/*

  * SQLElements object-oriented SQL parsing and generation library

  * 

  * Copyright (c) 2003, 2004, 2005 Israfil Consulting Services Corporation

  * Copyright (c) 2003, 2004, 2005 Christian Edward Gruber

  * All Rights Reserved

  * 

  *  This library is free software; you can redistribute it and/or modify 

  *  it under the terms of the GNU Lesser General Public License as published 

  *  by the Free Software Foundation; either version 2.1 of the License, or 

  *  (at your option) any later version.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 

  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 

  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 

  * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 

  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 

  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 

  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 

  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 

  * OF SUCH DAMAGE.

  *

  *  You should have received a copy of the GNU Lesser General Public License 

  *  along with this library; if not, please visit http://www.gnu.org/licenses/lgpl.html

  *

  * $Id: NaryConstraint.java 27 2006-01-14 07:50:08 -0500 (Sat, 14 Jan 2006) cgruber $

  */

 package org.israfil.sqlelements.constraints;

 import java.util.Arrays;

 import java.util.Set;

 import net.israfil.foundation.collections.ArraySet;

 import org.israfil.sqlelements.render.SQLRenderContext;

 /**

  * N-ary Constraint

  * A friendly parent for constraints that can have an infinite

  * number of operands, such as and, or, etc.  

  * i.e.: "(a=b) and (b=c) and (c=d)" is a valid SQL construction, but

  * can be represented (logically) by: and(condition1,condition2,condition3)

  * 

  * @author <a href="mailto:cgruber@israfil.net">Christian Edward Gruber </a>

  * @author Latest: $Author: cgruber $

  * @version $Revision: 27 $

  */

 public abstract class NaryConstraint implements ComplexConstraint

 {

     protected Constraint[] operands;

     protected String operatorText;

     protected NaryConstraint(String operatorText, Constraint ... operands) {

             this(operatorText,prepArray(operands));

     }

     protected static Set<Constraint> prepArray(Constraint[] array) {

             Set<Constraint> s = new ArraySet<Constraint>();

             if (array != null) s.addAll(Arrays.asList(array));

             return s;

     }

     protected NaryConstraint(String operatorText, Set<Constraint> operands) {

             if (operands == null) operands = new ArraySet<Constraint>(0);

         this.operatorText = operatorText;

         Set<Constraint> constraintSet = new ArraySet<Constraint>();

         for (Constraint c : operands) {

             if (c == null) continue;

             if (this.getClass().equals(c.getClass())) {

                 for(Constraint sub : ((NaryConstraint)c).operands){

                     constraintSet.add(sub);

                 }

             }

             else constraintSet.add(c);

         }

         this.operands = constraintSet.toArray(new Constraint[constraintSet.size()]);

     }

     public String render(SQLRenderContext context) {

         boolean first = true;

         String sql = "";

         for (Constraint c : this.operands) {

             if (!first) {

                 sql += " ";

                 sql += operatorText;

                 sql += " ";

             }

             else first = false;

             sql += ConstraintUtils.renderInParentheses(c,context);

         }

         return sql;

     }    

 }