BindingConfigParser.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.homematic.internal.bus;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.math.NumberUtils;
import org.openhab.binding.homematic.internal.config.BindingAction;
import org.openhab.binding.homematic.internal.config.binding.ActionConfig;
import org.openhab.binding.homematic.internal.config.binding.DatapointConfig;
import org.openhab.binding.homematic.internal.config.binding.HomematicBindingConfig;
import org.openhab.binding.homematic.internal.config.binding.ProgramConfig;
import org.openhab.binding.homematic.internal.config.binding.VariableConfig;
import org.openhab.binding.homematic.internal.converter.ConverterFactory;
import org.openhab.binding.homematic.internal.converter.state.Converter;
import org.openhab.core.items.Item;
import org.openhab.core.library.types.OnOffType;
import org.openhab.model.item.binding.BindingConfigParseException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Class to parse the key - value based config for an Homematic item.
 * <p>
 * Example:
 * </p>
 *
 * <pre>
 * Dimmer   Light_Kitchen     "Light Kitchen [%.2f]"   {homematic="address=KEQ0012345, channel=1, parameter=PRESS_SHORT"}
 *
 * Switch   Test_Program      "Start TestProgram"      {homematic="program=TestProgram"}
 *
 * Switch   Var_Holidaymode   "Holidaymode"            {homematic="variable=Holidaymode"}
 * </pre>
 *
 * @author Gerhard Riegler
 * @since 1.5.0
 */
public class BindingConfigParser {
    private static final Logger logger = LoggerFactory.getLogger(BindingConfigParser.class);

    /**
     * Parses the bindingConfig of an item and returns a HomematicBindingConfig.
     */
    public HomematicBindingConfig parse(Item item, String bindingConfig) throws BindingConfigParseException {
        bindingConfig = StringUtils.trimToEmpty(bindingConfig);
        bindingConfig = StringUtils.removeStart(bindingConfig, "{");
        bindingConfig = StringUtils.removeEnd(bindingConfig, "}");
        String[] entries = bindingConfig.split("[,]");
        HomematicBindingConfigHelper helper = new HomematicBindingConfigHelper();

        for (String entry : entries) {
            String[] entryParts = StringUtils.trimToEmpty(entry).split("[=]");
            if (entryParts.length != 2) {
                throw new BindingConfigParseException("Each entry must have a key and a value");
            }

            String key = StringUtils.trim(entryParts[0]);

            // convert entry id to device if necessary
            if ("id".equalsIgnoreCase(key)) {
                logger.info("Please change the Homematic binding with the attribute 'id' to 'address' in entry: "
                        + entry + " -> " + StringUtils.replace(entry, "id=", "address="));
                key = "address";
            }
            String value = StringUtils.trim(entryParts[1]);
            value = StringUtils.removeStart(value, "\"");
            value = StringUtils.removeEnd(value, "\"");

            try {
                helper.getClass().getDeclaredField(key).set(helper, value);
            } catch (Exception e) {
                throw new BindingConfigParseException("Could not set value " + value + " for attribute " + key);
            }
        }

        Converter<?> converter = null;
        // if (helper.isValidDatapoint() || helper.isValidVariable()) {
        // converter = instantiateConverter(helper.converter);
        // }

        BindingAction bindingAction = getBindingAction(item, helper.action);

        if (helper.isValidDatapoint()) {
            return new DatapointConfig(helper.address, helper.channel, helper.parameter, converter, bindingAction,
                    helper.isForceUpdate(), NumberUtils.toDouble(helper.delay));
        } else if (helper.isValidVariable()) {
            return new VariableConfig(helper.variable, converter, bindingAction, helper.isForceUpdate(),
                    NumberUtils.toDouble(helper.delay));
        } else if (helper.isValidProgram()) {
            if (!acceptsOnOffType(item)) {
                throw new BindingConfigParseException(
                        "Programs can only be attached to items which accepts OnOffType commands, ignoring item "
                                + item.getName());
            }
            return new ProgramConfig(helper.program, bindingAction);
        } else if (bindingAction != null) {
            return new ActionConfig(bindingAction);
        } else {
            throw new BindingConfigParseException("Invalid binding: " + bindingConfig);
        }
    }

    /**
     * If a converter is specified in the binding, try to instantiate it.
     */
    @SuppressWarnings("unused")
    private Converter<?> instantiateConverter(String converterName) {
        Converter<?> converter = null;
        if (converterName != null) {
            try {
                converter = (Converter<?>) Class.forName(converterName).newInstance();
            } catch (Exception e) {
                try {
                    converter = (Converter<?>) Class.forName(ConverterFactory.CONVERTER_PACKAGE + converterName)
                            .newInstance();
                } catch (Exception e1) {
                    logger.warn("Can't instantiate converter " + converterName + ", ignoring it!");
                }
            }
        }
        return converter;
    }

    /**
     * Parses the BindingAction if available.
     */
    private BindingAction getBindingAction(Item item, String action) {
        if (action == null) {
            return null;
        }

        BindingAction bindingAction = BindingAction.parse(action);
        if (bindingAction == null) {
            logger.warn("Can't parse action {}, only {} and {} allowed. Ignoring action parameter in item {}!", action,
                    BindingAction.RELOAD_VARIABLES, BindingAction.RELOAD_DATAPOINTS, item.getName());
        } else if (!acceptsOnOffType(item)) {
            logger.warn(
                    "Actions can only be attached to items which accepts OnOffType commands, ignoring action attribute in item {}!",
                    action, item.getName());
            bindingAction = null;
        }
        return bindingAction;
    }

    /**
     * Returns true, if the item accepts the OnOffType.
     */
    private boolean acceptsOnOffType(Item item) {
        return item.getAcceptedCommandTypes().contains(OnOffType.class);
    }

    /**
     * Helper class for parsing the bindingConfig.
     */
    private class HomematicBindingConfigHelper {
        public String address;
        public String channel;
        public String parameter;
        @SuppressWarnings("unused")
        public String converter;
        public String variable;
        public String program;
        public String action;
        public String forceUpdate;
        public String delay;

        protected boolean isValidDatapoint() {
            return StringUtils.isNotBlank(address) && StringUtils.isNotBlank(channel)
                    && StringUtils.isNotBlank(parameter);
        }

        protected boolean isValidVariable() {
            return StringUtils.isNotBlank(variable);
        }

        protected boolean isValidProgram() {
            return StringUtils.isNotBlank(program);
        }

        protected boolean isForceUpdate() {
            return "true".equalsIgnoreCase(forceUpdate);
        }
    }
}