/**
 *
 * Copyright (c) 2006-2017, Speedment, Inc. All Rights Reserved.
 *
 * 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:
 *
 * 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 com.speedment.runtime.core.internal.component.sql;

import static com.speedment.common.injector.State.STARTED;
import com.speedment.common.injector.annotation.Config;
import com.speedment.common.injector.annotation.ExecuteBefore;
import com.speedment.runtime.config.identifier.TableIdentifier;
import com.speedment.runtime.core.component.DbmsHandlerComponent;
import com.speedment.runtime.core.component.ManagerComponent;
import com.speedment.runtime.core.component.ProjectComponent;
import com.speedment.runtime.core.component.sql.SqlStreamOptimizerComponent;
import com.speedment.runtime.core.component.sql.SqlStreamSupplierComponent;
import com.speedment.runtime.core.component.sql.override.SqlStreamTerminatorComponent;
import com.speedment.runtime.core.db.SqlFunction;
import com.speedment.runtime.core.stream.parallel.ParallelStrategy;
import java.sql.ResultSet;
import java.util.Map;
import static java.util.Objects.requireNonNull;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Stream;

/**
 * The default implementation of the
 * {@link SqlStreamSupplierComponent}-interface.
 *
 * @author Per Minborg
 * @since 3.0.1
 */
public final class SqlStreamSupplierComponentImpl implements SqlStreamSupplierComponent {

    private final Map<TableIdentifier<?>, SqlFunction<ResultSet, ?>> prestart;
    private final Map<TableIdentifier<?>, SqlStreamSupplier<?>> supportMap;
    private @Config(name = "allowStreamIteratorAndSpliterator", value = "false") boolean allowStreamIteratorAndSpliterator;

    public SqlStreamSupplierComponentImpl() {
        this.supportMap = new ConcurrentHashMap<>();
        this.prestart = new ConcurrentHashMap<>();
    }

    @Override
    public <ENTITY> void install(TableIdentifier<ENTITY> tableIdentifier, SqlFunction<ResultSet, ENTITY> entityMapper) {
        prestart.put(tableIdentifier, entityMapper);
    }

    @ExecuteBefore(STARTED)
    @SuppressWarnings("unchecked")
    void startStreamSuppliers(
        final ProjectComponent projectComponent,
        final DbmsHandlerComponent dbmsHandlerComponent,
        final ManagerComponent managerComponent,
        final SqlStreamOptimizerComponent sqlStreamOptimizerComponent,
        final SqlStreamTerminatorComponent sqlStreamTerminatorComponent
    ) {

        prestart.forEach((tableIdentifier, entityMapper) -> {
            final SqlStreamSupplier<Object> supplier = new SqlStreamSupplierImpl<>(
                (TableIdentifier<Object>) tableIdentifier,
                (SqlFunction<ResultSet, Object>) entityMapper,
                projectComponent,
                dbmsHandlerComponent,
                managerComponent,
                sqlStreamOptimizerComponent,
                sqlStreamTerminatorComponent,
                allowStreamIteratorAndSpliterator
            );

            supportMap.put(tableIdentifier, supplier);
        });
    }

    @Override
    public <ENTITY> Stream<ENTITY> stream(TableIdentifier<ENTITY> tableIdentifier, ParallelStrategy parallelStrategy) {
        final SqlStreamSupplier<ENTITY> supplier = getStreamSupplier(tableIdentifier);
        return supplier.stream(parallelStrategy);
    }

    private <ENTITY> SqlStreamSupplier<ENTITY> getStreamSupplier(TableIdentifier<ENTITY> tableIdentifier) {
        @SuppressWarnings("unchecked")
        final SqlStreamSupplier<ENTITY> streamSupplier = (SqlStreamSupplier<ENTITY>) supportMap.get(tableIdentifier);
        return requireNonNull(streamSupplier,
            "No Sql Stream Supplier installed for table identifier "
            + tableIdentifier
        );
    }
}