DMDirc-Parser/src/com/dmdirc/parser/common/CallbackObjectSpecific.java

/*
 * Copyright (c) 2006-2009 Chris Smith, Shane Mc Cormack, Gregory Holmes
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package com.dmdirc.parser.common;

import com.dmdirc.parser.interfaces.SpecificCallback;
import com.dmdirc.parser.interfaces.ChannelInfo;
import com.dmdirc.parser.interfaces.ClientInfo;
import com.dmdirc.parser.interfaces.Parser;
import com.dmdirc.parser.interfaces.callbacks.CallbackInterface;

import java.util.ArrayList;
import java.util.Hashtable;

/**
 * CallbackObjectSpecific.
 * Superclass for all callback types that have a "specific" target.
 *
 * @author            Shane Mc Cormack
 */
public abstract class CallbackObjectSpecific extends CallbackObject {

    /** Hashtable for storing specific information for callback. */
    protected volatile Hashtable<CallbackInterface, String> specificData
            = new Hashtable<CallbackInterface, String>();

    /**
     * Create a new instance of the Callback Object.
     *
     * @param parser Parser That owns this callback
     * @param manager CallbackManager that is in charge of this callback
     * @param type The type of callback to use
     * @since 0.6.3m1
     */
    public CallbackObjectSpecific(final Parser parser, final CallbackManager<?> manager,
            final Class<? extends CallbackInterface> type) {
        super(parser, manager, type);
    }

    /**
     * Used to check if a channel matches the specificData.
     *
     * @param eMethod Object that is being called back to
     * @param cChannel ChannelInfo object for the channel to test
     * @return true if channel given matches the specifics for the method given
     */
    protected boolean isValidChan(final CallbackInterface eMethod, final ChannelInfo cChannel) {
        if (specificData.containsKey(eMethod)) {
            if (!myParser.getStringConverter().equalsIgnoreCase(cChannel.getName(),
                    specificData.get(eMethod))) {
                return false;
            }
        }
        return true;
    }

    /**
     * Used to check if a hostname matches the specificData.
     *
     * @param eMethod Object that is being called back to
     * @param sHost Hostname of user that sent the query
     * @return true if host given matches the specifics for the method given
     */
    protected boolean isValidUser(final CallbackInterface eMethod, final String sHost) {
        final String nickname = translateHostname(sHost);
        if (specificData.containsKey(eMethod)) {
            if (!myParser.getStringConverter().equalsIgnoreCase(nickname,
                    specificData.get(eMethod))) {
                return false;
            }
        }
        return true;
    }

    /**
     * Translates the specified hostname into the form which is used to
     * register specific callbacks (e.g. nickname).
     *
     * @param hostname The hostname to be parsed
     * @return The translated hostname
     */
    protected abstract String translateHostname(final String hostname);

    // We override the default add method to make sure that any add with no
    // specifics will have the specific data removed.
    /**
     * Add a new callback.
     *
     * @param eMethod Object to callback to.
     */
    @Override
    public void add(final CallbackInterface eMethod) {
        addCallback(eMethod);
        if (specificData.containsKey(eMethod)) {
            specificData.remove(eMethod);
        }
    }

    /**
     * Add a new callback with a specific target.
     *
     * @param eMethod Object to callback to.
     * @param specificTarget Target that must match for callback to be called.
     */
    public void add(final CallbackInterface eMethod, final String specificTarget) {
        add(eMethod);
        if (!specificTarget.isEmpty()) {
            specificData.put(eMethod, specificTarget);
        }
    }

    /**
     * Remove a callback.
     *
     * @param eMethod Object to remove callback to.
     */
    @Override
    public void del(final CallbackInterface eMethod) {
        delCallback(eMethod);
        if (specificData.containsKey(eMethod)) {
            specificData.remove(eMethod);
        }
    }

    /**
     * Actually calls this callback. The specified arguments must match those
     * specified in the callback's interface, or an error will be raised.
     *
     * @param args The arguments to pass to the callback implementation
     * @return True if a method was called, false otherwise
     */
    @Override
    public boolean call(final Object... args) {
        boolean bResult = false;

        final Object[] newArgs = new Object[args.length + 1];
        System.arraycopy(args, 0, newArgs, 1, args.length);
        newArgs[0] = myParser;

        createFakeArgs(newArgs);

        for (CallbackInterface iface : new ArrayList<CallbackInterface>(callbackInfo)) {
            if (type.isAnnotationPresent(SpecificCallback.class) &&
                    ((args[0] instanceof ClientInfo
                    && !isValidUser(iface, ((ClientInfo) args[0]).getHostname()))
                    || (args[0] instanceof ChannelInfo
                    && !isValidChan(iface, (ChannelInfo) args[0]))
                    || (!(args[0] instanceof ClientInfo
                    || args[0] instanceof ChannelInfo) &&
                    args[args.length - 1] instanceof String
                    && !isValidUser(iface, (String) args[args.length - 1])))) {
                continue;
            }

            try {
                type.getMethods()[0].invoke(iface, newArgs);
            } catch (Exception e) {
                final ParserError ei = new ParserError(ParserError.ERROR_ERROR,
                        "Exception in callback (" + e.getMessage() + ")",
                        myParser.getLastLine());
                ei.setException(e);
                callErrorInfo(ei);
            }
            bResult = true;
        }
        return bResult;
    }
}