D-Net

package eu.dnetlib.dhp.common.java.jsonworkflownodes;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

 * Extracts information about port name and its properties from a string

 * of a form "{port_name, property_1, property_2, ...}"

 * @author Mateusz Kobos

 */

public class StringPortSpecificationExtractor {

	private final String[] propertiesRegexp;

	private final String portSpecificationRegexp;

	private final Pattern pattern;

	public static class PortSpecification {

	    private final String name;

		private final String[] properties;

		public PortSpecification(String name, String[] properties) {

			this.name = name;

			this.properties = properties;

		}

        public String getName() {

            return name;

        }

        public String[] getProperties() {

            return properties;

        }

	}

	/**

	 * @param propertiesRegexp regular expressions specifying pattern for 

	 * each of the properties associated with a port. An example of a single 

	 * specification: {@code "[\\w\\.]+"}.

	 */

	public StringPortSpecificationExtractor(String[] propertiesRegexp){

		this.propertiesRegexp = propertiesRegexp;

		this.portSpecificationRegexp = createRegexpString("[\\w\\._]+", propertiesRegexp);

		this.pattern = Pattern.compile(this.portSpecificationRegexp);

	}

	private static String createRegexpString(String portNameRegexp, String[] propertiesRegexp){

		StringBuilder regexp = new StringBuilder();

		regexp.append("s*\\{\\s*");

		regexp.append("("+portNameRegexp+")");

		for(String propertyRegexp: propertiesRegexp){

			regexp.append(",\\s*("+propertyRegexp+")");

		}

		regexp.append("\\s*\\}\\s*");

		return regexp.toString();

	}

	private int getPropertiesCount(){

		return propertiesRegexp.length;

	}

	public PortSpecification getSpecification(String text){

		Matcher m = pattern.matcher(text);

		if(!m.matches()){

			throw new RuntimeException(String.format("Specification of " +

					"the port (\"%s\") does not match regexp \"%s\"", 

					text, portSpecificationRegexp));

		}

        final int expectedGroupsCount = getPropertiesCount()+1;

		if(m.groupCount() != expectedGroupsCount){

			StringBuilder groups = new StringBuilder();

			for(int i = 0; i < m.groupCount(); i++){

				groups.append("\""+m.group(i)+"\"");

				if(i != m.groupCount()-1) {

				    groups.append(", ");

				}

			}

			throw new RuntimeException(String.format(

				"Invalid output port specification \"%s\": got %d groups "+

				"instead of %d (namely: %s)", text, m.groupCount(), 

				expectedGroupsCount, groups.toString()));

		}

		String[] properties = new String[getPropertiesCount()];

		for(int i = 0; i < getPropertiesCount(); i++){

			properties[i] = m.group(i+2);

		}

		return new PortSpecification(m.group(1), properties);

	}

}