/*

 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.codemodel.internal;

// Currently only exports directive is needed in this model.

/**

 * Represents a Java module directive.

 * For example {@code "exports foo.bar;"} or {@code "requires foo.baz;"}.

 * @author Tomas Kraus

 */

public abstract class JModuleDirective {

    // Only ExportsDirective is implemented.

    /**

     * Module directive type. Child class implements {@code getType()} method which returns corresponding value.

     */

    public enum Type {

       /** Directive starting with {@code requires} keyword. */

       RequiresDirective,

       /** Directive starting with {@code exports} keyword. */

       ExportsDirective,

    }

    /** Name argument of module directive. */

    protected final String name;

    /**

     * Creates an instance of Java module directive.

     * @param name name argument of module directive.

     * @throws IllegalArgumentException if the name argument is {@code null}.

     */

    JModuleDirective(final String name) {

        if (name == null) {

            throw new IllegalArgumentException("JModuleDirective name argument is null");

        }

        this.name = name;

    }

    /**

     * Gets the type of this module directive.

     * @return type of this module directive. Will never be {@code null}.

     */

    public abstract Type getType();

    /**

     * Print source code of this module directive.

     * @param f Java code formatter.

     * @return provided instance of Java code formatter.

     */

    public abstract JFormatter generate(final JFormatter f);

    /**

     * Compares this module directive to the specified object.

     * @param other The object to compare this {@link JModuleDirective} against.

     * @return {@code true} if the argument is not {@code null}

     *         and is a {@link JModuleDirective} object with the same type

     *         and equal name.

     */

    @Override

    public boolean equals(final Object other) {

        if (this == other) {

            return true;

        }

        if (other instanceof JModuleDirective) {

            final JModuleDirective otherDirective = (JModuleDirective)other;

            return this.getType() == otherDirective.getType() && this.name.equals(otherDirective.name);

        }

        return false;

    }

    /**

     * Returns a hash code for this module directive based on directive type and name.

     * The hash code for a module directive is computed as

     * <blockquote><pre>

     *     {@code 97 * (type_ordinal_value + 1) + name.hashCode()}

     * </pre></blockquote>

     * using {@code int} arithmetic.

     *

     * @return a hash code value for this object.

     */

    @Override

    public int hashCode() {

        return 97 * (getType().ordinal() + 1) + name.hashCode();

    }

    /**

     * Gets the name of this module directive.

     * @return name of this module directive.

     */

    public String name() {

        return name;

    }

}