BinRpcCallbackHandler.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.communicator.server;

import java.io.EOFException;
import java.io.IOException;
import java.net.Socket;
import java.util.Map;

import org.openhab.binding.homematic.internal.binrpc.BinRpcResponse;
import org.openhab.binding.homematic.internal.communicator.HomematicCallbackReceiver;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Reads a BIN-RPC message from the socket and handles the method call.
 *
 * @author Gerhard Riegler
 * @since 1.5.0
 */
public class BinRpcCallbackHandler implements Runnable {
    private static final Logger logger = LoggerFactory.getLogger(BinRpcCallbackHandler.class);
    private final static boolean TRACE_ENABLED = logger.isTraceEnabled();

    private static final byte BIN_EMPTY_STRING[] = { 'B', 'i', 'n', 1, 0, 0, 0, 8, 0, 0, 0, 3, 0, 0, 0, 0 };
    private static final byte BIN_EMPTY_ARRAY[] = { 'B', 'i', 'n', 1, 0, 0, 0, 8, 0, 0, 1, 0, 0, 0, 0, 0 };
    private static final byte BIN_EMPTY_EVENT_LIST[] = { 'B', 'i', 'n', 1, 0, 0, 0, 21, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0,
            3, 0, 0, 0, 5, 'e', 'v', 'e', 'n', 't' };
    private static final byte BIN_LIST_METHODS_RESPONSE[] = { 'B', 'i', 'n', 1, 0, 0, 0, 45, 0, 0, 1, 0, 0, 0, 0, 2, 0,
            0, 0, 3, 0, 0, 0, 16, 's', 'y', 's', 't', 'e', 'm', '.', 'm', 'u', 'l', 't', 'i', 'c', 'a', 'l', 'l', 0, 0,
            0, 3, 0, 0, 0, 5, 'e', 'v', 'e', 'n', 't' };

    private Socket socket;
    private HomematicCallbackReceiver callbackReceiver;

    public BinRpcCallbackHandler(Socket socket, HomematicCallbackReceiver callbackReceiver) {
        this.socket = socket;
        this.callbackReceiver = callbackReceiver;
    }

    /**
     * Reads the event from the Homematic server and handles the method call.
     */
    @Override
    public void run() {
        try {
            BinRpcResponse response = new BinRpcResponse(socket.getInputStream(), true);
            if (TRACE_ENABLED) {
                logger.trace("Event BinRpcResponse: {}", response.toString());
            }
            byte[] returnValue = handleMethodCall(response.getMethodName(), response.getResponseData());
            if (returnValue != null) {
                socket.getOutputStream().write(returnValue);
            }
        } catch (EOFException eof) {
            // ignore
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
        } finally {
            try {
                socket.close();
            } catch (IOException ex) {
                // ignore
            }
        }
    }

    /**
     * Returns a valid result of the method called by the Homematic server.
     */
    private byte[] handleMethodCall(String methodName, Object[] responseData) throws Exception {
        if ("event".equals(methodName)) {
            handleEvent(responseData);
            return BIN_EMPTY_STRING;
        } else if ("listDevices".equals(methodName) || "deleteDevices".equals(methodName)
                || "updateDevice".equals(methodName)) {
            return BIN_EMPTY_ARRAY;
        } else if ("newDevices".equals(methodName)) {
            callbackReceiver.newDevices(null, null);
            return BIN_EMPTY_ARRAY;
        } else if ("system.listMethods".equals(methodName)) {
            return BIN_LIST_METHODS_RESPONSE;
        } else if ("system.multicall".equals(methodName)) {
            for (Object o : (Object[]) responseData[0]) {
                Map<?, ?> call = (Map<?, ?>) o;
                String method = call.get("methodName").toString();
                Object[] data = (Object[]) call.get("params");
                handleMethodCall(method, data);
            }
            return BIN_EMPTY_EVENT_LIST;
        } else {
            logger.warn("Unknown method called by Homematic server: " + methodName);
            return BIN_EMPTY_EVENT_LIST;
        }
    }

    /**
     * Populates the extracted event to the callbackReceiver.
     */
    private void handleEvent(Object[] parms) {
        String interfaceId = parms[0].toString();
        String address = parms[1].toString();
        String attribute = parms[2].toString();
        Object value = parms[3];

        callbackReceiver.event(interfaceId, address, attribute, value);
    }

}