pixes/lib/foundation/state_controller.dart

import 'package:flutter/material.dart';
import 'pair.dart';

class SimpleController extends StateController{
  final void Function()? refresh_;

  SimpleController({this.refresh_});

  @override
  void refresh() {
    (refresh_ ?? super.refresh)();
  }
}

abstract class StateController{
  static final _controllers = <StateControllerWrapped>[];

  static T put<T extends StateController>(T controller, {Object? tag, bool autoRemove = false}){
    _controllers.add(StateControllerWrapped(controller, autoRemove, tag));
    return controller;
  }

  static T putIfNotExists<T extends StateController>(T controller, {Object? tag, bool autoRemove = false}){
    return findOrNull<T>(tag: tag) ?? put(controller, tag: tag, autoRemove: autoRemove);
  }

  static T find<T extends StateController>({Object? tag}){
    try {
      return _controllers.lastWhere((element) =>
      element.controller is T
          && (tag == null || tag == element.tag)).controller as T;
    }
    catch(e){
      throw StateError("${T.runtimeType} with tag $tag Not Found");
    }
  }

  static T? findOrNull<T extends StateController>({Object? tag}){
    try {
      return _controllers.lastWhere((element) =>
      element.controller is T
          && (tag == null || tag == element.tag)).controller as T;
    }
    catch(e){
      return null;
    }
  }

  static void remove<T>([Object? tag, bool check = false]){
    for(int i=_controllers.length-1; i>=0; i--){
      var element = _controllers[i];
      if(element.controller is T && (tag == null || tag == element.tag)){
        if(check && !element.autoRemove){
          continue;
        }
        _controllers.removeAt(i);
        return;
      }
    }
  }

  static SimpleController putSimpleController(void Function() onUpdate, Object? tag, {void Function()? refresh}){
    var controller = SimpleController(refresh_: refresh);
    controller.stateUpdaters.add(Pair(null, onUpdate));
    _controllers.add(StateControllerWrapped(controller, false, tag));
    return controller;
  }

  List<Pair<Object?, void Function()>> stateUpdaters = [];

  void update([List<Object>? ids]){
    if(ids == null){
      for(var element in stateUpdaters){
        element.right();
      }
    }else{
      for(var element in stateUpdaters){
        if(ids.contains(element.left)) {
          element.right();
        }
      }
    }
  }

  void dispose(){
    _controllers.removeWhere((element) => element.controller == this);
  }

  void refresh(){
    update();
  }
}

class StateControllerWrapped{
  StateController controller;
  bool autoRemove;
  Object? tag;

  StateControllerWrapped(this.controller, this.autoRemove, this.tag);
}


class StateBuilder<T extends StateController> extends StatefulWidget {
  const StateBuilder({super.key, this.init, this.dispose, this.initState, this.tag,
    required this.builder, this.id});

  final T? init;

  final void Function(T controller)? dispose;

  final void Function(T controller)? initState;

  final Object? tag;

  final Widget Function(T controller) builder;

  Widget builderWrapped(StateController controller){
    return builder(controller as T);
  }

  void initStateWrapped(StateController controller){
    return initState?.call(controller as T);
  }

  void disposeWrapped(StateController controller){
    return dispose?.call(controller as T);
  }

  final Object? id;

  @override
  State<StateBuilder> createState() => _StateBuilderState<T>();
}

class _StateBuilderState<T extends StateController> extends State<StateBuilder> {
  late T controller;

  @override
  void initState() {
    if(widget.init != null) {
      StateController.put(widget.init!, tag: widget.tag, autoRemove: true);
    }
    try {
      controller = StateController.find<T>(tag: widget.tag);
    }
    catch(e){
      throw "Controller Not Found";
    }
    controller.stateUpdaters.add(Pair(widget.id, () {
      if(mounted){
        setState(() {});
      }
    }));
    widget.initStateWrapped(controller);
    super.initState();
  }

  @override
  void dispose() {
    widget.disposeWrapped(controller);
    StateController.remove<T>(widget.tag, true);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => widget.builderWrapped(controller);
}

abstract class StateWithController<T extends StatefulWidget> extends State<T>{
  late final SimpleController _controller;

  void refresh(){
    _controller.update();
  }

  @override
  @mustCallSuper
  void initState() {
    _controller = StateController.putSimpleController(() => setState(() {}), tag, refresh: refresh);
    super.initState();
  }

  @override
  @mustCallSuper
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  void update(){
    _controller.update();
  }

  Object? get tag;
}