package org.activityinfo.legacy.client.remote;

/*
 * #%L
 * ActivityInfo Server
 * %%
 * Copyright (C) 2009 - 2013 UNICEF
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */

import com.google.gwt.user.client.rpc.AsyncCallback;
import org.activityinfo.promise.Promise;
import org.activityinfo.legacy.client.AsyncMonitor;
import org.activityinfo.legacy.client.Dispatcher;
import org.activityinfo.legacy.client.monitor.MonitoringCallback;
import org.activityinfo.legacy.shared.command.Command;
import org.activityinfo.legacy.shared.command.result.CommandResult;

public abstract class AbstractDispatcher implements Dispatcher {

    @Override
    public final <T extends CommandResult> void execute(Command<T> command,
                                                        AsyncMonitor monitor,
                                                        AsyncCallback<T> callback) {

        if (monitor == null) {
            execute(command, callback);
        } else {
            execute(command, new MonitoringCallback(monitor, callback));
        }
    }


    /**
     * Wraps a legacy command dispatch in a new {@code Remote} object
     *
     * @param command the command to execute
     * @param <R>     the type of the {@code Command}'s {@code CommandResult}
     */
    public final <R extends CommandResult> Promise<R> execute(final Command<R> command) {
        final Promise<R> promise = new Promise<>();

        execute(command, new AsyncCallback<R>() {
            @Override
            public void onFailure(Throwable throwable) {
                promise.onFailure(throwable);
            }

            @Override
            public void onSuccess(R result) {
                promise.onSuccess(result);
            }
        });
        return promise;
    }

    @Override
    public Promise<CommandResult> apply(Command input) {
        return execute(input);
    }
}