/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package org.apache.jmeter.protocol.http.util.accesslog;

import java.io.Serializable;
import java.util.ArrayList;

import org.apache.jmeter.testelement.TestElement;
import org.apache.jmeter.util.JMeterUtils;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;
import org.apache.oro.text.MalformedCachePatternException;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.Perl5Compiler;

// For JUnit tests, @see TestLogFilter

/**
 * Description:<br>
 * <br>
 * LogFilter is a basic implementation of Filter interface. This implementation
 * will keep a record of the filtered strings to avoid repeating the process
 * unnecessarily.
 * <p>
 * The current implementation supports replacing the file extension. The reason
 * for supporting this is from first hand experience porting an existing website
 * to Tomcat + JSP. Later on we may want to provide the ability to replace the
 * whole filename. If the need materializes, we can add it later.
 * <p>
 * Example of how to use it is provided in the main method. An example is
 * provided below.
 * <p>
 * 
 * <pre>
 * testf = new LogFilter();
 * String[] incl = { &quot;hello.html&quot;, &quot;index.html&quot;, &quot;/index.jsp&quot; };
 * String[] thefiles = { &quot;/test/hello.jsp&quot;, &quot;/test/one/hello.html&quot;, &quot;hello.jsp&quot;, &quot;hello.htm&quot;, &quot;/test/open.jsp&quot;,
 * 		&quot;/test/open.html&quot;, &quot;/index.jsp&quot;, &quot;/index.jhtml&quot;, &quot;newindex.jsp&quot;, &quot;oldindex.jsp&quot;, &quot;oldindex1.jsp&quot;,
 * 		&quot;oldindex2.jsp&quot;, &quot;oldindex3.jsp&quot;, &quot;oldindex4.jsp&quot;, &quot;oldindex5.jsp&quot;, &quot;oldindex6.jsp&quot;, &quot;/test/index.htm&quot; };
 * testf.excludeFiles(incl);
 * System.out.println(&quot; ------------ exclude test -------------&quot;);
 * for (int idx = 0; idx &lt; thefiles.length; idx++) {
 * 	boolean fl = testf.isFiltered(thefiles[idx]);
 * 	String line = testf.filter(thefiles[idx]);
 * 	if (line != null) {
 * 		System.out.println(&quot;the file: &quot; + line);
 * 	}
 * }
 * </pre>
 * 
 * As a general note. Both isFiltered and filter() have to be called. Calling
 * either one will not produce the desired result. isFiltered(string) will tell
 * you if a string should be filtered. The second step is to filter the string,
 * which will return null if it is filtered and replace any part of the string
 * that should be replaced.
 * <p>
 * 
 */

public class LogFilter implements Filter, Serializable {

    private static final Logger log = LoggingManager.getLoggerForClass();

	/** protected members used by class to filter * */
	protected boolean CHANGEEXT = false;

	protected String OLDEXT = null;

	protected String NEWEXT = null;

	protected String[] INCFILE = null;

	protected String[] EXCFILE = null;

	protected boolean FILEFILTER = false;

	protected boolean USEFILE = true;

	protected String[] INCPTRN = null;

	protected String[] EXCPTRN = null;

	protected boolean PTRNFILTER = false;

	protected ArrayList EXCPATTERNS = new ArrayList();

	protected ArrayList INCPATTERNS = new ArrayList();

	protected String NEWFILE = null;

	/**
	 * The default constructor is empty
	 */
	public LogFilter() {
		super();
	}

	/**
	 * The method will replace the file extension with the new one. You can
	 * either provide the extension without the period ".", or with. The method
	 * will check for period and add it if it isn't present.
	 * 
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#setReplaceExtension(java.lang.String,
	 *      java.lang.String)
	 */
	public void setReplaceExtension(String oldext, String newext) {
		if (oldext != null && newext != null) {
			this.CHANGEEXT = true;
			if (oldext.indexOf(".") < 0 && newext.indexOf(".") < 0) {
				this.OLDEXT = "." + oldext;
				this.NEWEXT = "." + newext;
			} else {
				this.OLDEXT = oldext;
				this.NEWEXT = newext;
			}
		}
	}

	/**
	 * Give the filter a list of files to include
	 * 
	 * @param filenames
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#includeFiles(java.lang.String[])
	 */
	public void includeFiles(String[] filenames) {
		if (filenames != null && filenames.length > 0) {
			INCFILE = filenames;
			this.FILEFILTER = true;
		}
	}

	/**
	 * Give the filter a list of files to exclude
	 * 
	 * @param filenames
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#excludeFiles(java.lang.String[])
	 */
	public void excludeFiles(String[] filenames) {
		if (filenames != null && filenames.length > 0) {
			EXCFILE = filenames;
			this.FILEFILTER = true;
		}
	}

	/**
	 * Give the filter a set of regular expressions to filter with for
	 * inclusion. This method hasn't been fully implemented and test yet. The
	 * implementation is not complete.
	 * 
	 * @param regexp
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#includePattern(String[])
	 */
	public void includePattern(String[] regexp) {
		if (regexp != null && regexp.length > 0) {
			INCPTRN = regexp;
			this.PTRNFILTER = true;
			// now we create the compiled pattern and
			// add it to the arraylist
			for (int idx = 0; idx < INCPTRN.length; idx++) {
				this.INCPATTERNS.add(this.createPattern(INCPTRN[idx]));
			}
		}
	}

	/**
	 * Give the filter a set of regular expressions to filter with for
	 * exclusion. This method hasn't been fully implemented and test yet. The
	 * implementation is not complete.
	 * 
	 * @param regexp
	 * 
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#excludePattern(String[])
	 */
	public void excludePattern(String[] regexp) {
		if (regexp != null && regexp.length > 0) {
			EXCPTRN = regexp;
			this.PTRNFILTER = true;
			// now we create the compiled pattern and
			// add it to the arraylist
			for (int idx = 0; idx < EXCPTRN.length; idx++) {
				this.EXCPATTERNS.add(this.createPattern(EXCPTRN[idx]));
			}
		}
	}

	/**
	 * In the case of log filtering the important thing is whether the log entry
	 * should be used. Therefore, the method will only return true if the entry
	 * should be used. Since the interface defines both inclusion and exclusion,
	 * that means by default inclusion filtering assumes all entries are
	 * excluded unless it matches. In the case of exlusion filtering, it assumes
	 * all entries are included unless it matches, which means it should be
	 * excluded.
	 * 
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#isFiltered(String, TestElement)
	 * @param path
	 * @return boolean
	 */
	public boolean isFiltered(String path,TestElement el) {
		// we do a quick check to see if any
		// filters are set. If not we just
		// return false to be efficient.
		if (this.FILEFILTER || this.PTRNFILTER || this.CHANGEEXT) {
			if (this.FILEFILTER) {
				return filterFile(path);
			} else if (this.PTRNFILTER) {
				return filterPattern(path);
			} else {
				return false;
			}
		} else {
			return false;
		}
	}

	/**
	 * Filter the file. The implementation performs the exclusion first before
	 * the inclusion. This means if a file name is in both string arrays, the
	 * exclusion will take priority. Depending on how users expect this to work,
	 * we may want to change the priority so that inclusion is performed first
	 * and exclusion second. Another possible alternative is to perform both
	 * inclusion and exclusion. Doing so would make the most sense if the method
	 * throws an exception and tells the user the same filename is in both the
	 * include and exclude array.
	 * 
	 * @param file
	 * @return boolean
	 */
	protected boolean filterFile(String file) {
		// double check this logic make sure it
		// makes sense
		if (this.EXCFILE != null) {
			return excFile(file);
		} else if (this.INCFILE != null) {
			return !incFile(file);
		}
		return false;
	}

	/**
	 * Method implements the logic for filtering file name inclusion. The method
	 * iterates through the array and uses indexOf. Once it finds a match, it
	 * won't bother with the rest of the filenames in the array.
	 * 
	 * @param text
	 * @return boolean include
	 */
	public boolean incFile(String text) {
		// inclusion filter assumes most of
		// the files are not wanted, therefore
		// usefile is set to false unless it
		// matches.
		this.USEFILE = false;
		for (int idx = 0; idx < this.INCFILE.length; idx++) {
			if (text.indexOf(this.INCFILE[idx]) > -1) {
				this.USEFILE = true;
				break;
			}
		}
		return this.USEFILE;
	}

	/**
	 * Method implements the logic for filtering file name exclusion. The method
	 * iterates through the array and uses indexOf. Once it finds a match, it
	 * won't bother with the rest of the filenames in the array.
	 * 
	 * @param text
	 * @return boolean exclude
	 */
	public boolean excFile(String text) {
		// exclusion filter assumes most of
		// the files are used, therefore
		// usefile is set to true, unless
		// it matches.
		this.USEFILE = true;
		boolean exc = false;
		for (int idx = 0; idx < this.EXCFILE.length; idx++) {
			if (text.indexOf(this.EXCFILE[idx]) > -1) {
				exc = true;
				this.USEFILE = false;
				break;
			}
		}
		return exc;
	}

	/**
	 * The current implemenation assumes the user has checked the regular
	 * expressions so that they don't cancel each other. The basic assumption is
	 * the method will return true if the text should be filtered. If not, it
	 * will return false, which means it should not be filtered.
	 * 
	 * @param text
	 * @return boolean
	 */
	protected boolean filterPattern(String text) {
		if (this.INCPTRN != null) {
			return !incPattern(text);
		} else if (this.EXCPTRN != null) {
			return excPattern(text);
		}
		return false;
	}

	/**
	 * By default, the method assumes the entry is not included, unless it
	 * matches. In that case, it will return true.
	 * 
	 * @param text
	 * @return true if text is included
	 */
	protected boolean incPattern(String text) {
		this.USEFILE = false;
		for (int idx = 0; idx < this.INCPATTERNS.size(); idx++) {
			if (JMeterUtils.getMatcher().contains(text, (Pattern) this.INCPATTERNS.get(idx))) {
				this.USEFILE = true;
				break;
			}
		}
		return this.USEFILE;
	}

	/**
	 * The method assumes by default the text is not excluded. If the text
	 * matches the pattern, it will then return true.
	 * 
	 * @param text
	 * @return true if text is excluded
	 */
	protected boolean excPattern(String text) {
		this.USEFILE = true;
		boolean exc = false;
		for (int idx = 0; idx < this.EXCPATTERNS.size(); idx++) {
			if (JMeterUtils.getMatcher().contains(text, (Pattern) this.EXCPATTERNS.get(idx))) {
				exc = true;
				this.USEFILE = false;
				break;
			}
		}
		return exc;
	}

	/**
	 * Method uses indexOf to replace the old extension with the new extesion.
	 * It might be good to use regular expression, but for now this is a simple
	 * method. The method isn't designed to replace multiple instances of the
	 * text, since that isn't how file extensions work. If the string contains
	 * more than one instance of the old extension, only the first instance will
	 * be replaced.
	 * 
	 * @param text
	 * @return boolean
	 */
	public boolean replaceExtension(String text) {
		int pt = text.indexOf(this.OLDEXT);
		if (pt > -1) {
			int extsize = this.OLDEXT.length();
			this.NEWFILE = text.substring(0, pt) + this.NEWEXT + text.substring(pt + extsize);
			return true;
		} else {
			return false;
		}
	}

	/**
	 * The current implementation checks the boolean if the text should be used
	 * or not. isFilter( string) has to be called first.
	 * 
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#filter(java.lang.String)
	 */
	public String filter(String text) {
		if (this.CHANGEEXT) {
			if (replaceExtension(text)) {
				return this.NEWFILE;
			} else {
				return text;
			}
		} else if (this.USEFILE) {
			return text;
		} else {
			return null;
		}
	}

	/**
	 * create a new pattern object from the string.
	 * 
	 * @param pattern
	 * @return Pattern
	 */
	public Pattern createPattern(String pattern) {
		try {
			return JMeterUtils.getPatternCache().getPattern(pattern,
					Perl5Compiler.READ_ONLY_MASK | Perl5Compiler.SINGLELINE_MASK);
		} catch (MalformedCachePatternException exception) {
			log.error("Problem with pattern: "+pattern,exception);
			return null;
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.protocol.http.util.accesslog.Filter#reset()
	 */
	public void reset() {

	}
}
