/*

  * Copyright (c) 2006 - 2011 Michael Schierl

  * All rights reserved.

  * 

  * This program is free software: you can redistribute it and/or modify

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

  * the Free Software Foundation, either version 2 of the License, or

  * (at your option) any later version.

  * 

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  * 

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

  * along with this program.  If not, see <http://www.gnu.org/licenses/>.

  */

 package net.sf.jmatchparser.template.engine.template.command.plain;

 import net.sf.jmatchparser.template.engine.operation.CounterOperation;

 import net.sf.jmatchparser.template.engine.operation.IncrementCounterOperation;

 import net.sf.jmatchparser.template.engine.operation.JumpOperation;

 import net.sf.jmatchparser.template.engine.operation.Label;

 import net.sf.jmatchparser.template.engine.operation.LoopForkOperation;

 import net.sf.jmatchparser.template.engine.parameter.Parameter;

 import net.sf.jmatchparser.template.engine.template.PlainBlockCommandState;

 import net.sf.jmatchparser.template.engine.template.MatchTemplateImpl;

 public class LoopCommand extends Command {

         @Override

         public PlainBlockCommandState parse(MatchTemplateImpl template, String parameters) {

                 // Continue after the loop and fork inside the loop.

                 // The other way round is easier to code, but will cause

                 // a huge pile of queued of states to pile up if the loop repeats

                 // a lot of times.

                 Parameter[] params = Parameter.parseParameters(parameters, 0, 2, 1, template.getSpecialTags());

                 if (params[0] == null)

                         params[0] = Parameter.getLiteralParameter("0");

                 Label startLabel = new Label(), endLabel = new Label(), forkLabel = new Label();

                 CounterOperation co = new CounterOperation(template.getCurrentTemplatePosition());

                 template.appendOperation(co);

                 startLabel.setDestinationToNextCommand(template);

                 template.appendOperation(new LoopForkOperation(template.getCurrentTemplatePosition(), forkLabel, co, params[0], params[1]));

                 template.appendOperation(new JumpOperation(template.getCurrentTemplatePosition(), endLabel));

                 forkLabel.setDestinationToNextCommand(template);

                 return new LoopCommandState(template, co, startLabel, endLabel);

         }

         private class LoopCommandState extends PlainBlockCommandState {

                 private final CounterOperation co;

                 private final Label startLabel;

                 private final Label endLabel;

                 public LoopCommandState(MatchTemplateImpl template, CounterOperation co, Label startLabel, Label endLabel) {

                         super(template);

                         this.co = co;

                         this.startLabel = startLabel;

                         this.endLabel = endLabel;

                 }

                 @Override

                 public boolean canParse(String commandName) {

                         return commandName.equals("endloop");

                 }

                 @Override

                 public PlainBlockCommandState parseCommand(MatchTemplateImpl template,

                                 String commandName, String parameters) {

                         template.appendOperation(new IncrementCounterOperation(template.getCurrentTemplatePosition(), co));

                         template.appendOperation(new JumpOperation(template.getCurrentTemplatePosition(), startLabel));

                         endLabel.setDestinationToNextCommand(template);

                         return null;

                 }

         }

 }