import Decorator from '../core/Decorator';
import {FAILURE, SUCCESS, ERROR} from '../constants';

/**
 * This decorator limit the number of times its child can be called. After a
 * certain number of times, the Limiter decorator returns `FAILURE` without
 * executing the child.
 *
 * @module b3
 * @class Limiter
 * @extends Decorator
 **/

export default class Limiter extends Decorator {

  /**
   * Creates an instance of Limiter.
   * 
   * Settings parameters:
   * 
   * - **maxLoop** (*Integer*) Maximum number of repetitions.
   * - **child** (*BaseNode*) The child node.
   * 
   * @param {Object} params
   * @param {Number} params.maxLoop Maximum number of repetitions.
   * @param {BaseNode} params.child The child node.
   * @memberof Limiter
   */
  constructor({child = null, maxLoop} = {}) {
    super({
      child,
      name: 'Limiter',
      title: 'Limit <maxLoop> Activations',
      properties: {maxLoop: 1},
    });

    if (!maxLoop) {
      throw 'maxLoop parameter in Limiter decorator is an obligatory parameter';
    }
    
    this.maxLoop = maxLoop;
  }

  /**
   * Open method.
   * @method open
   * @param {Tick} tick A tick instance.
   **/
  open(tick) {
    tick.blackboard.set('i', 0, tick.tree.id, this.id);
  }

  /**
   * Tick method.
   * @method tick
   * @param {Tick} tick A tick instance.
   * @return {Constant} A state constant.
   **/
  tick(tick) {
    if (!this.child) {
      return ERROR;
    }

    var i = tick.blackboard.get('i', tick.tree.id, this.id);

    if (i < this.maxLoop) {
      var status = this.child._execute(tick);

      if (status == SUCCESS || status == FAILURE)
        tick.blackboard.set('i', i+1, tick.tree.id, this.id);

      return status;
    }

    return FAILURE;
  }
};