/**
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at

 * http://www.apache.org/licenses/LICENSE-2.0

 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { isValid } from './utils/typeChecks';

import {
  type EventName,
  type MouseTouchEvent,
  type MouseTouchEventCallback,
} from './SyntheticEvent';

export interface EventDispatcher {
  dispatchEvent: (
    name: EventName,
    event: MouseTouchEvent,
    other?: number,
  ) => boolean;
}

export default abstract class Eventful implements EventDispatcher {
  private _children: Eventful[] = [];

  private readonly _callbacks = new Map<EventName, MouseTouchEventCallback>();

  registerEvent(name: EventName, callback: MouseTouchEventCallback): this {
    this._callbacks.set(name, callback);
    return this;
  }

  onEvent(name: EventName, event: MouseTouchEvent, other?: number): boolean {
    const callback = this._callbacks.get(name);
    if (isValid(callback) && this.checkEventOn(event)) {
      return callback(event, other);
    }
    return false;
  }

  checkEventOn(event: MouseTouchEvent): boolean {
    for (const eventful of this._children) {
      if (eventful.checkEventOn(event)) {
        return true;
      }
    }
    return false;
  }

  dispatchEvent(
    name: EventName,
    event: MouseTouchEvent,
    other?: number,
  ): boolean {
    const start = this._children.length - 1;
    if (start > -1) {
      for (let i = start; i > -1; i--) {
        if (this._children[i].dispatchEvent(name, event, other)) {
          return true;
        }
      }
    }
    return this.onEvent(name, event, other);
  }

  addChild(eventful: Eventful): this {
    this._children.push(eventful);
    return this;
  }

  clear(): void {
    this._children = [];
  }
}