ConfigIterator.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.satel.config;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.openhab.model.item.binding.BindingConfigParseException;

/**
 * Helper class to iterate over elements of binding configuration.
 *
 * @author Krzysztof Goworek
 * @since 1.8.0
 */
class ConfigIterator implements Iterator<String> {

    private String bindingConfig;
    private String[] configElements;
    private int idx;

    /**
     * Construct iterator object for given configuration string.
     * 
     * @param bindingConfig
     *            configuration to iterate over
     */
    public ConfigIterator(String bindingConfig) {
        this.bindingConfig = bindingConfig;
        this.configElements = bindingConfig.split(":");
        this.idx = 0;
    }

    /**
     * Returns original configuration string.
     * 
     * @return configuration string
     */
    public String getBindingConfig() {
        return this.bindingConfig;
    }

    /**
     * Return an Enum for next configuration element.
     * 
     * @param enumType
     *            type of the enum
     * @param description
     *            description of enum for error message
     * @return parsed value of enum type
     * @throws BindingConfigParseException
     *             in case next element cannot be parsed as given enumeration
     */
    public <T extends Enum<T>> T nextOfType(Class<T> enumType, String description) throws BindingConfigParseException {
        try {
            return Enum.valueOf(enumType, next().toUpperCase());
        } catch (Exception e) {
            throw new BindingConfigParseException(String.format("Invalid %s: %s", description, getBindingConfig()));
        }
    }

    /**
     * Parses binding configuration options. This must be the last element of
     * the configuration.
     * 
     * @return parsed options as a map
     * @throws BindingConfigParseException
     *             in case there are more elements after options
     */
    public Map<String, String> parseOptions() throws BindingConfigParseException {
        // parse options: comma separated pairs of <name>=<value>
        Map<String, String> options = new HashMap<String, String>();

        if (hasNext()) {

            for (String option : next().split(",")) {
                if (option.contains("=")) {
                    String[] keyVal = option.split("=", 2);
                    options.put(keyVal[0].toUpperCase(), keyVal[1]);
                } else {
                    options.put(option.toUpperCase(), "true");
                }
            }

            if (hasNext()) {
                // options are always the last element
                // if anything left, throw exception
                throw new BindingConfigParseException(String.format("Too many elements: %s", getBindingConfig()));
            }
        }
        return options;
    }

    @Override
    public boolean hasNext() {
        return idx < this.configElements.length;
    }

    @Override
    public String next() {
        return this.configElements[idx++];
    }

    @Override
    public void remove() {
        // ignore
    }
}