CosemValue.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.dsmr.internal.cosem;

import java.text.ParseException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.openhab.binding.dsmr.internal.DSMRPort;
import org.openhab.core.types.State;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * CosemValue represents the mapping between COSEM formatted values and openHAB
 * type values
 *
 * @author M. Volaart
 * @since 1.7.0
 * @param <T>
 *            the openHAB type (subclass of {@link State})
 */
public abstract class CosemValue<T extends State> {
    /* logger */
    private static final Logger logger = LoggerFactory.getLogger(DSMRPort.class);

    /** openHAB value */
    protected T value;

    /* unit of this cosemValue */
    private final String unit;

    /* DSMR item identifier used by openHAB items */
    private final String dsmrItemId;

    /**
     * Creates a CosemValue
     * 
     * @param unit
     *            the unit of the value
     * @param dsmrItemId
     *            the DSMR item identifier
     */
    protected CosemValue(String unit, String dsmrItemId) {
        if (dsmrItemId == null) {
            logger.warn("dsmrBindingId = null is not supported, using empty String");
            dsmrItemId = "";
        }
        this.dsmrItemId = dsmrItemId;
        this.unit = unit;
    }

    /**
     * Parses the string value to the openHAB type
     * 
     * @param cosemValue
     *            the COSEM value to parse
     * @return T the openHAB value of this COSEM value
     * @throws ParseException
     *             if parsing failed
     */
    protected abstract T parse(String cosemValue) throws ParseException;

    /**
     * Sets the value of this CosemValue
     * <p>
     * This method will automatically parse the unit and the value of the COSEM
     * value string
     * 
     * @param cosemValue
     *            the cosemValue
     * @throws ParseException
     *             if parsing failed
     */
    public void setValue(String cosemValue) throws ParseException {
        if (unit.length() > 0) {
            // Check if COSEM value has a unit, check and parse the value
            Pattern p = Pattern.compile("(.*)\\*" + unit);
            Matcher m = p.matcher(cosemValue);

            if (m.matches()) {
                value = parse(m.group(1));
            } else {
                throw new ParseException("Unit of " + cosemValue + " is not " + unit, 0);
            }
        } else {
            // COSEM value does not have a unit, parse value
            value = parse(cosemValue);
        }
    }

    /**
     * Return the openHAB value
     * 
     * @return openHAB value subclass of {@link State}
     */
    public T getValue() {
        return value;
    }

    /**
     * Returns the unit of this COSEM value
     * 
     * @return the unit of this COSEM value
     */
    public String getUnit() {
        return unit;
    }

    /**
     * Returns the dsmrItemId of this COSEM value
     * 
     * @return the dsmrItemId of this COSEM value
     */
    public String getDsmrItemId() {
        return dsmrItemId;
    }

    /**
     * Returns String representation of this CosemValue
     * 
     * @return String representation of this CosemValue
     */
    @Override
    public String toString() {
        if (value != null) {
            return value.toString();
        } else {
            return "CosemValue is not initialized yet";
        }
    }
}