/*

 * Copyright 2007-2008 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.tools.classfile;

import java.io.IOException;

/**

 * See JVMS3, section 4.8.16.

 *

 *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If

 *  you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

public class Annotation {

    static class InvalidAnnotation extends AttributeException {

        InvalidAnnotation(String msg) {

            super(msg);

        }

    }

    Annotation(ClassReader cr) throws IOException, InvalidAnnotation {

        type_index = cr.readUnsignedShort();

        num_element_value_pairs = cr.readUnsignedShort();

        element_value_pairs = new element_value_pair[num_element_value_pairs];

        for (int i = 0; i < element_value_pairs.length; i++)

            element_value_pairs[i] = new element_value_pair(cr);

    }

    public Annotation(ConstantPool constant_pool,

            int type_index,

            element_value_pair[] element_value_pairs) {

        this.type_index = type_index;

        num_element_value_pairs = element_value_pairs.length;

        this.element_value_pairs = element_value_pairs;

    }

    public int length() {

        int n = 2 /*type_index*/ + 2 /*num_element_value_pairs*/;

        for (element_value_pair pair: element_value_pairs)

            n += pair.length();

        return n;

    }

    public final int type_index;

    public final int num_element_value_pairs;

    public final element_value_pair element_value_pairs[];

    /**

     * See JVMS3, section 4.8.16.1.

     */

    public static abstract class element_value {

        public static element_value read(ClassReader cr)

                throws IOException, InvalidAnnotation {

            int tag = cr.readUnsignedByte();

            switch (tag) {

            case 'B':

            case 'C':

            case 'D':

            case 'F':

            case 'I':

            case 'J':

            case 'S':

            case 'Z':

            case 's':

                return new Primitive_element_value(cr, tag);

            case 'e':

                return new Enum_element_value(cr, tag);

            case 'c':

                return new Class_element_value(cr, tag);

            case '@':

                return new Annotation_element_value(cr, tag);

            case '[':

                return new Array_element_value(cr, tag);

            default:

                throw new InvalidAnnotation("unrecognized tag: " + tag);

            }

        }

        protected element_value(int tag) {

            this.tag = tag;

        }

        public abstract int length();

        public abstract <R,P> R accept(Visitor<R,P> visitor, P p);

        public interface Visitor<R,P> {

            R visitPrimitive(Primitive_element_value ev, P p);

            R visitEnum(Enum_element_value ev, P p);

            R visitClass(Class_element_value ev, P p);

            R visitAnnotation(Annotation_element_value ev, P p);

            R visitArray(Array_element_value ev, P p);

        }

        public final int tag;

    }

    public static class Primitive_element_value extends element_value {

        Primitive_element_value(ClassReader cr, int tag) throws IOException {

            super(tag);

            const_value_index = cr.readUnsignedShort();

        }

        @Override

        public int length() {

            return 2;

        }

        public <R,P> R accept(Visitor<R,P> visitor, P p) {

            return visitor.visitPrimitive(this, p);

        }

        public final int const_value_index;

    }

    public static class Enum_element_value extends element_value {

        Enum_element_value(ClassReader cr, int tag) throws IOException {

            super(tag);

            type_name_index = cr.readUnsignedShort();

            const_name_index = cr.readUnsignedShort();

        }

        @Override

        public int length() {

            return 4;

        }

        public <R,P> R accept(Visitor<R,P> visitor, P p) {

            return visitor.visitEnum(this, p);

        }

        public final int type_name_index;

        public final int const_name_index;

    }

    public static class Class_element_value extends element_value {

        Class_element_value(ClassReader cr, int tag) throws IOException {

            super(tag);

            class_info_index = cr.readUnsignedShort();

        }

        @Override

        public int length() {

            return 2;

        }

        public <R,P> R accept(Visitor<R,P> visitor, P p) {

            return visitor.visitClass(this, p);

        }

        public final int class_info_index;

    }

    public static class Annotation_element_value extends element_value {

        Annotation_element_value(ClassReader cr, int tag)

                throws IOException, InvalidAnnotation {

            super(tag);

            annotation_value = new Annotation(cr);

        }

        @Override

        public int length() {

            return annotation_value.length();

        }

        public <R,P> R accept(Visitor<R,P> visitor, P p) {

            return visitor.visitAnnotation(this, p);

        }

        public final Annotation annotation_value;

    }

    public static class Array_element_value extends element_value {

        Array_element_value(ClassReader cr, int tag)

                throws IOException, InvalidAnnotation {

            super(tag);

            num_values = cr.readUnsignedShort();

            values = new element_value[num_values];

            for (int i = 0; i < values.length; i++)

                values[i] = element_value.read(cr);

        }

        @Override

        public int length() {

            int n = 2;

            for (int i = 0; i < values.length; i++)

                n += values[i].length();

            return n;

        }

        public <R,P> R accept(Visitor<R,P> visitor, P p) {

            return visitor.visitArray(this, p);

        }

        public final int num_values;

        public final element_value[] values;

    }

    public static class element_value_pair {

        element_value_pair(ClassReader cr)

                throws IOException, InvalidAnnotation {

            element_name_index = cr.readUnsignedShort();

            value = element_value.read(cr);

        }

        public int length() {

            return 2 + value.length();

        }

        public final int element_name_index;

        public final element_value value;

    }

}