Input.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.lcn.input;

import java.util.Arrays;
import java.util.Collection;
import java.util.LinkedList;

import org.openhab.binding.lcn.connection.Connection;
import org.openhab.core.events.EventPublisher;
import org.openhab.core.items.Item;
import org.openhab.core.types.Command;

/**
 * Parent class for all input data read from LCN-PCHK.
 *
 * @author Tobias J�ttner
 */
public abstract class Input {

    /** Visitor pattern: Implemented by all concrete types related to visualization. */
    public interface VisualizationVisitor {

        /**
         * Called to check for visualization of output-port status input.
         * 
         * @param input the input
         * @param cmd the current openHAB command to check for visualization
         * @param item the current openHAB item to check for visualization
         * @param eventPublisher the {@link EventPublisher} that will will receive updates
         * @return true to indicate visualization was successful
         */
        boolean visualizationHandleOutputStatus(ModStatusOutput input, Command cmd, Item item,
                EventPublisher eventPublisher);

        /**
         * Called to check for visualization of relays status input.
         * 
         * @param input the input
         * @param cmd the current openHAB command to check for visualization
         * @param item the current openHAB item to check for visualization
         * @param eventPublisher the {@link EventPublisher} that will will receive updates
         * @return true to indicate visualization was successful
         */
        boolean visualizationHandleRelaysStatus(ModStatusRelays input, Command cmd, Item item,
                EventPublisher eventPublisher);

        /**
         * Called to check for visualization of binary-sensors status input.
         * 
         * @param input the input
         * @param cmd the current openHAB command to check for visualization
         * @param item the current openHAB item to check for visualization
         * @param eventPublisher the {@link EventPublisher} that will will receive updates
         * @return true to indicate visualization was successful
         */
        boolean visualizationBinSensorsStatus(ModStatusBinSensors input, Command cmd, Item item,
                EventPublisher eventPublisher);

        /**
         * Called to check for visualization of variable status input.
         * 
         * @param input the input
         * @param cmd the current openHAB command to check for visualization
         * @param item the current openHAB item to check for visualization
         * @param eventPublisher the {@link EventPublisher} that will will receive updates
         * @return true to indicate visualization was successful
         */
        boolean visualizationVarStatus(ModStatusVar input, Command cmd, Item item, EventPublisher eventPublisher);

        /**
         * Called to check for visualization of LEDs and logic-operations status input.
         * 
         * @param input the input
         * @param cmd the current openHAB command to check for visualization
         * @param item the current openHAB item to check for visualization
         * @param eventPublisher the {@link EventPublisher} that will will receive updates
         * @return true to indicate visualization was successful
         */
        boolean visualizationLedsAndLogicOpsStatus(ModStatusLedsAndLogicOps input, Command cmd, Item item,
                EventPublisher eventPublisher);

        /**
         * Called to check for visualization of key-locks status input.
         * 
         * @param input the input
         * @param cmd the current openHAB command to check for visualization
         * @param item the current openHAB item to check for visualization
         * @param eventPublisher the {@link EventPublisher} that will will receive updates
         * @return true to indicate visualization was successful
         */
        boolean visualizationKeyLocksStatus(ModStatusKeyLocks input, Command cmd, Item item,
                EventPublisher eventPublisher);

    }

    /** Interface for parsers. */
    private interface Parser {

        /**
         * Tries to parse the given input text.
         * Will return a list of parsed {@link Input}s. The list might be empty (but not null).
         * 
         * @param input the input data received from LCN-PCHK
         * @return the parsed {@link Input}s (never null)
         */
        Collection<Input> tryParseInput(String input);

    }

    /**
     * Registered parsers.
     * Will be used to create {@link Input} objects from read input.
     */
    private static final LinkedList<Parser> inputParsers = new LinkedList<Parser>();

    /** Initializes static data once this class is first used. */
    static {
        // Register parsers
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return AuthUsername.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return AuthPassword.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return AuthOk.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return LcnConnState.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModAck.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModSk.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModSn.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModStatusOutput.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModStatusRelays.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModStatusBinSensors.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModStatusVar.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModStatusLedsAndLogicOps.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return ModStatusKeyLocks.tryParseInput(input);
            }
        });
        inputParsers.add(new Parser() {
            @Override
            public Collection<Input> tryParseInput(String input) {
                return Arrays.asList((Input) new Unknown(input));
            } // Will "catch" everything
        });
    }

    /**
     * Parses the given input (received from LCN-PCHK).
     * 
     * @param input the text to parse
     * @return the parsed {@link Input} list. Will always contain at least one element
     */
    public static Collection<Input> parse(String input) {
        for (Parser p : inputParsers) {
            Collection<Input> ret = p.tryParseInput(input);
            if (!ret.isEmpty()) {
                return ret;
            }
        }
        throw new Error();
    }

    /**
     * Applies data to the given connection.
     * 
     * @param conn the connection which belongs to this {@link Input}
     */
    public abstract void process(Connection conn);

    /**
     * Visitor pattern.
     * Will call the concrete type's {@link VisualizationVisitor} method to visualize the given item.
     * 
     * @param handler the visitor handler
     * @param conn the connection which belongs to this {@link Input}
     * @param cmd the current openHAB command to check for visualization
     * @param item the current openHAB item to check for visualization
     * @param eventPublisher the {@link EventPublisher} that will will receive updates
     * @return true to indicate visualization was successful
     */
    public abstract boolean tryVisualization(VisualizationVisitor handler, Connection conn, Command cmd, Item item,
            EventPublisher eventPublisher);

}