/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.bcel.verifier.exc;

/**
 * Instances of this class are thrown by BCEL's class file verifier "JustIce" whenever verification proves that some
 * constraint of a class file (as stated in the Java Virtual Machine Specification, Edition 2) is violated. This is
 * roughly equivalent to the VerifyError the JVM-internal verifiers throw.
 */
public abstract class VerifierConstraintViolatedException extends RuntimeException {
    // /** The name of the offending class that did not pass the verifier. */
    // String name_of_offending_class;

    private static final long serialVersionUID = 2946136970490179465L;

    /** The specified error message. */
    private String detailMessage;

    /**
     * Constructs a new VerifierConstraintViolatedException with null as its error message string.
     */
    VerifierConstraintViolatedException() {
    }

    /**
     * Constructs a new VerifierConstraintViolatedException with the specified error message.
     */
    VerifierConstraintViolatedException(final String message) {
        super(message); // Not that important
        detailMessage = message;
    }

    /**
     * Constructs a new VerifierConstraintViolationException with the specified error message and cause
     */
    VerifierConstraintViolatedException(final String message, final Throwable initCause) {
        super(message, initCause);
        detailMessage = message;
    }

    /**
     * Extends the error message with a string before ("pre") and after ("post") the 'old' error message. All of these three
     * strings are allowed to be null, and null is always replaced by the empty string (""). In particular, after invoking
     * this method, the error message of this object can no longer be null.
     *
     * @param pre string to prepend.
     * @param post string to append.
     */
    public void extendMessage(String pre, String post) {
        if (pre == null) {
            pre = "";
        }
        if (detailMessage == null) {
            detailMessage = "";
        }
        if (post == null) {
            post = "";
        }
        detailMessage = pre + detailMessage + post;
    }

    /**
     * Returns the error message string of this VerifierConstraintViolatedException object.
     *
     * @return the error message string of this VerifierConstraintViolatedException.
     */
    @Override
    public String getMessage() {
        return detailMessage;
    }
}
