/*
 * 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
 *
 *      http://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.logging.log4j.plugins.di;

import org.apache.logging.log4j.plugins.di.spi.DependencyChain;

/**
 * Exception thrown when a circular dependency is encountered.
 */
public class CircularDependencyException extends InjectException {
    public CircularDependencyException(final Key<?> key, final DependencyChain dependencies) {
        super(formatMessage(key, dependencies));
    }

    private static String formatMessage(final Key<?> key, final DependencyChain dependencies) {
        final StringBuilder sb = new StringBuilder("Circular dependency encountered: ");
        for (final Key<?> dependency : dependencies) {
            sb.append(dependency).append(" -> ");
        }
        return sb.append(key).toString();
    }
}
