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/***

 * ASM: a very small and fast Java bytecode manipulation framework

 * Copyright (c) 2000-2005 INRIA, France Telecom

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. 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.

 * 3. Neither the name of the copyright holders 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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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.objectweb.asm.signature;

/**

 * A signature visitor that generates signatures in string format.

 *

 * @author Thomas Hallgren

 * @author Eric Bruneton

 */

public class SignatureWriter implements SignatureVisitor {

    /**

     * Buffer used to construct the signature.

     */

    private final StringBuffer buf = new StringBuffer();

    /**

     * Indicates if the signature contains formal type parameters.

     */

    private boolean hasFormals;

    /**

     * Indicates if the signature contains method parameter types.

     */

    private boolean hasParameters;

    /**

     * Stack used to keep track of class types that have arguments. Each element

     * of this stack is a boolean encoded in one bit. The top of the stack is

     * the lowest order bit. Pushing false = *2, pushing true = *2+1, popping =

     * /2.

     */

    private int argumentStack;

    /**

     * Constructs a new {@link SignatureWriter} object.

     */

    public SignatureWriter() {

    }

    // ------------------------------------------------------------------------

    // Implementation of the SignatureVisitor interface

    // ------------------------------------------------------------------------

    public void visitFormalTypeParameter(String name) {

        if (!hasFormals) {

            hasFormals = true;

            buf.append('<');

        }

        buf.append(name);

        buf.append(':');

    }

    public SignatureVisitor visitClassBound() {

        return this;

    }

    public SignatureVisitor visitInterfaceBound() {

        buf.append(':');

        return this;

    }

    public SignatureVisitor visitSuperclass() {

        endFormals();

        return this;

    }

    public SignatureVisitor visitInterface() {

        return this;

    }

    public SignatureVisitor visitParameterType() {

        endFormals();

        if (!hasParameters) {

            hasParameters = true;

            buf.append('(');

        }

        return this;

    }

    public SignatureVisitor visitReturnType() {

        endFormals();

        if (!hasParameters) {

            buf.append('(');

        }

        buf.append(')');

        return this;

    }

    public SignatureVisitor visitExceptionType() {

        buf.append('^');

        return this;

    }

    public void visitBaseType(char descriptor) {

        buf.append(descriptor);

    }

    public void visitTypeVariable(String name) {

        buf.append('T');

        buf.append(name);

        buf.append(';');

    }

    public SignatureVisitor visitArrayType() {

        buf.append('[');

        return this;

    }

    public void visitClassType(String name) {

        buf.append('L');

        buf.append(name);

        argumentStack *= 2;

    }

    public void visitInnerClassType(String name) {

        endArguments();

        buf.append('.');

        buf.append(name);

        argumentStack *= 2;

    }

    public void visitTypeArgument() {

        if (argumentStack % 2 == 0) {

            ++argumentStack;

            buf.append('<');

        }

        buf.append('*');

    }

    public SignatureVisitor visitTypeArgument(char wildcard) {

        if (argumentStack % 2 == 0) {

            ++argumentStack;

            buf.append('<');

        }

        if (wildcard != '=') {

            buf.append(wildcard);

        }

        return this;

    }

    public void visitEnd() {

        endArguments();

        buf.append(';');

    }

    /**

     * Returns the signature that was built by this signature writer.

     *

     * @return the signature that was built by this signature writer.

     */

    public String toString() {

        return buf.toString();

    }

    // ------------------------------------------------------------------------

    // Utility methods

    // ------------------------------------------------------------------------

    /**

     * Ends the formal type parameters section of the signature.

     */

    private void endFormals() {

        if (hasFormals) {

            hasFormals = false;

            buf.append('>');

        }

    }

    /**

     * Ends the type arguments of a class or inner class type.

     */

    private void endArguments() {

        if (argumentStack % 2 == 1) {

            buf.append('>');

        }

        argumentStack /= 2;

    }

}