/**
 * 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.camel.spi;

import org.apache.camel.Service;
import org.apache.camel.TypeConverter;

/**
 * Registry for type converters.
 * <p/>
 * The utilization {@link Statistics} is by default disabled, as it has a slight performance impact under very high
 * concurrent load. The statistics can be enabled using {@link Statistics#setStatisticsEnabled(boolean)} method.
 *
 * @version 
 */
public interface TypeConverterRegistry extends Service {

    /**
     * Utilization statistics of the this registry.
     */
    interface Statistics {

        /**
         * Number of attempts
         */
        long getAttemptCounter();

        /**
         * Number of successful conversions
         */
        long getHitCounter();

        /**
         * Number of attempts which cannot be converted as no suitable type converter exists
         */
        long getMissCounter();

        /**
         * Number of failed attempts during type conversion
         */
        long getFailedCounter();

        /**
         * Reset the counters
         */
        void reset();

        /**
         * Whether statistics is enabled.
         */
        boolean isStatisticsEnabled();

        /**
         * Sets whether statistics is enabled.
         *
         * @param statisticsEnabled <tt>true</tt> to enable
         */
        void setStatisticsEnabled(boolean statisticsEnabled);
    }

    /**
     * Registers a new type converter
     *
     * @param toType        the type to convert to
     * @param fromType      the type to convert from
     * @param typeConverter the type converter to use
     */
    void addTypeConverter(Class<?> toType, Class<?> fromType, TypeConverter typeConverter);

    /**
     * Registers a new fallback type converter
     *
     * @param typeConverter the type converter to use
     * @param canPromote  whether or not the fallback type converter can be promoted to a first class type converter
     */
    void addFallbackTypeConverter(TypeConverter typeConverter, boolean canPromote);

    /**
     * Performs a lookup for a given type converter.
     *
     * @param toType        the type to convert to
     * @param fromType      the type to convert from
     * @return the type converter or <tt>null</tt> if not found.
     */
    TypeConverter lookup(Class<?> toType, Class<?> fromType);

    /**
     * Sets the injector to be used for creating new instances during type conversions.
     *
     * @param injector the injector
     */
    void setInjector(Injector injector);

    /**
     * Gets the injector
     *
     * @return the injector
     */
    Injector getInjector();

    /**
     * Gets the utilization statistics of this type converter registry
     *
     * @return the utilization statistics
     */
    Statistics getStatistics();

}