/*
 * Copyright (c) 2010, 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.api.command;

public final class EnabledState implements IEnabledState {

    /**
     * A enabled state constant for enabled = true
     */
    public static final EnabledState ENABLED = new EnabledState();

    /**
     * A enabled state constant for enabled = false. This enabled state has no reason!
     * For better usability of the application provide information why its is disabled
     * to the user with help of the method {@link #disabled(String)}
     */
    public static final EnabledState DISABLED = new EnabledState(false, null);

    private final boolean enabled;
    private final String reason;

    private EnabledState() {
        this(true, null);
    }

    private EnabledState(final boolean enabled, final String reason) {
        this.enabled = enabled;
        this.reason = reason;
    }

    @Override
    public boolean isEnabled() {
        return enabled;
    }

    @Override
    public String getReason() {
        return reason;
    }

    /**
     * Creates a new enabled state that is disabled
     * 
     * @param reason The reason why it is disabled
     * 
     * @return The created enabled state
     */
    public static EnabledState disabled(final String reason) {
        return new EnabledState(false, reason);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + (enabled ? 1231 : 1237);
        result = prime * result + ((reason == null) ? 0 : reason.hashCode());
        return result;
    }

    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final EnabledState other = (EnabledState) obj;
        if (enabled != other.enabled) {
            return false;
        }
        if (reason == null) {
            if (other.reason != null) {
                return false;
            }
        }
        else if (!reason.equals(other.reason)) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "EnabledState [enabled=" + enabled + ", reason=" + reason + "]";
    }

}