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/*
 * The MIT License
 *
 *  Copyright (c) 2022, Mahmoud Ben Hassine ([email protected])
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a copy
 *  of this software and associated documentation files (the "Software"), to deal
 *  in the Software without restriction, including without limitation the rights
 *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *  copies of the Software, and to permit persons to whom the Software is
 *  furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included in
 *  all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *  THE SOFTWARE.
 */
package org.jeasy.rules.api;

/**
 * Abstraction for a rule that can be fired by a rules engine.
 *
 * Rules are registered in a namespace of rule of type {@link Rules} in which they must have a
 * unique name.
 *
 * @author Mahmoud Ben Hassine ([email protected])
 */
public interface Rule extends Comparable {

  /** Default rule name. */
  String DEFAULT_NAME = "rule";

  /** Default rule description. */
  String DEFAULT_DESCRIPTION = "description";

  /** Default rule priority. */
  int DEFAULT_PRIORITY = Integer.MAX_VALUE - 1;

  /**
   * Getter for rule name.
   *
   * @return the rule name
   */
  default String getName() {
    return DEFAULT_NAME;
  }

  /**
   * Getter for rule description.
   *
   * @return rule description
   */
  default String getDescription() {
    return DEFAULT_DESCRIPTION;
  }

  /**
   * Getter for rule priority.
   *
   * @return rule priority
   */
  default int getPriority() {
    return DEFAULT_PRIORITY;
  }

  /**
   * This method implements the rule's condition(s). Implementations should handle any
   * runtime exception and return true/false accordingly
   *
   * @return true if the rule should be applied given the provided facts, false otherwise
   */
  boolean evaluate(Facts facts);

  /**
   * This method implements the rule's action(s).
   *
   * @throws Exception thrown if an exception occurs when performing action(s)
   */
  void execute(Facts facts) throws Exception;
}