/*
 * 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.
 *
 * Other licenses:
 * -----------------------------------------------------------------------------
 * Commercial licenses for this work are available. These replace the above
 * Apache-2.0 license and offer limited warranties, support, maintenance, and
 * commercial database integrations.
 *
 * For more information, please visit: https://www.jooq.org/legal/licensing
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */
package org.jooq;

import org.jooq.impl.DefaultRecordMapper;
import org.jooq.impl.DefaultRecordMapperProvider;

import org.jetbrains.annotations.NotNull;

/**
 * A provider for {@link RecordMapper} instances.
 * <p>
 * In order to inject custom {@link Record} to <code>POJO</code> mapping
 * behaviour, users can supply a custom {@link RecordMapperProvider} to their
 * {@link Configuration} instances. This provider will be used in any of these
 * methods (non-exhaustive list):
 * <h3><code>Cursor</code></h3>
 * <ul>
 * <li>{@link Cursor#fetchInto(Class)}</li>
 * <li>{@link Cursor#fetchNextInto(Class)}</li>
 * </ul>
 * <h3><code>Record</code></h3>
 * <ul>
 * <li>{@link Record#into(Class)}</li>
 * </ul>
 * <h3><code>Result</code></h3>
 * <ul>
 * <li>{@link Result#intoMap(Field, Class)}</li>
 * <li>{@link Result#intoMap(Field[], Class)}</li>
 * <li>{@link Result#intoGroups(Field, Class)}</li>
 * <li>{@link Result#intoGroups(Field[], Class)}</li>
 * <li>{@link Result#into(Class)}</li>
 * </ul>
 * <h3><code>ResultQuery</code></h3>
 * <ul>
 * <li>{@link ResultQuery#fetchMap(Field, Class)}</li>
 * <li>{@link ResultQuery#fetchMap(Field[], Class)}</li>
 * <li>{@link ResultQuery#fetchGroups(Field, Class)}</li>
 * <li>{@link ResultQuery#fetchGroups(Field[], Class)}</li>
 * <li>{@link ResultQuery#fetchInto(Class)}</li>
 * <li>{@link ResultQuery#fetchOneInto(Class)}</li>
 * </ul>
 * <h3><code>DAO</code></h3>
 * <ul>
 * <li>Most {@link DAO} methods make use of any of the above methods</li>
 * </ul>
 * <p>
 * While not strictly required, it is advisable to implement a
 * <code>RecordMapperProvider</code> whose behaviour is consistent with the
 * configured {@link RecordUnmapperProvider}.
 * <p>
 * The general expectation is for a {@link RecordMapperProvider} to be
 * side-effect free. Two calls to {@link #provide(RecordType, Class)} should
 * always produce the same {@link RecordMapper} logic and thus mapping
 * behaviour, irrespective of context, other than the {@link Configuration} that
 * hosts the {@link Configuration#recordMapperProvider()}. This effectively
 * means that it is possible for jOOQ to cache the outcome of a
 * {@link #provide(RecordType, Class)} call within the context of a
 * {@link Configuration} or any derived context, such as an
 * {@link ExecuteContext}, to greatly improve performance.
 *
 * @author Lukas Eder
 * @see RecordMapper
 * @see Configuration
 */
@FunctionalInterface
public interface RecordMapperProvider {

    /**
     * Provide a <code>RecordMapper</code> instance.
     * <p>
     * Implementations are free to choose whether this method returns new
     * instances at every call or whether the same instance is returned
     * repetitively.
     * <p>
     * A <code>RecordMapper</code> instance should be able to map any number of
     * records with the same <code>RecordType</code>. For example, for
     * {@link Record#into(Class)}, <code>provide()</code> and
     * {@link RecordMapper#map(Record)} are called only once. For
     * {@link Result#into(Class)}, <code>provide()</code> is called only once,
     * but {@link RecordMapper#map(Record)} is called several times, once for
     * every <code>Record</code> in the <code>Result</code>.
     *
     * @param recordType The <code>RecordType</code> of records that shall be
     *            mapped by the returned <code>RecordMapper</code>.
     * @param type The user type that was passed into {@link Record#into(Class)}
     *            or any other method.
     * @return A <code>RecordMapper</code> instance.
     * @see RecordMapper
     * @see DefaultRecordMapper
     * @see DefaultRecordMapperProvider
     */
    @NotNull
    <R extends Record, E> RecordMapper<R, E> provide(RecordType<R> recordType, Class<? extends E> type);
}
