/* 
    <<plugin>>
    conditional TEST plugin
    Dirk Frederickx April 2006

    This program 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 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package brushed.jspwiki.conditional;

import org.apache.log4j.Logger;
import com.ecyrd.jspwiki.*;
import com.ecyrd.jspwiki.plugin.*;
import org.apache.oro.text.*;
import org.apache.oro.text.regex.*;
import java.util.*;

/**
 *  Includes body of plugin based on presence of page or variable
 *  or based on value of page or variable
 *
 *  <P>Parameters</P>
 *  <UL>
 *    <LI>page: name of the wiki page; default is current page
 *    <LI>name: name of a wiki variable (optional)
 *    <LI>match: regexp; when matching page content or variable value, yields true
 *    <LI>except: regexp; when matching page content or variable value, yields false
 *  </UL>
 *
 *  @author Dirk Frederickx
 */
public class TEST
       implements WikiPlugin
{
    //private static Logger log = Logger.getLogger( ReferredPagesPlugin.class );
    private WikiEngine     m_engine;
    private StringBuffer   m_result  = new StringBuffer();
    private PatternMatcher m_matcher = new Perl5Matcher();
    private Pattern        m_matchPattern;
    private Pattern        m_exceptPattern;
    
    public static final String PARAM_BODY   = "_body";
    public static final String PARAM_PAGE   = "page";
    public static final String PARAM_NAME   = "name";
    public static final String PARAM_MATCH  = "match";
    public static final String PARAM_EXCEPT = "except";
    public static final String RETURN_OK    = "true";

    public String execute( WikiContext context, Map params )
        throws PluginException
    {    
        m_engine = context.getEngine();        

        WikiPage page = context.getPage();
        String testpagename = (String)params.get( PARAM_PAGE );
        if( testpagename != null ) 
        {
          if( !m_engine.pageExists( testpagename ) )  return ""; //page not present
          page = m_engine.getPage( testpagename );
        }
        if( page == null ) return ""; // page not present 

        String content = null;
        
        String testvar = (String)params.get( PARAM_NAME );
        if( testvar != null )
        {
          content = m_engine.getVariable( context, testvar );
          if( content == null ) return ""; //variable not present
        }
        else
        {
          content = m_engine.getPureText( page );
        }

        String matchPattern = (String) params.get( PARAM_MATCH );
        if( matchPattern == null ) matchPattern = ".*";

        String exceptPattern = (String) params.get( PARAM_EXCEPT );
        if( exceptPattern == null ) exceptPattern = "^$";        

        // pre compile all needed patterns
        // glob compiler :  * is 0..n instance of any char  -- more convenient as input 
        // perl5 compiler : .* is 0..n instances of any char -- more powerful
        //PatternCompiler g_compiler = new GlobCompiler();
        PatternCompiler compiler = new Perl5Compiler();
        try
        {
          m_matchPattern  = compiler.compile( matchPattern, Perl5Compiler.SINGLELINE_MASK );        
          m_exceptPattern = compiler.compile( exceptPattern, Perl5Compiler.SINGLELINE_MASK );
        }
        catch( MalformedPatternException e )
        {
          if( m_matchPattern == null ) 
            throw new PluginException("Illegal match pattern detected.");
           
          if( m_exceptPattern == null ) 
            throw new PluginException("Illegal except pattern detected.");
        }
                  
        if(  m_matcher.matches( content , m_exceptPattern ) ) return ""; //matched except pattern 
        
        if( !m_matcher.matches( content , m_matchPattern  ) ) return ""; //no match with match pattern

        m_result.append( "<div class=\"conditional-plugin\">" );
        
        String body = (String)params.get( PARAM_BODY );
        if( body == null ) 
        {
          m_result.append( RETURN_OK );
        }
        else
        {
          m_result.append( m_engine.textToHTML( context, body ) );
        }
        
        m_result.append ( "</div>" ) ;
          
        return m_result.toString() ;
    }
    
}