{* setHandler randomFile="client.someone.handler.misc.RandomFile" *}

{* randomFile root=$cgi.DOCUMENT_ROOT prefix="item_ID_" dir="/factoids/promo/" *}
{* randomFile root=$cgi.DOCUMENT_ROOT prefix="item_ID_" dir="/factoids/funfacts/" *}

package client.someone.handler.misc

import java.util.Hashtable;
import java.util.Vector;
import organic.servlet.broker.*;
import java.io.File ;
import java.io.FileReader ;
import java.io.BufferedReader ;

public class RandomFile implements HandlerInterface {

	// Standard error messages
	static final String kErrMissingDirArg = 
		"RandomFile: error: missing dir arg: " +
		"usage: \{* randomFile dir=\"e:\\\" *}";
	static final String kErrInvalidDirArg = 
		"RandomFile: error: invalid directory argument value: " ;

	public Object handleToken(String tokenName,
			    Hashtable args,
			    Request request)
       throws HandlerException
 	{
		try {

			// Get the root argument passed to us
			String rootArg = (String) args.get( "root" ) ;

			// Get the dir argument passed to us; complain if missing.
			String dirArg = (String) args.get( "dir" ) ;
			if ( dirArg == null || dirArg.equals("") )
				return kErrMissingDirArg ;

			// Get filesInDir or return appropriate error message
			File dir = new File( rootArg + dirArg ) ;
			String files[] = dir.list() ;
			int filesInDir ;
			try { filesInDir = files.length ; }
			catch (Exception e) { return kErrInvalidDirArg + "\"" + rootArg + dirArg + """ ; }

			// Get the prefix argument passed to us
			String prefixArg = (String) args.get( "prefix" ) ;

			// Get the suffix argument passed to us
			String suffixArg = (String) args.get( "suffix" ) ;

			Vector filesThatQualify = QualifyFiles( files, prefixArg, suffixArg ) ;

			BufferedReader in = new BufferedReader(
				new FileReader( rootArg + dirArg + filesThatQualify.elementAt(
					(int) ( Math.random() * filesThatQualify.size() )))) ;

			StringBuffer contents = new StringBuffer() ;
			String oneLine ;
			while ( ( oneLine = in.readLine() ) != null )
				contents.append( oneLine ).append(" ") ;
			in.close() ;

			return contents ;

		} catch (Exception e) { throw new HandlerException(e); }
	}

	// -----------------------------------------------------
	// Qualify the filenames based on prefix and/or suffix.
	// -----------------------------------------------------
	public Vector QualifyFiles(String[] files, String prefixArg, String suffixArg) {

		StringBuffer b = new StringBuffer() ;
		String fn = new String() ;
		Vector filesThatQualify = new Vector(1) ;
		for ( int i = 0 ; i < files.length ; i++ ) \{
			fn = files[i] ;
			if ( prefixArg != null && !prefixArg.equals("") )
				if ( !fn.startsWith( prefixArg ))
					fn = "" ;
			if ( suffixArg != null && !suffixArg.equals("") )
				if ( !fn.endsWith( suffixArg ))
					fn = "" ;
			if ( !fn.equals("") )
				filesThatQualify.addElement( files[i] ) ;
		}
		return filesThatQualify ;
	}
}