/*
 * This is eMonocot, a global online biodiversity information resource.
 *
 * Copyright © 2011–2015 The Board of Trustees of the Royal Botanic Gardens, Kew and The University of Oxford
 *
 * eMonocot is free software: you can redistribute it and/or modify it under the terms of the
 * GNU Affero General Public License as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * eMonocot 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 Affero General Public License for more details.
 *
 * The complete text of the GNU Affero General Public License is in the source repository as the file
 * ‘COPYING’.  It is also available from <http://www.gnu.org/licenses/>.
 */
package org.emonocot.harvest.common;

import java.util.HashSet;
import java.util.Map.Entry;
import java.util.Set;
import java.util.regex.Pattern;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.job.flow.FlowExecutionStatus;
import org.springframework.batch.core.job.flow.JobExecutionDecider;

/**
 * @author jk00kg
 *
 * Utility class to inspect the execution for a provided parameter
 */
public class ParameterPresenceDecider implements JobExecutionDecider {

	private Logger logger = LoggerFactory.getLogger(ParameterPresenceDecider.class);

	/**
	 *
	 */
	private Object parameter;

	private Pattern pattern;

	/**
	 * @return the parameter
	 */
	public Object getParameter() {
		return parameter;
	}

	/**
	 * @param parameter the parameter to set
	 */
	public void setParameter(Object parameter) {
		this.parameter = parameter;
	}

	/**
	 * @param regex the pattern to set
	 */
	public void setPattern(String regex) {
		this.pattern = Pattern.compile(regex);
	}

	/* (non-Javadoc)
	 * @see org.springframework.batch.core.job.flow.JobExecutionDecider#decide(org.springframework.batch.core.JobExecution, org.springframework.batch.core.StepExecution)
	 */
	@Override
	public FlowExecutionStatus decide(JobExecution jobExecution,
			StepExecution stepExecution) {
		//TODO Possible extension point to delegate to a callback/add option to run additional checks here
		//Look for the parameter in the ExecutionContext
		FlowExecutionStatus returnStatus = null;
		Set<Object> toCheck = new HashSet<Object>(stepExecution.getJobParameters().getParameters().keySet());
		toCheck.addAll(stepExecution.getJobParameters().getParameters().values());
		for(Entry<String, Object> entry : stepExecution.getExecutionContext().entrySet()) {
			toCheck.add(entry.getKey());
			toCheck.add(entry.getValue());
		}
		if(parameter != null) {
			logger.debug("Looking for parameter " + parameter);
			searchForParameter(toCheck);
		}
		if(pattern != null && !"parameter".equals(returnStatus.toString())) {
			logger.debug("Trying to match against pattern " + pattern.pattern());
			for(Object value : toCheck) {
				if(pattern.matcher(value.toString()).matches()){
					returnStatus = new FlowExecutionStatus("pattern");
					break;
				}
			}
		}

		//Assume false
		return returnStatus;
	}
	protected FlowExecutionStatus searchForParameter(Set<Object> values) {
		if(values.contains(parameter)) {
			return new FlowExecutionStatus("parameter");
		}
		return new FlowExecutionStatus("not found");
	}

}