/*
 * Copyright (c) 2012, grossmann
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the jo-widgets.org nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

package org.jowidgets.tools.command;

import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import org.jowidgets.api.command.EnabledState;
import org.jowidgets.api.command.IEnabledChecker;
import org.jowidgets.api.command.IEnabledState;
import org.jowidgets.util.Assert;
import org.jowidgets.util.event.IChangeListener;

public final class EnabledCheckerCompositeBuilder {

    private final List<IEnabledChecker> checkers;

    public EnabledCheckerCompositeBuilder() {
        this.checkers = new LinkedList<IEnabledChecker>();
    }

    public EnabledCheckerCompositeBuilder add(final IEnabledChecker checker) {
        Assert.paramNotNull(checker, "checker");
        checkers.add(checker);
        return this;
    }

    public IEnabledChecker build() {
        return new EnabledCheckerComposite(checkers);
    }

    private class EnabledCheckerComposite implements IEnabledChecker {

        private final List<IEnabledChecker> checkers;
        private final Set<IChangeListener> changeListeners;

        EnabledCheckerComposite(final List<IEnabledChecker> checkers) {
            this.checkers = checkers;
            this.changeListeners = new LinkedHashSet<IChangeListener>();

            final IChangeListener changeListener = new IChangeListener() {
                @Override
                public void changed() {
                    for (final IChangeListener listener : changeListeners) {
                        listener.changed();
                    }
                }
            };

            for (final IEnabledChecker checker : checkers) {
                checker.addChangeListener(changeListener);
            }
        }

        @Override
        public IEnabledState getEnabledState() {
            for (final IEnabledChecker checker : checkers) {
                final IEnabledState enabledState = checker.getEnabledState();
                if (!enabledState.isEnabled()) {
                    return enabledState;
                }
            }
            return EnabledState.ENABLED;
        }

        @Override
        public void addChangeListener(final IChangeListener listener) {
            Assert.paramNotNull(listener, "listener");
            changeListeners.add(listener);
        }

        @Override
        public void removeChangeListener(final IChangeListener listener) {
            Assert.paramNotNull(listener, "listener");
            changeListeners.remove(listener);
        }

    }
}