/*
 * 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.functions;

import java.io.Serializable;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import org.apache.jmeter.engine.util.CompoundVariable;
import org.apache.jmeter.samplers.SampleResult;
import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.util.JMeterUtils;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;

/**
 * The function represented by this class allows data to be read from CSV files.
 * Syntax is similar to StringFromFile function. The function allows the test to
 * line-thru the data in the CSV file - one line per each test. E.g. inserting
 * the following in the test scripts :
 * 
 * ${_CSVRead(c:/BOF/abcd.csv,0)} // read (first) line of 'c:/BOF/abcd.csv' ,
 * return the 1st column ( represented by the '0'),
 * ${_CSVRead(c:/BOF/abcd.csv,1)} // read (first) line of 'c:/BOF/abcd.csv' ,
 * return the 2nd column ( represented by the '1'),
 * ${_CSVRead(c:/BOF/abcd.csv,next())} // Go to next line of 'c:/BOF/abcd.csv'
 * 
 * NOTE: A single instance of each different file is opened and used for all
 * threads.
 * 
 * To open the same file twice, use the alias function: __CSVRead(abc.csv,*ONE);
 * __CSVRead(abc.csv,*TWO);
 * 
 * __CSVRead(*ONE,1); etc
 * 
 */
public class CSVRead extends AbstractFunction implements Serializable {
	private static final Logger log = LoggingManager.getLoggerForClass();

	private static final long serialVersionUID = 232L;
	
	private static final String KEY = "__CSVRead"; // Function name //$NON-NLS-1$

	private static final List desc = new LinkedList();

	private Object[] values; // Parameter list

	static {
		desc.add(JMeterUtils.getResString("csvread_file_file_name")); //$NON-NLS-1$
		desc.add(JMeterUtils.getResString("column_number")); //$NON-NLS-1$
	}

	public CSVRead() {
	}

	public Object clone() throws CloneNotSupportedException {
		return super.clone();
	}

	/**
	 * @see org.apache.jmeter.functions.Function#execute(SampleResult, Sampler)
	 */
	public synchronized String execute(SampleResult previousResult, Sampler currentSampler)
			throws InvalidVariableException {
		String myValue = ""; //$NON-NLS-1$

		String fileName = ((org.apache.jmeter.engine.util.CompoundVariable) values[0]).execute();
		String columnOrNext = ((org.apache.jmeter.engine.util.CompoundVariable) values[1]).execute();

		log.debug("execute (" + fileName + " , " + columnOrNext + ")   ");

		// Process __CSVRead(filename,*ALIAS)
		if (columnOrNext.startsWith("*")) { //$NON-NLS-1$
			FileWrapper.open(fileName, columnOrNext);
			/*
			 * All done, so return
			 */
			return ""; //$NON-NLS-1$
		}

		// if argument is 'next' - go to the next line
		if (columnOrNext.equals("next()") || columnOrNext.equals("next")) { //$NON-NLS-1$ //$NON-NLS-2$
			FileWrapper.endRow(fileName);

			/*
			 * All done now ,so return the empty string - this allows the caller
			 * to append __CSVRead(file,next) to the last instance of
			 * __CSVRead(file,col)
			 * 
			 * N.B. It is important not to read any further lines at this point,
			 * otherwise the wrong line can be retrieved when using multiple
			 * threads.
			 */
			return ""; //$NON-NLS-1$
		}

		try {
			int columnIndex = Integer.parseInt(columnOrNext); // what column
																// is wanted?
			myValue = FileWrapper.getColumn(fileName, columnIndex);
		} catch (NumberFormatException e) {
			log.warn(Thread.currentThread().getName() + " - can't parse column number: " + columnOrNext + " "
					+ e.toString());
		} catch (IndexOutOfBoundsException e) {
			log.warn(Thread.currentThread().getName() + " - invalid column number: " + columnOrNext + " at row "
					+ FileWrapper.getCurrentRow(fileName) + " " + e.toString());
		}

		log.debug("execute value: " + myValue);

		return myValue;
	}

	/**
	 * @see org.apache.jmeter.functions.Function#getArgumentDesc()
	 */
	public List getArgumentDesc() {
		return desc;
	}

	/**
	 * @see org.apache.jmeter.functions.Function#getReferenceKey()
	 */
	public String getReferenceKey() {
		return KEY;
	}

	/**
	 * @see org.apache.jmeter.functions.Function#setParameters(Collection)
	 */
	public synchronized void setParameters(Collection parameters) throws InvalidVariableException {
		log.debug("setParameter - Collection.size=" + parameters.size());

		values = parameters.toArray();

		if (log.isDebugEnabled()) {
			for (int i = 0; i < parameters.size(); i++) {
				log.debug("i:" + ((CompoundVariable) values[i]).execute());
			}
		}

		checkParameterCount(parameters, 2);

		/*
		 * Need to reset the containers for repeated runs; about the only way
		 * for functions to detect that a run is starting seems to be the
		 * setParameters() call.
		 */
		FileWrapper.clearAll();// TODO only clear the relevant entry - if possible...

	}
}