/*
 * Copyright 2017 Graz University of Technology EAAF-Core Components has been developed in a
 * cooperation between EGIZ, A-SIT Plus, A-SIT, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by the European
 * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
 * compliance with the Licence. You may obtain a copy of the Licence at:
 * https://joinup.ec.europa.eu/news/understanding-eupl-v12
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the Licence
 * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the Licence for the specific language governing permissions and limitations under
 * the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text file for details on the
 * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
 * works that you distribute must include a readable copy of the "NOTICE" text file.
*/

package at.gv.egiz.eaaf.core.impl.idp.process.model;

import java.io.Serializable;

import at.gv.egiz.eaaf.core.impl.idp.process.ProcessDefinitionParser;

/**
 * Represents a single transition from a {@link StartEvent} or
 * {@linkplain TaskInfo Task} to another {@linkplain TaskInfo Task} or
 * {@link EndEvent}.
 *
 * @author tknall
 *
 */
public class Transition implements Serializable {

  private static final long serialVersionUID = 1L;

  private String id;
  private String conditionExpression;
  private ProcessNode from;
  private ProcessNode to;

  /**
   * Returns the process node (effectively a {@link StartEvent} or
   * {@linkplain TaskInfo Task}) the transition is pointing from.
   *
   * @return The transition's source process node (never {@code null} if
   *         transition comes from a process definition from
   *         {@link ProcessDefinitionParser}).
   */
  public ProcessNode getFrom() {
    return from;
  }

  /**
   * Sets the process node the transition is pointing from.
   *
   * @param from The transition's source process node.
   */
  public void setFrom(final ProcessNode from) {
    this.from = from;
  }

  /**
   * Returns the process node (effectively a {@linkplain TaskInfo Task} or
   * {@link EndEvent}) the transition is pointing to.
   *
   * @return The transition's destination process node (never {@code null} if
   *         transition comes from a process definition from
   *         {@link ProcessDefinitionParser}).
   */
  public ProcessNode getTo() {
    return to;
  }

  /**
   * Sets the process node the transition is pointing to.
   *
   * @param to The transition's destination process node.
   */
  public void setTo(final ProcessNode to) {
    this.to = to;
  }

  /**
   * Returns the unique identifier of the transition.
   *
   * @return The unique identifier (may be {@code null}).
   */
  public String getId() {
    return id;
  }

  /**
   * Sets the unique identifier of the transition.
   *
   * @param id The unique identifier.
   */
  public void setId(final String id) {
    this.id = id;
  }

  /**
   * Returns the condition expression for this transition.
   *
   * @return The condition expression (may be {@code null}).
   */
  public String getConditionExpression() {
    return conditionExpression;
  }

  /**
   * Sets the condition expression for this transition.
   *
   * @param conditionExpression The condition expression.
   */
  public void setConditionExpression(final String conditionExpression) {
    this.conditionExpression = conditionExpression;
  }

  @Override
  public String toString() {
    final StringBuilder builder = new StringBuilder();
    if (id != null) {
      builder.append("id=");
      builder.append(id);
    }
    if (from != null) {
      if (builder.length() > 0) {
        builder.append(", ");
      }
      builder.append("from.id=");
      builder.append(from.getId());
    }
    if (to != null) {
      if (builder.length() > 0) {
        builder.append(", ");
      }
      builder.append("to.id=");
      builder.append(to.getId());
    }
    if (conditionExpression != null) {
      if (builder.length() > 0) {
        builder.append(", ");
      }
      builder.append("conditionExpression=");
      builder.append(conditionExpression);
    }
    builder.insert(0, "Transition [");
    builder.append("]");
    return builder.toString();
  }

}