/*
 * Copyright 2017-2020 original authors
 *
 * Licensed 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 io.micronaut.context.exceptions;

import io.micronaut.inject.BeanDefinition;

import java.util.Iterator;

Exception thrown when a bean is not unique and has multiple possible implementations for a given bean type.
Author:
Graeme Rocher
Since:
1.0/**
 * Exception thrown when a bean is not unique and has multiple possible implementations for a given bean type.
 *
 * @author Graeme Rocher
 * @since 1.0
 */
public class NonUniqueBeanException extends NoSuchBeanException {

    private final Class targetType;
    private final Iterator possibleCandidates;

    
Params:
targetType – The target type
candidates – The bean definition candidates
Type parameters:
<T> –        The type/**
     * @param targetType The target type
     * @param candidates The bean definition candidates
     * @param <T>        The type
     */
    public <T> NonUniqueBeanException(Class targetType, Iterator<BeanDefinition<T>> candidates) {
        super(buildMessage(candidates));
        this.targetType = targetType;
        this.possibleCandidates = candidates;
    }

    
Type parameters:
<T> – The type
Returns:
The possible bean candidates/**
     * @param <T> The type
     * @return The possible bean candidates
     */
    public <T> Iterator<BeanDefinition<T>> getPossibleCandidates() {
        return possibleCandidates;
    }

    
Type parameters:
<T> – The type
Returns:
The bean type requested/**
     * @param <T> The type
     * @return The bean type requested
     */
    public <T> Class<T> getBeanType() {
        return targetType;
    }

    private static <T> String buildMessage(Iterator<BeanDefinition<T>> possibleCandidates) {
        final StringBuilder message = new StringBuilder("Multiple possible bean candidates found: [");
        while (possibleCandidates.hasNext()) {
            Class next = possibleCandidates.next().getBeanType();
            message.append(next.getName());
            if (possibleCandidates.hasNext()) {
                message.append(", ");
            }
        }
        message.append("]");
        return message.toString();
    }
}