/*

 * 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.tools.javadoc.main;

import com.sun.javadoc.*;

import com.sun.tools.javac.code.Attribute;

import static com.sun.tools.javac.code.TypeTag.BOOLEAN;

/**

 * Represents a value of an annotation type element.

 *

 *  <p><b>This is NOT part of any supported API.

 *  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>

 *

 * @author Scott Seligman

 * @since 1.5

 */

public class AnnotationValueImpl implements AnnotationValue {

    private final DocEnv env;

    private final Attribute attr;

    AnnotationValueImpl(DocEnv env, Attribute attr) {

        this.env = env;

        this.attr = attr;

    }

    /**

     * Returns the value.

     * The type of the returned object is one of the following:

     * <ul><li> a wrapper class for a primitive type

     *     <li> <code>String</code>

     *     <li> <code>Type</code> (representing a class literal)

     *     <li> <code>FieldDoc</code> (representing an enum constant)

     *     <li> <code>AnnotationDesc</code>

     *     <li> <code>AnnotationValue[]</code>

     * </ul>

     */

    public Object value() {

        ValueVisitor vv = new ValueVisitor();

        attr.accept(vv);

        return vv.value;

    }

    private class ValueVisitor implements Attribute.Visitor {

        public Object value;

        public void visitConstant(Attribute.Constant c) {

            if (c.type.hasTag(BOOLEAN)) {

                // javac represents false and true as integers 0 and 1

                value = Boolean.valueOf(

                                ((Integer)c.value).intValue() != 0);

            } else {

                value = c.value;

            }

        }

        public void visitClass(Attribute.Class c) {

            value = TypeMaker.getType(env,

                                      env.types.erasure(c.classType));

        }

        public void visitEnum(Attribute.Enum e) {

            value = env.getFieldDoc(e.value);

        }

        public void visitCompound(Attribute.Compound c) {

            value = new AnnotationDescImpl(env, c);

        }

        public void visitArray(Attribute.Array a) {

            AnnotationValue vals[] = new AnnotationValue[a.values.length];

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

                vals[i] = new AnnotationValueImpl(env, a.values[i]);

            }

            value = vals;

        }

        public void visitError(Attribute.Error e) {

            value = "<error>";

        }

    }

    /**

     * Returns a string representation of the value.

     *

     * @return the text of a Java language annotation value expression

     *          whose value is the value of this annotation type element.

     */

    @Override

    public String toString() {

        ToStringVisitor tv = new ToStringVisitor();

        attr.accept(tv);

        return tv.toString();

    }

    private class ToStringVisitor implements Attribute.Visitor {

        private final StringBuilder sb = new StringBuilder();

        @Override

        public String toString() {

            return sb.toString();

        }

        public void visitConstant(Attribute.Constant c) {

            if (c.type.hasTag(BOOLEAN)) {

                // javac represents false and true as integers 0 and 1

                sb.append(((Integer)c.value).intValue() != 0);

            } else {

                sb.append(FieldDocImpl.constantValueExpression(c.value));

            }

        }

        public void visitClass(Attribute.Class c) {

            sb.append(c);

        }

        public void visitEnum(Attribute.Enum e) {

            sb.append(e);

        }

        public void visitCompound(Attribute.Compound c) {

            sb.append(new AnnotationDescImpl(env, c));

        }

        public void visitArray(Attribute.Array a) {

            // Omit braces from singleton.

            if (a.values.length != 1) sb.append('{');

            boolean first = true;

            for (Attribute elem : a.values) {

                if (first) {

                    first = false;

                } else {

                    sb.append(", ");

                }

                elem.accept(this);

            }

            // Omit braces from singleton.

            if (a.values.length != 1) sb.append('}');

        }

        public void visitError(Attribute.Error e) {

            sb.append("<error>");

        }

    }

}