/*******************************************************************************
 * Copyright (c) 2015-2018 Skymind, Inc.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Apache License, Version 2.0 which is available 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 ******************************************************************************/

package org.datavec.api.transform.ops;

import lombok.Getter;
import lombok.NonNull;
import org.datavec.api.transform.condition.Condition;
import org.datavec.api.writable.Writable;

import java.util.List;

import static org.nd4j.shade.guava.base.Preconditions.checkArgument;
import static org.nd4j.shade.guava.base.Preconditions.checkNotNull;

/**
 * A variant of {@link DispatchOp} that for each operation, tests the input list of {@Writable} elements for a {@link Condition},
 * before dispatching the appropriate column of this element to its operation.
 *
 * Operations are, as with {@link DispatchOp} bound one-to-one to a column.
 * However, the operation's {@link Condition} are per-record (a {@link Writable} list).
 *
 * Created by huitseeker on 5/14/17.
 */
public class DispatchWithConditionOp<U> extends DispatchOp<Writable, U>
                implements IAggregableReduceOp<List<Writable>, List<U>> {


    @Getter
    @NonNull
    private List<Condition> conditions;


    public DispatchWithConditionOp(List<IAggregableReduceOp<Writable, List<U>>> ops, List<Condition> conds) {
        super(ops);
        checkNotNull(conds, "Empty condtions for a DispatchWitConditionsOp, use DispatchOp instead");

        checkArgument(ops.size() == conds.size(), "Found conditions size " + conds.size() + " expected " + ops.size());
        conditions = conds;
    }

    @Override
    public void accept(List<Writable> ts) {
        for (int i = 0; i < Math.min(super.getOperations().size(), ts.size()); i++) {
            Condition cond = conditions.get(i);
            if (cond.condition(ts))
                super.getOperations().get(i).accept(ts.get(i));
        }
    }

}
