() {
    MediaQueryData? mq = MediaQuery.maybeOf(context);
    if (mq == null) mq = MediaQueryData.fromView(View.of(context));

    return mq;
  }

  void _markNeedsBuildIfAllowed(Element el) {
    if (_canMarkedToBuild != null) {
      final widget = el.widget, widgetName = el.widget.runtimeType.toString();

      if (widget is! SU && !_canMarkedToBuild!.contains(widgetName)) return;
    }

    el.markNeedsBuild();
  }

  void _updateTree(Element el) {
    _markNeedsBuildIfAllowed(el);
    el.visitChildren(_updateTree);
  }

  void _revalidate([void Function()? callback]) {
    final oldData = _mediaQueryData;
    final newData = _newData();

    if (newData == null) return;

    if (oldData == null || widget.rebuildFactor(oldData, newData)) {
      setState(() {
        _mediaQueryData = newData;
        _updateTree(context as Element);
        callback?.call();
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final mq = _mediaQueryData;

    if (mq == null) return SizedBox.shrink();

    ScreenUtil.configure(
      data: mq,
      designSize: widget.designSize,
      splitScreenMode: widget.splitScreenMode,
      minTextAdapt: widget.minTextAdapt,
    );

    return widget.builder?.call(context, widget.child) ?? widget.child!;
  }

  @override
  void dispose() {
    _binding.removeObserver(this);
    super.dispose();
  }
}